JANUARY 29, 1981

THE

NAUTILUS

ISSN 0(i2«-13.ll

Vol. 95

No. 1

A quarterly

devoted to

malacology and

the interests of

conchologists

Founded 1889 bv Henry A. PilsbiT- C<jntinued by H. Burrington Baker.

Editor-in-Chief: R. Tucker Abbott

EDITORIAL COMMITTEE

CONSULTING EDITORS

Dr. William J. Clench

Curator Emeritus

Museum of Comparative Zoology

Cambridge, Mass. 02138

Dr. William K. Emerson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

Dr. Aurele La Rocque

Department of Geology

The Ohio State University

Columbus, Ohio 43210

Dr. James H. McLean

Los Angeles County Museum of Natural History

900 Exposition Boulevard

Los Angeles, California 90007

Dr. Arthur S. Merrill

103 West 8th Avenue

Cudjoe Gardens

Summerland Key, Florida 33043

Dr. Donald R. Moore

Division of Marine Geology

School of Marine and Atmospheric Science

10 Rickenbacker Causeway

Miami, Florida 33149

Dr. Joseph Rosewater

Division of Mollusks

U.S. National Museum

Washington, D.C. 20560

Dr. G. Alan Solem

Department of Invertebrates

Field Museum of Natural History

Chicago, Illinois 60605

Dr. David H. Stansbery

Museum of Zoology

The Ohio State University

Columbus, Ohio 43210

Dr. Ruth D. Turner

Department of Mollusks

Museum of Comparative Zoology

Cambridge, Mass. 02138

Dr. Gilbert L. Voss

Division of Biology

School of Marine and Atmospheric Science

10 Rickenbacker Causeway

Miami, Florida 33149

Dr. Charles B. Wurtz

3220 Penn Street

Philadelphia, Pennsylvania 19129

EDITOR-IN-CHIEF

Dr. R. Tucker Abbott

American Malacologists, Inc.

Box 2255, Melbourne, Florida 32901

Mrs. Cecelia W. Abbott

Business and Subscription Manager

P.O. Box 22.55

Melbourne, Florida 32901

Tlie Nautilus (USPS 374-980)

ISSN 0028-1344

OFFICE OF PUBLICATION

American Malacologists, Inc. (United Parcel Address:

2208 South Colonial Drive, Melbourne, FL 32901)

Mail: Box 2255, Melbourne. FL 32901

Second Class Postage paid at Melbourne, Florida

and other post offices

Subscription Price: $12.00 (see inside back cover)

$14.00 (foreign); institutions $18.00

THE

NAUTILUS

Volume 95, number 1 — January 29, 1981

ISSN 0028-1344

CONTENTS

Henryk Bronislaw Stenzel (Obituary by Harold W. Harry) 1

Richard S. Houbrick

Anatomy and Systematics of Gourmya gourmyi (Prosobranchia: Cerithidiidae),

a Tethyan Relict from the Southwest Pacific 2

Clement L. Counts, III

Corbiculafluminea (Bivalvia: Sphaeriacea) in British Columbia 12

Branley A. Branson and Daniel H. Barrett

Analysis of Some Characteristics in Twenty Four Populations of Western U.S.

Pleurocerid Snails 14

Robert C. Bright

A New Record of Valvata sincera ontariensis F. C. Baker from Minnesota 20

Ralph W. Taylor and Romie C. Hughart

The Freshwater Naiads of Elk River, West Virginia, with a Comparison

of Earlier Collections 21

Angeles Alvarino and John R. Hunter

New Records of Alloposus mollis Verrill (Cephalopoda, Octopoda)

from the Pacific Ocean 26

Terrence J. Frest and Leslie P. Fay

Vertigo meramecensis (Pulmonata: Pupillidae) from the

Niagaran Escarpment, Iowa 33

Bretton W. Kent

Feeding and Food Preferences of the Muricid Gastropod, Ceratostomafoliatum 38

C. Cliff Coney, Wallace A. Tarpley and Robert Bohannan

A Method of Collecting Minute Land Snails 43

Publications Received ii Meetings 37

PUBLICATIONS RECEIVED

Brown, David S. Freshwater Snails of Africa and their

Medical Importance. 487 pp., 153 pis. 1980. Taylor and

Francis. Ltd., London. Distributed in the Americas by

American Malacologists, Inc., P. 0. Box 22.').'), Melbourne,

FL 32901. Hardback, £25 in England, $55.00 U.S. Exten-

sive coverage.

Waren, Anders. 1980. Marine Mollusca Described by .John

Gwyn .Jeffreys, with the Location of the Type Material.

Special Publication, no. 1, Conch. Soc. Great Britain and

Ireland, 66 pp., 8 pis. $12.50. A very valuable taxonomic

tool, including a biography, bibliography and lists of .Jef-

freys' new names.

Nautilus macromphahiii in Captivity. 1980. Edited by T.

Hamada, I. Ohata and T. Okutani. Takai University Press,

Tokyo. 80 pp., 55 color pis., hardback. $33.00. A detailed

account by 17 Japanese scientists on rearing, behavior,

biometrics, distribution and biology of the New Caledonia

Nautilus.

Petuch, Edward J. 1979. Twelve New Indo- Pacific Gastro-

pods. Nemouria, no. 23, pp. 1-21. New taxa include Guild-

fordia, Zelippistes, Pseudocypraea, Morum, Axymene,

Oliva. Agatrix and 5 Conns. Several seem to be subjec-

tive synonyms.

Cernohorsky, W. 0. 1980. Revision of the Australian and

New Zealand Tertiary and Recent Temperate Species of

the Family Costellariidae. Records Auckland Inst. and.

Mus. vol. ie, pp. 109-169.

Davidson, Alan. 1979. North Atlantic: Seafood. 512 pp.

Numerous text drawings. Viking Press, N. Y. $15.95.

Hardback. Excellent book of recipes and natural history of

edible fish (with 30 pages on mollusks). Excellent cookery

bibliography.

Arakawa, K. Y. (translated by K. B. tlillnior). 1980. Preven-

tion and Removal of Fouling on Cultured Oysters; A

Handbook for Growers. Maine Sea Grant Technical Re-

port 56, 38 pp. Ira C. Darling Center, Walpole, ME 04573.

Boletin del Grupo de Estudios Malacol, "Arango". June

1980. No. 2, 19 pp. Biography of Rafael Arango; List of

moilu.sca from Isla de La Juventud, Cuba.

Solem, Alan. 1979. Camaenid Land Snails from Western and

Central Australia. Pt. 1, Taxa with Trans- Australian Dis-

tribution. Records Western Australian Mus., Suppl. no.

10, 142 pp., 35 figs. A thorough study of 10 genera, in-

cluding the new Melostrachia, and 7 new species.

1979. Some Mollusks from Afghanistan. Fieldi-

ana: Zoology (new series), no. 1 , 89 pp., 32 figs. 37 taxa, in-

cluding a new Pupilla are reported upon.

Lan, T. C. 1980. Rare Shells of Taiwan in Color. Privately

published, T. C. Lan, 40 Lane 105, Liao-ning St., Taipei,

Taiwan. 144 pp., illus. in color. This is a magnificently il-

lustrated book of 77 rare and uncommon marine mollusks,

with additional illustrations of some cameos and ancient

forms of Chinese shell money. The book contains species

not likely to be found in the average museum or private

collection. $18.00.

Walls, Jerry G. 1980. Conchs, Tibias and Harps. 191 pp., il-

lus. in color. T. F. H. Publications, Neptune, NJ 07753.

This is a useful and colorful guide to the Strombidae and

Harpidae. Most of the information was evidently from out-

of-print numbers of Indo-Patific Mollusca. $9.95.

Johnson, Richard I. 1980. Zoography of North American

Unionacea (Mollusca: Bivalvia) North of the Maximum

Pleistocene Glaciation. Bull. Mus. Comp. ZooL, Harvard,

vol. 149, no. 2, pp 189, 20 pis. An exhaustive and well-

illustrated account of unionids that moved north as the

Pleistocene glaciers receded. A complementary study of

the fish hosts by an ichthyologist would be welcome.

STATEMENT OF OWNERSHIP, /MANAGEMENT AND CIRCULA-

TION (Required by) Act of October 23, 1962: Section 4396. Title

39. United States Code, and postal regulation 132-622.

1. Title of publication: THE NAUTILUS.

2. Date of filing, September 25, 1980.

3. Frequency of Issue: Quarterly (4 per year).

4. Location of known office of publication: 2208 South

Colonial Dr., Melbourne, FL 32901.

5. Location of the Headquarters of General Business Offices

of the Publishers: 2208 South Colonial Dr., Melbourne, FL

32901.

6. Names and addresses of publisher, editor, and manag-

ing editor: Publisher, American Molacologists, Inc., P.O.

Box 2255, Melbourne, FL 32901. Editor, R, Tucker Abbott,

P.O. Box 2255, Melbourne, FL 32901. Business Manager,

Mrs. Cecelia W. Abbott, P.O. Box 2255, Melbourne, FL

32901.

7. Owner: American Molacologists, Inc., P.O. Box 2255,

Melbourne, FL 32901.

8. Known bondholders, mortgages, and other security

holders owning or holding 1 percent or more of total

amount of bonds, mortgages or other securities: none.

9. Extent and Nature of Circulation:

Average Single

12 Mos. Issue

A. Total No, copies Printed (Net Press) 900 900

B. Paid Circulation

1. Sales through dealers and carriers,

street vendors and counter sales none none

2. Mail subscriptions 714 731

C. Total Paid Circulation 714 731

D. Free Distribution (including samples)

by mail carrier or other means 14 14

E. Total Distribution (Sum of C&D) 728 745

F. Office use, left-over, unaccounted and

back start subscription copies 172 155

G. Total (Sum of E&F)-should equal net

press run shown in A. 900 900

I certify that the statements made by me above ore correct and

complete.

(signed) R. Tucker Abbott, Editor

Vol. 95(1)

January 29, 1981

THE NAUTILUS

1

Henryk Bronislaw Stenzel

(1899-1980)

Henryk Bronislaw Stenzel was born in

Pabinanice, Poland, on 7 February 1899. When

he was 23 years old he obtained the degree of

Doctor of Philosophy in Geology from the

University of Breslau, where he remained as

assistant lecturer for two more years. In 1925

he joined the faculty of the Department of

Geology at Texas Agricultural and Mechanical

College (now Texas A & M University), where

he taught for nine years, during which time he

became a U.S. citizen. There the extensive array

of fossil mollusks from the Stone City outcrop of

middle Eocene age on the nearby Brazos river

attracted his attention.

A firm believer in the maxim that the present

is a key to the past, he augmented his observa-

tions on fossils by excursions into the study of

living marine mollusks. Since the ones which in-

terested him most were in remote areas of the

world, he was chiefly limited to reviewing the

literature. A master chapter on the Living

Nautilus in the Treatise on Invertebrate Paleon-

tology (1964) was one result. In this he recogniz-

ed five living species, and presented a map

showing where they had been found alive, as

well as where their shells had drifted.

In 1934 he joined the Bureau of Economic

Geology of the University of Texas at Austin.

There his teaching was chiefly guiding the

research of graduate students, but he spent

much more time in fieldwork. His studies on the

geology of various regions of eastern Texas

were mostly published by the Bureau. His

research interests turned to the systematics of

oysters, which are abundant and diversified in

the Cretaceous and Tertiary deposits of Texas.

Undaunted by the extreme variations in

oysters, he first undertook the review of all

generic names which had been proposed in the

group, the determination of the essential

characters of each genus on the basis of their

type species, and thereby the elimination of

superfluous names by detecting synonyms and

homonyms. As with his study of Nautilus, this

project went very slowly in a region where

scientific libraries are limited in size.

After 20 years at the Bureau of Economic

Geology and three years as Chairman of the

Department of Geology of the University of

Houston, he became a consulting geologist for

the Shell Development Co., in Houston. In his

ten years with this company he was able to

devote more time to oyster systematics, and

during that period he also participated at Rice

University as a teacher of summer field courses

on Gulf Coast geology.

In 1967 he moved to Baton Rouge, and as

Visiting Professor of Geology at Louisiana State

University, he was able to complete his study of

oysters. This was published as a special volume

of the Treatise on Invertebrate Paleontology. It

undoubtedly has put the systematics of oysters

on a firm foundation, far surpassing all the

previous work on the subject.

In Baton Rouge he lived alone, having been

widowed many years before, and his three

daughters having married and moved to distant

places. His health gradually deteriorated.

Donating his library to Louisiana State Univer-

sity, he returned to Houston in 1977, where,

following a long illness, he passed away on 5

September 1980. A member of numerous geolo-

gical societies, he was past president of the

Society of Economic Paleontology and Min-

eralogy (1949-1950) and of the Paleontological

Society (1955-1956). He was a scholar and a

gentleman with the grace and elegance of by-

gone generations, a pleasant companion and

captivating racconteur of malacological vi-

gnettes. He is truly missed by his many friends.

-Harold W. Harry, 4612 Evergreen, Bel-

laire, Texas 77401.

THE NAUTILUS

January 29, 1981

Vol. 95(1)

ANATOMY AND SYSTEMATICS OF GOURMYA GOURMYI

(PROSOBRANCHIA: CERITHIIDAE), A TETHYAN RELICT

FROM THE SOUTHWEST PACIFIC

Richard S. Houbrick

Associate Curator, Department of Invertebrate Zoology '

National Museum of Natural History

Smithsonian Institution, Washington, D.C. 20560

ABSTRACT

Gourmya gourmyi (Crosse, 1861) a Tethyan relict cerithiid snail, is the sole sur-

vivor of a long lineage that can be traced back to the Eocene of the Paris Basin. It

is today restricted to subtidal coral reefs of island groups around New Caledonia

where it lives at moderate depths on hard substratum. The shell is stocky and the

siphonal canal is crossed over by the base of the outer shell lip giving the aperture

a circular appearance. Ocelli are present on the inhalant siphon. These, a large

esophageal gland, extensive gastric shield and the arrangement of the spermato-

phore chamber and seminal receptacle are unique anatomical features which

establish Gourmya as a valid genus in the family Cerithiidae.

Gourmya gourmyi (Crosse) is a relatively

large cerithiid with an unusual shell morphology

that lives on subtidal coral reefs in a restricted

part of the tropical southwest Pacific. It is not

well-known and is uncommon in most museum

collections. Although figured in a few recent

popular shell books (Dance, 1974; Cernohorsky,

1978), it has been largely ignored in the scien-

tific literature. This species is the sole survivor

of a genus that was represented in the Tethys

Sea during the Tertiary.

I noted in the 1977 issue of the Kepple Bay

Tidings, a shell club newsletter, that specimens

of this species had recently been taken at the

Bellona Reefs in the Chesterfield Islands. Dur-

ing a recent collecting trip to New Caledonia, I

acquired several preserved specimens and ex-

amined a few more preserved animals at the

Australian Museum, Sydney. Although these

specimens were poorly preserved, I was able to

study the gross anatomy and to make a few his-

tological preparations of this rare prosobranch.

I have examined specimens from the major mal-

acological collections, surveyed the literature

and reviewed the fossil taxa of Gourmya. The

results of this study establish Gourmya as a

valid genus in the family Cerithiidae and define

the geographic and ecological range of this relict

species.

Abbreviations used in text:

AMNH- American Museum of Natural History

AMS- Australian Museum, Sydney

BM(NH)- British Museum (Natural History)

NMHNP- National Museum d'Histoire Na-

turelle, Paris

NMV- National Museum, Victoria

USNM- United States National Museum

Family Cerithiidae Fleming, 1828

Genus Gourmya Fischer

Gourmya "Bayle" (in M.S), Fischer, 1884:680 (Type species,

by original designation: Cerithium gourmyi Crosse,

r861).-Vignal, 1897:1-2. -Cossman, 1906:67-69.-

Thiele, 1929:213. -Wenz, 1940:765, fig. 2215.- Nordsieck,

1968:69. -Cernohorsky, 1978:.53.

Description -Stout, solid, turreted shell with

moderately inflated whorls and large body

whorl. Sculpture smooth to moderate with pro-

minent thickened varix along edge of outer lip.

Aperture large with deep anal canal and central-

ly located, tubular, straight siphonal canal. Base

of outer lip extends over siphonal canal but is

not attached to it. Radula typically cerithioid,

taenioglossate (2 -i- 1 + 1 -i- 1 -t- 2). Pallial gono-

ducts open, males aphallic. Siphorial eyes pre-

sent on inhalant siphon.

/?emar/c,s - Members of this genus first ap-

peared in the Tethys Sea during the Eocene and

Vol. 95(1)

January 29, 1981

THE NAUTILUS

are found as fossils in the Paris Basin formation.

The anatomy of the single, uncommon living

species, Gourmya gourmyi (Crosse) unequiv-

ocally places it in the family Cerithiidae. Gour-

mya species are distinctive due to the unusual

physiognomy of the shell aperture, anterior

siphonal canal and outer lip; consequently,

members of this genus are not easily confused

with other cerithiid groups.

Fischer (1884) used the manuscripts of Bayle

in proposing Gom-mya (Cossmann, 1906:68) but

Bayle should not be considered the author of the

name, which is properly attributed to Fischer.

Nordsieck (1968:69) considered Thericium

Monterosato, 1890, to be a subgenus of Gour-

mya and referred all Mediterranean species of

Cerithium to Gourmya. but gave no reasons for

this strange allocation. Thericium is normally

regarded as a subgenus of Cerithiuin Bruguiere,

1789, and members of the genera Cerithium and

Thericir ■ ^ffir little or no resemblance to those

of Gourr^fL^ in shell characters, certain

anatomical features and ecology. I thus find

Nordsieck's (1968) classification unacceptable.

Due to convergent shell characters, members

of the genus Terehralia Swainson, 1840, family

Potamididae Fleming, resemble Gourynya, and

the living species, Gourmya gourmyi, was re-

garded by some earlier workers as a potamidid

(see synonymy below).

Synonymy -

Cerithium gourmyi Crosse, 1861:171-173, pi. 6. figs. 1-2

(Holotype: NMHNP, not registered; Paratype: BM{NH)

1896.12.1.7; not registered; Type-locality: New Caledonia,

here restricted to Noumea). - Sowerby, 1866, pi. 290, fig.

325.-Vignal, 1897:1. -Cossmann, 1906:67. -Dance, 1974:

67.

Pyrazus Gourmyi Crosse. Sowerby, 1865: pi. 1, fig. 3.

Potamides (Terebralial Gourmyi Crosse. Tryon, 1887:160,

pi. 32, fig. 48.

Cerithium (-?l Gourmyi Crosse. Kobelt, 1888:6-8, pi. 1,

figs. 4-5.

Cerithium (Gourmya) gourmyi Crosse. Cernohorsky, 1978:

53, pi. 14, fig. 1.

DESCRIPTION

Shell -(¥\g. 1). Adult shell stocky, solid, tur-

reted and comprising 19 moderately inflated

whorls having apical angle of 40-45 degrees.

Shell length ranges from 30-63 mm; shell width

from 14-27 mm (see Table 1 for summary of

shell measurements). Adult whorls slightly con-

vex, sculptured with numerous fine spiral striae.

Suture incised, distinct. Early whorls pink or

white, usually eroded and with protoconch miss-

ing. Body whorl obese and with thick, smooth

varix at edge of outer lip. Aperture circular-

ovate, about one-third the length of the shell.

Columella concave, smooth and lacking columel-

lar callus. Anal canal (Fig. la) deeply incised,

marked by strongly raised ridge extending well

into shell aperture. Siphonal canal (Fig. Id)

straight, tubular, located at mid anterior of

shell. Outer lip smooth, circular and begins at

middle of body whorl. Base of outer lip extends,

hook-like, over siphonal canal but is not fused to

it (Figs, la, e, h). Periostracum yellow-tan,

moderately thick and covering entire shell in

fresh specimens. Shell color white, overlain with

axial blotches of tan or brown. Intensity of color

and pattern of blotches variable. Juvenile shells

more typically cerithioid in shape. Anterior

canal of juveniles less tubular than in adults and

outer lip does not extend over siphonal canal.

Operculum (Fig. 3g) ovoid, moderately thick,

brown and paucispiral with nucleus near outer

edge. Attached side with shiny attachment scar

that is deeply impressed and marked with incis-

ed spirals and curves. Operculum fits snugly in-

to aperture about one-third of the way back

from outer lip.

Radula-(¥\g. 2). Radular ribbon taenioglos-

sate, long, about one-fourth the length of the

shell and has 75 rows of teeth that show con-

siderable wear at distal end. Rachidian tooth

quadrate, about 0.12 mm long. Basal plate of

rachidian has short rounded basolateral projec-

tion and longer basomedial projection. Central

cusp of rachidian wide, spade-shaped, flanked

on each side with two small pointed denticles.

Top of rachidian has slight medial depression.

Lateral tooth rhomboidal with flattened basal

plate and slender basolateral extension. Cutting

edge serrated with one sharp denticle, a long,

wide triangular cusp and two to three small

rounded denticles, respectively. Marginal teeth

spatulate, curved at tips which are cusped on in-

ner surface with a large pointed cusp at the tip

and two smaller denticles on the inner side. In-

THE NAUTILUS

January 29. 1981

Vol. 95(1)

FIG. 1. Shells o/Gourmya KOLirmyi. showing apertural. dorsal, anterior and lateral views, a-d) Specimenfrom

Brodie Cay. Marion Reef. 19° 10 'S. 152°17'E (AMS CW8915: U-ix20.6 mm); e-g) Specimm from Bampton

Reef. Chesterfield Islands (AMNH 18002; 6.3x26.7 mm); h) Lectotype o/Cerithium gourmyi Crosse, 1861 from

New Caledonia (NMHNP, not registered; i2.S mm Umg).

Vol. 95(1)

January 29, 1981

THE NAUTILUS

TABLE 1. Aiudytsiti of shfll characters (measiiremfnts in

mm).

No., number of snails; x, mean; Sd, standard deviation.

ner marginals bear one cusp on outer side; outer

marginals smooth.

Animal-(Fig. 3). The head-foot region of pre-

served snails is a pink-orange color. The broad

head has relatively short cephalic tentacles,

each of which bears a tiny black eye at its

thickened base. The foot is large, broad, and has

a deep propodial furrow that appears to be lined

with numerous glandular cells that probably

produce mucus. The mantle edge is lined with

numerous wide and narrow papillae. The wider,

longer papillae are separated from each other by

three tiny narrow papillae (Fig. 3, pp). The ex-

halant siphon is marked by a deep fold and con-

vex ridge on the external mantle surface (Fig. 3,

rex.). The inhalant siphon is a long extension of

the mantle edge and comprises several folds

that form a deep latitudinal notch in the mantle

(Fig. 3, inho). The undersurface of the inhalant

siphon bears 6-7 thick, orange colored ocelli

(Fig. 3, inho). Each ocellus is externally ovoid

and has a small black circle in its center. Sec-

tions of the inhalant siphon show that the ocelli

are indeed pit-shaped eyes. Each ocellus forms a

deep invagination in the mantle and is surround-

ed by connective tissue within which may be

seen neurites and a few small ganglia. A vertical

section through an ocellus reveals a series of

elongate epithelial cells with large nuclei at their

proximal bases and capped at their distal ends

with a cornea-like squamous epithelium. This

bundle of elongate epithelial cells (Fig. 4, ce) is

surrounded by tiny granules of black pigment

(Fig. 4, bp). The entire structure probably func-

tions as a lens. Light is concentrated in the rod-

like epithelial cells and directed interiorly.

Beneath the lens is a large spherical body of fine

linearly arranged material (Fig. 4, rd) which

may comprise many fine rods of retinal cells, but

it appears acellular. At the base of the spherical

body is a thin layer of large ovoid cells with dark

FIG. 2. SEM micrographs of radida. Left: detaih of rachidian tooth and lateral teeth. Note inner

marginal teeth at right, folded over laterals and showing the small ctisp on outer lateral surface of

tooth; Right: detail of half row ofradular -ribbon with marginal teeth folded back to show insertion on

basal membrane. (Rachidian tooth 0.12 mm long).

THE NAUTILUS

January 29, 1981

Vol. 95(1)

cme

•eg

FIG. 3. Anatomy o/Gourmya gourmyi Crosse. A) Head and anterior part of mantle cavity. Mantle has been cut

and folded to one side; B) Pallial oinduct removed from mantle cavity and oriented with distal portion at bot-

tom; 15 mm. length; C) Spernuitophore chamber and seminal receptacle removed from pallial oinduct; k mm,

length; D) Cross-section of spermatophore receptacle and seminal receptacle made at dotted line in C; E)

Anterior alimentary tract showing buccal mass, nerve ring and esophagus; F) Cross-section through mid-

esophagus made at dotted line in E; G) Obverse of operculum showing attachment scar (shaded); 15 mm length;

eg, ciliated groove; cme, cut mantle edge; ct, ctenidium; dpo, distal pallial oviduct, dsr, d>ict of.-ieminal recep-

tacle; eg, esophageal gland; espc, ejnthelial lining of spermatophore chamber; hg, hypiihranchial gland; il, in-

ner lamina; inho, inhalant siphon and ocelli; j, jaw; Isg, left salivary gland; mes, mid-esophagus; od, odo7i-

tophore; ol, outer lamina; os, osphradium; ospc, opening to spermatophore chamber; pes, posterior esophagus;

pp, pallial papilkw; ppo, proxim/il pallial oviduft; r, radula; rex, ridge forming exhalant siphon; rpg, right

pletiral ganglion; rs, radula sar; rsg, right salivary gland; rt, radular tensor muscle; sec, supraesophageal

connective; seg, supraesophageal ganglion; sn, snout; sp, spennatophore; spc, spermatophore chamber; sr,

sem.inal receptacle; t, tentacle; wbc, wall of buccal cavity.

Vol. 95(1)

January 29, 1981

THE NAUTILUS

If :

^•^Xiu:*

VC

i*"

rd

B • •.'• .

FIG. 4. Longitudinal section through the uihahmt siphon

showing a pallial eye (Length of eye: 0.1 mm). A, Pallial eye

in relation to mantle edge; B, Detail of pallial eye showing

internal structure: bp, pigmented cells surrounding

"cornea": ce, elongate epithelial cells comprising "cornea":

rd, area interpreted as rods of retinal cells; rt, retinal cells:

VC, vacuolated cells.

staining cell walls and large nuclei filled with

dark staining granules (Fig. 4, rt). These appear

to be pigmented photoreceptor cells of the reti-

na. A thick mass of large vacuolated cells with

small nuclei and weakly defined cell boundaries

surrounds the receptor cells. This last cell layer

comprises most of the ocellus and is embedded

in the muscular tissue of the mantle edge (Fig.

4, vc).

When the mantle cavity is opened by a dorsal

longitudinal cut, the layout of the mantle organs

is typically cerithioid.

The hypobranchial gland (Fig. 3A, hg) is a

wide, thick structure extending back about one

third the length of the mantle cavity. The rec-

tum is a thick tube filled with several transverse

layers of fine tubular fecal pellets that consist of

fine carbonate sediment, green algal particles

and detritus, and strands of filamentous green

algae. It is detached from the mantle wall at its

distal end where it becomes a free tube that

opens about 3-4 mm behind the distal part of the

pallial gonoduct. A deep fold in the mantle roof

lies in apposition to the anus and corresponds to

the exhalant siphonal ridge seen on the external

mantle roof.

The osphradium (Fig. 3A, os) is tan, thin and

bipectinate, lies close to the ctenidium, and ex-

tends most of the mantle cavity length. At its

distal end it becomes a fine worm-like ridge

which ends near the edge of the exhalant siphon.

The ctenidium (Fig. 3A, ct) is monopectinate

and comprised of numerous long triangular fila-

ments.

The pallial gonoducts are open in both sexes

and males are aphallic. This arrangement is

typically cerithioid and may be compared with

what has been described for other cerithids

(Houbrick, 1971, 1976, 1978).

In females, the thick glandular pallial oviduct

is basically a slit tube comprising outer and in-

ner laminae (Fig. 3B, ol, il). There are no sperm

collecting gutters or ducts in the wall of the

outer lamina (Fig. 3B, ol) for most of its length,

but the proximal end bears a large kidney-

shaped spermatophore chamber (Fig. 3B, spc) in

its wall. This lies close to the free edge of the

outer lamina and appears as a large, light yellow

structure with a finely wrinkled surface. When

closely observed, the proximal part of the outer

lamina is seen to be a complex structure that in-

cludes a seminal receptacle (Fig. 3B, C, D, sr)

and internal duct as well as the spermatophore

chamber (Fig. 3D, spc). The spermatophore

chamber opens to the lumen of the pallial ovi-

duct by a latitudinal slit on the free edge of the

outer lamina (Fig. 3C, D, ospc) and may contain

as many as two spermatophores. Spermato-

phores (Fig. 3D, sp) are pale yellow, tear

shaped, and are roughly the size of the sper-

matophore chamber. They are placed with their

rounded ends lodged in the proximal part of the

chamber, and when present, cause the chamber

to bulge. The interior of the spermatophore

chamber is lined with columellar epithelial cells

(Fig. 3D, espc). Another thin latitudinal slit lies

8 THE NAUTILUS

January 29, 1981

Vol. 95(1)

along the edge of the spermatophore chamber

(Fig. 3n. spc) and within the free wall formed by

this slit is found the seminal receptacle (Fig. 3C,

D, sr).

The seminal receptacle appears to have a

small duct (Fig. 3C, D, (isr) leading from it to the

underside of the free wall. This opening is sur-

rounded by fingerlike wrinkles and is easily

seen. By means of this duct, sperm exit from the

seminal receptacle into the slit and thence into

the lumen of the pallial oviduct to fertilize ova as

they move down the oviducal groove of the ovi-

duct. There is no apparent connection between

the spermatophore chamber and the seminal re-

ceptacle and its duct, but sperm are free to move

from one slit to the other. The exact mechanism

of sperm transfer is unknown. Tiny pink ova

were seen in the oviducal groove and develop-

ment is presumably indirect.

The alimentary system (Fig. 3E, F) of Gour-

mya gourmyi is that of a typical herbivorous

cerithiid. The mouth lies at the top of a bilobed

snout, recessed between the lobes. A pair of

smooth ovate chitinous jaws (Fig. 3E, j) with

smooth cutting edges, each about 1 mm long and

0.73 mm wide, lie at the anterior end of the buc-

cal cavity. The buccal mass is large and the long

radular ribbon (Fig. 3E, r) ends in a thickened

radula sac that curls upwards (Fig. 3E, rs). Two

thick radular tensor muscles (Fig. 3E, rt) extend

from the walls of the head and insert laterally on

the posterior buccal mass. The paired salivary

glands are loose string-like lobes and lie dorsally

on the dorsal buccal mass and anterior esopha-

gus, in front of the nerve ring (Fig. 3E). A por-

tion of the left salivary gland (Fig. 3E, Isg)

passes through the nerve ring. No salivary ducts

were found. Immediately behind the nerve ring

the esophagus narrows and makes a sharp turn

upwards, expanding slightly. The mid-esopha-

gus (Fig. 3E, mes) has a deep ventral food

groove and a broad, flat dorsal food channel

(Fig. 3F). A large paired esophageal gland, (Fig.

3E, eg) comprising two longitudinal strips, lies

along the mid-esophagus. (Fig. 3F). Sections of

this gland show that it has many fine deep folds

and diverticula which may be seen through its

thin dorsal wall. The posterior esophagus (Fig.

3e, pes) has numerous longitudinal folds but is

otherwise simple in structure. The stomach is

basically the same as in other cerithiids. It is

unusual in having a very large chitinous gastric

shield with an extensive base and a main sorting

area with numerous serially arranged leaflets.

The cerebral ganglia (Fig. 3E, eg) are about

2.1 mm long and are nearly fused, while the

pleural ganglia lie below, close to the cerebrals.

The supraesophageal connective (Fig. 3E, sec) is

thick and the supraesophageal ganglion (Fig.

3E, seg) is moderately large. The RPG ratio

(length of the pleuroesophageal connective di-

vided by the sum of the length of the right

pleural ganglion, the supraesophageal connec-

tive, and the supraesophageal ganglion) was

0.62, indicating a moderately concentrated

nerve ring.

Records -LOYALTY ISLANDS: Mare Id

(AMS C3714); NEW CALEDONIA: Noumea

(NMV); Bambui, He des Pins (AMNH 186748);

30 meters, reef near Dumbea, (USNM 795115);

29 meters, outer slope St. Vincent Reef, off Baie

de Vincent (USNM 795116); CHESTERFIELD

ISLANDS: 7 meters, NE end, Anchorage Id

(AMS C. 86642); Bampton Reefs (AMS C

108914; C 108913); Seaward face of He Longue

(USNM 795122); 9 meters Bellona Reef (White-

head, 1977:3); AUSTRALIA: 5-25 meters top of

coral bommies, Brodie Cay, Marion Reef,

19°10'S, 152°17'E (AMS C 108915).

DISCUSSION

Synonymic Remarks -Crosse (1861:173) nam-

ed this species after Mr. Gourmy, from whose

collection the first specimens were described.

Several authors (Sowerby, 1865; Tryon, 1887)

have mistakenly referred this species to the

potamidid genera Pyrazns Montfort, 1810 and

Potamides Brongniart, 1810, but the similarities

in shell morphology are convergent. Members of

the Potamididae are estuarine snails and differ

considerably from marine cerithiids. Crosse

(1861:173) compared Gourmya gourmyi with

Terebralia species (potamidids) but noted that

the latter were ecologically very different from

the marine dwelling Gourmya species. He also

compared Gourmya with Cerithium adv^tum

Kiener, 1841. The latter species only resembles

Gourmya superficially and never has the aper-

Vol. 95(1)

January 29, 1981

THE NAUTILUS

tural features that distinguish Gourmya. Ceri-

thium adustum lacks the siphonal eyes, has a

different radula and belong to the TheHcium

lineage. Kobelt (1888:8) was unsure of the pro-

per allocation of Gownnya gounnyi and assign-

ed it, with some doubt, near a group of species

that he placed in the genus Vertagiis Schu-

macher, 1817 i = Rhinodavis Swainson, 1840)

but which are now regarded as members of the

genus Pseudovertagtis Vignal, 1904 (Houbrick,

1978). He noted that the base of the outer lip of

Gourmya was similar to that seen in Pseudo-

vergagtLS aluco (Linnaeus, 1758). This similarity

is superficial because the animals are quite dif-

ferent. Cossmann (1906) repeatedly spells Gour-

mya incorrectly as Gourmyia.

The pallial ocelli of Gourmya are unlike the

well defined eyes found on its cephalic tentacles

and on most mesogastropods. They appear to be

more like the pit-shaped eyes of Haiiotis as

depicted by Welsch and Storch (1973:176-177)

but differ from Haiiotis by having a bundle of

rod-shaped epithelial cells and a ring of dark pig-

ment on the surface which I interpret as a lens.

The ocelli somewhat resemble the eye of Tri-

chotropis as shown by Fretter and Graham

(1962:316). I have observed siphonal ocelli in one

other cerithid, Rhinoclavis (Proclava) kochii

(Philippi, 1848). Rhinoclavis species and some

Cerithium species have large siphonal ganglia

and elaborately pigmented inhalant siphons that

seem to serve some sensory function. These

have not been histologically investigated but

probably bear some sensory structures. Johans-

son (1956) described a very similar eye in the

potamidid Tympanotomis. Thus, the presence of

siphonal ocelli in Gourmya, although unusual, is

not unprecedented among the Cerithiinae.

The serially arranged leaflets in the sorting

area of the stomach of Gourmya are similar to

those I have seen in the stomach of Campanile

symbolicum Iredale, 1917, family Campanilidae

Douville, 1904 (Houbrick, 1980, in press). Cam-

panile is another Tethyan relict and the last of a

long lineage of a large family of Tertiary snails.

This structure is not present in other anatomi-

cally known species of Cerithiidae and Potami-

didae.

Ecology - Gourmya gourmyi, although uncom-

mon in museum collections, is probably not a

rare gastropod in its restricted range and

habitat. Cernohorsky (1978:53) stated that it

lives in the intertidal zone but this is erroneous.

All museum specimens have been collected at

depths ranging from 5-30 meters and at an

average depth of 17.5 meters on rocky substrata

associated with coral reef slopes. According to

Australian collectors, specimens are usually

found on algal covered rocky surfaces on fore

reef drop-offs. As divers using SCUBA investi-

gate that zone in this part of the Pacific, more

specimens will undoubtedly be found.

The most striking feature of the shell of this

species is the unusual, centrally placed siphonal

canal over which extends the base of the outer

lip. These peculiarities of the aperture and

siphon create a flattened circular apertural

plane that allows the snail to withdraw its head

and foot and clamp down on the hard substra-

tum for protection. Communication with the ex-

ternal environment is maintained through the

siphonal canal by means of the ocelli and sen-

sory receptors on the siphonal mantle edge.

Another deterrent to predation is the thickened

varix on the edge of the outer lip. No observa-

tions have been made on living animals and their

associations but most live-taken specimens have

Capulus danieli (Crosse) attached near the shell

apex. Stomach contents, fecal pellet analysis

and the anatomy of the alimentary system in-

dicate that Gourmya is a herbivorous grazer.

The relatively long radular ribbon suggests a

grazing habit on coarse surfaces.

Fossil Record -Gourmya romeo (Bayan,

1870), a Tethyan Eocene species, is unequiv-

ocally a Gourmya species and is well illustrated

by Bayan (1870: pi. 9, fig. 5) and Cossman (1906:

pi. 1, figs. 8-9). Its shell shape is very close to

the living species, Gourmya gourmyi. Cossmann

(1906:68) stated that Bayle, whose manuscripts

were used by Fischer (1884) in proposing Gour-

mya, designated Cerithium romeo Bayan as the

"genoplesiotype" of Gourmya. Both Bayan

(1870:37) and Cossmann (1906:68) noted its

resemblance to the living species described by

Crosse (1861:171-173) as Cerithium gourmyi,

but it is unlikely that the two are conspecific.

An Oligocene species, Cerithium ocirrohoe Or-

10 THE NAUTILUS

January 29, 1981

Vol. 95(1)

bigny, 1850, has also been referred to Gourmya

by Vignal (1897:69-70) and Cossmann (1906:69).

I have not examined specimens of this species,

but illustrations of it in the literature support its

allocation to Gourmya. Cossmann (1906:69) fur-

ther cited the Miocene species Ceritkium kiips-

teini Michelotti, 1847 and Cerithium geminatum

Grateloupe, 1832 (non Sowerby, 1816) as rep-

resentatives of Gourmya. I have not seen these

species and cannot comment on their allocation

to the genus. I have examined the holotype of

Cerithium parungpo7denge7ise K. Martin, 1899

(RMGM St 10391), a Pliocene species from Java,

which, as K. Martin (1899:204) and Cossmann

(1906:69) remarked, appears to be closely re-

lated to Gourmya gourrnyi. I believe that this

fossil is either the direct ancestor of Gourmya

gourmyi or conspecific with it and am inclined to

accept the latter opinion. Many other living

cerithids have records extending back as far as

the Miocene.

Geographic Range -(Fig. 5). The range of this

species is restricted to the New Hebrides (Cer-

nohorsky, 1978:53), New Caledonia, the Ches-

terfield Islands and Marion Reef, in the Coral

Sea.

Conclusions -I regard Gourmya as a good

genus because its lineage may clearly be traced

in the fossil record to the Eocene. The living

species' habitat in deeper waters of coral reefs

FIG. 5. Geographic distribution 0/ Gourmya gourmyi.

suggests that members of this genus exploited

an adaptive zone different from those of most

other cerithiid groups. The peculiar features of

the shell, such as the shape of the aperture,

outer lip and siphonal canal, further set this

group apart from other cerithiids. The presence

of siphonal ocelli, a highly developed esophageal

gland, large gastric shield and the arrangment

of the spermatophore chamber and seminal re-

ceptacle at the proximal end in the outer lamina

of the pallial oviduct are distinctive anatomical

features that support the standing of Gourmya

as a separate group. Open pallial gonoducts,

aphallic males and the basic anatomy establish

its inclusion in the Cerithiidae and suggest a

close relationship with the genera Cerithium

Bruguiere, Pseudovertagus Vignal, and Rhino-

clavis Swainson.

Members of the genus Gourmya were present

in the Tethys Sea from the Eocene through the

Miocene but became extinct after the Miocene

and the closure of the Tethys. A fossil from Java

confirms the presence of the genus in the Indo-

Pacific during the Pliocene. The sole survivor of

this lineage, Gourmya gourmyi, is today

restricted to island groups in the Coral Sea

around New Caledonia.

ACKNOWLEDGMENTS

I thank Dr. Philippe Bouchet, of the Paris

Museum, and Dr. Winston Ponder of the Aus-

tralian Museum, Sydney, for supplying me with

preserved specimens and providing facilities for

dissection. I also thank Dr. William K. Emerson,

American Museum of Natural History, and Mr.

Janssen of The Leiden Museum for the loan of

specimens in their charge. The original draft of

this paper was reviewed by Dr. Edward Petuch,

University of Maryland, and Dr. Joseph Rose-

water, Smithsonian Institution. Ms. Cathy

Lamb kindly proofread the final manuscript and

assisted with the preparation of material for

SEM. Photography was done by Mr. Victor

Krantz of the Smithsonian Photographic Serv-

ices. Photomicrographs of the radula were sup-

plied by the Smithsonian Scanning Electron

Microscope Laboratory. Part of this research

was supported by a Smithsonian Research

Foundation Grant.

Vol. 95 (1)

January 29, 1981

THE NAUTILUS 11

LITERATURE CITED

Bayan, F. 1870. Etudes faites dans la collection de I'Ecole

lies Mines sur des fossiles nouivaiut ou mal coymits. Pre-

mier Fascicule. Mollusques Tertiairies. Paris, 162 pp,

20 pis.

Bruguiere, J. G. 1789. Encyclopedie Methodique, Histoire

Naturelle des Vers. Paris, 1(1): 344 pp.

Brongniart, A. 1810. Sur des terrains qui paroissent avoir

ete sous I'eau douce. Annales museum d' Histoire Naturelle

de Paris. 15(89-90):357-405, pis. 22-23.

Cernohorsky, W. 0. 1978. Tropical Pacific Marine Shells.

Sydney, 352 pp, 68 pis.

Cossmann, M. 1906. Essaif de Paleoconchologie Comparee.

vol. 7. Paris, 248 pp.

Crosse, H. 1861. Description d'especies nouvelles. Journal

de Conchyliologie 9:171-173, pi. 6, figs. 1-2.

Dance, S. P. 1974. The Collector's Encyclopedia of Sliells.

New York 288 pp, illustrated.

Douville, H. 1904. Mollusques Fossiles, In: Morgan, J. De.

Mission Scientifique en Perse. Vol. 3, Etudes Geologi-

ques, part 4, Paleontologie: 191-380, pi. 25-50.

Fischer, P. 1884 (1880-1887). Manuel de Conchyiiologie et

de paleontologie conchyliologique. Paris, xxiv + 1396 pp,

23 pis.

Fleming. J. 1828. Mollusks, Encyclopedia Britannica. sup-

plement to editions 4-6, vol. 3, part 1. Edinburg.

Fretter, V. and A. Graham. 1962. Britwh Prosobranch Mol-

lusks. Ray Society, London. 755 pp, illustrated.

Grateloupe, J. D. S. 1832. Tableau (suite du) des coquilles

fossiles qu'on rencontre dans les terrans calcaires ter-

tiaires (faluns) des environs de Dax, department des

Landes; par M. Grateloup, membre honoraire. 5'" Article.

Actes de la Societe Linneenne de Bordeaux. 5(29):263-282.

Houbrick, R. S. 1971. Some aspects of the anatomy, repro-

duction and early development of Cerithium nodulosum

(Bruguiere) (Gastropoda, Prosobranchia). Pacific Science

24(4):560-565.

1974. The Genus Cerithium in the Western

Atlantic. Johnsonia. 5(50):33-84, pis. 13-48.

1978. The family Cerithiidae in the Indo-Pacific,

Part 1: The genera Rhinoclaris. Pseudovertagus and

Clavocerithium. Monographs of Marine Moll usca. No. 1:

1-130, 98 pis.

Houbrick, R. 1980. Anatomy, biology and systematies (jf

Campanile symbolicum Iredale with reference to adaptive

radiation of the Cerithiacea (Gastropoda: Prosobranchia).

Malacologia, in press.

Iredale, T. 1917. More molluscan name changes, generic and

specific. Proceedings of the Malacological Society of Lon-

don. 12(6):322-330.

Johansson, J. 1956. On the anatomy of Tympanotonus fus-

catus (L.), including a survey of the open pallial oviducts

of The Cerithiacea. Atlantidae Report. No. 4:149-166,

pi. 1.

Kiener, L. C. 1841 (1841-1842). Species general et icono-

graphie des coquilles vii'antes. Genre Cerite. Paris, vol. 5,

104 pp, 32 pis.

Kobelt, W. 1888-1889. Die Gattung Cerithium. 297 pp, 47

pis. In Martini, F. H. W. and J. H. Chemnitz, Neues sys-

tematisches Conchy lien-Cabinet, etc., 1(26). Nurenburg.

Linnaeus, C. 1758. Systema naturae per regno tria naturae.

Editio decima, reformata. Stockholm, vol. 1, Regnum

animale, 824 pp (Jan. 1).

Martin, K. 1899. Die Fossilien von Java. Sammlungen des

Geologischen Reichs-Museums in Leiden. Neue Folge,

1(6-8):133-221, pis. 36-45.

Michelotti, G. 1847. Descriptions des Fossiles des terrains

Miocenes de I'ltalie Septentrionale. Hollandsche Maat-

schappij der Wetenschappen, Haarlem. Natuurkundige

Verhandeiingen 3(2):

Monterosato, M. 1890. // naturalista SicUiano 9(7): 140-

151; 157-166.

Montfort, D. de. 1810. Conchyiiologie systematique et class-

ification methodique des coquilles. Paris, 2 vol., 676 pp.

Nordsieck, F. 1968. Die europdischen Meeres-Gehdu.se-

schnecken ( Prosobranchia) vom Eismeer bis Kapverden

und Mittelmeer. Stuttgart, 273 pp, 31 pis.

Orbigny, A. d'. 1850. Prodrome de Paleontologie Strati-

graph ique universelle des Animauj: Mollusq^tes et Rayon-

nesfaisant suite au cours Elementaire de Paleontologie et

de Geologic Stratigraphiques. Paris, 1269 pp.

Schumacher, C. E. 1817. Essai d'une nouveau septeme des

habitations des vers testaces. Copenhagen, 287 pp, 22 pis.

Sowerby, J. 1816. The Mineral Conchology of Great Britain.

London, vol. 1.

Sowerby, G. W. 1855. Thesaurus Conchiliorum. or mono-

graphs of genera of shells. Vol. 2, Cerithium: 847-859, pis.

176-756. London.

1866. As above. Supplementanj. pi. 290. Ceri-

thium.

1865. In Reeve, Conchologia Iconica: or illustra-

tions of the shells of molluscous animals, vol. 15, Ceri-

thium. 20 pis. -I- index. London.

Swainson, W. 1840. A treatise on Malacology or the Natural

History of Sliells and Shellfish. London, 419 pp.

Thiele, J. 1931. Handbveh der Systematisches Weichtier-

kunde. Jena, 2 vols.

Tryon, G. W. 1887. Manual of Conchology: structural a7id

><ystematic: with illustrations of the species. First series: 9:

Cerithium, pp. 127-149, pis. 20-29. Philadelphia.

Vignal, L. 1897. Note sur le Cerithium iGoui'mya) ocirrhoe

A. d'Orbigny. Journal de Conchyiiologie 45:69-70.

Welsch, U. and V. Storch. 1973. Comparative Animal Cyto-

logy and Histology. Seattle, 343 pp, illustrated.

Wenz. W. 1938-1944. Gastropoda, Teil 1, Allgemeiner Teil

und Prosobranchia. In Schindewolf, Handbuch der Pald-

zoologie, vol. 6 Berlin, vii-n 1639 pp.

12 THE NAUTILUS

January 29, 1981

Vol. 95(1)

CORBICULA FLUMIXEA (BIVALVIA: SPHAERUCEA)

IN BRITISH COLUMBIA!

Clement L. Counts, III

College of Marine Studies

Universit}' of Delaware

Lewes. Delaware 19958 USA

ABSTRACT

Corbicula fluminea (Milllerj is reported from Vancouver Island, British Colum-

bia. The specimens were located in the collection of the United States National

Museum of Natural History and represent the first record of C. fluminea in

Canada arid are the oldest documented specimens of the species in North America

Since the first report of CorMcuia fluminea

(MuUer, 1774) in North America from specimens

coUected in 1938 in the Columbia River Basin of

Oregon and Washington (Burch, 1944), these

clams have spread across the United States and

substantial populations now exist in 28 states

(Sinclair and Isom, 1963; Fox, 1969, 1970:

Clench, 1970, 1971; Eckbald, 1975; Crumb,

1977; Morris and Taylor, 1978; Britton and Mor-

ton, 1979; Mathiak,' 1979). Clarke (1973), in an

extensive review of the MoUusca of the Cana-

dian Interior Basin, did not report C. fluminea

from Canada and no other Canadian records for

the species have appeared in the literature.

During a study of the zoogeography of bi-

valves in the genus Corbicvla at the United

States National Museum of Natural Historj',

Washington, D.C., a lot of Corbicula (probably

C. fluminea) collected in Canada was discovered

(USNM 363020). The shells (3 specimens) were

collected 24 February 1924 at Nanaimo, Van-

couver Island, British Columbia by an unknown

person and were sent to the United States Na-

tional Museum by Mrs. Ida Oldroyd. The label

accompanying the lot states "Dead on beach.

Probably a Japanese import". No record of liv-

ing C. fluminea at the collection site was found

in the catalog.

Collections of freshwater mollusks by the

Field Museum of Natural History' (Chicago) at

Nanaimo in 1953 did not reveal the presence of

'University of Delaware College of Marine Studies Contribu-

tion No. 154.

Corbicula fluminea (Haas, 1954). A review of

distributional records for specimens in the

genus Corbicula in the collections of the

Museum of Natural Sciences, National Muse-

ums of Canada, Ottawa, the Nanaimo Mollusca

collections of the Rev. G. W. Taylor at the

Delaware Museum of Natiiral Historj- and the

collections of the Pacific Biological Station,

Nanaimo, failed to reveal any additional records

for C. fluminea in Canada (Muriel F. I. Smith,

pers. comm., 1979; R. Jensen, pers. comm.,

1980; D. Quayle, pers. ccmm., 1980).

The introduction of Corbicula fluminea into

North America is generally attributed to

Chinese immigrants- (Fox, 1969; Britton and

Morton, 1979). There is, however, some debate

as to when the introduction of this bivalve occur-

red. Fox (1969) postulated C. fluminea was in-

troduced by immigrants from the Canton region

who arrived in western North America during

the late 1840's to work in the gold camps and

mines and on the transcontinental railroad. Al-

though there is an established tradition of eat-

ing C. fluminea among the Cantonese (who call

it the Prosperit>' Clam) (Miller and McClure,

1931) it has not been estabhshed whether these

clams could survive long periods in environ-

ments similar to those in ships of the period.

Britton and Morton (1979) also attribute the im-

portation of C. fluminea to the Chinese but place

the introduction of the founding population

sometime during the mid-1930's when many

Chinese came to the United States and Canada

to escape national and international conflicts in

Asia. The present report places the arrival of C.

Vol. 95(1)

January 29, 1981

THE NAUTILUS 13

fluminea in North America during the early- to

mi(i-1920's.

The absence of other Canadian records of Cor-

hicula fluminea raises questions about its

biology and distribution. Sport fishermen have

used C. fluminea as a bait for many years (Fox,

1969; Britton and Morton, 1979) and the spread

of this species in the United States has been at-

tributed to these sportsmen who throw unused

clams into streams (Britton and Morton, 1979).

Abbott (1975) noted tropical fish hobbyists may

similarly be responsible for the spread of these

clams. Since C. fluminea is a consecutive pro-

tandrous hermaphrodite (Kraemer, 1978) very

few clams are necessary to establish a popula-

tion if environmental conditions are within ac-

ceptable limits for survival. It may be that

USNM 363020 were discarded, either as bait or

as the remains of a meal, into waters whose

physicochemical characteristics were unsuit-

able. This speculation is not supported, how-

ever, by climatic, geologic and phytogeogi'aphic

data for British Columbia (Clarke, 1973) which

demonstrate that the environment of the south-

western portion of the province is like that of

western Oregon and Washington and northern

California where C. fluminea has thrived for

over 30 years (Fox, 1969). The absence of C.

fluminea in the Canadian Interior Basin (Clarke,

1973) and present-day British Columbia also

supports the hypothesis recommended by

Thompson and Sparks (1977) that C. fluminea is

incapable of being carried to new localities in the

gastrointestinal tract of migratory waterfowl.

The specimens in USNM 363020 are signifi-

cant as they are the only record of Corbicula

fluminea in Canada and also the earliest docu-

mented specimens of the species in North

America.

ACKNOWLEDGMENTS

I wish to thank Arthur H. Clarke and Joseph

Rosewater, United States National Museum of

Natural History for making their facilities avail-

able to me. I am also indebted to Muriel F. I.

Smith, Museums of Natural Sciences, National

Museums of Canada, Daniel Quayle, Pacific

Biological Station and Russell Jensen, Delaware

Museum of Natural History for their research of

Corbicula records. I also wish to thank Diane M.

Muni for her assistance in gathering distribution

records and R. Tucker Abbott for his sugges-

tions and review of the manuscript.

LITERATURE CITED

Abbott, R. T. 1975. Beware the Asiatic freshwater clam.

Tropwal Fish Hobkjists 23:15.

Britton, J. C. and B. Morton. 1979. Corhicula in North

America: the evidence reviewed and evaluated. Proc.

First Internat. Corbicula Symp. pp. 250-287.

Burch, J. Q. 1944. Checklist of west American mollusks.

Minutes Conchol. Club California 38:18.

Clarke, A. H. 1973. The freshwater molluscs of the Canadian

Interior Basin. Malarologia 13:1-509.

Clench, W. J. 1970. Corhicula marulensis Philippi in lower

Florida. The Nautilus 84:36.

1971. Corhicula manilensis (Philippi) in Okla-

homa. The Nautilus 85:145.

Crumb, S. E. 1977. Macrobenthos of the tidal Delaware

River between Trenton and Burlington, New Jersey.

Chesapeake Set. 18:253-265.

Eckbald, J. W. 1975. The Asiatic clam, Corhicula. in the

upper Mississippi River. Th£ NuMtilui; 89:4.

Fox, R. 0. 1969. The Corhtcula story: a progress report.

Western Soc. Malacol., 11 pp.

1970. The Corbicula story: chapter two. West-

ern Soc. Malacol., 5 pp.

Haas, F. 1954. Non-marine mollusks from the Pacific Slope

of North America. The Nautilus 67:94-96.

Kraemer, L. R. 1978. Corhicula fluminea (Bivalvia: Sphae-

riacea): the functional morphology of its hermaphroditism.

Bull. Amer. Malacolog. Union 1978:40-49.

Mathiak, H. A. 1979. A River Survey of the Unionid Mussels

of Wisconsin 1973-1977. Sand Shell Press (Horicon, Wis-

consin). 75 pp.

Miller, R. C. and F. A. McClure. 1931. The freshwater clam

industry of the Pearl River. Lingnan Sci. Jour. 10:

307-322.

Morris, J. S. and R. W. Taylor. 1978. A survey of the fresh-

water mussels (Bivalvia: Unionidae) of the Kanawha River

of West Virginia. The Nautilus 92:153-155.

Sinclair, R. M. and B. G. Isom. 1963. Further Studies m the

Introdwed Asiatif Clam (Corbicula) in Tennessee. Ten-

nessee Stream Pollution Control Bd., Tennessee Dept.

Publ. HIth., v-^79pp.

Thompson, C. M. and R. E. Sparks. 1977. Improbability of

dispersal of adult Asiatic clams, Corbicula manilensis,

via the intestinal tract of migratory waterfowl. Amer.

Midi. Nat. 98:219-223.

14 THE NAUTILUS

January 29, 1981

Vol. 95(1)

ANALYSIS OF SOME CHARACTERISTICS IN TWENTY FOUR

POPULATIONS OF WESTERN U.S. PLEUROCERID SNAILS'

Branley A. Branson and Daniel H. Barrett

Department of Biological Sciences

Eastern Kentucky University

Richmond, Kentucky 40475

ABSTRACT

Statistical analysis of the average obesity index and average apertural index in

2Jt populations of pleurocerid snails from the western United States indicates

broad overlapping of those characteristics in Goniobasis plicifera and G. silicula

and a clusteriyig ofG. orickensis, G. chacei, G. coquillensis, G. yreckaensis, G.

hemphilli maupinensis, G. hemphilli dallesensis and G. plicifera bulimoides

distinct from the G. plicifera-silicula complex. This cluster of species andlor races

needs to be re-elevated in order to determine interrelationships.

INTRODUCTION

In its natural western U.S. range, the family

Pleuroceridae was apparently rather wide-

spread during Tertiary times (Henderson,

1935c), becoming progressively more segre-

gated and depauperized in individual basins with

the post-Pleistocene dessication of various

drainages. At present, representatives of the

family are distributed from British Columbia

through western Washington and Oregon to

northern California, but not extending south to

San Francisco (Henderson, 1932). There are a

few additional species in the western United

States and Canada, such as the so-called

Goniobasis columbiensis Whiteaves from the up-

per Columbia River in eastern British Columbia,

a species which is probably conspecific with G.

livescens (Menke) of the Niagara River and

many Great Lakes tributaries (Goodrich, 1937).

Furthermore, there are a few highly depauper-

ized pleurocerids isolated in some Great Basin

springs in Washoe County, Nevada, Lassen

County, California, and some Columbia River

tributaries. However, Goodrich (1935, 1944)

judged these species to be more closely related

to eastern U.S. species than to those of the

Pacific slope.

It is the Pacific species which are very confus-

ing. Henderson's (1935a, b) work on this group

'Supported by Sigma Xi-RESA ami P>asU'rn Keiitiici<y t'ni-

versity faculty grants.

attempted to clarify some of the relationships,

although additional confusion emerged; he did

demonstrate the high degree of variability in the

species and successfully delineated certain

ranges. According to Goodrich (1935a), typical

G. silicula (Gould, 1847) is confined to western

Washington, although various authors have re-

ported specimens under that name from Oregon

and northern California. The race usually

reported from northwestern Oregon is G.

silicula bairdiana Lea, whereas G. s. nidens

(Reeve) is the nominal race of the Olympic

Peninsula. Another putative race in this species,

G. s. shastae-nsis (Lea) was described from the

Shasta and Scott rivers of California. Goyiio-

basis plicifera (Gould) is distributed in north-

western Oregon and southwestern Washington

(Henderson, 1935a) where it is supposedly not

distinguishable from the nominal species G.

oregonensis Tryon and G. bulimoides (Tryon)

(Goodrich, 1942).

Other species described from the West Coast

include G. draytoni Lea from Astoria, Oregon

and Walla Walla, Washington, G. acutifilosa

Stearns, G. occata (Hinds) from California

(Henderson, 1935a) and G. nigrina (Lea) from

headwater streams in Oregon and northern Cal-

ifornia (Goodrich, 1942). In addition, Henderson

(1935a, b) described nine new species and sub-

species: G. hemphilli from near Portland,

Vol. 95 (1)

January 29, 1981

THE NAUTILUS 15

Oregon, G. hemphilli dallesensis, the Dalles,

Oregon, G. hemphilli maupinensis, Deschutes

River, Oregon, G. yrekaensis, Shasta River,

California and the Rogue River and creeks in ad-

jacent Oregon, G. yrekaensis obscura, Wonder,

Oregon, G. orickemsis, Orick, California, G. co-

quillensis, Coquille River, Oregon, G. chacei.

Smith River, Del Norte County, California, and

G. acutifilosa pitteiisis. Fall River, California.

In reviewing the Pleuroceridae of the Pacific

Coast, Goodrich (1942) separated all of the

species into two main categories on the basis of

sculpture and indicated that Henderson's

(1935a, 1)) nine new forms were probably based

upon trivial characteristics which were useful in

distinguishing local races but not species and

subspecies. Goodrich's (1942) categories includ-

ed the Goniobasis occata group, with G. occata

of the Sacramento and San Joaquin rivers in

California and G. acutifilosa Stearns of Siskiyou

and Shasta counties, California, and the Gonio-

basis plicifera (Lea) group, with G. plicifera, G.

silicula and G. nig7'ina (Lea). Goodrich (1942)

included G. shastaensis Lea, G. rudens Reeve,

G. rubiginosa Lea and G. bairdiana Lea in the

synonymy of G. silicula.

In addition, one of us (Branson, 1977) col-

lected 55 specimens from the South Nemah

River at Nemah, Washington, and 26 from Sut-

ton Creek north of Florence, Oregon, which

seemed intermediate in shell sculpturing and

proportions between G. plicifera and G. silicula.

stimulating the desire to conduct a more exten-

sive comparison than possible at the time.

Goodrich (1942) explained such observations by

postulating that it might not be possible to make

precise demarcations between some species,

specifically G. plicifera and G. silicula.

Thus, the purpose of this paper is to present

the results of a fairly extensive comparison of

several of the western pleurocerid snails based

upon two characteristics of the shell.

It has been known for a long time that the

shell sculpturing in G. silicula is highly variable,

tending to be well-developed in the main

streams and nearly to completely absent in

headwaters and springs (Goodrich, 1942). Such

variation may result from differences in water

chemistry, current, presence or absence of

limestone, and climatic differences between

headwaters and downstream sites (Bailey, Pearl

and Windsor, 1932). There is also growth-re-

lated variation because of changes in relative

proportions of height to width (Walker, 1900), a

ratio that is also apparently influenced by ex-

posure to wave action (Wiebe, 1926).

MATERIALS AND METHODS

Twenty four populations (see collecting data

below) of pleurocerid snails from various West

Coast localities were analyzed by straight for-

ward analysis of variance and Student-New-

man-Keuls a posteriori methods. Two charac-

teristics were utilized, the "average obesity in-

dex", a feature which varies directly with aver-

age width and indirectly with average length

(Wiebe, 1926) and the average apertural index,

with similar relationships. Shell height was

measured to the uppermost extent of the last

suture to avoid bias caused by apex erosion, and

the greatest girth was measured by means of

dial calipers accurate to 0.01 mm.

COLLECTING DATA

In the following list, each station is assigned a

number for ease of reference in the statistical

tables and text. The names appearing in this list

are those applied by the various authors of the

forms indicated. The figures in parentheses are

the sample sizes.

1. Goniobasis plicifera bulimoides (Tryon).

Willamette River just above Eugene, Oregon

(9).

2. Goniobasis plicifera oregonensis (Tryon).

Small creek, 38 air miles north of Astoria,

Oregon (7).

3. Goniobasis circumlineata Tryon. Geyser

Creek, Sonoma County, California (2).

4. Goniobasis hemphilli niaupinensis Hender-

son. Deschutes River at Maupin, Oregon (7).

5. Goniobasis orickensis Henderson. Red-

wood Creek at Orick, Humboldt County, Califor-

nia (15).

6. Goniobasis yrekaensis obscura Henderson.

16 THE NAUTILUS

January 29, 1981

Vol. 95(1)

Small creek, two miles south of Wonder, Jose-

phine Countj', Oregon (16).

7. Goniobasis draytoni (Lea). Sonoma Coun-

ty, California (25).

8. Gordobasis coquiUensis Henderson. Co-

quille. Oregon (3).

9. Goniobasis chacei Henderson. Bear Creek,

Del Norte Countj". California (8).

10. Goniobasis yrekaensis Henderson. Shasta

River, 3.4 km above mouth, Siskiyou County,

California (19).

11. Goniobasis hemphilli dallesensis Hender-

son. Mni Creek, The Dalles, Oregon (17).

12. Goniobasis siUcula ((}ould). Black River.

Washington State Route 12, Chehalis Indian

Reservation (57).

13. Goniobasis silicula. Small spring,

tributarj' to Black River, near Grars Harbor,

Washington (81).

14. Goniobasis silicula. East Fork of Satsop

River, Schafer State Park, Washington (81).

15. Goniobasis silicula. Skokomish River, 0.5

km above mouth. Washington (24).

16. Goniobasis silicula. Cranberrj' Creek,

near Ocosta, Washington (20).

17. Goniobasis silicula. Humptuhps River.

Humptulips Quadrangle, Washington (16).

18. Goniobasis silicuta. Fairchild Creek,

tributary- to Humptulips River, Humptulips

Quadrangle, Washington (29).

19. Goniobasis silicula. Caldwell Creek,

WjTioochee Valley. Washington (17).

20. Goniobasis silicula. Scatter Creek,

Tenino, Washington (7).

21. Goniobasis silicula. Small creek. 7 miles

north of Vancouver, Washington (15).

22. Goniobasis plicifera (Lea). Small creek at

Millersylvania State Park. Washington (22).

23. Goniobasis plicifera. South Nemah River,

near coast, Washington (55).

24. Goniobasis plicifera. Sutton Creek. U.S.

Highway 101, 6 miles north of Florence, Oregon

(26).

DISCUSSION

As expected, the overall analysis of variance

for the characteristics delineated above dem-

onstrated verj- highly significant variance com-

ponents (P<0.001). Because of this, a stepwise

Newman-Keuls a posteriori test was calculated

for both sets of characteristics (Tables 1. 2).

The first treatment (Table 1) divided the pop-

ulations into two groups. Group A included the

following populations: 1 fG. plicifera buli-

moides), 4 (G. hemphilli maupinensis), 5 (G.

orickensis), 6 (G. yrekaensis), 8 (G. coquiUensis),

9 {G. chacei), 11 (G. hemphilli dallesensis) and 17

(G. silicula). Group B. included: 2 (G. plicifera

oregonensis), 3 (G. circumlineata), 7 (G. dray-

toni). 12. 13, 14, 15. 16. 18. 19. 20, 21 ^all G.

sUicula), 22, 23, 24 (aU G. plicifera). and 10 (G.

yrekaensis).

The second analysis di\ided the populations

into three categories. Group A included: 2 (G.

plicifera oregonensis). 10 (G. yrekaensis). 15, 16,

17, 19, 20 (aU G. silicula), 22. 24 fG. plicifera):

group B included: 1 (G. plicifera bulimoides). 3

(G. circumlineata). 4 (G. hemphilli mau-

pinensis), 6(G. yrekaensis), KG. draytoni), 8fG.

coquiUensis), 11 (G. hemphilli), 13, 14. 18, 21 (all

G. silicula), and 23 (G. plicifera); and group C: 5

fG. orickensis). 9 (G. chacei). and 12 (G. silicula).

Excluding G. circumlineata and G. draytoni,

the range of which is far outside that of the

other forms (Sacramento River basin), these

analyses make some important points. For one

thing, thej' reaffirm (Goodrich's (1942) obsen^a-

tions that there is often broad overlap in the

characteristics of G. silicula and G. plicifera,

principally because of environmentally stimu-

lated variability-. It also appears that Cjoodrich

(1942) was correct in assuming that G. plicifera

oregonensis was merely a variant form of typical

G. plicifera.

On the other hand, analysis of the average

apertural index (Table 1) demonstrates a strong

clustering of G. orickensis, G. chacei, G. coquil-

lensis, G. yreckaensis, G. hemphilli maupinen-

sis, G. hemphilli dallesensis and G. plicifera

bulimoides as contrasted with the other forms.

There is a modest bit of overlapping in the case

of G. yrekaensis with population 10 in the

plicifera-silicula complex. In the case of the

second character (Table 2), the analysis shows

three clusters with regard to Henderson's

(1935a, b) species and races, one for population

10 (G. yrekaensis from the Shasta River), one

for G. hemphilli, G. hemphilli maupinensis, G.

Vol. 95 (1)

January 29, 1981

THE NAUTILUS 17

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18 THE NAUTILUS

January 29, 1981

Vol. 95(1)

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Vol. 95 (1)

January 29, 1981

THE NAUTILUS 19

plicifera bulimoides, G. coquilleTisis, and popula-

tion 6 of G. yrekaensis obscura, and the third

cluster for G. orickensis, G. draytoni and G.

chacei.

Goodrich (1942) listed G. plicifera bulimoides

as a synonym of G. plicifera, and all of Hender-

son's (1935a, b) other forms as species incerta,

hinting that all of these were probably variants

of either G. plicifera or G. siiicula, or both.

However, in view of the results reported here,

this view does not appear acceptable. Goodrich

(1942) himself stated that, "until a system of

nomenclature shall have been devised that can

deal with peculiarities of groups, clusters, or col-

onies, each by itself, it appears wasest to keep to

the course followed in the treatment of the Pleu-

roceridae east of the Rocky Mountains." In the

eastern United States, nearly every river sys-

tem has its own peculiar pleurocerid fauna, even

though some of the systems lie in close prox-

imity to one another. If we follow Goodrich's

(1942) logic, extrapolating the condition of

eastern streams to the West, then it should

follow that western drainages may also have ex-

perienced pleurocerid divergence so that differ-

ing drainages would possess differing species

complexes of this complicated molluscan family.

Hence, it is concluded that Henderson's (1935a,

b) species, possibly including G. plicifera buli-

moides, actually form a closely related complex

of species and/or races as distinct from the G.

plicifera-G. siiicula complex. However, this

complex needs to be re-evaluated as a group in

order to determine interrelationships.

LITERATURE CITED

Bailey, J. L., R. Pearl and C. P. Winsor. 1932. Variation in

Goniobasis rnrginica and Anculosa carinata under natural

conditions. Biol. Gen. Band 8:607-634.

Branson, B. A. 1977. Fresh water and terrestrial Mollusca

of the Olympic Peninsula, Washing^ton. The Veliger

19:310-330.

Goodrich, C. 1935. A species of Goniobasis new to the Great

Basin. Th£ Nautilus 49:66.

1937. Goniobasis columiriensis Whiteaves. The

Nautilus 50:82-84.

1942. The Pleuroceridae of the Pacific Coastal

drainage, including the Western Interior Basin. Oec. Pap.

Mus. Zool. U. Mifh. 469:1-4.

1944. Pleuroceridae of the Great Basin. Occ.

Pap. Mus. Zool. U. Mich. 485:1-4.

Henderson, J. 1932. The range of Polygyra and of Gonio-

basis in California. The Nautilus 46:4-6.

1935a. West American species of Goniobasis,

with descriptions of new forms. The Nautilus 48:94-99.

1935b. West American species of Goniobasis,

with descriptions of new forms. The Nautilus 48:130-134.

1935c. Fossil non-marine Mollusca of North

America. Geol. Soc. Amer. Spec. Pap. 3:225-231.

Walker, B. 1900. Changes with growth of Lithasia oboimta

(Say). The Nautilus 13:97-98.

Wiebe, A. H. 1926. Variations in the fresh water snail,

Goniobasis livesce7is. Ohio J. Set. 26:49-68.

Specimen Shells

Offering microscopic and miniature (to "t inch) .shells

from the Florida Keys, with accurate locality data Al.'m

unsorted grunge: write for list.

Margaret Teskey

P.O. Box 273

Big Pine Key. Fl. 330J,3

PHILLIP W. CLOVER

COLLECTOR & DEALER IN

WORLD WIDE SPECIMEN

SEA SHELLS p. O. Box 83

Glen Ellen, CA 9S442

FREE SHELL LISTS

SPECIALISTS IN

CYPRAEA^ CONUS^ VOLUTA

margineLla, Mif RA, MUREX

20 THE NAUTILUS

January 29, 1981

Vol. 95(1)

A NEW RECORD OF VALVATA SINCERA ONTARIENSIS F. C. BAKER

FROM MINNESOTA

Robert C. Bright

Bell Museum of Natural History

University of Minnesota

Minneapolis, Minnesota

During the summer of 1970 a large series of

mollusk and seed samples were obtained from

the surface of sediments of lakes and ponds in

northern Minnesota by Hilary Birks. One sam-

ple, from Little Spring Lake, Lake County, con-

tained a specimen of the rare Valvata sincera

forma ontariensis F. C. Baker.

Although the specimen is damagaed (part of

the apex is missing, as is the terminal portion of

the shell beneath the periostracum) it exhibits

the loose coiling, round entire aperture, wide

umbilicus, and the sharp, thin, lamellar ribs of

the periostracum described by Baker (1931). The

periostracal lamellae are fairly evenly spaced

and most are directed posteriorly. With the

periostracum removed, the shell would appear

much like the form described by LaRoque (The

Nautilis 46: p. 199) as V. I. mccolli from the late

Wisconsin marl in Grey County, Ontario,

Canada. I agree with Clarke (Malacologia 13: p.

225) that mccolli is a synonym of ontarwvsis but

consider them to be forma, rather than true

subspecies.

Little Spring Lake is located in a spruce forest

in SWV4, sec. 29, T61N, RlOW, about 20 miles

southeast of Ely, Minnesota. The lake is small,

being about 300 yards long and 150 yards wide.

It is densely vegetated except for an open space

in the east end, where the maximum depth at-

tained is 11 feet. The specimen was collected

about five yards offshore at the western end of

the lake in about two feet of water. There the

vegetation was dense (ca. 80 percent cover) and

was dominated by Nymphaea odorata, Nuphar

variegatum, Potamogeton (3 spp.), Najasflexilis.

and Megalodonta beckii. Other mollusks taken

from the bottom nearby include Marstonia

decepta, Valvata tricarinata, Gyraulus parvits,

Valvata sincera, Sphaerium sp., and Pisidium

sp. The bottom sediments were fine-grained and

muddy.

The only previously published records of on-

tariensis are from Ontario, Canada. The plate

photographs were provided by Roger Woo.

Hilary Birks (Cambridge University) provided

the habitat data.

REFERENCES CITED

Baker, F. C. 19.31. Description of a new variety of Valvata

ieunsi Currier. The Nautilus 44:119.

Clark, A. H. 1973. The freshwater mollusks of the Canadian

Interior Basin. Malacologia 13(l-2):225.

LaRoque, A. 1932. A new variety of Valvata lewisi from the

Pleistocene of Ontario. Can. Field Naturalist 46(9):199.

FIG. 1. Apical view o/ Valvata sincera /orma ontariensis, Bell MNH No. P3578. xi5.

FIG. 2. Apertural view of the same .•specimen. The terminal portion of the last whorl is slightly distorted because

the shell is mv^sing beneath the periostracum. x 15

Vol. 95 (1)

January 29, 1981

THE NAUTILUS 21

THE FRESHWATER NAIADS OF ELK RIVER, WEST VIRGINIA

WITH A COMPARISON OF EARLIER COLLECTIONS

Ralph W. Taylor and Romie C. Hughart

Department of Biology Sciences

Marshall University

Huntington, WV 25701

ABSTRACT

During the summers of 1978 and 1979 an extensive surtjey of the freshwater

mussels of the Elk River was conducted. A total of eighteen species ofunionacean

clams, plus the exotic Asian clam, Corbicula fluminea, were collected. A search of

the collections of several miiseums produced evidence that earlier workers had,

over the last one hundred years, taken a total of twenty-07ie species from the Elk

River. Lampsilis orbiculata, Dysnomia torulosa rangiana, Cyclonaias tuber-

culata and Lampsilis ovata, which had been reported earlier, were not found and

m.ust be presurned no longer present in the Elk. Corbicula fluminea has spread

throughout the Elk River. Fusconaia m. maculata, Lampsilis radiata luteola.

Elliptic dilatata, Ptychobranchus fasciolaris and Actinonaias ligamentina

carinata are presently the dominant species.

Information on the freshwater naiads in-

habiting the streams of West Virginia is all but

non-existent. Until recently, the poor roads and

rugged terrain of the region have made it rather

difficult to reach most parts of the state. A few

hardy individuals, most notably Dr. A. E. Ort-

mann, carried out limited expeditions into the

state around the turn of the century. Other less

well-known biologists have collected in West

Virginia but none of their work was published,

even though, fortunately, some of their material

was deposited in museums around the country.

Contemporary papers by Morris and Taylor

(1979) and Taylor (1980) report mussel faunas of

the Kanawha and Ohio Rivers, respectively.

David Stansbery and Carol Stein (Ohio State

University Museum of Zoology) have collected

extensively throughout West Virginia in recent

years but none of their work has as yet been

published. We shall in this paper report material

collected in the Elk River during the summers of

1978 and 1979, and in addition compare and con-

trast our findings with those of other investi-

gators. We believe this to be the first extensive

survey to have been carried out on the Elk.

THE ELK RIVER

The Elk River orginates in a sparsely pop-

ulated mountainous area in Pocahontas County,

W. Va., and flows approximately due west for

181 miles to its confluence with the Kanawha

River at Charleston, W. Va. It traverses valleys

with steep, high walls. Most of the basin is heavi-

ly forested and remains essentially untainted by

man. The only pollutants present are those orig-

inating in a few local industries and a small

amount of human sewage. The actual amount of

raw sewage discharged into the stream is not

known, but it probably has a significant effect

on such water quality parameters as bacterial

county, plant nutrients and turbidity (W. Va.

(Geological and Economic Survey, 1973). There

are no major cities in the Elk River basin, and

mining and timbering activity is limited, hence

the Elk is a stream of fairly high quality. The

bottom substrate consists primarily of cobble,

silt and sand. The main stem of the Elk averages

a fall of 168 feet per mile. The best collecting is

in or near shoal areas. The river, throughout

most of the collecting area, averaged 50 meters

in width and less than two meters in depth.

METHODS

Shells were hand-picked from the shallows

and river banks. Only live specimens, or those

which obviously had been recently killed, were

22 THE NAUTILUS

January 29, 1981

Vol. 95(1)

collected. Specimens were returned to the lab-

oratory where they were cleaned, positively

identified and accessioned in to the Marshall

University Malacological Collections. Voucher

specimens have been placed with the Ohio State

University Museum of Zoology. All scientific

names used in this paper are those currently be-

ing used by Stansbery (1979). A total of 15

localities were designated as collecting sites and

visited at irregular intervals during the two

summers.

COLLECTING SITES

Site 1 60 yards down river from the base of

Sutton Dam, near Sutton (Braxton County)

Site 2 along Rt. 16, 7.5 miles east of the Brax-

ton/Clay County line (Braxton County)

Site 3 along Rt. 16, 3.2 miles west of the Brax-

ton/Clay County line (Clay County)

Site 4 near a small roadside park on Rt. 16,

15.3 miles west of the Braxton/Clay County line

(Clay County)

Site 5 along Rt. 16, 15.9 miles west of the

Braxton/Clay County line (Clay County)

Site 6 Secondary Rd. 5, 4.3 miles west of in-

tersection with Rt. 16 (Clay County)

Site 7 Secondary Rd. 5, 4.8 miles west of the

intersection with Rt. 16 (Clay County)

Site 8 Secondary Rd. 5, 6.4 miles west of the

intersection with Rt. 16 (Clay County)

Site 9 Secondary Rd. 5, near Camp Elk, 8.3

miles west of the intersection with Rt. 16 (Clay

County)

Site 10 Secondary Rd. 5, downstream of

Camp Elk, 8.7 miles west of the intersection

with Rt. 16 (Clay County)

Site 11 Secondary Rd. 5, 3.0 miles east of the

intersection with Rt. 4 (Clay County)

Site 12 Secondary Rd. 5, 2.4 miles east of the

intersection with Rt. 4 (Clay County)

Site 13 small roadside park on Rt. 4 at the

Clay/Kanawha County line

Site 14 below the bridge at Queen Shoals

(Kanawha County)

Site 15 along U.S. 119 southeast of the Rt.

4 -U.S. 119 intersection at Clendenin (Kanawha

County)

RESULTS

A total of 18 species of unionacean clams, plus

the exotic Asian clam Corbicula harm, were col-

lected. These data are presented in Table 1. All

collecting sites, with the execption of Site 1 (im-

mediately below Sutton Dam), produced some

usable material.

In order to get the most information available

on previous collections made in the Elk River,

the first author visited several museums (spring

1980) and searched the holdings for West Vir-

ginia material. The museums visited were as

follows:

Field Museum of Natural History - Chicago

U.S. National Museum -Washington, D.C.

Carnegie Museum (Car. I.)- Pittsburgh

Ohio State University Museum of Zoology

(OSU)- Columbus

Harvard University Museum of Compara-

tive Zoology (MCZ)- Boston

The results of this search are presented in

Table 2. Elk River specimens were found at the

Ohio State University Museum, the Carnegie In-

stitute Museum and the Harvard University

Museum of Comparative Zoology.

In all, 21 species of unionids have been col-

lected in the Elk River by earlier investigators.

The vast majority of the museum material was

collected 50 to 100 years ago, with most of the

work having been done by Dr. A. E. Ortmann of

the Carnegie Institute.

The only contempory report on the mussels of

the Elk River was by Bates (1971). This paper

was based on limited collecting (two localities -

single collection at each) and listed only eight

species. The species found by Bates were: Ellip-

tio dilatata, Fusconaia jlava. Quadrula pustu-

hsa, Adinonaias l. carinata, Lampsilis fas-

ciola, Lampsilis ventricosa, Ligumia recta and

Oboi'aria subrotunda. With the exception of

Quadrula pustulosa all species that Bates

reported had been previously collected and were

found in the museum collections.

In this paper we report Lampsilis radiata

luteola { = Lampsilis siliquoidea) for the first

time as appearing in the Elk River. This species,

while never occurring in large numbers at any

one site, nevertheless is quite widespread and

was collected at 11 of the 15 designated sites.

Also reported for the first time in the Elk

River is the exotic Asian import Corbicula

Vol. 95(1)

January 29, 1981

THE NAUTILUS 23

Table 1. Abundance and distribution uf Elk River Mussels (R = Rare, M = Moderately Common, C = Very Common).

Species

Strophi tus u. undulatus (R)

Lasmigona costata (M)

Quadrula £. pustulosa (R)

Amblema p . pi i cat a ( M )

Fusconaia tn. maculata (C)

Fusconaia f lava ( R)

Pleurobema clava (R)

Pleurobema sintoxia ( R)

Ell ipt lo crassidens ( R)

EllipUu dilatata (C)

Ptychobrttnuhus fasciolaris (C )

Act monaias 1 . carinata ( C )

Obovaria subrotunda (C )

Ligumia recta (C)

Villusa ins I R)

Lamps 1 lis r . luteola ( C )

Lampsilis vent ricosa (C )

Lampsilis fasciola ( R )

Curbicuia leana ( C )

Table 2. Museum records from the Elk River (locality data are as they were recorded on original tags).

Species

Strophitus u. undulatus

Alasmidonta marginata

Lasmigona costata

Amblema p. plicata

Fusconaia m. maculata

Locality

Gassaway

Shelton

Clay

Sutton

Gassaway

Shelton

Sutton

Shelton

Gassaway

Mouth O'Brien Ck,

Below Sutton Dam

Mouth Twistabout Ck.

.2 mi. below Little Sandy Ck.

Sutton

Gassaway

Shelton

Below Queen Shoals Bridge

Mouth of Laurel Ck.

Below Sutton Dam

Below King Shoals Run

Gassaway

Mouth O'Brien Ck.

24 THE NAUTILUS

January 29, 1981

Vol. 95(1)

Fusconaia flava

Cyclonaias tuberculata

Pleurobema clava

Below mouth Little Sandy Ck.

Below Blue Ck. bridge

Mouth Twistabout Ck.

Mouth O'Brien Ck.

Rt. 11 bridge N.E. of Clay

Frame town

Glendon

Elkhurst

Rt. 6') bridge 2 mi. N.W. of Kelso

Mouth Twistabout Ck.

5.8 mi. W. of Fayetteville

Mouth O'Brien Ck.

Below Sutton Dam

Mouth Buffalo Ck.

1 mi . N.E. of Clay

Frametown

Gassaway

Above Twistabout Ck.

01 endon

Shelton

Gassaway

Sutton

Pleurobema sintoxia

At Twistabout Ck.

OSU

43883

Elliptio crassidens

Ptychobranchus fasciolaris

Actinonaias 1 . carinata

Obovaria subrotunda

Truncilla truncata

Ligumia recta

Villosa i. iris

.2 mi. below Queen Shoals

Frametown

Glendon

Gassaway

Shelton

Sutton

Clay

1 mi. N. of Clay

Above Twistabout Ck.

Shelton

Sutton

Gassaway

1 mi. N. of Clay

Shelton

Gassaway

Below Sutton Uam

Rt . 64 bridge 4 mi . E. Fayetteville

Mouth O'Brien Ck.

U.S. Rt. 64 bridge E. of Fayetteville

Mouth O'Brien Ck.

Mouth Twistabout Ck.

Shelton

Clay

Gassaway

Above Twistabout Ck.

Elkhurst

1 mi. N.E. of Clay

Mouth Buffalo Ck.

5 mi . E. of Fayetteville

Shelton

Sutton

Vol. 95(1)

January 29, 1981

THE NAUTILUS 25

Species

Locality

JJuminea (also referred to as manilensis Philippi

and leana Prime). Thomas and Mackenthun

(1964) were the first to recognize Corhicula in

the Kanawha River at Charleston, W. Va. near

the mouth of the Elk River. It has since spread

into the Elk and is presently distributed

throughout our study area as far upstream as

Sutton Dam.

Of the 21 species reported by earlier investi-

gators, we did not find the following six: Alas-

midonta marginata, Cyclonaias tuberculata,

Epioblasma torulosa rangiana, Lainpsilis orbi-

culata, Lampsilis ovata and TriinHlla truncata.

The Elk River is a stream of fairly good quali-

ty and is at the present time supporting a good

population composed of a relatively large

number of kinds of unionid mussels. Fusconaia

m. maculata, Lampsilis r. luteola, Elliptio

dilatata, Ptychobranchns fasciolaris and Ac-

tinonaias I. carinata are the dominant species in

the Elk River. Only two specimens of Pleuro-

beyna clava were found in the entire study. This

species is very nearly extinct in this river at this

time, while fairly large collections of it were

made 50 years ago. A single fresh specimen of

Elliptio crassidens was found. It is our belief

that this species is also in danger of extinction in

the Elk River in the very near future.

ACKNOWLEDGMENTS

Special thanks to the museum curators who so

graciously opened the collections to me. To the

many others associated with the museums, I ex-

tend my heartfelt appreciation (R. W. Taylor).

Some of the material presented in this paper

was submitted by the second author to the

Biological Sciences Department at Marshall

University as partial fulfillment of the re-

quirements for the Master of Science Degree.

LITERATURE CITED

Bates, J. M. 1971. Mussel Investigations of the State of West

Virginia. U. S. Bureau of Commercial Fisheries. 91 pp.

Morris, J. S. and R. W. Taylor. 1979. A Survey of the Fresh-

water Mussels of the Kanawha River of West Virginia. TJw

Nautilus 92{4):\53-l55.

Stansbery, D. H. 1979. Naiad Mollusks of the Ohio River

Drainage System. The Ohio State University Museum of

Zoology (mimeographed). 1 p.

Taylor, R. W. 1980. A Sunvy of the Freshwater Mussels of

the Ohio River from Greenup Locks and Dam to Pitts-

burgh, Pa. U.S. Army Corps of Engineers, Huntington/

Pittsburgh Districts. 71 pp.

Thomas, N. A. and K. M. Mackenthun. 1964. Asiatic Clam

Infestation at Charleston, West Virginia. The Nautilus

78(1):28.

West Virginia Geologic and Economic Survey. 1973. The Elk

River Basin: A Report on Water Pollution in the Elk River

and Its Tributaries. 39 pp.

26 THE NAUTILUS

January 29, 1981

Vol. 95 (1)

NEW RECORDS OF ALLOP.OSUS MOLLIS VERRILL (CEPHALOPODA,

OCTOPODA) FROM THE PACIFIC OCEAN

Angeles Alvarino and John R. Hunter

National Oceanic and Atmospheric Administration

National Marine Fisheries Service

Southwest Fisheries Center

La Jolla, California 92038

ABSTRACT

Two specimens o/ Alloposus mollis (Alloposidae) captured off southern Califor-

nia are described and illustrated. The anatomical characteristics of the species

are discussed, and its distribution is reviewed.

Alloposv^s mollis is a relative rarely captured

mesopelagic cephalopod. Records of this species

are few and locations scattered. The published

illustrations and descriptions are rather in-

complete and diagrammatic because of the lack

of specimens in good condition of preservation.

Verrill (1880) originally described the species

from specimens collected off New England in

the North Atlantic. Additional specimens were

reported by Verrill (1881) and Hoyle (1886) from

off Newport, Rhode Island, the mouth of the

Chesapeake Bay, and in other parts of the

Atlantic (Joubin, 1895, 1900; Robson, 1930 for

his A. hardyi; Thore, 1949; Adam, 1960). Ijima

and Ikeda (1902) described an allied species, A.

pacificus, from the Sagami Sea, Japan, and this

species was recorded also for Sagami Bay,

Japan, by Sasaki (1929). Berry (1914) suggested

that the evidence was not sufficient to warrant

two different species. Similarly, A. hardyi is

believed to be synonymous with A. mollis

(Thore, 1949). Specimens belonging to the fami-

ly Alloposidae obtained at Pailolo Channel,

Hawaii and other ALBATROSS stations in the

Pacific (Hoyle, 1904; Berry, 1914) were con-

sidered to belong to A. mollis. Alloposidae

material from the DANA collections, including

specimens from the Atlantic, Indo-Pacific

(05°52'N, 131°14'E) and the Indian Ocean

(04°52'N, 77°08'E), were placed by Thore (1949)

under A. mollis. Young (1972) obtained one

specimen from Santa Catalina Basin, California

(33°23'N, 118°49'W). This specimen, judging

from the illustrations, was not complete and in

bad condition of preservation, facts also explain-

ed by Young (1972) when he comments ". . . very

large, but rather poorly preserved specimen".

Two specimens of A. mollis in excellent condi-

tion were taken off the southern California

coast during survey cruises conducted by the

National Marine Fisheries Service's R/V

DAVID STARR JORDAN. These records to-

gether with the one by Young (1972) are the

first reported specimens obtained from the

North American Pacific. This report documents

these records, provides a description and il-

lustration of the specimens and review, the

distribution and external morphology of the

species.

Alloposus mollis Verrill, 1880

Material examined -The specimens collected

were: Specimen A (200 mm total length, head

and mantle) captured July 18, 1976 (2349 hours

PST) at 33°23'N, 117°43'W in a six feet Isaacs-

Kidd midwater trawl towed to a maximum

depth of 70 m; and Specimen B (67 mm total

length, head and mantle to base of arms) col-

lected March 24, 1977 (0410 hours PST) at

33°31.8'N, 117°58'W, in a midwater trawl tow-

ed at a maximum depth of 7 m. Both specimens

were females.

Description -These animals are ovoid in

shape, widest at the head region. They are soft

and of smooth gelatinous consistency, translu-

cent, and covered with small red spots, giving

the whole animal a brick-purple color. The head

is large, short and slightly broader than the

body. The mantle opening is wide and full, and

in two broad pouches, extending dorsally from

Vol. 95 (1)

January 29, 1981

THE NAUTILUS 27

FIG. 1. A-Lateral left m.eu> o/A]loposus mollis (Specimen Bl: B-Dorso lateral left mew o/"Allopo-

sus mollis (Specimen B).

the ventral point of the commissure towards the

level of the eyes (Fig. 1). The eyes are large and

prominent, covered by the eye lid. The lid has a

small central opening which can be expanded to

expose the entire eye (Figs. 2A and 2B). The

funnel is large and is embedded with the gela-

tinous tissue of the head, except for the top

which is free, reaching to a level higher than the

upper edge of the eyes. The olfactory organ, a

flat round lump, is located posteriorly to the

eyes.

The arms are stout and short, relative to the

body length (head and mantle), and they de-

crease in length from the dorsal to the ventral

side. They are connected at the base by a broad

membrane, web or umbrella, which attains the

greatest extension between the dorsal pair of

arms. The suckers are arranged in a straight

row of 3 to 4 (ventral arms) or 4 to 6 (dorsal

arms), from the mouth to the point on the arm

where the web starts. At this point the suckers

begin to deviate from a straight course to an in-

cipient zig zag arrangement, which becomes

more evident along the webbed and the free part

of the arms (Fig. 2C). This pattern occurs in

both specimens we collected, in Verrill's syn-

type, and in all other specimens we received

from the Division of Mollusks at the Smithso-

nian Institution, which included the material ex-

amined by Berry (1914). Measurements from

our specimens are given in Table 1.

DiscMssiori- The arrangement of the suckers

on the arms is an important character and sub-

ject to some disagreement and confusion in the

literature. Ijima and Ikeda (1902) described an

allied species, A. pacificus. from the Sagami

Sea, subsequently reported by Sasaki (1929)

from the same body of water in the Sagami Bay,

Japan. Berry (1914) stated that the anatomical

differences between A. pacificus and A. mollis

were insufficient to establish a new species. Ac-

cording to Ijima and Ikeda (1902) the suckers of

A. pacificus were arranged in a single row for

most of the length of the arm, and were biserial-

ly arranged only on the free part of the arm,

that is, from the edge of the web to the outer tip

of the arm. This same characteristic was men-

tioned by Robson (1930) for A. hardyi. Verrill

(1880) specifies that the suckers are "large,

single, in two alternating rows," and Verrill

28 THE NAUTILUS

January 29, 1981

Vol. 95(1)

(I4

(2 a.

FIG. 2 . A - Eye urith the eyelid exparwfed, exposing the eye (Specimen Al: B - Righ t eye with sphineier

of eyelid contracted; the diameter of the opening corresponds to that of the pupil of the eye (Specimen

B); C- Detail of the crown of arms and. interarms web, and the disposition of the siwkers of female

Alloposus mollis (from both Specimen A and Specimen B).

(1881) states that the suckers "are in two rows

or rather in a single more or less zig zag row

which most conspicuously approached the two

rowed condition after reaching the margin of

the umbrella (at about the 13th sucker on the

dorsal arms)." Robson (1930) explained for A.

hardyi that "suckers tend to be uniserial or very

widely alternating except about or just beyond

the margin of the web, where they are more or

less biserial." The suckers in our specimens are

arranged, as explained above, in a straight row

from the mouth to the point where the web

starts, and at this point the suckers initiate an

incipient zig zag arrangement, which becomes

clearly evident along the webbed and free part

of the arms (Fig. 2C). The suckers are 1 to 12

mm in diameter and their number varies from

12 (Thore, 1949) to 155 per arm (Joubin, 1900).

The proportions of the body in A. mollis

change slightly with age; older specimens have

relatively shorter bodies and longer arms than

young individuals.

The only sexual dimorphism in Alloposidae is

the third right arm, hectotylus of males. The

males have 7 normal arms and the hectotylized

arm. Verrill (1881) reported a hectotylus reach-

ing 200 mm in length and 20 mm in width, with

two rows of large 4-mm diameter, 6 or 7 lobed

suckers, with a terminal process 30 mm long

and 7 mm diameter.

Most of the specimens of A. mollis obtained by

other authors were partially destroyed, injured

during trawling, or only fragments of large in-

dividuals. Our specimens were alive and in ex-

cellent condition when brought on deck, and the

morphological structures were accurately main-

tained (Fig. 3). No dissections were made to ex-

amine the internal atatomy or stomach content,

because we felt it was important to keep the

specimens in good conditon.

Vol. 95 (1) January 29, 1981 THE NAUTILUS 29

TABLE 1. Meristic data on the specimens o/Alloposus mollis collected off California.

FIG. 3. Alloposus mollis (Specimen B), length 67 mm.

Distribution -Alloposus mollis is a cosmopol-

itan species, usually found near tropical and sub-

tropical oceanic regions (Tables 2 and 3; Fig. 4).

The majority of the deep-sea cephalopods were

collected in trawls and probably are adept at

avoiding nets of all types. The capture of our

specimen B (Fig. 3) was observed by biologists

on deck of vessel, and it was efficiently avoiding

capture, when net was directly towed in pursuit

of the specimen. Similarly, Thore (1949) sug-

gested thati4. mollis may only appear to be rare

because of their ability to avoid capture. A.

mollis may inhabit the open sea during certain

phases of its life cycle, and remain in deep and

bottom layers of the continental slope during

other (Thore; 1949).

Our specimens were both juvenile females

30 THE NAUTILUS

Januai^- 29. 19S1

Vol. 95(1)

TIDT r -T

■■ •,'"" ycv'.ii •izt:2 r^, .-L

»•«■•«. Ts .

I «e-37

:"• I'ter-at'tg. |

i-'cact.zei'cnc «--

r 1 :* wee , arer

il:r

Sara C<tj1<m inlii

f33-23-«. nj-JS'i-,

Vol. 95 (1)

Januarj' 29, 1981 THE NAUTILUS 31

TABLE 3. Data im specimens fmm the Smithstmian Institution.

of lenc"-

soeciinens nr

=osit ion

Depth Date

I rele 12 j

I » 60

4 males variab Is

I • 120

1 » 55

Several * med ium

2 * 55

I * large

I * ^5

I * S8

59 *52' K-~C*55 ' ft icTT Knooe isianc) coC

Hawaiian Islands (Pai lolo Channel ) 530. ■i

2I°06'N-I56°I3'W (Hawaiian Islands ) 586

21°0rN-l56°43'W (Hawaiian Islands) 5^.7

12°24'N-82°2i'W (Caricbean Sea )

28°I7'N-86°2!'W ( Gulf of Mexico )

IB°52'N-94=50'W ( Gulf of Mexico )

2i^i'N-S7=49'W ( Gulf of Mexico )

23°CiO'N-35°20'W ( Gulf of Mexico )

29=46'N-38°25'W ( Gulf of Mexico )

612.7

671

612.7

567

521

36.5

22 July, 1902

5 Apr! 1, 1 968

17 Nc^., 1968

22 Nov., 1968

20 June, 1959

5 June, 1970

U Aug., 1970

27 Aug., 1970

U A^r;i,l972

* Due TO bad condition of preservation of sceci-ens, sex could nc"

Total lencth induces -eac and nanrle.

• PUBLISHED RECORDS

X PRESENT DATA

o SPECIMENS FROM THE SMITHSONIAN INST.

FIG. 4. Distribution o/Alloposus mollis.

32 THE NAUTILUS

January 29, 1981

Vol. 95(1)

(200 mm and H7 mm in total length) and were

taken at 70 m and 7 m depth respectively. Ac-

cording to Verrill (1881) the bathymetric range

of the species extends to 2462 m depth, and

fragments of specimens were taken from 3173

m depth. Berry (1914) states that it extends

from 180 m to more than 900 m depth. Voss

(1967) explains that Alloposidae appear to be

distributed in the upper 400 m, although they

may extend to more than 3000 m depth, and

that larvae and juveniles occur in the upper

100 m.

Populations of A. mollis probably are strati-

fied ontogenically, as is often the case in oceanic

animals.

The temperature of the surface waters at the

time of capture of our two specimens was

14.6°C (Specimen A), and 13.0°C (Specimen B),

which is well within the range of temperature

recorded for the species (Thore, 1949).

Cephalopods are important in the food web of

the oceans, as they constitute the main food of

dolphins, sperm whales, other sea mammals,

turtles, Thunnidae, sharks and other large fish.

Joubin (1895, 1900) found fragments of A.

mollis (dorsal region and tentacular crown) in a

region of the Atlantic where sperm whales were

feeding, but found no A. mollis in their

stomachs, possibly because of the difficulty in

identifying digested gelatinous remains.

ACKNOWLEDGMENTS

We would like to extend our appreciation to

Dr. Joseph Rosewater and Michael J. Sweeney,

Division of Mollusks, Smithsonian Institution,

for providing us for comparative analysis the

syntype and good amount of material of Allo-

posus mollis. We are also grateful to Carol A.

Kimbrell for obtaining Specimen A, here stud-

ied, from the trawl collections at the Southwest

Fisheries Center, to Daniel L. Gittings (Li-

brarian, SWFC) and Nelson Ross (NODC) for

their great cooperation in providing us with

valuable literature pertinent to this subject. We

also like to thank Roy M. Allen for the prepara-

tion of the distributional map.

LITERATURE CITED

Adam, W. 1960. Les Cephalopodes de L' Institut Fran^ais

d'Afrique Noire. Pt. II. Bull. Inst. Frangais Afriqiie Noire,

Ser. A (2):465-511.

Berry, S. S. 1909. Diagnoses of new Cephalopodes from the

Hawaiian Islands. Proc. U.S. Natl. Mus. 37(1713):

407-419.

1914. The Cephalopoda of the Hawaiian Islands.

Bull. Bur. Comm. Fish. 32(1912):255-362.

Hoyle, W. E. 1886. Report on the Cephalopoda collected by

H. M. S. Challenger during the years 1873-1876. IN: Voy-

age of the Challenger, 16:I-VI, 1-246.

1904. Reports on the dredging operations off the

west coast of Central America, by the R/V Albatross

(1899-1900). VI Report on the Cephalopoda collected by

the research vessel Albatross. Bull. Mas. Comp. Zool.

Harvard College 43:1-71.

Ijima, I. and S. Ikeda. 1902. Notes on a specimen of Amphi-

tretus obtained in the Sagami Sea. Annot. Zool. Japan

4:85-101.

Joubin, L. 1895. Contribution a I'etude des Cephalopodes de

I'Atlantique Nord. Resultats des Campagnes Scientifiques

Prince de IMonaco, (9): 1-63.

1900. Cephalopodes provenant des campagnes

de la PRINCESS-ALICE (1891-1897). Resultats des

Campagnes Scientifiques Prince de Monaco, 1889, 17:

1-135.

Robson, G. S. 1930. Cephalopoda. Discovery Rep. 2:

371-402.

Sasaki, M. 1929. A monograph of the Dibranchiata Cephalo-

pods of the Japanese and adjacent waters. Jour. Fac.

Agric. Hokkaido Univ., Sapporo, Japan, Suppl. 20:1-357.

Thore, S. 1949. Investigations on the DANA Octopoda. Part

i. Bolitaenidae, Amphitretidae, Vitreledonellidae and

Alloposidae. Dana Report 33:1-85.

Verrill, A. E. 1880. Notice on the remarkable marine fauna

occupying the outer banks off the southern coast of New

England. Anwr. Jour. Sci. Ser. 3, 20:390-403.

1881. Reports on the results of the dredging

under the supervision of A. Agassiz. Report on cephalo-

pods and some additional species dredged by the U.S. Fish

Commission steamer FISH HAWK, during the season of

1880. Bull. Mus. Cmnp. Zool. Harvard College 8:99-116.

1884. Second catalogue of mollusca recently

added to the fauna of New England coast and adjacent

part of the Atlantic, consisting mostly of deep sea species,

with notes on others previously recorded. Trans. Conn.

Acad. Sci. 6:139-294.

Voss, G. L. 1967. The biology and bathymetric distribution

of deep-sea cephalopods. Studies Trap. Oceanogr. 5:

511-535.

Young, R. E. 1972. The Systematics and areal distribution

of pelagic Cephalopods from the Seas off southern Cali-

fornia. Smithsonian Contrib. Zool. 97:1-108.

Vol. 95(1)

January 29, 1981

THE NAUTILUS 33

VERTIGO MERAMECENSIS (PULMONATA: PUPILLIDAE) FROM THE

NIAGARAN ESCARPMENT, IOWA

Terrence J. Frest and Leslie P. Fay

Department of Geology

The University of Iowa

Iowa City, Iowa 52242

ABSTRACT

The snail. Vertigo meramecensis Van DevendeT was found at four' localities

along the Niagaran Escaryynent in Fayette, Clayton, arid Dubuque Counties,

Iowa. Though more variable in morphology than originally reported, the species

is easily distinguishable from V. gouldi with which it occurs. In Iowa, V. mera-

mecensis inhabits steep, damp, well-forested talus slopes with extensive calcare-

ous rock outcrops.

Vertigo meramecensis was recently described

from the Northern Ozark Plateau (Crawford

County, Missouri) with sixteen individuals con-

stituting the type series (Van Devender, 1979).

Recent collecting in northeastern Iowa has turn-

ed up about fifty more individuals from four

localities in Fayette, Clayton, and Dubuque

Counties (Fig. 1). Two of these are drift collec-

tions but the species was collected alive at the

two other sites (localities 3 and 4) in 1975 and

1979. Small litter samples were also taken in

August, 1979 at both localities to insure ade-

quate representation of all land snail species.

The Iowa collections materially enlarge the

range of V. meramecensis and provide much ad-

ditional information on the species' morphology

and ecological requirements (discussed below).

Van Devender's full description is confirmed in

essentially all respects by our material. Though

the species is closely related to the notoriously

variable V. goiddi gouldi (Binney) (see Pilsbry,

1948), which is common in collections from all

four localities, we encountered little difficulty in

separating adult specimens of meramecensis

from gouldi, even without recourse to a micro-

scope or hand lens.

The Iowa localities are more than 300 miles to

the north of the type locality. All four are

situated on the Niagaran Escarpment of north-

eastern Iowa, a well dissected area with steep,

heavily wooded bluffs unsuited for farming and

with extensive outcrops of Silurian limestones

FIG. 1. Map uf part of central United

States showing knoum distribution of

Vertigo meramecensis Van Devender.

and dolomites (Kankakee, Edgewood, and Hop-

kinton Formations). All are within a few miles of

the Iowa portion of the Driftless Area, a region

long known to harbor unusual land mollusks

(Imlay, 1973). This portion of Iowa historically

was among the most densely forested areas in a

largely prairie state, and because of its rugged

34 THE NAUTILUS

January 29, 1981

Vol. 95 (1)

topography is probably the least disturbed by

agriculture (Hartley, 1966).

Suitable habitat for V. meramecensu in Iowa

is likely limited to the eastern third of the state

and, possibly, the Loess Hills of extreme west-

ern Iowa. However, brief searches in the most

nearly ecologically equivalent areas in Fremont,

Boone, Linn, Johnson, and Lee Counties failed

to produce any specimens, and many north-

eastern Iowa localities also lack the species.

Although obviously much more work needs to be

done on its distribution, it is probable that V.

meramecensis will prove to be rare and very

local in occurrence in Iowa, and confined to the

northeastern corner. Until the range of V.

meramecensis is better known some caution

against overcollecting or other damage should

be exercised. It would be particularly unfor-

tunate if the type locality (subject to periodic

flooding if the proposed Meramec dam were

built, according to Van Devender, 1979) were

lost.

Specimens used for this paper have been

deposited in the collections of the Field Museum

of Natural History (FMNH).

LOCALITIES

1. Drift at base of east-facing slope along

Brush Creek, Brush Creek Canyon State Pre-

serve, NEV4, NEV4, SEV4, SE'A, sec. 17, T92N,

R7W, Wadena 7V2' quadrangle, Fairfield Twp.,

Fayette Co., Iowa.

2. Drift at base of north-facing bluff above

Bear Creek, Bixby State Park, center SEV4,

SEV4, SWV4, sec. 23, T91N, R5W, Edgewood

7V2' quadrangle, Lodomillo Twp., Clayton Co.,

Iowa.

3. Live collection and litter sample from

dense upland woods on northwest-facing slope

above a tributary to Bear Creek, SV2, SEV4,

SE'A, SWV4, sec. 23, T91N, R5W, Edgewood

7V2' quadrangle, Lodomillo Twp., Clayton Co.,

Iowa.

4. Live collection and litter sample from west-

facing forested talus slope above Point Hollow

Creek, White Pine Hollow State Preserve,

NW'/4. SWV4, NEV4, SE'A, sec. 7, T90N, R2W,

New Vienna 7V2' quadrangle, Liberty Twp.,

Dubuque Co., Iowa.

DISCUSSION

Morphology: Our specimens range in length

from 1.72 mm to 2.11 mm, slightly larger than

Van Devender's but with a comparable mean

length (x = 1.83). The observed widths (1.05 to

1.20 mm, x= 1.08) show an identical range but

somewhat smaller mean (x=1.10 for the

Missouri specimens). Thus, Iowa specimens are

quite similar to the type lot in dimensions but

slightly more slender (mean H/D=1.66 vs. 1.62

for the Missouri holotype). According to Van

Devender (1979:71) half of the Crawford Co.,

Missouri, specimens lack a subcolumellar lamel-

la. More than 90 percent of the Iowa material

show some sign of a subcolumellar lamella, but

this is usually vestigial (Figs. 2a-d). None have

the subcolumellar as well-developed as the col-

umellar; only one or two lack it completely. In

most Iowa V. meramecensis, both palatals are

equally recessed from the lip edge; nearly all

have a knob-like lower palatal, and the long,

slightly curved lower palatal present in 19 per-

cent of the Missouri specimens characterizes a

smaller percentage (<5 percent) of the Iowa

specimens.

Although both V. meramecensis and V. gouldi

gouldi are somewhat variable, mixed lots can

be separated on several features. Van Devender

(1979:72) emphasizes the smaller teeth and

more open aperture of V. meramecensis; she

also notes that the less massive and straighter

parietal of V. meramecensis tends to point

toward the lower palatal, while that of V. gouldi

gouldi points between the two palatals. We have

illustrated some examples of both species (com-

pare Figs. 2a-d with 2e-h) in which these tenden-

cies are less pronounced, but even the two most

similar examples are clearly separable on aper-

tural characters alone (Figs. 2k and 1). Aside

from the teeth, the aperture of V. gouldi gouldi

is more elongate and the outer lip more strongly

constricted.

Some differences in gross shell characters

should also be mentioned. V. meramecensis has

more evenly expanding, slightly shouldered

whorls; associated V. gouldi gouldi tend to have

Vol. 95(1)

January 29, 1981

THE NAUTILUS 35

^^^i.^'?**/

41^^^

FIG. 2. Vertigo nieramecensis VanDevender(cdl deposited in the Field Museum of Natural History).

a, Largest mature specimen, 2.11 mm. Dubuque Co., la. b, Vertigo meramecensis Van Devender. 2.05

mm. Clayton Co., la. c, Vertigo meramecensis Van Devender. 1.89 mm. Clayton Co., la. d. Vertigo

meramecensis Van Devender. 1.89 mm. Clayton Co., la. e. Vertigo gouldi gouldi (Binney). 2.11 mm.

Fayette Co., la. f. Vertigo gouldi gouldi (Binney). 1.9U mm. Fayette Co., la. g. Vertigo gouldi gouldi

(Binney). 1.92 mm. Fayette Co., la. h. Vertigo gouldi gouldi (Binney). 1.82 mm. Fayette Co., la. i. Ver-

tigo gouldi gouldi (Binney). 2.07 mm. Clayton Co.. la. j. Vertigo meramecensis Van Devender. Dubu-

que Co., la. k. Vertigo gouldi gouldi (Binney). Enlargernenl of aperture. Fayette Co., la. 1, Vertigo

meramecensis Van Devender. Enlargement of aperture. Clayton Co., la. a-j, approximately 25 x ; k-1,

approximately 45 x.

36 THE NAUTILUS

January 29. 1981

Vol. 95(1)

the ultimate and penultimate whorls about equal

in width and more evenly rounded. Iowa speci-

mens of both are not distinguishable on color

(chestnut) and have equally sharply and regular-

ly striate mature shell surfaces (Missouri V.

meramecensis are more strongly and irregularly

striate, according to Van Devender, op. cit.).

Shells with mature apertures have between 3V2

and 5 whorls.

Ecology: Both Iowa localities with live V.

meramecensis are comparatively steep, pro-

tected lower slopes with deep, loamy soil and

well developed litter interspersed with talus

blocks of Niagaran dolomite. The forest is

dominated by hard maples [e.g., Acer saccha-

rum) and basswood, with common red oak, hick-

or}', and dogwood. High slopes at Locality 4 also

have common yew (Taxus canadensis) and white

pine (Pirnis strobiis). Both support land snails

(see Table 1), with Carychium exiguum most

abundant. Both retain some mositiire even in

late August. Trees are more common and varied

at the Clayton Co. locality; the slope at Locality

4 is less stable, more steep, and closer to the

creek floodplain, hence moister. The majority of

the species collected (slugs were not retained)

are common to both (77 percent): those peculiar

to one or the other (Locality 3: Stenotrema

fratemum. Discus patulus, Gastrocopta cor-

ticaria. Vertigo tridentata. Locality 4:

Cochlicopa luhrica, Gastrocopta tappaniana,

Striatura milium) tend to support the observed

differences in tree cover and moisture mention-

ed above. Both localities are good examples of

habitat 7 of Thorne (1964:19), defined from the

same area. Comparable slopes are situated in

the immediate vicinitj- of Localities 1 and 2 also;

these have not yet been litter sampled.

Land snails associated with V. meramecensis

at the type locality are low in diversity (Table 1),

ver>' likely because the collection was made

after dark on a limestone bluff; a litter sample

was evidently not practical. Nevertheless, the

general features (wooded limestone bluffs) ap-

pear comparable to Iowa occurrences. In sum-

mary, V. meramecensis seems to prefer rich,

deep, moist, well-wooded slopes associated with

extensive calcareous rock exposures.

Vertigo meramecensis is as yet unknown as a

TABLE 1. Assoclstea of V. i

leceaalB Van Devender.

LocMlltj A Locsllcy 3-

Crswford Co.. Dubuque Co., Clayton Co.,

Trlodopala albolabcla (S'r)

T. fosterl (Baker)

Mesodoo thyroldus (Say)

H. laletua (Blnney)

AtloKona prottmda (Say)

Baplotreaa concavxm (Say)

StenotccBa barbatua (Clapp)

S. f ratemuD (Say)

Hendersoala occulca (Say)

Angulsplra aleemata (Say)

Discus patulus (Deshayes)

Cochlicopa lubrlca (Muller)

Zooltoldes arboreus (Say)

Clyphallna Indentata (Say)

Sespylcrea electrlna ((wjuld)

Caacrocopta contracta (Say)

C. cortlcaria (Say)

C. holzlngerl (Sterkl)

C. pencodoti (Say)

C. tap part laja (Adaas)

Columella edeotula (Drapamauld)

Hellcodlscus parallelus (Say)

H. slDRleyaous (Pllsbry)

H»<alla BlntKCuXa (Blnney)

Carychl'^ ealnma (Say)

Striatura ■lllua (Morse)

Eucopuliig fulvus (Mull«r)

St rob Hops labyrlnthlca (Say)

Punetua lalnut Isslaja (Lea)

Guppya sterkU CDall)

Vertigo gouldl gouldl (Blnney)

V. tridentata Wolf

TABLE 1. Associates ofV. meramecensis Van Devender.

Pleistocene fossil. However, since many mem-

bers of the V. gauldi complex do have fossil

records (La Rocque, 1970; Browne & Bruder,

1968) it is possible that V. uneramecensis has

been overlooked. Few if any published faunal

lists from Iowa or higher latitude Pleistocene

sites contain faunas with species compositions

like those of Localities 3 and 4, possibly because

the climate was cooler in the summers than to-

day. A distinctly boreal or Rocky Mountain land

snail element is present in many northern loess

faunas (Leonard & Frye, 1954).

In contrast the Iowa V. meramecensis sites

contain a peculiar fauna combining predomi-

nantly northern elements (Striatura milium,

Vol. 95(1)

January 29, 1981

THE NAUTILUS 37

Hendersonia occulta) with predominantly south-

ern elements here near the northern end of their

range (Discuss patulus. Guppya sterkii). Occur-

rence on the Niagaran Escarpment near or

within the Driftless Area is not coincidental.

Most Hendersonia occulta colonies occur within

this region, as does the only reported colony of

the definite Pleistocene relict Discus macclin-

tocki (Hubricht, 1972). This type of fauna may

have been widespread in the late Pleistocene in

the southern United States, especially in Wis-

consinan loesses associated with the Mississippi

River. Hence, the most comparable fossil faunas

are those of the Peoria Loess and ?Wisconsinan

and younger talus deposits of eastern Missouri

and adjacent Illinois, Kentucky, Tennessee,

Mississippi, and Louisiana (e.j?.. Hubricht, 1961,

1962, 1964a, 1964b; he also notes the unusual

mix of normally disparate elements). These

localities probably should be rechecked for V.

meramecensis.

ACKNOWLEDGMENTS

Costs of this study were partially underwrit-

ten by a contract with the Iowa State Preserves

Advisory Board. We are particularly grateful to

Board Ecologist, Dean Roosa, for his continued

support and advice.

LITERATURE CITED

Browne, Ruth G. and Pamela M. Bruder. 1968. Wiscon-

sinan molluscan faunas friim Henderson County, Ken-

tucky. Bull. American Paleontology 54:191-27.5.

Hartley, Thomas G. 1966. The Flora of the "Driftless Area."

Univ. Iowa Studies in Nat. Hist. 21, 174 p.

Hubricht, Leslie. 1961. Land snails from the loess of Missis-

sippi. Sterkiana 3:11-14.

1962. Pleistocene land snails of southern Missis-

sippi and adjacent Louisiana. Sterkiana 8:1-11.

1964a. Some Pleistocene land snail records from

Missouri and Illinois. Sterkiana 13:7-17.

1964b. Pleistocene land snails from the talus of

Kentucky and Tennessee. Sterkiana 16:3-4.

1972. Endangered land snails of the eastern

United States. Sterkiana 45:32-33.

Imlay, Marc J. 1973. The case for a Driftless National Park.

Bull. American Malacological Union, Irw.. March, 1973,

pp. 7-8.

La Rocque, Aurele. 1970. Pleistocene Mollusca of Ohio. Part

4. Ohw Geol. Survey Bull. 62:555-800.

Leonard, A. Bryon and John C. Frye. 1954. Ecological con-

ditions accompanying loess deposition in the Great Plains

region of the LInited States. Jour. Geology 62:399-404.

Pilsbry, Henry A. 1948. Land Mollusca of North America

(North of Mexico), Vol. II, Part 2, Acad. Nat. Sci. Philadel-

phia. Monographs 3:521-1112.

Thorne, Robert F. 1964. Relict nature of the flora of White

Pine Hollow Forest Reserve, Dubuque County, Iowa.

Umv. Iowa Studies in Nat. Hiiit. 20, 33 pp.

Van Devender. Amy Schrader. 1979. A new Vertigo (Pul-

monata: Pupillidae) from the Ozarkian Uplift. The Nauti-

lus 93:70-73.

MEETINGS

50th AMU Anniversary

Meetings in Florida 1981

Ft. Lauderdale, on the southeast coast of

Florida, will be the site of the next annual

meeting of the American Malacological Union to

be held July 19-24, 1981. A special symposium.

Functional Anatomy of Mollusca as Related to

Higher Category Systematics, is being organiz-

ed by President Richard S. Houbrick (Dept. of

Invertebrate Zoology, National Museum of Nat-

ural History, Smithsonian Institution, Wash-

ington, D. C. 20560). Watch for further details

about this special meeting which promises to

draw malacologists from throughout the world.

1981 Western Society

of Malacologists

The 14th Annual Meeting of the W. S. M. will

be held at San Diego State University, San

Diego, California, between June 23 and 26,

1981. The meeting will feature symposia and

contributed papers on Molluscan topics, ex-

hibits, shell and book auction, and field trips. All

interested persons are invited to attend. For

more information please contact Bruce Fowler,

Secretary, 5512 Blossom Terrace Ct., San Jose,

California 95124.

38 THE NAUTILUS

January 29, 1981

Vol. 95(1)

FEEDING AND FOOD PRE'FERENCES OF THE MURICID GASTROPOD

CERATOSTOMA FOLIATUM

Bretton W. Kent'

Department of Zoology

Oregon State University

Corvallis, Oregon 97331

ABSTRACT

Laboratory experiments and field observations of the carnivorous snail

Ceratostoma foliatum were used to determine whether or not a previously hypoth-

esized dietary shift during ontogeny occurred and to examine the factors affecting

prey choice. The hypothesized dietary shift from specialization on barnacles to

generalization on bivalves did not occur. Both small (<bO mm) and large (>50

mm) C. foliatum preyed largely on two bivalves species, Adula californiensis and

Protothaca staminea, consistently choosing the latter even though it required

drilling and yielded less energy per capture. C. foliatum apparently select P.

staminea because they are less likely to be dislodged by rough waves while feeding.

The gastropod Ceratostoma foliatum (Gmelin)

is a common inhabitant of rocky shores along

the northeast Pacific rim from Alaska to Califor-

nia. Despite its large size (>100 mm) and com-

moness its ecology is poorly known. Functional

morphology (Spight and Lyons 1974, Palmer

1977) and life history patterns (Spight et ai,

1974) have been examined in some detail, but

only a few feeding observations have been

made. Spight et al. (1974) suggest that C.

foliatum may follow a dietary strategy similar to

that of Muricanthvs nigritus (Philippi) (Paine

1966). Small M. nigritus are specialists on acorn

barnacles while large individuals (>40-50 mm

shell length) are generalists on gastropods. This

dietary shift during ontogeny presumably oc-

curs due to the increased energy demands of

larger M. nigritus (Paine 1966). With C.

foliatum the hypothesized dietary shift is from

specialization on barnacles to generalization on

bivalves. Based on the presumed adaptiveness

of the labial spine on the outer lip of C. foliatum.

Spight and Lyons (1974) suggest that the

dietary shift should occur when the spine is func-

tionally complete.

The purpose of this study is to examine two

'Present address: Department of Zoology, University of

Maryland, College Park, Maryland 20742.

aspects of feeding in C. foliatum,. First, what are

the preferred prey, and what factors affect

these preferences? Second, does a dietary shift

occur during ontogeny when the labial spine

becomes functionally complete?

MATERIALS AND METHODS

The study site was located along the southeast

margin of Boiler Bay, Oregon. The area consists

of scattered mudstone benches separated by

surge channels. The stone is heavily perforated

by boring organisms, principally bivalves in the

families Pholadidae (Nettastomella rostrata.

Penitella penita and Zirfaea pilsbryi) and

Mytilidae (Adula californiensis). Empty pholad

burrows are inhabited by a variety of nestling

species, including the bivalves, Protothaca

staminea (Veneridae) and Hiatella arct.ica

(Hiatellidae). Mussels (Mytilus califomianus)

and small acorn barnacles (Balanus glandula)

are scattered over the study site. The density of

potential prey was determined by a random

quadrat method. A bench-mark was established

in the center of the study site using a 2.5 cm

diameter white plastic disc held in place with a

5.1 cm long masonry nail. A double set of ran-

dom numbers was used to determine the north-

south and east- west coordinates of each sample.

Quadrats were 15x15 cm on the siu-face and

Vol. 95(1)

January 29, 1981

THE NAUTILUS 39

rock was removed to a depth where no further

boreholes were evident on the newly exposed

rock surface. Snails found feeding during these

searches were measured (shell length from ape.x

to tip of siphonal canal) and the prey identified

and measured. The method of attack was also

noted.

The laboratory experiments were conducted

in a 50 X 50 cm clear Plexiglas tank with con-

stantly circulating 3.3% seawater. Water depth

was maintained at 4 cm. During the study water

temperature varied from 15-17°C. Eight snails,

ranging from 31 to 69 mm shell length were

placed in the tank and starved for seven days.

Eight specimens of each of six prey species (i.e.,

B. glandula. A. caJifoniiensis. M. californianuji.

N. rostrata, P. staminea, and Z. pilsbryi) were

then placed in the tank. Individual prey were

placed randomly using a grid system and two

sets of random numbers for determining coor-

dinates. Specimens for each species represented

the full size range available in the field. Prey

items were replaced with another individual of

the same species and size when eaten. The tank

was covered during the experiment with black

plastic. The experiment was checked at least

every 12 hours. As with the field observations C.

foliatum length, prey species, prey length and

method of attack were recorded. Two prey

species. P. penita and//, ardica, were not abun-

dant enough to be used in the laboratory studies.

Caloric contents of the prey species were

determined using a Parr oxygen bomb calori-

meter (Anonymous, 1960). Prey were dried to a

constant weight at 80°C, the dried tissues were

removed from the shell and then tested accord-

ing to the protocol in the Parr manual.

RESULTS

C. foliatum of all sizes use two different

methods of attacking prey. Bivalves with an ob-

vious siphonal gape (i.e., A. califoryiiensis) were

attacked by direct eversion of the proboscis

through the gape. The siphonal region of the

bivalve shells attacked in this manner showed no

evidence of drilling activity, strongly suggesting

that the radula and accessory boring organ were

not used to enlarge the siphonal gape before

proboscis eversion. Snails feeding in this man-

ner had the head placed directly over the sipho-

nal gape of the prey. The anterio-lateral corners

of the propodium were extended anteriorly and

medially to form a short tubular channel be-

tween the mouth and siphonal gape. The pro-

boscis was extended through this channel. The

labial spine was frequently observed pressed

against the substrate to assure a firm purchase

while feeding.

A different method of attack is used against

prey such as Protothaca staminea which lacks a

prominent siphonal gape. These prey were drill-

ed through the valves, a mechanism widely used

by muricid gastropods (see review by Carriker

and Williams 1978). In the study area P.

staminea normally occurs in empty Penitella

penita burrows which have a small external

opening and a spacious interior partially filled

with sediment. C. foliatum feeding on these

clams fold the lateral margins on the anterior

half of the foot dorso-medially to form a tubular

channel for the proboscis. This portion of the

foot is everted through the burrow opening,

and, once into the interior of the burrow it

becomes greatly inflated (Fig. 1). Presumably

FIG. 1. Ceratostoma foliatum edge-drilling a Pro-

tothaca staminea iii an empty pholad burrow. Is,

labial spine: rv, right varii: dv, dorsal varix; ef,

everted portion of foot tvitk right and left halves

folded dorsally to form a tubular channel for the

proboscis.

40 THE NAUTILUS

January 29, 1981

Vol. 95(1)

Ihe swelling is brought about by the transfer of

body fluids into the extended portion of the foot.

The anterior tip of the foot is attached to the

prey, thus bringing the accessory boring organ

and the radula (at the tip of the everted pro-

boscis) close to the prey's valves. Of the clams

attacked in this manner, 82% were drilled at the

juncture of the valve edges where the shell is

thinnest. The remaining 18% were drilled

through one of the valves. The labial spine is not

important in anchoring the snail to the sub-

strate, since it is rarely pressed against the

-substrate as it is when A califomiensis is being

attacked. I have found C. foliatum harder to

remove from the substrate when it is feeding on

P. staminea rather than on A. calif oniiensis

simply because of the difficulty of pulling the

swollen portion of the foot through the small

burrow opening.

Spight and Lyons (1974) suggested that the

diet of C. foliatum should shift at a shell length

of 60 mm since at this size the labial spine be-

comes functionally complete. The C. foliatum at

Boiler Bay reach a smaller size than those in

Spight and Lyon's study. With the exception of

a single, high-spired specimen of 82 mm, none of

168 individuals examined during the study ex-

ceeded 70 mm. The labial spine of Boiler Bay C.

foliatum becomes functional when the shell

reaches a length of about 50 mm. Because of this

difference, I use 50 mm as the predicted size at

which the dietary shift should occur in all the

analyses which follow.

The results of the field feeding observations

for small (<50 mm) and large (>50 mm) C.

foliatum for the period of April to August 1976

are compared using the chi-square test. Only

those prey items eaten are listed in Table 1.

TABLE 1. Field observations of feeding by small (<50 mm)

and large (>50 mm) Ceratostoma foliatum. Diets for the two

size classes are compared using the chi-square test (3?) and

show no significant relationship between size and diet (x' =

2.S3. p>0.05).

Other available prey are listed in Table 3. Diet is

not related to size (x^ = 2.33, p>0.05). A similar

treatment for laboratory feedings also shows no

significant relationship between size and diet

(x2= 1.39, p>0.05; Table 2). A dietary shift does

not occur when the labial spine becomes func-

tional in C. foliatum from Boiler Bay.

TABLE 2. Lnhorntory feeding observations for small (4:50

mm) and large 050 mm) Ceratostoma foliatum. Diets are

compared using the chi-square test and show no significant

correlation between size and diet fx'' = l-39. p>0.05).

31 to 50 mm 51 to 69 mm

Number % Number %

eaten Diet eaten Diet

C foliatum size range

Prey species

Adula califomiensis 1 13 4 22

Mytilus califomianus 0 0 2 11

Protothaca staminea 7 87 12 67

A number of prey characteristics may affect

prey choice, although two, energy content (see

review by Pyke et al. 1977) and abundance (Rap-

port 1971, Emlen 1973, Estabrook and Dunham

1976), are frequently considered to be the most

important. The energy content of each prey

species and the abundance of each species in

both the field and laboratory observations are

listed in Table 3. Only those species in families

on which C. foliaium is known to prey are in-

cluded in Table 3 (Spight et al. 1974, this paper).

Because there was no relationship between size

and diet within each set of observations the re-

sults were pooled (Table 3). The two most pre-

ferred prey (P. staminea and A. califomiensis)

are both high in energy content and common.

But neither energy content nor abundance alone

is an adequate predictor of preferred prey. The

energetically most valuable prey (A. califomien-

sis) only represented 21% of the laboratory diet,

while P. staminea accounted for 71% of the

laboratory diet. This preference for P. staminea

is even more surprising, since P. staminea must

be drilled before it can be eaten. Such drilling is

not required for feeding on A. califomiensis. In

the field, A. califomiensis and P. staminea each

represent 49% of the diet. This change is pre-

sumably the result of A. califomiensis being

almost twice as common as P. staminea (Table

3). However, A'^. rostrata, which is also nearly

twice as common as P. staminea was not eaten

Vol. 95(1)

January 29, 1981

THE NAUTILUS 41

TABLE 3. Summary of prey charactertistics and percent of diet in laboratory andfield conditions.

Since there is no significant difference between the diets of small and large snails in either the

laboratory or the field the data haiv been combined urithin each treatment.

even though C. foliatum has been observed

feeding on other Pholadidae (Spight et al. 1974).

DISCUSSION

The labial spine appears to allow C. foliatum a

greater purchase while feeding on certain prey,

such as Adula californiensis, and possibly also

during quiescent periods. A mature labial spine

is clearly not needed to feed on bivalves, since

small C. foliatum with poorly developed spines

readily do so. Whether very small C. foliatum

(about 10 mm or less), which lack a labial spine,

can successfully attack bivalves is unknown.

Such small snails are difficult to find in the com-

plex environment at Boiler Bay.

The absence of the hypothesized dietary shift

may be partially due to the time of the year of

the study. Barnacle densities were particularly

low at Boiler Bay while the field study was in

progress (Table 3). Under such conditions spe-

cialization on barnacles may not be a viable

alternative for small C. foliatum. Spight, et al.

(1974) have found that C. foliatum responds to

yearly fluctuations in barnacle density. When

barnacles are abundant they are heavily preyed

upon by C. foliatum. During lean years bar-

nacles are infrequently eaten. Spight, et al. do

not list the prey eaten when barnacles are rare,

but the observations reported here suggest that

C. foliatum of all sizes prey on bivalves when

barnacles are unavailable.

Several factors affect prey selection. Energy

content and abundance are important, since the

two preferred prey (P. staminea and A. califor-

niensis) are both common and energy rich, but

do not adequately explain why /I. californiensis

is not more frequently eaten that it is. This

mussel is the most abundant prey, has the high-

est energy content, and requires no preparatory

drilling before ingestion. Yet A. califomiensis is

only eaten as frequently as P. staminea which is

both lower in abundance and energy content

and requires drilling prior to ingestion. One pos-

sible explanation for this paradox is the reduced

risk to the snail of being dislodged. Feeding C.

foliatum were frequently observed to be in more

exposed positions than quiescent snails. Preda-

tors (Palmer 1977) or heavy surf (Menge 1978,

pers. observ.) can readily remove exposed

snails. Palmer (1977) has shown that the foliated

varices of large C. foliatum significantly in-

creases the probability that the snail will land

with the aperture down, protecting the vulner-

able foot from predatory fish. Palmer's results

were obtained in still water, so it is unclear

whether the same results would be obtained in

surf. At Boiler Bay dislodged snails are fre-

quently found being held upside down on the

dorsal surface of the sea urchin Strongylocen-

trotus purpuratus. Normally this accounts for

less than 1% of the C. foliatum observed,

although after a storm as much as 11% of the

population may be stranded on urchins (Kent,

unpubl.). Stranded C. foliatum. probably perish

since they appear to lack any means of escape.

Snails feeding in exposed positions would be

most susceptible to being dislodged. The in-

creased ability to remain attached while feeding

42 THE NAUTILUS

January 29, 1981

Vol. 95(1)

on P. staminea (due to the inflated foot) would

reduce the risk of being dislodged and increase

the "value" of P. staminea as a prey item. A.

caUfomien,'iis is more abundant and higher in

energy content, but feeding on A. califomiensis

incurs greater risk of being dislodged by

predators or heavy wave action.

The relative risks of being dislodged may also

explain the concurrent development of the labial

spine and the foliated varices in C. foliatwm. In

small C. foliatum the labial spine and varices are

absent or poorly developed, but become increas-

ingly well developed as the snail grows larger

(Spight and Lyons 1974). At Boiler Bay small C.

foliatum. are most frequently observed in crev-

ices and depressions where they would be rela-

tively immune to disturbance by either preda-

tory fish or surf. Larger C. foliatum have few

refugia and are more exposed, particularly

when feeding. Large varices would reduce fish

predation but would increase the risk of being

dislodged by surf (Palmer 1977). The labial spine

conteracts this tendency by assuring a firm pur-

chase to the substrate.

The labial spine of C. foliatum is not used for

attacking new types of prey. Rather it functions

as a handy tool for assuring a firm purchase

while feeding in exposed positions. Where an

even firmer purchase can be obtained by anchor-

ing the foot in a burrow the labial spine is not

used. At Boiler Bay the risk of being dislodged

appears to be so high that prey preferences of C.

foliatum, have been affected.

ACKNOWLEDGMENTS

I wish to thank C. J. Bayne and J. C. Ruther-

ford for helping during early stages of this

work, J. L. Kent for assistance during the field

work, and M. L. Reaka, E. M. Bird, and J. A.

Veil for helpful discussions. I would like to thank

G. J. Vermeij and T. M. Spight for their com-

ments on this manuscript.

LITERATURE CITED

Anonymous 1960. Oxygen bomb calorimetry and combus-

tion methods. Technical manual no. 130. Parr Instrument

Co., Moline, Illinois.

Carriker, M. R. and L. G. Williams. 1978. The chemical

mechanism of shell dissolution by predatory boring gas-

tropods: a review and an hypothesis. Malacologia 17:

143-156.

Emlen, J. M. 1973. Ecology: an evolutionary approach.

Addison-Wesley Pub. Co., Reading, Mass., 493 pp.

Estabrook, G. F. and A. E. Dunham. 1976. Optimal diet as a

function of absolute abundance, relative abundance, and

relative value of available prey. Amer. Natur. 110:

401-413.

Menge, B. A. 1978. Predation intensity in a rocky intertidal

community. Relation between predator foraging activity

and environmental harshness. Oecologia 34:1-16.

Paine, R. T. 1966. Function of labial spines, composition of

diet, and size of certain marine gastropods. Veliger 9:

17-24.

Palmer, A. R. 1977. Function of shell sculpture in marine

gastropods: hydrodynamic destabilization in Ceratostoma

foliatum. Science 197:1293-129.5.

Pyke, G. H., H. R. Pulliam and E. L. Charnov. 1977. Opti-

mal foraging: a selective review of theories and tests.

Quart. Rev. Biol. 52:137-154.

Rapport, D. J. 1971. An optimization model of food selection.

Amer. Natur. 105:575-587.

Spight, T. M., C. Birkeland and A. Lyons. 1974. Life his-

tories of large and small murexes (Prosobranchia: Muri-

cidae). Marine Biol. 24:229-242.

Spight, T. M. and A. Lyons. 1974. Development and func-

tions of the shell sculpture of the marine snail Ceratosto-

ma foliatum. Marine Biol. 24:77-83.

Major Research and Identification

Classic for Sale

Lovell Reeve's CONCHOLOGIA ICONICA

(1843-1878)

This is the largest and most famous of the

19th century master works on conchology,

containing 1,840 exquisite handpainted litho-

graphic plates of many hundreds of new

species. This excellent set, bound in contem-

porary blue buchram in 23 volumes, contains

all the then-known marine mollusks of the

world. It lacks the land and freshwater parts

dealing with such groups as Helix and Uyiio.

The set has unusually fine colored plates of

Murex, Voluta, Cypraea. Pecten. Coyius, Tur-

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tion, there are 43 plates photostated of rare,

unattainable parts. Write: Dr. R. Tucker Ab-

bott, P. 0. Box 2255, Melbourne, FL 32901.

Vol. 95 (1) January 29, 1981 THE NAUTILUS 43

A METHOD OF COLLECTING MINUTE LAND SNAILS

C. Cliff Coney', Wallace A. Tarpley and Robert Bohannan

Department of Biological Sciences

East Tennessee State University

Johnson City, Tennessee 37601

ABSTRACT

A method is described which will facilitate the processing of leaf litter for dead

shells of the Pupillidae and other molluscan micro-fauna by utilizing floatation of

the shells against the different density gradients of water and xylene hydrocar-

bons. Most of the undamaged dead shells which were present in the original sam-

ple may be recovered by this process.

County and state records for the Pupillidae

and other minute land snails indicate widely

scattered distributions when compared to the

reported ranges of the larger and more obvious

land snails. This may be due to the difficulty en-

countered in processing large amounts of leaf

litter for its molluscan micro-faunal content.

The method of collection of minute land snails

used by previous workers has largely been car-

ried out by a process of sifting dried moss and

leaf litter debris, followed by a laborious and

time-consuming ordeal of hand-picking the

residue (La Rocque, 1974; Smith, 1910; Sterki,

1887). Laver (1878) introduced the method of

winnowing leaf litter in the wind, and thereby

utilizing the force of the wind to carry away the

unwanted debris. This method unfortunately in-

troduces bias into the sample by the certain loss

of such genera as Punctum, Striatura, and Ver-

tigo. A more suitable means of separating the

majority of the leaf litter debris involves the in-

novative addition of water floatation to the

original process of dry sifting of leaf litter

(Evans, 1972).

We have developed a method which will pro-

vide a maximum yield of molluscan shells with a

minimum expenditure of time and effort. A leaf

litter or moss sample is taken so as to include

from 5 cm to 10 cm of soil. This will insure ade-

quate sampling of the fine leaf/soil interface

where many of the minute gastropods thrive.

The contents of the sample should be placed on a

screen having a 5-mm-square mesh which has

been suspended over a deep bucket. The sample

can then be gradually washed with water

through the screen and into the bottom of the

bucket. The fraction of sample which remains on

the 5-mm screen should be searched for large

land snails. Examination of the contents of the

bucket after the initial washing phase will reveal

a layer of detritus containing dead mollusk

shells floating on the surface as a result of air

trapped within their spires; the heavier fraction

of soil and rock detritus will have settled to the

bottom of the bucket. The floatant should be

skimmed off the surface of the water and placed

on a No. 60 mesh brass screen and allowed to

drain. We have found it desirable to gently wash

this fraction with tap water to remove the finest

particles of floatant. The remaining fine detritus

containing small mollusk shells should then be

dried in an oven at about 60 °C until the sample

is completely dried. Forty-eight hours is usually

sufficient drying time unless the sample con-

tains a large amount of rotted wood or bog

humus.

When thoroughly dry, the sample should be

sifted into a beaker containing xylene and allow-

ed to settle out for approximately one hour with

periodic agitation until the fine debris stops fall-

ing to the bottom of the beaker. The remaining

suspended floatant can then be skimmed off the

surface of the liquid and placed on filter paper

and allowed to drain dry at room temperature.

When dry, this remaining fraction can be ex-

amined under a stereoscopic microscope or hand

lens and the mollusk shells removed by touching

a probe wetted with ethyl alcohol to the shells

'Present address: Dept. of Biology, Coastal Carolina College, Conway, S.C. 29526.

44 THE NAUTILUS

January 29, 1981

Vol. 95(1)

which will adhere to the probe. The shells may

be collected in a vial of alcohol and subsequently

dried at 60°C if desired.

A word of caution! Xylene has been determin-

ed to be a possible carcinogen; therefore, one

should be sure that the work area is well ven-

tilated and skin contact avoided as this sub-

stance may be absorbed through the skin with

prolonged use. Other hydrocarbons such as

toluene or benzene may be substituted providing

the above precautions are adhered to.

Unfortunately, the above described floatation

technique cannot be employed on clastic clay

samples from Pleistocene cave deposits since

the shells from these deposits are typically filled

with clay. The following method has been found

to yield satisfactory results for examining

Pleistocene cave deposits for the molluscan

micro-faunal contents. The sample is dried in an

oven at 60°C until thoroughly dry, then it is

covered with a hydrocarbon such as kerosene or

varsol and allowed to stand overnight. After

decanting the hydrocarbon, the sample is im-

mediately covered with a mixture of boiling

water and detergent and allowed to sit for a few

hours. This will allow the clay to be broken up in-

to finely particulate sediments thus preparing

the sample for gentle washing through a 5 mm

square mesh screen and into a collection bucket.

After the contents of the sample remaining on

the screen are examined, the fraction of sample

collected in the bottom of the bucket is poured

on to a No. 60 mesh brass screen and washed

thoroughly with water. The fraction remaining

on the No. 60 mesh brass screen is then dried in

an oven at 60°C. The dried sample may then be

examined under a stereoscopic microscope for

molluscan content.

ACKNOWLEDGMENTS

We would like to thank Dr. Jeff G. Wardeska

for suggesting the possibility of hydrocarbon

floatation. We are also indebted to Dr. Dan M.

Johnson and Mr. Charles H. Coney for critically

reading the manuscript.

LITERATURE CITED

Evans, John G. 1972. Land Snail in Archaeology. Seminar

Press, London. xiiH-436 pp., 145 figs.

La Rocque, Aurele. 1974. Short notes on land snails. In: How

to Study and Collect Shells: A symposium, 4th ed. Ameri-

can Malacological Union, pp. 69-71.

Laver, Henry. 1878. Suggestions for finding the smaller

land shells. The Quarterly Journal of Conchology . 1:264.

Smith, Herbert H. 1910. Directions for Collecting Land

Shells. Museum of the Geological Survey of Alabama.

12 pp.

Sterki, Victor. 1887. Hcnt) to Collect Small Land Shells. The

Conchologist's Exchange, l(ll):67-68.

Vol. 95(1)

January ^9, 1981

THE NAUTILUS 45

GUIDE TO THE NUDIBRANCHS OF CALIFORNIA

INCLUDING MOST SPECIES FOUND FROM ALASKA TO OREGON

B^ C\R> R, McDonald AND

ddited B\ R Juikt-r

Des.tine(i to be the "bible lor tidepool dnd scubj biologists, the

Guide (o Ihe Mudibrantlr. ol Calilornia will equally serve those

researchers from Alaska and Pacific Canada to Oregon The extensive

informal ionon the specialized toods and habitats ot each species will

aid not only in identification but also in ecological analyses.

Unique among similar guides, this book has the advantage ol ex-

tensive keys, authoritative information and convenient [ihylogenefic

organization. This book will be welcomed by marine hinlogisis

amateur naturalists, marine aquarium enthusiasts, and students ol

oceanography.

Years in the making, this compact account gives the stientific

essentials to all the known nudibranchs snails ol Caliform.i, uu ludmg

the higher classification and descriptions of eaih genus with iheir

type-species. With top quality in photography and undeisl.indable

concise morphological descriptions identilKalions ot species are

made much easier

american malacologists

Pi HLISHEKS of DlSnM:TI\'E BiVKS O.V MliLLUSKS

P O BOX 2255

MELBOURNE FLORIDA 32901

• BIOLOGY

• KEY TO SPECIES

• GENERIC DESCRIPTIONS

• SPECIES DESCRIPTIONS

• 112 COLOR PLATES OF LIVING ANIMALS

• CC:)LLECTING TECHNIQUES

• PHOTOGRAPHING TECHNIQUES,

• ANATOM\

.m'^l

• BIBLK^GRAPhn

i'^

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m^^^'^

M\

sS%

Freshwater Snails of Africa and their Medical Importance

by David S. Brown

DISCOUNT PRICE TO

NAUTILUS SUBSCRIBERS

$49.00 (plus postage)

Regular price

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For the first time:

A comprehensive account of freshwater snjiils

in Africa and neighbouring islands.

An exhaustive guide to species

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An invaluable reference work for malacologists,

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Published by TAYLOR & FRANCIS LTD, LONDON.

Distributed in the Americas by AMERICAN MALACOLOGISTS, INC. FLORIDA.

The knowledge resulting from Intensive study in recent years is

brought together for the first time in this book. Dr. Brown presents

a systematic synopsis of nearly 400 species, most of them

illustrated, together with chapters on host/parasite relations, snail

control, ecology, distribution and biogeography, accompanied by

many maps, photographs of shells and drawings.

Dr. David S. Brown is a senior scientist on the staff of the Medical

Research Council of Great Britain and has been based for 20 years

at the British Museum (Natural History) working with a team on

research into host/parasite relations. During long periods of field-

work in Africa, he has studied the entire gastropod fauna of fresh

and brackish waters over large areas of the continent.

450 pp. 230 X 152nim (9 x 6"

0 85066 145 5 Cloth

153 Figs.

46 THE NAUTILUS

January 29, 1981

Vol. 95(1)

REVIEW

Brown, Davis S. 1980. Freshwater Snails of

Africa and their Medical Importance. 487 pp. ,

153 pis. Taylor and Francis, Ltd., London.

Distributed in the Americas by American

Malacologists, Inc., P. 0. Box 2255, Mel-

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$55.00 U.S.

Dr. Brown's book on the "Freshwater Snails

of Africa" is a welcome addition to regional

faunal works of Africa, such as Pallary, 1909

(Egypt); Pilsbry and Bequaert, 1927 (Zaire,

former Belgian Congo); Connolly, 1939 (South

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Wright, 1963 (Angola), and Brown, 1965

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The book begins with a systematic synopsis

(Chapters 2, 3 and 4) of the Prosobranchia and

the Basommatophora of the Euthyneura. The

families and genera of African freshwater

gastropods can be identified by means of keys

(Chapter 2). The systematic synopsis includes

distributional maps and information about

ecology and parasites. Such essential informa-

tion is presented for nearly 400 species, almost

all illustrated in photographs or line drawings.

Facts relevant to the study of biogeography are

particularly difficult to segregate, and are found

in many chapters. Investigators on snail biology

and distribution have expended a great amount

of effort in trying to explain the local distribu-

tions of particular snails in terms of physical and

chemical limiting factors in the environment;

some observations from the field and laboratory

are summarized (Chapters 10 and 11). Chapter

12 deals with regional faunas and is an excellent

feature of the book. For each zone there is a list

of species encountered, with up-to-date nomen-

clature. These regions include North and

Southern Africa, large lakes and major river

basins. In addition to a subject index, there is a

very useful taxonomic index. An Appendix in-

cludes methods used in studying snails.

This book is a must for those interested in the

freshwater snails of Africa, their up-to-date

systematic status, their geographic distribution,

ecology, and their medical and economic impor-

tance.-£'rni/.e A. Malik, Tulane University,

New Orleans.

american malacologists

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color pis , text figs lllus Catalog and classifications

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THE

NAUTILUS

ISSN 0028-1344

Vol. 95

No. 2

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THE

NAUTILUS

Volume 95, number 2 - April 30, 1981

ISSN 0028-1344

CONTENTS

Terrence J. Frest and R. Sanders Rhodes II

Oreohelix strigosa cooperi (Binney) in the Midwest Pleistocene 47

C. M. Way, Daniel J. Hornbach and Albert J. Burky

Seasonal Metabolism of the Sphaeriid Clam, Musculium partumeium,

from a Permanent and a Temporary Pond 55

Robert S. Prezant

Taxonomic Re-evaluation of the Bivalve Family Lyonsiidae 58

James F. Quinn, Jr.

A New Genus of Turbinellidae (Gastropoda: Prosobranchia), with the

Description of a New Species from the Caribbean Sea 72

William K. Emerson and Anthony D'Attilio

Remarks on Muricodrupa Iredale, 1918 (Muricidae: Thaidinae),

with the Description of a New Species 77

Bruce Einsohn

New Records of Land Mollusca in New York City 82

Arthur H. Clarke

Corbicula Jluminea, in Lake Erie 83

Marc J. Imlay, John W. Arthur, Barbara J. Halligan and John H. Steinmetz

Life Cycle of the Freshwater Snail Campelama decisum (Viviparidae)

in the Laboratory 84

Marian E. Havlik

The Northern Extension of the Range of Anodonta suborbiculata Say

(Bivalvia: Unionidae) 89

Emile A. Maiek and W. Lobato Paraense

Some Peruvian Hydrobiids, Potential Snail Hosts of Paragonimiasis 91

Ralph W. Taylor

Freshwater Naiades of Eagle Creek, a Tributary

of the Kentucky River (Unionidae) 93

Leroy H. Poorman and David K. Mulliner

A New Species of Crosslandia (Nudibranchia: Dendronotacea)

from the Gulf of California 96

News 88

Vol. 95(2)

April 30, 1981

THE NAUTILUS 47

OREOHELIX STRIGOSA COOPERI (BINNEY)

IN THE MIDWEST PLEISTOCENE

Terrence J. Frest and R. Sanders Rhodes II

Department of Geology

The University of Iowa

Iowa City, Iowa 52242

ABSTRACT

The pulmonate gastropod, Oreohelix strigosa cooperi (Binney), occurs in the

lower few feet of the Peoria Loess (Pleistocene: Wisconsinan) in a narrow band of

localities from, southwestern Iowa to western Illinois, disjunct by more than 3^0

miles east of the nearest moderyi occurrence. New localities include the western-

most and easternmost Pleistocene stations for the subspecies. The Peoria Loess is

dated at 22,000 to 12,500 RCYBP, making the bettey-- documented Pleistocene 0. s.

cooperi sites Woodfordian in age. Occurrence of Oreohelix and a distinctive

associated molluscan faunule implies cooler and drier summers, and perhaps

winters, and coniferous forest cover in part of the Peoria Loess outcrop area.

The genus Oreohelix is a characteristic ele-

ment of the Rocky Mountain molluscan province

(Henderson, 1931) and is frequently the only

large land snail at many northern and central

Rockies localities (Pilsbry, 1939). Its current

distribution is centered in Idaho, Nevada,

Wyoming, Montana, and Utah, but during Late

Pleistocene one species ranged as far east as Il-

linois (Fig. 1). This subspecies, originally con-

sidered to be typical Patula strigosa Gould

(McGee and Call, 1882: Keyes, 1888), was first

relegated to the subspecific rank, 0. strigosa

cooperi Binney, by Shimek (1890). It was re-

garded as a distinct fossil subspecies (iowensis)

by Pilsbry (1898 and 1916). He later relegated 0.

strigosa iowensis to the synonymy of Oreohelix

strigosa cooperi (Binney), and considered these

smaller fossils from Iowa and Illinois as similar

to modern specimens (Pilsbry, 1939:445).

Literature records of varying value are avail-

able for several Iowa and Illinois counties. Our

collections and museum collections substantiate

some old records but others remain to be veri-

fied (Table 1). Most old localities cannot be

recollected due to the ephemeral nature of many

Pleistocene outcrops.

In the course of this study new county records

for Mills and Linn Counties, Iowa and new local-

ities in Polk and Johnson Counties, Iowa and

Rock Island County, Illinois were accumulated.

Recently collected material, as well as that from

completely described old localities, apparently

FIG. 1. Map showing approximate recent (gray) and Pleis-

tocene (bla£k) distribution o/Oreohelix. Recent distribution

based on Pilsbry (1939. fig. 296,312). as modified by Be-

quaert and Miller (1973. fig. !f).

48 THE NAUTILUS

April 30, 1981

Vol. 95(2)

TABLE 1. OccMrrence Data /or Oreohelix strigosa cooperi

(Bintiey). Starred localities have been collected by the

authors.

occurs within a few feet of the base of the Peoria

Loess. This formation was deposited between

22,000 and 12,500 RCYBP and can exceed 75

feet in thickness (Willman and Frye, 1970).

Wood associated with Oreohelix at Locality 5- la

dates from 17,170 ±205 RCYBP.

At this locality and one other, Oreohelix is

associated with abundant spruce macrofossils.

This, together with the occurrence of Oreohelix

as a member of a distinct faunule within the

Peoria Loess, indicates a drier and much cooler

climate during the Woodfordian for parts of

Iowa and western Illinois. Peoria Loess Oreohe-

lix apparently indicate a short-lived incursion of

Rocky Mountain elements (and climates) into a

limited area of the Midwest during the Wood-

fordian. The Midwest fossil localities are the on-

ly ones for 0. s. cooperi; the easternmost occur-

rence of live specimens is in west central South

Dakota, about 350 miles west of the nearest fos-

sil occurrence (Mills County, Iowa).

All new material has been placed in the Repos-

itory, Department of Geology, The University of

Iowa (specimens prefixed by the letters SUI).

Old collections are at the U. S. National Museum

of Natural History (NMNH), Academy of Natur-

al Sciences of Philadelphia (ANSP), and The

University of Iowa Museum of Natural History

(IMNH).

LOCALITIES

In the course of this study Oreohelix was col-

lected from several previously unrecorded sites

in Illinois and Iowa, and one Illinois locality was

successfully recollected (Morrison, 1943: Rock

Island County). Provenance and location are

summarized below.

1-1. Mills Co., Iowa. Giangreco local fauna.

Alluvial channel fill associated with Peoria

Loess, SEV4, NWV4, SW'A, SEV4, sec. 14, T71N,

R43W, Mills Co., Iowa. Collected by junior

author, 1972.

2-1. Polk Co., Iowa. Saylorville Reservoir sec-

tion. Unoxidized Peoria Loess beneath Wiscon-

sinan glacial till from Iowa Geological Survey

drill hole, NEV4, NEV4, NWV4, sec. 20, T80N,

R29W, Des Moines NW 7V2' quadrangle. Oreo-

helix and other snails associated with abundant

wood and spruce needles. Collected by George

Hallberg, 1976.

5-1. Johnson Co., Iowa. Conklin Quarry sec-

tion. Peoria Loess above face of River Products

Co. Conklin Quarry, Iowa City, NWV4, SE'A,

SEV4, sec. 32, T80N, R6W, Iowa City West 7V2'

quadrangle. Oreohelix from two sites (a) uncom-

monly in unoxidized basal Peoria swale fill on

north facing slope above S. wall of quarry, asso-

ciated with well preserved wood and spruce

needles, seeds, some small mammals as well as

other snails; wood date 17,170 ±205 RCYBP;

and also in lower several feet of deoxidized loess

overlying swale fill; (b) commonly in oxidized

Peoria Loess on east facing slope above S. wall

of quarry; at this site a barren deoxidized layer

of coarse loess separates the fossiliferous unit

from the underlying weathered till. Collected by

authors and Leslie P. Fay, 1977-1979.

5-2. Johnson Co., Iowa. Iowa City Airport

section. Peoria Loess in borrow pit NW of Iowa

City Airport, NE corner, NWV4, SWV4, SWV4,

sec. 16, T79N, R6W, Iowa City West 7V2' quad-

rangle. Collected by Leslie P. Fay and senior

author. 1978.

5-3. Johnson Co., Iowa. Pentacrest Apart-

ments section. Peoria Loess in excavation for

Pentacrest Apartments, Burlington and Capital

Vol. 95(2)

April 30, 1981

THE NAUTILUS 49

Streets, Iowa City, SWV4, SEV4, SWV4, SWV4,

sec. 10, T79N, R6W, Iowa City West 7V2' quad-

rangle. Collected by senior author, 1979; no

longer exposed.

5-4. Johnson Co., Iowa. Lake MacBride sec-

tion. Natural exposure of Peoria Loess along in-

termittent stream on N. side of N. arm of Lake

MacBride, Lake MacBride State Park, center

SV2, SWV4, NWV4, sec. 29, T81N, R6W, Ely 7V2'

quadrangle. Collected by authors, 1977 and

1978.

8-1. Rock Island Co., Illinois. Copperas Creek

section. Peoria Loess in bank of Copperas

Creek, SWV4, NWV4, NWV4, sec. 30, T16N,

R6W, Blanchard Island 7V2' quadrangle. Same

as Morrison (1943:104). Horberg's (1956:30)

Locality 5 may also be the same locality: he

gives a detailed section, most of which is no

longer exposed, but did not find Oreohelix.

Recollected in 1979 by Leslie P. Fay.

8-2. Rock Island Co., Illinois. Moline Airport

East section. Peoria Loess exposed in borrow

pit for Moline Airport, SWV4, NWV4, SWV4,

NWV4, sec. 29, T17N, RIW, Milan 7V2' quad-

rangle. Collected by Leslie P. Fay, 1975.

8-3. Rock Island Co., Illinois. Coal Creek sec-

tion. Peoria Loess exposed in Peterson Bros.

Co. borrow pit along Coal Creek, NEV4, NWV4,

NEV4, NWV4, sec. 27, T17N, RIW, Milan 7V2'

quadrangle. Collected by Dr. Ann Foster and

senior author, 1978 and 1979.

Because 0. s. cooperi is generally quite rare,

careful collecting is required to secure speci-

mens. For example, processing of over 3,500

pounts of matrix from the Mills County site

(Locality 1-1) yielded fewer than a dozen

Oreohelix. Where possible each locality was

visited several times: both hand and bulk collect-

ing methods were used. Bulk samples weighed a

minimum of one hundred pounds; generally sev-

eral times that weight was collected, sieved, and

picked for fossils.

DISTRIBUTION

Reported Pleistocene occurrences of 0.

strigosa cooperi are summarized in Table 1 and

mapped on Fig. 2. Recent collecting has sub-

stantiated the presence of 0. s copperi in

Johnson and Polk Counties, Iowa, and in Rock

/

FIG. 2. Map showing Midwest Pleistocene distribution of

Oreoheli.x strigosa cooperi (Binney) by county. Large dots in-

dicate areas from which specimens have been examined by

the authors; small dots are unsubstantiated literature

records. Localities: Iowa-1, Mills Co.; 2, Polk Co.; 3,

Clayton Co.; 4, Linn Co.; 5, Johnson Co.; 9, Muscatine Co.;

10, Louisa Co.; 11, Des Moines Co.; Illinois-6, Carrol Co.; 7,

Whiteside Co.; 8, Rock Island Co.; 12, Cass Co.

Island County, Illinois, and has added Mills

County, Iowa to the list. Museum collections are

available for Rock Island County, Illinois, and

for Johnson, Linn (previously collected but un-

published), Muscatine, and Polk Counties, Iowa.

We have not been able to substantiate literature

records for Carrol, Cass, and Whiteside Coun-

ties, Illinois, and for Louisa, Clayton, and Des

Moines Counties, Iowa.

The unsubstantiated literature records vary in

credibility. Carrol, Clayton, and Whiteside

County specimens were identified by R. E. Call

(Chamberlin and Salisbury, 1888:285, 286;

McGee, 1891:448). The Des Moines County col-

lection was made by Leverett and identified by

C. T. Simpson (Leverett, 1899:169). B. Shimek

provided the faunal lists for the Louisa County

site (Udden, 1901:113). The Cass County record

was based on specimens collected by J. F.

Snyder and originally identified as Helix

solitaria Say, i.e.. Anguispira kochi (Pfeiffer).

Shimek (in Leverett, 1899:173) stated that these

specimens probably were 0. s. cooperi since A.

kochi has not been found in Woodfordian sedi-

ments in Illinois (although present in Altonian

and Farmdalian sediments farther south.

Leonard and Frye (1960) thought Shimek's sug-

gestion might be valid. On the other hand,

Baker (1931:290) regarded all Illinois records as

doubtful, since his collections from the same

counties did not contain Oreohelix. Leonard and

Frye (1960) also did not encounter the species in

50 THE NAUTILUS

April 30, 1981

Vol. 95(2)

central, western, or southern Illinois. However,

because 0. >s. cooperi is normally quite rare and

hence easily overlooked, and because the

chances of misidentification are slim, we ten-

tatively accept all of the above records. A report

of 0. s. cooperi from Tazwell County, Illinois

(Baker, 1922:58) is not plotted on Fig. 2 because

it was based on fragments only and Baker later

(1931:290) referred these to Triodopsis multi-

Lineata wanlessi (Baker).

Baker (1920, 1928) records 0. s. cooperi in

what he termed Yarmouth, Sangamon, and

Peorian deposits. These stratigraphic assign-

ments must be reevaluated because considerable

refinement of Pleistocene stratigraphy has

taken place since Baker's work. Nearly all well-

documented Midwest 0. s. cooperi occurrences

are from the basal few feet of the Peoria Loess

(as defined by Willman and Frye, 1970 in Il-

linois) or equivalents, and therefore Woodfor-

dian in age. Possible exceptions are the Mills

County specimens, which came from an alluvial

channel probably associated with the Peoria

Loess (and hence very likely Woodfordian), and

some Muscatine specimens reported by Udden

(1899:328) from a so-called "ante-glacial silt."

This unit has not been restudied since Udden's

work and as a result is of uncertain age. The

Peoria Loess in Illinois spans the Woodfordian

substange and dates from 22,000 to 12,500

RCYBP (Willman and Frye, 1970:125); in Iowa

the largely equivalent "Wisconsinan" Loess is

considered by Ruhe (1969:87) to date from

29,000 to 14,000 RCYBP.

As presently known, fossil 0. s. cooperi occurs

in a narrow band (average width: 30 mi.)

stretching 340 miles from southwestern Iowa to

eastern Iowa and western Illinois (Fig. 2). The

species appears to be absent from the well-

studied Peoria Loess of Nebraska and Kansas

(Frankel, 1965; Leonard, 1952), Missouri

(Pauken, 1969), Indiana (Johnson, 1965) and the

Illinois and lower Mississippi River valleys in Il-

linois (Leonard and Frye, 1960). Living Oreohe-

lix is endemic to the Rocky Mountain and South-

western Molluscan Provinces; it is the dominant

genus in the former (Bequaert and Miller, 1973).

0. strigosa in one or another form occupies

nearly the whole of the genus range (Fig. 1), i.e.,

from eastern Washington, southeastern British

Columbia and southern Alberta south through

Montana, Wyoming, extreme western South

Dakota and the west half of Colorado to New

Mexico and northern Mexico. To the west it oc-

curs in Arizona and southeastern Nevada north

through Utah and Idaho. Modern 0. s. cooperi

occurs on the northeastern periphery of this

range, in the Cypress Hills of Alberta and in the

Black Hills of South Dakota (Pilsbry, 1939). This

very limited distribution may be an artifact of

spotty collecting. On the other hand the extant

colonies could represent pre-glacial relicts

(Taylor, 1965:606), i.e.. a form widely dis-

tributed prior to the Pleistocene whose range

was reduced substantially during it. Alterna-

tively, 0. s. cooperi may be a recently evolved

form adapted to a Pleistocene climate and sur-

viving only in areas still retaining similar condi-

tions as a glacial relict (e.g., the Midwest

endemic Discus macclintocki (Baker), wide-

spread in the Midwest Pleistocene but now re-

stricted to an extremely limited area in north-

eastern Iowa (Hubricht, 1972)). The limited

fossil record and present distribution of the

genus argue against the last two possibilities.

Other species presently limited to the Rocky

Mountain Molluscan Province inhabited the

Midwest during the Pleistocene, especially the

Wisconsinan (e.g., Disctis shimeki. Columella

alticola). Moreover, although other Midwest

endemics are now known to survive in north-

eastern Iowa, no relict populations of Rocky

Mountain species have yet been encountered

(Frest and Fay, in prep.). At its nearest point

the Pleistocene range of the subspecies is dis-

junct some 340 miles from its modern range.

SHELL MORPHOLOGY

Although they are characteristically smaller,

fossil specimens of 0. s. cooperi agree very

closely with Binney's original description

(quoted in Pilsbry, 1939:443) based on recent

shells. Measurements of the fifty largest speci-

mens from Locality 4 show a considerable range

in width and height (W max= 13.8 mm, W min =

10.3 mm, H max = 10.8 mm,_H min = 6.5 mjii; see

also FJg^3), but the means (W= 11.7 mm, H = 8.0

mm, H/W = 0.68) are similar to Pilsbry's type of

Vol. 95(2)

April 30, 1981

THE NAUTILUS 51

0. c. iowmsis (ANSP 10922: W=11.4 mm,

H=7.7, H/W = 0.68). Large Recent specimens

can exceed 20 mm in diameter. In a series from

Lawrence County, South Dakota closely ap-

proaching the dirnensions of fossil specimens the

five_largest have W = 15.5 mm, H= 11.9 mm, and

HAV = 0.77. The umbilical width of both recent

and fossil specimens is about one-fifth the shell

diameter (Pilsbry, 1939:443-444).

Fossil specimens which retain original shell

color generally have the two color bands char-

acteristic of Oreohelix (Fig. 3b, e, h) but occa-

sionally the upper band is faint or absent (Fig.

3q). The base frequently has one or more smaller

bands (Fig. 31, r); these also are sometimes faint

or absent (Fig. 3f, o). The initial whorls are near-

ly smooth (Fig. 3c); later whorls have faint to

moderate irregular transverse sculpture and

subordinate spiral sculpture (Fig. 3a, d, g, j, m,

p). Juveniles are sharply keeled and quite dis-

tinct from any other Peoria Loess snails. Mature

specimens, fossil or modern, have the aperture

strongly deflected and thickened. Fossil speci-

mens are not as extreme in this regard as are

some modern ones (compare Fig. 3q with Pils-

bry, 1939: Fig. 279:34-36). Large fossil

specimens have from 5 to 5V2 whorls (Fig. 3p),

as do many recent adults.

ECOLOGY

Relatively little recent ecological data is

available for Oreohelix. Hendersen and Daniels

(1916) found most species to be calciphiles; the

commonest situation is in landslides or talus at

the base of limestone cliffs (Henderson and

Daniels, 1916; Pilsbry, 1939; Jones, 1940).

These same authors note that it mostly occurs in

widely scattered, locally dense colonies, a few

feet or yards in diameter. We have collected or

observed Oreohelix (0. subrudis, 0. pygmaea, 0

yavapai extremitatis, 0. strigosa depressa) in

such situations in Wyoming and Alberta. In

most cases colonies were clearly delimited by

dead shells; commonly a wide scatter of very low

density surrounds a much smaller area with nu-

merous Oreohelix. Occasionally only a part of

the area with common dead shells seemed to be

currently occupied by living individuals. With

proper rock or debris cover and calcereous soil.

forest is not required by most Oreohelix, and the

nature of the vegetation is irrelevant (Hender-

son and Daniels, 1916:317). 0. strigosa depressa

is found "indifferently under either rock or

vegetative cover" (Henderson and Daniels, op.

cit.) in colonies as described above. This form

was collected by Hoff (1962) on the ground, in

litter, and under rocks, mostly in mixed aspen,

spruce, and fir stands in New Mexico. No speci-

i5c information is available for 0. s. cooperi

other than that the South Dakota specimens

were found in forest on limestone (Pilsbry,

1939:444), but its requirements are probably

similar to those of 0. s. depressa.

Pleistocene specimens are found in compar-

able situations. Though lacking rock cover,

vegetated Peoria Loess would provide an ade-

quately calcareous habitat for Oreohelix because

it is generally quite calcareous where not subse-

quently leached; samples analyzed by Frye,

Glass, and Willman (1962:49) averaged 9.15 per-

cent CO2, and X-ray analyses in Willman and

Frye (1970:174-175) showed an average of 16

counts/sec. carbonate minerals in the <2u frac-

tion, mostly dolomite. The subspecies is rare at

most exposures, with only a few individuals be-

ing found {e.g., Shimek (1989) collected a total of

85 specimens from all localities he visited). How-

ever, at one Johnson County site (Locality 4)

over 365 0. s. cooperi were found. This situation

seems analogous to the modern areal distribu-

tion; unless exposures were very extensive at a

given locality one would expect to find dense col-

onies infrequently compared to the less rare oc-

currence of scattered individuals. Locality 5-1

exemplifies both situations: the colony at (b) pro-

vided most specimens (including all juveniles)

while the two scattered occurrences at (a)

together yielded fewer than a dozen specimens.

Our other localities each had fewer than twelve

Oreohelix.

Two dozen other land snail species are found

with 0. s. cooperi at our localities: the most fre-

quent associates are listaed in Table 2. The

fauna shows a mix of Holarctic and Nearctic ele-

ments, many of which are currently restricted

to either the Northern or Rocky Mountain Mol-

luscan Provinces in North America; others are

52 THE NAUTILUS

April 30, 1981

Vol. 95(2)

FIG. 3. Oreohelix strigosa cooperi, Peoria Loess, Johnson County. Iowa: Locality 5-lh. a-b, SUI

U9(iG0. diameter=U.6 mm; c, SUI 1,9661. diameter = 3.7 mm; d-f, SUH9662. diameter = 12.1, mm.; g-i,

SUI 1,9668. diameter = 12.0 mm; j-1, SUI 1,9661,. diameter =12.3 mm; m-o, SUI 1,9665, diameter = 12.1,

mm: p-r, SUI 1,9666. diameter= 13.3 mm.

SO widely distributed as to be valueless as snails. There are no southern (Austroriparian)

ecological indicators. Only two (Hendersonia oc- elements and only 60 percent of the associated

culta, Triodopsis multilineata) are Interior species live currently in Iowa or Illinois; these

Vol. 95(2)

April 30, 1981

THE NAUTILUS 53

TABLE 2. Common associates o/Oreohelix strigosa cooperi

(Binney) in the Peoria Loess.

are mostly widespread and tolerant species.

Large snails are low in diversity and absolute

numbers. Even if the Interior species are elimi-

nated no modern fauna corresponds exactly to

that associated with fossil 0. .s. cooperi. How-

ever, nearly all of the remainder do occur with

modern Oreohelix. The most similar associations

are those reported by Beetle (1954, 1957, 1961)

from Wyoming, Karlin (1961) from Montana,

Colorado, and New Mexico, and Hoff (1962)

from New Mexico (with Oreohelix as a consti-

tuent) and by Wayne (1959) from northeastern

Manitoba (without Oreohelix). Essentially all of

the ecologically restricted species (Discus

shimeki, Vallonia gracilicosta, Pupilla. mus-

corum. Columella altricola, Vertigo alpestris

oughtoni, V. modesta) are forms able to survive

the cold, somewhat arid conditions of the high

Rockies or northern Canada. None is restricted

to forest, though most have been found in asso-

ciation with trees, especially coniferous forests.

Karlin (1961) studied the relation of vegetation

types to land snail distribution in Montana, Col-

orado, and New Mexico. Of the fifteen associa-

tions he discriminated, land snails were most

abundant in pure aspen stands, mixed lodgepole

pines and aspens, and mixed Englemann spruce-

lodgepole pine-aspen forests (1961:61-62). Pure

conifer forests commonly had few snails, al-

though he assumes that "very small snail popula-

tions do exist in most coniferous woods" (1961:

65). Aspens especially would characterize burn-

ed or otherwise disturbed areas in largely

spruce forests. Disturbance, and establishment

of aspen, lodgepole pine, or mixed stands, leads

to rapid local population increases for many land

snail species (op. cit.). Except under the most

favorable conditions of preservation, the nu-

merically and areally dominant spruce would be

the major plant macrofossil found in a deposit

accumulated in an area with the cited plant

associations. Karlin (1961:64) also found land

snail abundance to be directly correlated with

availability of free calcium.

At two localities in the Peoria Loess (5- la and

2-1) 0. c. cooperi occurred with abundant con-

ifer wood and spruce needles: no plant macro-

fossils were preserved at the other localities. It

can be inferred that Peoria Loess localities with

Oreohelix had a climate with colder, drier sum-

mers (and possibly winters as well); the most

likely vegetation would be spruce forest (with

some aspen as the major deciduous component),

possibly reduced to comparatively bare ground

in areas nearest the ice margins. Our climatic in-

terpretation is analogous to that suggested by

Taylor (1965) for parts of the Wisconsinan Great

Basin. He believes that the "cool-steppe fauna"

of this region in the Early Wisconsinan indicates

cooler summers, a lower mean annual tempera-

ture, and precipitation no greater (and possibly

less) than at present (Taylor, 1965:603-604).

However, this description applies to only a small

part of the total Peoria Loess (Late Wiscon-

sinan) outcrop area; more southerly locales with

different land snail assemblages undoubtedly

had a somewhat different climate and flora. Lo-

calities with Oreohelix, as noted above, have a

distinctive fauna atypical of the Peoria Loess as

a whole (see, e.g.. the lists of Leonard and Frye,

1960). It is very likely that much of the contro-

54 THE NAUTILUS

AprU 30, 1981

Vol. 95(2)

versy surrounding interpretation of Peoria

Loess ecology (Shimek, 1930, 1931; Baker,

1928; Leonard and Frye, 1960; Taylor, 1965)

results in part from failure to discriminate

molluscan associations in fine enough detail

(Frest and Fay, in prep.). In any case, there is

strong evidence that the most severe Pleisto-

cene climatic changes in the Midwest occurred

during the Wisconsinan (Taylor, 1965).

ACKNOWLEDGMENTS

Numerous individuals aided this project at one

time or another. We are especially indebted to

Leslie P. Fay (The University of Iowa) for infor-

mation and samples from some Illinois localities.

Professor Lon D. Drake and the Department of

Geology (The University of Iowa) arranged for

the radiocarbon date of wood from Locality

5- la. The University of Iowa Alumni Geology

Fund partially funded this publication. Dr. Ann

Foster (The University of Iowa) provided speci-

mens from the Coal Creek section (Locality

8-3). George Hallberg (Iowa Geological Survey)

supplied material from and information on a

Survey core from Locality 2-1, as well as a

preliminary lithologic description of Locality

5-1. Herbert M. Spitz (Dresser Industries) col-

lected some of the Wyoming comparative ma-

terial. Margaret Frest typed the first draft; the

final version was typed by Gwen Fay.

LITERATURE CITED

Bain, H. F. 1897. Geology of Polk County. Iowa Geol. Survey

Ann. Kept. 9:263-412.

Baker, Frank C. 1920. The Life of the Pleistocene, or Glacial

Period. Univ. Illinois Bull. 17, 476 p.

1922. Pleistocene Mollusca from Northwestern

and Central Illinois. Jour, of Geology 30:43-62.

1928. Molluscan life of the loess deposits of Il-

linois. Illinois Acad. Sci. Transactions 20:269-292.

1931. Pulmonate mollusca peculiar to the Pleis-

tocene Period particularly the loess deposits. Jour, of

Paleontology 5:270-292.

Beetle, Dorothy E. 1954. Terrestrial and aquatic Mollusca of

Albany County, Wyoming. The Nautilus 67:121-129.

. 1957. The Mollusca of Teton County, Wyoming.

The Nautilus 71:12-22.

1961. Mollusca of the Big Horn Mountains. The

Nautilus 74:95-102.

Bequaert, Joseph C. and Walter B. Miller 1973. The Mol-

lusca of the arid Southwest. Univ. Arizona Press, Phoenix.

271 p.

Cameron, Cornelia C. 1940. The fossils of the Peoria loess of

Iowa. Unpublished Ph.D. thesis, Univ. of Iowa. 79 p.

Chamberlin, T. C. and R. D. Salisbury 1888. Preliminary

paper on the Driftless Area of the Upper Mississippi

Valley. U. S. Geol. Survey Ann. Rept. 6:199-322.

Frankel, Larry C. 1965. Pleistocene geology and paleoeco-

logy of parts of Nebraska and adjacent areas. Unpublished

Ph.D. dissertation, Univ. of Nebraska, 297 p.

Frye, John C, H. D. Glass, and H. B. Willman 1962. Strati-

graphy and mineralogy of the Wisconsinan loesses of Il-

linois. Illinois Geol. Survey Circ. 334, 55 p.

Henderson, Junius 1931. Molluscan provinces in the western

United States. Univ. Colorado Studies 18:173-186.

Henderson, Junius and L. E. Daniels 1916. Hunting Mollus-

ca in Utah and Idaho. Acad. Nat. Sci. Philadelphia Proc.

69:315-339.

Hoff, C. Clayton 1962. Some terrestrial gastropoda from

New Mexico. Southwestern Nat. 7: 51-63.

Horberg, Leland 1956. Pleistocene deposits along the Mis-

sissippi Valley in central-western Illinois. Illinois Geol.

Survey Rept. Inv. 192, 39 p.

Hubricht, Leslie. 1972. Endangered land snails of the east-

ern United States. Sterkiana 45:33.

Johnson, Gerald H. 1965. The stratigraphy, paleontology,

and paleoecology of the Peoria Loess (Upper Pleistocene)

of southwestern Indiana. Unpublished Ph.D. thesis, In-

diana Univ., 229 p.

Jones, David T. 1940. A study of the Great Basin land snail

Oreohelix strigosa depressa (Cockerell). Univ. Utah Bull.

31:1-43.

Karlin, Edward J. 1961. Ecological relationships between

vegetation and the distribution of land snails in Montana,

Colorado, and New Mexico. Amer. Midland Nat. 65:

60-66.

Keyes, Charles R. 1888. An annotated catalogue of the Mol-

lusca of Iowa. Bull. Essex Inst. 20:61-83.

1890. Notes on the distribution of certain loess

fossils, ^rm-r. Geol. 4:119-121.

Keyes, Charles R. and R. E. Call 1892. On a Quaternary sec-

tion eight miles southeast of Des Moines, Iowa. Iowa Acad.

Sci. Proc. 1, pt. 2:30.

Leonard, A. Byron 1952. Illinoian and Wisconsinan mollus-

can faunas in Kansas. Univ. Kansas Paleontol. Cont. 9

(Mollusca, Art. 4), 38 p.

Leonard, A. Byron and John C. Frye 1960. Wisconsinan mol-

luscan faunas of the Illinois Valley region. Illinois (}eol.

Survey Circ. 304, 32 p.

Leverett, Frank C. 1899. The Illinois glacial lobe. U. S. Geol.

Survey Monogr. 38, 817 p.

McGee, William J. 1891. The Pleistocene history of north-

eastern Iowa. U. S. Geol. Survey Ann. Rept. 11:189-757.

McGee, William J, and R. E. Call 1882. On the Loss and asso-

ciated deposits of Des Moines. Amer. Jour, of Sci. 124:

202-223.

Morrison, J. P. E. 1943. Oreohelix east of the Mississippi.

The Nautiliui 56:l0i.

Pauken, Robert J. 1969. A population study of the Pleisto-

cene molluscan faunas in loess of the Missouri River Basin

Vol. 95(2)

April 30, 1981

THE NAUTILUS 55

in Missouri. Unpublished Ph.D. dissertation, Univ. of Mis-

souri-Columbia, 192 p.

Pilsbry, Henry A. 1916. Notes on the anatomy of Oreohelix.

with a catalogue of the species. Acad. Nat. Sci. Phil-

adelphia Proc. 68:340-.59.

1939. Land Mollusca of North America (North of

Mexico), V. 1 pt. 1. Acad. Nat. Sci. Philadelphia Mono-

graphs 3:1-573.

Ruhe, Robert V. 1969. Quaternary landscapes in Iowa. Iowa

State Univ. Press, Ames, 255 p.

Shimek, Bohumil 1888. Notes on the fossils of the loess at

Iowa City, lovis.. Amer. Geol. 1:149-152.

1890. The Mollusca of eastern Iowa. Univ. of

louiaStud. Nat. Hist. 1:56-81.

1898. Is the loess of aqueous origin? Iowa Acad.

ditions. Ecology 11:673-686.

1931. Ecological conditions during loess deposi-

Sci. Proc. 5:32-45.

1930. Land snails as indicators of ecological con-

tion. Univ. Iowa Stud. Nat. Hist. 14:38-54.

Taylor, Dwight W. 1965. The study of Pleistocene non-

marine mollusks in North America, m Wright. H. E., .Jr.

and David G. Frey (eds.). The Quaternary of the United

States. Princeton University Press: Princeton, New

Jersey, 922 p.

Udden, J. A. 1899. Geology of Muscatine County. Iowa Geol.

Survey Ann. Kept. 9:249-388.

1901. Geology of Louisa County. Iowa Geol. Sur-

vey Ann. Kept. 11:57-126.

Wayne. William J. 1959. Inland mollusks from Hudson Bay,

Manitoba. The Nautilus 72:90-95.

Willman, H. B. and John C. Frye 1970. Pleistocene strati-

graphy of Illinois. Illinois Geol. Survey Bull. 94, 204 pp.

SEASONAL METABOLISM OF THE SPHAERIID CLAM, MUSCULIUM

PARTUMEIUM, FROM A PERMANENT AND A TEMPORARY POND

C. M. Way, Daniel J. Hornbach' and Albert J. Burky

Department of Biology

University of Dayton

Dayton, Ohio 45469, USA

ABSTRACT

Seasonal metabolic rates were exayninedfor the sphaeriid clam. Musculium par-

tumeium (Say) from a permanent and a temporary pond. For the fall-bom.

generation from, the permanent pond and for the single generation from the tem-

porary pond, metabolic rates peak during periods of greatest growth and

reproduction. Metabolic rates were consistently higher for the permanent pond

population. These rates for Musculium partumeium extend the available informa-

tion on the family Sphaeriidae to the genus Musculium.

One important aspect of the ecology of an

organism is its seasonal pattern of metabolism.

The majority of the investigations on the

metabolic rates of freshwater molluscs have

dealt with gastropods (Berg et al., 1962; Berg

and Jonasson, 1965; Burky, 1971; Burky,

Pacheco, and Pereyra, 1972; McMahon, 1973;

Calow, 1976). Metabolic studies of sphaeriid

'Present Address; Department of Biology. University of

Virginia, Charlottesville, Virginia 22901.

clams have been limited. However, there are

reported rates on Pisidiuyn (Johnson and

Brinkhurst, 1971b; Jonasson, 1972; Holopainen

and Ranta, 1977a, b; Alimov, 1975; Burky and

Burky, 1976) and Sphaerium (Alimov, 1975;

Waite and Neufeld, 1977; Collins, 1967). The

study of Pisidium walkerii by Burky and Burky

(1976) is the only seasonal metabolic study in the

literature. This study assessed the seasonal

metabolic rates of the sphaeriid clam, Muscu-

lium partumeium (Say) from a permanent and a

temporary pond.

56 THE NAUTILUS

April 30, 1981

Vol. 95(2)

MATERIALS AND METHODS

Clams were collected from a temporary and a

permanent pond in SW Ohio (see Way et al.,

1980, for a description of the two ponds). The

clams were sorted into 6-8 visual size categories

(2-30 clams per chamber, depending on size)

and oxygen consumption was measured month-

ly at field temperature with Clark-type O2 elec-

trodes (YSI Model 53 moniter, YSI Model 5331

bath stirrer and chambers) using the acrylic

chamber modification described by Burky

(1977). After each experiment shell lengths

(SL = greatest anterior-posterior dimension)

were measured. Clams were dried to constant

weight at 90° C, and they were subsequently

analyzed for total nitrogen using a Coleman

Model 29 nitrogen analyzer. Total dry weights

were converted to tissue weights using shell cor-

rection values from Burky et al. (1979). Oxygen

consumption values are expressed as Qo2 = m1

02/mg dry tissue/hr and Qo2 = m1 02/Mg tissue

N/hr. Tissue nitrogen can be assumed to repre-

sent protein and helps express the respiration

rates in terms of more realistic energy equiva-

lents.

RESULTS AND DISCUSSION

In order to consider seasonal metabolic rates

it is necessary to briefly outline the life histories

of the two populations (from Way et al., 1980).

The ephemeral, or temporary, pond (DW) usual-

ly has a single generation per year. Clams are

born (mean SL at birth = 1.4 mm) in the spring

and early summer (May-July), remain dormant

as juveniles in the dry substrate (August-

January), begin growth in March (reaching adult

SL of 5.9 to 10.1 mm in July), reproduce, and

then die as the pond dries during the summer.

The permanent pond (AM) has two generations

per year. The first generation is born (mean SL

at birth = 1.4 mm) in the spring between May

and July (AM-SG). These individuals initiate

growth during late August (reaching adult SL of

4.4 to 8.0 mm in November), and reproduce be-

tween September and November. Some adults

of the spring generation overwinter and con-

tribute to the next spring generation. Young of

the fall, permanent pond, generation (AM-FG)

overwinter as subadults (mean SL = 2.4 mm) and

experience rapid growth and reproduction in

late spring (reaching adult SL of 3.8 to 7.5 mm

in July). Most clams of the fall generation die by

the end of July, but a few survive to contribute

to the new fall generation.

For M. partumeium there is no inverse rela-

tionship between metabolic rate and size within

size series of adults or juveniles. Thus in the

metabolic rate equation, M = ^l 02/clam/hr =

kW", b=l. In this study b was not significantly

different from 1 for any date. Values of b not

significantly different from one have been re-

ported for gastropods (Daniels and Armitage,

1969; McMahon, 1973; and others), and for the

sphaeriid clam Pisidiutn walkerii (Burky and

Burky, 1976). It is also indicated in the data of

Collins (1967) for Sphcierium occidentale and

Johnson and Brinkhurst (1971b) on several

genera of Pisidium. One possible explanation

for the absence of a size-rate relationship is the

small size range of clams within a particular

generation. This idea is supported by the fact

that for a number of dates where the size range

of clams utilized was very small, the regression

of log M on log tissue weight was not significant

(prob. F<0.05). Burky and Burky (1976) discuss

the possible effects of brooding young on b-value

(sphaeriids are ovoviviparous) and the signifi-

cance of a b-value of one on energy partitioning

in P. walkerii. Consequently, oxygen expressed

as nl 02/mg dry tissue/hr or y.\ 02/Mg N/hr were

averaged for all individuals, regardless of size,

within a generation, i.e. all adult values were

averaged on a given date as were values for

juveniles.

Oxygen consumption for adults of the ephem-

eral pond (DW) population at field temperature

(FT) ranges from 0.58 ^il02/mg tissue/hr, stan-

dard error (SE) = 0.04 (or 12.31 i^Wi^g N/hr; SE

= 0.46) for clams of mean SL = 7.57 mm in July

(FT = 20°C) to 3.23 ^lOa/mg tissue/hr, SE = 0.17

(or 22.65 tilOzl^g N/hr; SE = 1.20) for clams of

mean SL = 6.54 in May (FT= 14°C). Oxygen con-

sumption averaged 2.29 fil02/mg tissue/hr (or

12.81 Ml02/Mg N/hr) for newborns (May- July) at

field temperatures of 14-20°C.

Values for adults of the permanent pond,

spring generation, (AM-SG) range from 0.49

Ml02/mg tissue/hr, SE = 0.08 (or 4.39 Ml02/Mg

Vol. 95(2)

April 30, 1981

THE NAUTILUS 57

N/hr, SE = 0.78) to 1.55 ^iWmg tissue/hr (or

14.14 Ml02/Mg N/hr) for clams of mean SL = 6.34

in November (FT = 7.0°C) and for clams of mean

SL = 5.97 in May (FT= 15°C) respectively. New-

borns of AM-SG (mean SL= 1.4 mm) collected in

August (FT = 20-25 °C) average 2.18 Ml02/mg

tissue/hr (or 15.56 ^102/^5 N/hr). Permanent

pond, fall generation (AM-FG) juveniles (mean

SL = 3.16 mm) have metabolic rates averaging

1.64 Ml02/mg tissue/hr (or 14.29 nlOJi^g N/hr)

during November-May (FT = 7-15°C), while

adults have rates ranging from 1.91 ^102/mg

tissue/hr, SE = 0.75 (or 19.79 Ml02/Mg N/hr, SE =

7.67) for clams of mean SL = 5.43 mm in July

(FT = 20°C) to 3.36 Ml02/mg tissue/hr, SE = 0.74

(or 35.35 ^^\02l^^g N/hr, SE = 8.34) for clams

(mean SL = 5.35 mm) in June (FT= 18.5°C).

The comparable values reported in the litera-

ture are for the genus Pisidium,: 0.35 to 0.87

;jl02/mg tissue/hr at field temperatures for P.

walkerii (Burky and Burky, 1976); 0.09, 0.15,

and 0.33 Ml02/mg tissue/hr at 11°C, 16°C, and

8°C for P. casertanum (Berg et al., 1962; Berg

and Jonasson, 1965); and 0.43, 1.08, 1.15, and

1.30 Ml02/mg tissue/hr at 20 °C for P. caser-

tanum, P. ventricosum, P. henslowanum, and P.

casertanum, respectively (calculated using a 0.5

mg standard clam for Johnson and Brinkhurst,

1971b). Values for other sphaeriids have been

reported by Collins (1967), Alimov (1975), and

Waite and Neufeld (1977), but oxygen consump-

tion is expressed per tissue wet weight or total

wet weight (including shell) and thus are not

comparable.

Oxygen consumption for the fall generation at

the permanent pond (AM) rapidly increases dur-

ing the months of April and May (2.33 to 4.15

MlOg/mg tissue/hr), corresponding to the period

of peak growth and reproduction, with a subse-

quent decline over the summer months (4.15

^lOa/mg tissue/hr in May to 1.91 Hl02nig tissue/hr

in late July). Patterns of growth and reproduc-

tion for overwintering clams at the ephermal

pond (DW) are similar to those of the perma-

nent, fall generation (AM-FG) (Way et al., 1980;

Hornbach et al., 1980). Therefore it is not sur-

prising that the annual patterns of respiration of

overwintering ephemeral pond (DW) clams are

very similar when compared to the permanent

pond ones (AM-FG). Rates increase from April

to May (1.42 to 3.23 ^dOj/mg tissue/hr) and then

decrease from May to July (3.23 to 0.58 ^ilOg/mg

tissue/hr) when the pond dries. The annual

respiratory pattern is the same for ephemeral

(DW) and permanent (AM-FG) pond generations

when the values are based on tissue nitrogen,

but oxygen consumption rates are consistently

higher for the latter. Clams of the permanent

pond (AM-FG) partition more of the total assimi-

lated energy to respiration than do those of the

ephemeral pond (DW) (56% vs. 38% for AM-FG

and DW, respectively; Burky, Hornbach and

Way, unpublished data), thus ephemeral pond

(DW) clams can direct a greater fraction of the

total assimilated energy to growth and repro-

duction.

ACKNOWLEDGMENTS

We would like to thank Mr. J. Koestner,

Director of the Dayton Museum of Natural His-

tory for permission to collect clams from the

pond at Drew Woods (owned by the Eliza Miller

Tree Farm, Pike Timberlands, Inc.); Mr. Paul

Knoop and Mr. Jack Wood of the Aullwood

Audubon Center for permission to collect clams

from the marsh pond; and Dr. G. L. Mackie for

having confirmed our identification of these

clams as Musculium partumeium (Say). Spec-

imens are on deposit with the Museum of

Zoology, University of Michigan, Ann Arbor,

Michigan for the ephemeral pond clams (DW)

(Voucher No. 250040) and permanent pond pop-

ulations (AM) (Voucher No. 250037). This study

has been supported in part by grants to Dr.

Albert J. Burky from The Ohio Biological

Survey and the University of Dayton Research

Council.

LITERATURE CITED

Alimov. A. F. 1975. The rate of metabolism in freshwater

bivalve mollusks. Smi. J. Ecol. (Engl, Transl. Ekologiya)

6:6-13.

Berg, K. anri P. M. Jonasson. 196.5. Oxygen consumption of

profundal lake animals at low oxygen content of the water.

Hydrobiologia 26:131-143.

Berg, K., P. M. Jonasson and K. W. Ockelmann. 1962. The

respiration of some animals from the profundal zone of a

lake. Hydrobiologia 9:1-39.

Burky, A. J. 1971. Biomass turnover, respiration and inter-

population variation in the stream limpet, Femssia rivu.-

laris (Say). Ecol Monogr. 41:235-251.

58 THE NAUTILUS

April 30, 1981

Vol. 95(2)

^_^____ 1977. Respiratory chambers for measuring oxy-

gen consumption of small aquatic molluscs with Clarke-

type polarographic electnxles. Malaeol. Kev. 10:71-72.

Burky, A. J. and K. A. Burky. 1976. Seasonal respiratory

variation and acclimation in the clam, Pisidium walkerii

Sterki. Comp. Biochem. Physwl. 55A: 109-114.

Burky, A. J., J. Pacheco and E. Pereyra. 1972. Tempera-

ture, water and respiratory regimes of an amphibious

snail, Pomacea urcciis (Muller). from the Venezuelan

savannah. Biol. Bull 143:304-316.

Burky, A. J., M. A. Benjamin, D. M. Catalano and D. J.

Hornbach. 1979. The ratio of calcareous and organic shell

components of freshwater sphaeriid clams in relation to

water hardness and trophic conditions. J. Moll. Stud.

45:312-321.

Calow, P. 1976. The respiratory strategies of two species

of freshwater gastropods (Ancylus fluviatilis Moll, and

Planorbis contortus Linn.) in relation to temperature,

oxygen concentration, body size and season. Physiol.

Zool. 48:114-129.

Collins, T. W. 1967. Oxygen uptake, shell morphology and

dessication of the fingernail clam, Sphaerium occidentale

Prime. Ph.D. Dissertation. Univ. of Minnesota. (Diss.

Abstr. 288:5238, Order No. 68-07294).

Holopainen, I. J. and E. Ranta. 1977a. Respiration of Pisi-

dium amnmim (Bivalvia) measured by infrared gas analy-

sis. Olfcos 28:196-200.

1977b. Carbon dioxide output in the respiration

of three Pisidiuvi species (Bivalvia: Sphaeriidae).

Oecologia 30:1-8.

Hornbach, D. J., C. M. Way and A. J. Burky. 1980. Repro-

ductive strategies in the freshwater sphaeriid clam, Mus-

culium partumeium (Say), from a permanent and a tem-

porary pond. Oecologia 44:164-170.

Johnson, M. G. and R. 0. Brinkhurst. 1971b. Production of

benthic macroinvertebrates of Bay of Quinte and Lake On-

tario. J. Fish. Res. Bd. Canada 28:1699-1714.

Jonasson, P. M. 1972. Ecology and production of the pro-

fundal benthos in relation to phytoplankton in Lake

Esrom. Oikos Suppl. 14:1-148.

McMahon, R. F. 1973. Respiratory variation and acclimation

in the freshwater limpet, Laevapex fuscus. Biol. Bull.

145:492-508.

Waite, J. and G. Neufeld. 1977. Oxygen consumption by

Sphaerium simile. Comp. Biochein. Physiol. 57A:373-375.

Way, C. M., D. J. Hornbach and A. J. Burky. 1980. Compar-

ative life history tactics of the sphaeriid clam, Muscu-

lium partumeium. (Say), from a permanent and a tempo-

rary pond. Amer. Midi. Nat. 104:319-327.

TAXONOMIC RE-EVALUATION OF THE BIVALVE

FAMILY LYONSIIDAEi

Robert S. Prezant

College of Marine Studies

University of Delaware

Lewes, Delaware 19958

ABSTRACT

The taxonomy of the marine lyonsiid bivalves is reviewed and redefinitions of

the family and genera are offered. These lyonsiids are divisible into three distinct

genera, Lyonsia, Entodesma, and Mytilimera, based primarily upon

periostracum and calcareous shell structure, umbonal length ratios, modifica-

tions of the mantle edge including the presence of arenophilic radial mantle

glands, morphology of the pedal gape, comparative sizes of adductor muscles, mor-

phology and size of the foot and byssal systems, modifications of the siphons and

general habitats. Some changes in generic taxonomy are suggested. It is also

recommended that the present subgeneric taxafor the marine Lyonsiidae be aban-

doned since these lower ranks indicate ecomorphs and not tru£ taxonomic units.

Few modern workers have concerned them-

selves with the systematics of the bivalve sub-

class Anomalodesmata. Existing reports are

'College of Marine Studies, University of Delaware Contri-

bution No. 151.

conflicting and have thrown the taxonomy of

this heterogeneous group into a state of confu-

sion and disarray. The subclass contains such

diverse members as the elongated and cylin-

drical clavagellid watering-pot shells, the

Vol. 95(2)

April 30, 1981

THE NAUTILUS 59

laterally compressed pandorids and the "car-

nivorous" septibranchs.

The Lyonsiidae are also members of this poor-

ly understood subclass. This family, comprising

some 20 (Boss, 1971) to 45 species, exhibits

characteristics which easily distinguish the

group. The subfamilial taxonomy is less precise.

Several different versions of lyonsiid taxonomy

place from one to twelve extant genera in the

family. Some recent authors (Abbott, 1974;

Narchi. 1968; Prezant, 1979a) place three gen-

era in the Lyonsiidae: Lyonsia, Eyitodesma, and

Mytilimeria. Habe (1977) puts four genera in

the lyonsiids of Japan (Lyonsia, Allogramu,

Bentholyonsia and Agriodesma). and Keen

(1969), five genera in the family (Lyoiisia,

Allograma, Entodesma. Mytilimeria and

Ostomya). Habe first introduced Bentholyonsia

as a subgenus (1952), then (1977) elevated it to

generic status. The characteristics distinguish-

ing this genus from Lyonsia are obscure. Mor-

rison (1943) described a new genus and species

of lyonsiid, Guianadesma sinuosum, from

freshwater rivers of Guyana. This species, ac-

cording to Morrison, is the only lyonsiid known

to lack an internal calcareous ossicle, the

lithodesma, which divides the resilium into two

portions. G. siniwsum has many other lyonsiid

characteristics in soft parts and shell (overall

shell shape, edentulous hinge, fused mantle

lobes), but the exact classification must remain

tentative until the internal morphology and shell

microstructure have been more critically ex-

amined. Yonge (1952) felt that Lyonsiidae

should include Agriodesma and the three genera

advocated by Abbott (1974). Thiele (1935)

classified Agriodesma and Entodesma as

subgenera of Lyonsia while Dall (1903) placed

Entodesma and Lyonsia s.s. as subgenera of

Lyonsia, and Allograma and Philippina as sec-

tions of Entodesma. According to Lamy (1928),

the only valid genus in the family is Lyonsia,

with Entodesma, Agriodesma, and Allograma

being subgenera. Yokes (1980) has listed ten re-

cent, genera in the family: Agriodesma,

Allograma, Anticorbula, Bentholyonsia, En-

todesma, Guianadesma, Lyonsia, Mytilimeria,

Philippina, and Phlycticoncha.

Increased data on soft part morphology, be-

havior, and paleontology accumulated since the

earlier studies have left us with more data on

which to draw for taxonomic interpretations.

Many early bivalve taxonomic systems were

based on a single or very few characteristics,

such as fusion of mantle lobes (Dumeril, 1806;

Fleming, 1822; Latreille, 1825), shell symmetry

and pallial sinus (Linnaeus, 1758; Orbigny,

1843), pedal system (Gray, 1847; Lankester,

1883), adductor muscles ("Philippi, 1853), gills

(Fischer, 1886; Pelseneer, 1889; Ridewood,

1903), hinge system (Neumayr, 1884; Dall,

1895), and type of stomach (Purchon, 1959). Dall

(1895, 1913) and Douville (1896, 1912, 1913),

and later Cox (1960) and Newell (1965), pro-

moted total organism taxonomy with corre-

lating evidence, as available, from paleontology.

For many taxa, sufficient data are now available

to permit us to follow this holistic approach in

classifying mollusks based on distinct char-

acteristics of the entire animal.

Recent work on the mantle edge and shell of

the Lyonsiidae (Prezant, 1980; 1981) required a

corresponding examination of the morphology

and behavior of numerous members of this fami-

ly and has prompted this re-evaluation of the

group's higher taxonomy.

Institutional Abbre^nations

A/VSP- Academy of Natural Sciences of Phila-

delphia, Philadelphia, Pennsylvania

CAS - California Academy of Sciences, San

Francisco, California

LAMN -hos Angeles County Museum of Nat-

ural History, Los Angeles, California

AfCZ- Museum of Comparative Zoology, Har-

vard University, Cambridge, Massachusetts

AM/V//- National Museum of Natural History,

Smithsonian Institution, Washington, D.C.

METHODS AND MATERIALS

Lyonsia fioridana, L. hyalina, L. califomica,

Entodesma saxicola and Mytilimeria nuttalli

were collected live and observed in the labor-

atory on a running seawater table at 12°-18°C

at 30 ppt salinity. Individuals of the genus Lyon-

sia were placed on a sterile, fine sand substra-

tum. L. fioridana were originally collected from

60 THE NAUTILUS

April 30, 1981

Vol. 95(2)

Blind Pass, Sanibel Island, Florida, in shallow

waters in a fine-to medium-grained sand and

shell substratum. L. hyalina were collected

from depths of 14-20 meters in Nahant Bay,

Massachusetts, and Delaware Bay, Delaware, in

fine sands. Living specimens of L. californica

and M. nuttalli were collected from along the

coastline of Venice, California. Specimens of

live E. saxicola were collected just subtidally on

Shaw Island, Washington.

Museum specimens included: Lyonsia gouldii

(MCZ), L. californica (LAMN), L. pugetensis

(NMNH), Entodesma beana (NMNH), E.

cuneata (ANSP), E. patagonica (ANSP,

NMNH), E. saxicola (CAS), E. truncatissima

(ANSP), and Mytilimeria nuttalli (CAS). Spec-

imens of E. fretalis and E. chilensis, both found

among the colonial tunicate Pyura chilensis,

were obtained from Corral Bay, Chile. These

were fixed in Zenker's fluid or 10% formalin

prior to observations.

Measurements were taken to the nearest 0.5

mm with a pair of Mitutoya calipers. Umbonal

length ratio measurements are defined as the

ratio of the longitudinal distance from the umbo

to the anteriormost part of the shell to the

horizontal distance from the umbo to the pos-

teriormost part of the shell. Histological and

electron microscopical techniques are described

in detail elsewhere (Prezant, 1979a, b, 1980). In

brief, specimens were fixed in Zenker's fluid or

10% formalin, embedded in polyester wax, sec-

tioned at 5-10 ^im and stained with Heidenhain's

or Groat's hematoxylin and eosin or a modifica-

tion of the Pantin trichrome (Prezant, 1979a).

For scanning elctron microscopy, shells were

dried in ethanol or critically point dried, coated

with a thin layer of carbon and gold and examin-

ed at accelerating voltages to 15-30 k V in a

Philips PSEM 501.

RESULTS

The family Lyonsiidae is composed of three

valid marine genera: Lyonsia, Entodesma, and

Mytilimeria. Species within the genus Lyonsia

are usually found vertically oriented and partial-

ly buried in fine sands or muds with their

posterior fifth to third exposed above the

substratum. This intertidal to deeply benthic

genus has an active foot but produces only a few

weak byssal threads to aid in attachment and

stabilization. Further stability within the

substratum is obtained by adhesion of foreign

particles, often forming a dense coat over the

periostracum which adds to the surface area and

weight of the bivalve (Prezant, 1979a, b, 1980).

Ansell (1967) described the burrowing activities

of L. norwegica (Gmelin) as very slow. Stanley

(1970) concluded the same for L. hyalina. Obser-

vations of L. californica, hyalina and floridana

in the present study showed that these bivalves

burrowed to their usual partially buried position

within two to four minutes. They often travers-

ed short distances while in the substratum, as

revealed by numerous trails left in the sediment.

All three species showed photosensitivity and

responded to shadows by withdrawing their

siphons and adducting their valves.

Species of the more sedentary genus, Ento-

desma, are usually found intertidally or just sub-

tidally, nestled within rocky crevices or among

algal holdfasts, tunicates or sponges. The genus

possesses the largest individuals of the family

and also the thickest shelled members. En-

todesma, especially as juveniles, can adhere

foreign particles to their shell but, unlike Lyon-

sia, are attached by numerous, thick and strong

byssal threads. The nestling habit of these bi-

valves often produces distorted shells reflecting

compressions or modifications of growth within

their, often small, rocky crevices. This habit

results in great variability in shell shape of in-

dividuals in a given species, and makes shell

form a difficult characteristic to use in species

determination.

The third lyonsiid genus, composed of a single

known species, Mytilimeria nuttalli, has as-

sumed a totally sessile life-style embedded

within compound tunicates (Eudistoma psam-

mion and Distaplia occidentalis) usually in the

intertidal zone, although Smith and Gordon

(1948) report finding this bivalve in depths of

about 20 meters. The larvae of M. nuttalli in-

itially settle upon and are eventually encased by

the growing ascidian colony (Yonge, 1952). The

clams maintain a narrow siphonal slit in the asci-

dian test that is forced apart by protrusion of

their siphons and seals tightly when the siphons

Vol. 95(2)

April 30, 1981

THE NAUTILUS 61

PERIOSTRACUM

FOOT AND BYSSAL SYSTEM

intertidal to deep benthic;

partially buried in fine

sands or muds

thin radially spinulated;

often sand covered; radial

striae

elongate with less than

1:2.5 umbonal length ratio;

thin prismatic, biphasic

nacre

thin, non-muscular edge

with numerous multi-

cellular mantle glands

opening into periostracal

groove

isomyarian to slightly

heteromyarian

active foot is long and

laterally flattened;

well developed byssal

gland produces a few,

thin byssi; pedal gape

long and narrow with

no internal rim

narrow lumens; numerous,

small variously colored,

pigmented spots; numerous

small photoreceptors on

exhalent siphon

ENTODESMA

intertidal to subtidal;

usually nestled in rocky

crevices or among algal

holdfasts, tunicates or

sponges

thick, wrinkled; may

have partial extraneous

cover; radial striae

elongate with greater than

1:2.5 umbonal length ratio;

often a thick homogeneous

layer; always a thin pris-

matic and biphasic nacre

thick, muscular mantle

edge with many mantle

glands as juvenile that

open distal to periostracal

groove

slightly heteromyarian

small, cylindrical foot;

well developed byssal

gland produces many

thick byssi ; pedal

aperture is circular

and has a raised internal

rim

very muscular with

medium diameter lumens;

no photoreceptors

intertidal to just subtidal

embedded within compound

ascidians

thin; golden brown; surface

pitted with crater-like

pores

globular shell with less

than 1:2.5 umbonal length

ratio; thin homogeneous,

thick prismatic, biphasic

nacre

muscular, deeply pigmented

mantle edge; no arenophilic

radial mantle glands

heteromyarian

small cylindrical foot;

poorly developed byssal

gland produces a few,

thin byssal threads; small,

circular pedal gape

very broad si phonal

no photoreceptors

TABLE 1. Comparison of the major generic differences within the family Lyo7isiidae.

LyonsiaarenosaMoWer, 1842

LyoTisia califomica Conrad, 1837

Lyonsiafloridana Conrad, 1849

Lyonsiagouldii Da\\, 1915

Lyonsia hyalina Conrad. 1831

Lyonsia norwegica Gmelin. 1791

Lyonsia puget£7is is Dall, 1913

Entodesma beana (Orbigny, 1842)

Entodesma chilensis (Philippe, 1845)

Entodesma cuneata (Gray , 1828)

Entod£smafretalis{'D3[\, 1915)

Entodesma patagonica (Orbigny, 1846)

Entodesma saxicola Baird, 1863

Entodesma, truncatissima Pilsbury, 1865

My tilimeria nuttalli Conrad, 1837

1:1.9

1:2.1

1:1.9

1:1.3

1:1.5

1:1.6

1:1.5

1:5.9

1:6.7

1:4.8

1:4.7

1:3.8

1:2.8

1:4.6

1:1.6

TABLE 2. Average ratio of distance from umbo to anterior

shell edge and posterior shell edge to umbo. Higher ratios

mean greater distance from umbo to posterior edge than from

imibo to anterior edge of shell. Measurements exclude any

overlap of periostracum at the shell edge.

are withdrawn. Mytilimeria iiuttalli, as a

juvenile (Yonge, 1952) and when removed from

its host as an adult, can produce a few thin,

weak byssal threads. Based upon the globular

shell shape, this species appears the least lyon-

siid like, but shell ultrastructure and internal

anatomy reveal that it is indeed a member of the

Lyonsiidae.

Detailed morphological differences between

the three genera of Lyonsiidae are noted in the

following definitions and in Tables 1 and 2.

Systematics

Family Lyonsiidae, Fischer, 1887

Shell typically inequivalve with left valve

generally larger and extending slightly beyond

right; shell usually with a weakly developed

prismatic layer and a thick biphasic (lenticular

plus sheet) nacre; periostracum often well de-

veloped and extending beyond shell edge espe-

cially in posterior region; internal resilium split

by a well developed lithodesma; resilium pos-

sesses a dense array of long, aragonitic needles

which lie in a plane normal to hinge and litho-

desma; mantle edges fused (Type C fusion

(Yonge, 1957)) by the inner and middle folds

leaving only four openings into the mantle

cavity (inhalent and exhalent siphons, pedal

aperture, fourth pallial atrium); mantle edge

may possess discrete multicellular, club-shaped

mantle glands which secrete a mucoid substance

in conjunction with periostracum and function

in adhesion of foreign particles to shell exterior;

siphons short, split, with short fringes or ten-

62 THE NAUTILUS

April 30, 1981

Vol. 95(2)

FIGS. 1-6. 1, Lyonsia pugetensis, Sitka Harbor. Alaska: length = 2S mm. 2, Lyonsia californica,

Venice, California; kmjth = 19 mm. 3, Lyonsia hyalina. Marthas Vineyard, Massachusetts; length = 17

rrmi. 4, Lyonsia floridana, Sanibel Island, Florida; length = 10 mm. 5, Entodesma saxicola, Friday

Harbor, Washington; length = S9 mm. 6, Entodesma truncatissima, Hokkaido, Japan: length = 67 mm.

Vol. 95(2)

April 30, 1981

THE NAUTILUS 63

FIGS. 7-12. 7, Entodesma cuneata, Iquiqui. Peru: length=36 mm. 8, Entodesma patagumca, Punta

Balneario. Argentina: length = 17 mm.. 9, Entodesma fretalis, Corral Bay, Chile: length =31 mm. 10,

Entodesma chilensis, Corral Bay. Chile: length = -22 mm. 11, Entodesma beana, Myrtle Beach. South

Carolina: length = 28 mm. 12, Mytilimeria nuttalli, Venice, California; length = 2i mm.

64 THE NAUTILUS

April 30, 1981

Vol. 95(2)

tacles; anterior few filaments of inner demi-

branch of gill fused with inner portion of palp

(Category II, Stasek, 1963); outer demibranch

of gill composed of a single, upturned lamella

(Type E, Atkins, 1937); Type IV stomach

(Purchon, 1958, 1960); simultaneous herma-

phrodites with large ova possessing numerous,

thick gelatinous coats.

Genus Lyonsia Turton, 1822

Figs. 1-4

Type Mya striata Montagu, 1815 ( =M. norwegica Gmelin,

1791).

1788 Mya Chemnitz, Conch. Cab. 10:345, pi. 170, figs. 1647-

1648. (non-binomial).

1802 Pandora Bosc, Hist. Nat. Coq. 2:243. Non Bruguiere,

1797.

1802 Pandore Bosc, Hist. Nat. Coq. 2:243, pi. 14, fig. 1.

(error for Pandora).

1822 Lyonsia Turton, Conch. Insul. Brit. p. 35, pi. 3, figs.

6-7.

1827 Magdala, Brown, lUustr. Recent Conch. Great Brit.,

pi. 11, figs. 1, 2 and 10.

1827 Hiatella Brown, Illustr. Recent Conch. Great Brit.,

pi. 16, figs. 26-27. Non Bosc, 1801.

1830 Tetragonoste Deshayes, Encycl. Method., Vers 3:590.

(vernacular name).

1833 Myatella Brown, Conch. Text-Book, p. 142, pi. 16.

figs. 12 and 30.

1833 Pandorina Scacchi, Osserv. Zool., p. 14, Non Borg

St. Vincent, 1827 (Protozoa).

1835 Osteodesma Deshayes, in Lamarck, Anim. s. vert., 2nd

Ed., 6:85, 129. Non Blainville, 1825.

1926 Eudorina Pascher, Arch. Protestenk. 53:470-471.

1969 Arerwlyonsia Nordsieck, Die europaeischen Meere-

smuscheln eis. Kapverden. Mittlemeer, Schwarzes Meer,

p. 156. (Type: arenosa Moller, 1842).

Shell elongate, inequilateral, posterior region

from umbones usually longer and tapering to a

truncated siphonal region; shell with siphonal

gape; typically a dense cover of foreign ma-

terial, usually sand, covering at least a portion

of the shell's exterior; shell radially ornamented

with numerous, small truncated spines; perio-

stracum thin with fine radial striations and

adherent mucoid strands emanating from man-

tle edge; small but prominent lithodesma; pris-

matic shell layer thin and lenticular and sheet

nacre layers well developed; ratio of distance

from umbo to anterior edge and umbo to poster-

ior edge usually around 1:2.5; anterior/posterior

shell axis parallel to body axis (measured from

dorsal edge of adductor muscles); mantle edge

and siphons thin and nonmuscular; band of nu-

merous, small darkly pigmented photoreceptor

organs present on exhalent siphon; arenophilic

mantle glands numerous, lining most of mantle

edge at regular intervals and secreting a mucoid

product into the periostracal groove and over

the periostracum; periostracal groove well

defined; unfused portions of mantle edge reveal

typical three-fold edge; pedal aperture long,

narrow and lacking internal rim; foot long,

laterally flattened, active with well developed

byssal gland producing only a few, fine byssal

threads; isomyarian to slightly heteromyarian;

adductor scars poorly delimited on shells;

shallow burrowers in fine sands or muds.

Entodesma Philippi, 1845

Figs. 5-13

Type Entodesma chilensis Philippi, 1845.

1818 Mya Lamarck, Anim. s. vert. 5:461. (in part).

1830 Tetragonoste Deshayes, Encycl. Method., Vers 2:590.

(vernacular name).

1835 Osteodesma Deshayes in Lamarck, Anim. s. vert.,

2nd Ed. 6:75, 84.

1845 Entodesma Philippi, Arch. Naturgesch. 2:52, 53.

1849 Tetragostea Herrmannsen, Index Genera Moll. 2:565.

1909 Agriodesma Dall, Proc. U.S. Nat. Mvs. 37:284.

Thick-shelled bivalves with a thick, often

brown or green, periostracum; valves commonly

crack when dried; lithodesma large; periostra-

cum often with radial striations; typically rock

crevice or algal holdfast dwellers that may con-

form to shape of nesting site; shell often with

byssal notch located posterio-ventrally; anter-

iorrposterior length ratio from umbones greater

than 1:2.5; adult shells often with thick, outer

granular homogeneous layer, always with a

weak prismatic and biphasic nacre; anterior/

posterior body axis not parallel to shell longi-

tudinal axis; mantle edge and siphons extremely

muscular; arenophilic radial mantle glands

usually present in juveniles where they open

distal to the periostracal groove; arenophilic

mantle glands may gradually be lost with

growth; inner mantle epithelium densely packed

with mucocytes; periostracal groove and mantle

folds poorly defined; siphons often brightly col-

ored and lacking photoreceptors; foot small,

cylindrical with well developed byssal gland pro-

ducing numerous thick, strong threads; pedal

Vol. 95(2)

April 30, 1981

THE NAUTILUS 65

gape small, circular with raised internal rim;

muscle scars usually well defined; slightly

heteromyarian with anterior adductor smaller

than posterior adductor and displaced ventrad;

some indication of temporary marsupium in

suprabranchial chamber.

Genus Mytilimeria Conrad, 1837

Fig. 14

Type Mytilimeria nutfalii Conrad, 1837.

1837 Mytilimeria Conrad. Journ. Acad. Nat. Sci. 7:246-

247, pi. 19, fig. 5.

Thin-shelled bivalves with rounded shells; um-

bones may be slightly recurved; periostracum

thin and often light golden-brown color; no

radial ornamentation but periostracum covered

with numerous small, crater like pores; usually

embedded within compound tunicates; perio-

stracum firmly attached to ascidian host and

often peels away when the clam is removed from

the tunicate; lithodesma short, squat;

anterior:posterior umbonal length ratio usually

less than 1:2.5; adult shells with thin

homogeneous layer, well-developed prismatic

layer and a biphasic nacre; anterior/posterior

body axis oblique to shell longitudinal axis;

mantle edge broad and flat with well developed

orbital musculature; mantle edge contains a

deep purple pigment; lacks mantle glands; si-

phons muscular with wide atrial diameters and

no photoreceptors; siphons with numerous api-

cally situated and brightly pigmented short

fringes, often appearing to match coloration of

host tunicate; inner mantle epithelium with a

dense array of mucocytes; foot very small, cylin-

drical with poorly developed byssal glands able

to produce only a few thin byssal threads; pedal

aperture very small, circular; heteromyarian

with anterior adductor small and displaced ven-

trad.

Entodesma beana (Orbigny, 1842)

new combination

Figs. 11. 13

1845 Lyonsia beana Orbigny, Sagra, Hist. Cuba, Moll. 2:

225, pi. 25, figs. 26-28.

1850 Lyonsia braziliensis Gould, Proc. Boston Soc. Nat.

Hist. 3:219.

1857 Osteodesma orbigny Fischer, Journ. Conchyl. 11:383,

pi. 11, figs. 7-8.

1928 Lyonsia beana Lamy, Journ. Conchyl. 72:2.58.

fa id

FIG. 13. Entodesma beana soft part morphology.

While still listing it as Lyonsia beana (sub-

genus Philippia), Abbott (1974) suspected that

this "may be an Enfodesyna." Moore (1969) noted

that the type for Philippina (placed within En-

todesma) is Lyonsia beana. Many characteris-

tics of this species immediately remove it from

Lyonsia and place it in the redefined genus En-

todesma. The overall shell shape is entodesmid;

that is, it is anteriorly gently tapered to a round-

ed edge with the umbo located very close to the

anterior of the shell. The posterior end of the

shell is broad and truncate and the anterior/

posterior length ratio form the umbo is close to

1:6. The periostracum is thick, brown and wrin-

kled in places (especially posteriorly), and there

is rarely a partial sand cover on the shell. The

ventral edge of the shell has a shallow byssal

notch. Juvenile shell consists of a thin prismatic

layer and a thick sheet nacre (Prezant, 1980b).

The apparent lack of a lenticular nacre in

juveniles is a rare modification of lyonsiid shells.

Larger specimens of E. beana possess a typical

biphasic nacre (i.e., composed of lenticular plus

sheet nacre). There are several weak radial

striations aligning the shell. Muscle scars are

well defined on the internal shell. The litho-

desma is long and narrow.

The mantle edge of E. beana is muscular with

dense bundles of oribtal muscles. The fourth

pallial artrium is extremely small and difficult to

discern but is located directly beneath the pos-

terior adductor muscle. Arenophilic mantle

glands line a part of the mantle edge in juve-

66 THE NAUTILUS

April 30, 1981

Vol. 95(2)

niles, usually along the posterior pedal gape and

the siphons, and open distal to the periostracal

groove. Specimens examined (NMNH) from

Cape Hatteras, North Carolina, southward to

the coast of Brazil, were found in algal or

seagrass beds, in gravel or associated with

sponges or coelenterates. Many of these

specimens had a partial sand cover near the

byssal notch or near the posterior shell region.

This sediment coat correlates well with the loca-

tion of the mantle glands.

The small, wormlike foot expands dorsally in-

to a distended region with a very large, circular

byssal orifice. The byssal groove runs almost the

entire length of the posterior side of the foot. A

small, circular pedal aperture is present and has

a distinct, raised internal rim.

E. beana is heteromyarian with a small

anterior adductor muscle located ventrally,

below the anterior part of the ctenidia. The

anterior adductor muscle is narrow and situated

in an oblique position along the ventral cur-

vature of the anterior shell edge. The posterior

adductor muscle is about twice as large as the

anterior adductor and is oval in sagittal section.

The former is situated well away from the shell

edge while the anterior adductor is located very

close to the shell edge.

The muscular siphons lack photoreceptors but

are well endowed with numerous, small ten-

tacles.

In one specimen the narrow suprabranchial

chamber was densely packed v/ith numerous,

large eggs. During the study this has also been

observed in E. chiiensis and E. saxicola. This

finding may be indicative of a temporary mar-

supium in some species of Entodesma.

Entodesma fretalis (Dall, 1915)

new combination

Figs. '.>. 11

1915 Lymsia fretalis Dall, Proc. U.S. Nat. Mus. 49:454.

The type locality for this species is the Straits

of Magellan at a depth of about 38 meters (Dall,

1915). The type description of the species cor-

responds with the generic redefinition offered

here and, indeed, Eydodesrrm fretalis and E.

chiiensis are quite similar. In all specimens

recently examined, shells are distinctly ento-

FIG. 14. Entodesma fretalis soft part morphology.

desmid. The valves are only slightly tapered

anteriorly but are broad and truncated poster-

iorly. The average umbo length ratio is 1:4.6,

the umbo being located very close to the an-

terior edge.

The periostracum is ornamented with several

raised radial striations and is usually thick and

brown, and extends beyond the shell edge (es-

pecially posteriorly). The shell proper is com-

posed of thin prismatic, thick lenticular, and

thick sheet nacre in juvenile specimens. Large

adult shells have not been examined ultrastruc-

turally. The lithodesma is large, usually about

1/5 the shell length.

The mantle edge is highly muscular, especially

with radial musculature. The inner mantle

epithelium is densely packed with mucocytes.

Many arenophilic radial mantle glands are pre-

sent in juveniles which open distal to the perio-

stracal groove. Secretion from these glads pene-

trates the periostracum, and there is sporadic,

partial sand adhesion on some shells. A small

fourth pallial atrium is present directly beneath

tlie posterior adductor muscle.

The foot is very small and appears to be dorso-

ventrally compressed in preserved specimens.

There is a very large byssal orifice and a well

defined byssal groove which runs almost to the

tip of the foot. The small, circular pedal aper-

ture has a raised internal rim.

Entodesma fretalis is heteromyarian with the

posterior adductor being about IV2 times the

Vol. 95(2)

April 30, 1981

THE NAUTILUS 67

size of the anterior adductor. The anterior ad-

ductor is also displaced ventrally so that the dor-

sal edge of the latter is aligned with the ventral

edge of the posterior adductor. Thus the body

axis is oblique to the shell longitudinal axis. The

anterior adductor is also compressed in the

anterio-posterior plane.

The siphons of this species are very muscular

and are apically covered with a dense array of

short, frilly tentacles. There are no photorecep-

tors on the siphons.

Dissection of several specimens revealed

densely packed ova within the suprabranchial

chamber similar to conditions found in En-

todesma beana and E. saxicola. The eggs seem

to align neatly along the branchial filaments.

Entodesma cuneata (Gray, 1828)

Fig. 7

1828 Anatina cuneata Gray, Spicilegia Zoologica 1:6, pi. 3,

fig. 12.

1843 Osteodesma cuneata Hanley, Cat. Recent Bivalve

Shells: 25.

1843 Osteodesma cuneata Deshayes. Treat, elem. Conch.

1:215, pi. 9, figs. 7-8.

1846 Lyonsia cuneata Orbigny, Voy. Amer. merid 5(Moll.):

518.

1856 Mytilimeria cuneata H. and A. Adams. Gen. Recent

Moll. 2:364.

1907 Lyonsia cuneata Mehdll and Standen, Mar. Moll. Scot-

tish Nation. Antarct. Exped., Trans. R. Soc. Edinburgh

46:151.

1909 Entodesma cuneata Dall, Shells Peru, Proc. U.S. Nat.

Mus. 37:259.

1914 Lyonsia cuneata Melvill and Standen. Ann. Mag. Nat.

Hist. 13(8): 136.

1928 Lyonsia (Entodesmu) cuneata Lamy, Journ. Conchyl.

72:256.

1951 Entodesma cuneata Carcelles and Williamson, Rev.

Inst. Nac. Inv. Cienc. Nat. 2:348.

1972 Entodesma cuneata Dell, Recs. Dominion Mus. 8(3):

29, fig. 23.

Dall, (1909), on the basis of shell characteris-

tics, was the first to place Lyonsia cuneata in

Entodesma. Soft parts have not been examined,

but shell ultrastructure (Prezant, 1981) appears

to substantiate this generic change. Large speci-

mens of E. cuneata have a thick brown perio-

stracum which is often frayed and wrinkled (es-

pecially posteriorly). The shells have a thick,

well developed granular homogeneous layer lo-

cated above a poorly developed prismatic layer

and a biphasic nacre. There is a large, recurved

lithodesma.

Dall (1910) synonymized Entodesma cuneata

and E. chilensis on the basis of reports of other

authors but retracted this synonymy in his

review of some Anomalodesmata (1915) where

he states that E. chilensis and E. cuneata are

"very different" shells. As Dell (1972) points out,

entodesmids are typically found nestled within

rocky crevices and their growth form conforms

to their surroundings. Thus species of En-

todesma can vary in shape according to their

habitat. However, distinct differences in length

to umbo ratios, and the broad, round posterior

margin in E. chilensis as compared to the long,

tapering, truncated siphonal margin in E.

cuneata, indicates these are separate species. A

detailed examination of soft parts oiE. cuneata

is still a necessity.

Entodesma patagonica (Orbigny, 1846)

Fig. 8

1846 Lyonsia patagonica Orbigny, Voy. dans I'Amer. Merid.

5:517, pi. 81, figs. 13-14.

1915 Lyonsia patagonica Dall, Proc. U.S. Nat. Mus. 49:

454.

1928 Lyonsia patagonica Lamy, Journ. Conchyl. 72:258.

1944 Lyonsia patagonica Carcelles, Rev. Mus. La Plata

3:292, pi. 14, fig. 113.

1967 Lyonsia patagonica Castellanos, An. Com. Inv. Cient.

Buenos Aires 8:280, pi. 24, figs. 11-12.

1972 Entodesma patagonica Dell, Recs. Dominion Mus.

8(3):31, fig. 26.

In his 1915 work on the Anomalodesmata of

the west coast of America, Dall again wrote that

Lyonsia patagonica "is probably an Entodesma".

Dell (1972) examined the type specimens at the

British Museum of Natural History and confirm-

ed this diagnosis on the basis of gross shell mor-

phology. Juvenile shells of this species have a

thin prismatic layer and a biphasic nacre. There

is a long, thin lithodesma. The umbonal length

ratio of this species is about 1:3.8 and thus fits

the Eyitodesma pattern well. The soft parts of

this species also confirm its identity as an En-

todesma. The mantle edge and siphons are

highly muscular. There are no photoreceptors.

Mantle glands are numerous in juveniles and

open distal to the periostracal groove. A small

fourth pallial atrium is present below the

68 THE NAUTILUS

April 30, 1981

Vol. 95(2)

posterior adductor. In this species the fourth

atrium has a slightly raised internal rim.

The foot is small and cylindrical, and has a

very large byssal orifice. The pedal aperture is

small and circular and has a well defined raised

internal rim.

The species is slightly heteromyarian with a

large, circular, posterior adductor muscle (in

sagittal section) and a smaller, ovoid, anterior

adductor which is slightly ventrad.

DISCUSSION

The taxonomic development of the family

Lyonsiidae reflects the gradual accumulation of

data on these bivalves and the incorporation of

these data into the groups' systematics. Dall

(1903) originally placed only the genus Lyonsia

in the lyonsiids with two subgenera: Lyonsia s.s.

and Entodesma, with the latter divided into two

sections, Allograma (Dall, 1903) and Philippina

(Dall, 1900). In 1915, Dall gave Allograma sub-

generic status and added Agriodesma as a sec-

tion of the subgenus Entodesma. Conrad (1837)

thought Mytilimeria was allied with the my-

tilids but Dall (1915) tentatively placed the

genus Mytilimeria in the Lyonsiidae. Habe

(1952) gave generic status to Allograma with

Bentholyonsia as a subgenus. Habe (1977) divid-

ed the Japanese Lyonsiidae into four genera:

Lyonsia, Allograma. Bentholyonsia and Agrio-

desma. It is apparent thai Allograma, described

by Habe (1977) and Dall (1903) as being very

thin shelled and having fine radial striations

over the shell, short siphons with numerous

fringes or tentacles, anterior-posteriorly

elongated shell with a circular anterior end and

an elongated posterior end with a siphonal gape,

is not separable from Lyonsia as here defined.

The umbones are also situated close to the mid-

point of the longitudinal axis of the shell (um-

bonal length ratio of about 1:1.2). Allograma

certainly does not belong as a subtaxon of the

thicker shelled, more heterogeneously shaped

and more posteriorly drawn out Entodesma and

characteristics oi Allograma are not sufficient

to warrant generic status. Taxonomic charac-

teristics of species oi Allograma overlap exten-

sively with characteristics of Lyonsia and these

bivalves should therefore be transferred to the

latter genus.

A similar situation exists for Bentholyonsia,

originally described by Habe (1952). Habe (1977)

described this genus as very thin shelled, ovoidal

ellipsoidally shaped, with a circular anterior

end, and a straight wider posterior end with a

siphonal gape, having a shell with fine radial

ribs, a glossy shell interior, and found living on

fine sands. Moore (1969) maintains subgeneric

status for Bentholyonsia on the basis of radially

arranged granules on the shell's exterior, a lack

of radial ribs, a posterior shell gape and a large

lithodesma. The apparent conflict concerning

radial ornamentation may indicate poor defini-

tion of terms, condition of material, or a vari-

able character not valid in diagnosis at or above

the species level. The overall definition never-

theless fits the genus Lyonsia well. The umbo is

situated centrally in Bentholyonsia and approx-

imates a 1:1 umbonal length ratio. Species of

Bentholyonsia should be transferred to Lyonsia.

Species of Agriodesma on the other hand

should be allocated to Entodesma. This relation-

ship was recognized by Abbott (1974) when he

placed Agriodesma as a subgenus oi Entodesma.

The umbonal length ratios of Japanes species of

Agriodesma. described by Habe (1977) range

from 1:3.8 to 1:5.6, obviously within the Ento-

desma range. Habe (1977) defined individuals in

this "genus" as medium to large in size, having

an anteriorly situated umbo, radial ribbing of

the shell, thick brown periostracum in larger

specimens, commonly ovoidal ellipsoid, poster-

ior end of shell wide and straight, having a

glossy interior, and often living among the roots

of seaweeds. This same author tentatively syno-

nymized E. truncatissima with A. naviculum

(A. Adams and Reeve, 1850).

The use of subgenera or sections for lyonsiids

by many early authors (Lamy, 1928; Dall, 1909,

Thiele, 1935) and continued by Keen (1971) and

Abbott (1974) in their comprehensive volumes

on American molluscs, breaks the family down

into several minor components which only serve

to confuse the taxonomy. These subdivisions are

Imsed upon variable characteristics, such as

periostracal color and surface topography (i.e.,

the subgenus Agriodesma Dall, 1909 of the

Vol. 95(2)

April 30, 1981

THE NAUTILUS 69

genus Entodesma. is distinguished from Ento-

desma s.s. by its coarse periostracum, and the

subgenus Phlycticoncha Bartsch and Rehder,

1940 ( = Phlyctiderma. 1939) may have a zigzag

coloration of the thin periostracum). The vari-

ability in color morphs and periostracal or-

namentation or thickness, which are often worn

smooth due to abrasion or growth habits, render

these distinctions unreliable. Within the Lyon-

siidae, divisions between the three marine

genera are clear, and the variability within a

given species sufficient to warrant the disuse of

subgeneric taxa and use only of generic and

specific ranks.

Definitions offered in this paper should be ap-

plicable to all marine lyonsiids. It is important to

note that there is a strong association between

internal anatomy, ecology, and shell structure;

for example, the overall modification of shell

gape corresponds well with the degree of he-

teromyarianism and changes of habitat. As in

mussels, increased dependence upon a byssal

system results, in evolutionary terms, in ex-

panded importance of the posterior region of the

bivalve, i.e., the siphonal area and associated

shell and structures. Increased stabilization and

decreased exposure resulting from firm byssal

attachment within crevices resulted in a more

pronounced elaboration of the posterior region

of species of Entodesma than in Lyonsia. Yonge

(1952) cites these differences as extending inter-

nally to include the adductor muscles, and

leading, in part, to the more pronounced hetero-

myarian condition found in Entodesma. The

elaboration of the siphonal area has resulted in a

hypertrophy of the active posterior region. Par-

tially because of the endosymbiont habit that

results in external well distributed support,

Mytilimeria nuttalli has assumed a circular or

globular shape.

Taxonomic definitions of the marine genera

offered here reveal a plasticity of the Lyonsiidae

that partially accounts for their phylogenetic

and ecologic divergence. The slender shell and

relatively active pedal system of Lyonsia are

well adapted for burrowing. The weak byssal

system is supplemented by the extraneous sand

coat on their shells, and this adhesion is sup-

ported by the mucoprotein produced by the

arenophilic mantle glands (Prezant, 1979a). The

mucoid secretion adheres firmly to the perio-

stracum and is entangled among the numerous

shell spinules (Prezant, 1979b). The high nacre

content of the shell allows the valves to remain

thin yet strong and fracture resistant. Light-

shadow reactive siphonal photoreceptors serve

the bivalve in detecting large predators in

shallow waters, and also in the detection of

light-dark cycles. The adaptive significance of

the shell ultrastructure is discussed elsewhere

as is the role and phylogenetic implications of

the arenophilic radial mantle glands (Prezant,

1980; 1981).

Many species of Entodesma have assumed a

life-style nestled within crevices along a rocky

intertidal shoreline. These bivalves are often ex-

posed to harsh physical stresses from tidal im-

pacts and have developed a thick periostracum

and shell and an energetically inexpensive, frac-

ture resistant, homogeneous layer (Prezant,

1981). Thick byssal threads help secure the ani-

mal in place. A reduction in the number of are-

nophilic radial mantle glands occurs with

growth and increased shell thickness. The nest-

ling habit probably affords protection from

some potential predators. Entodesma lacks

photoreceptors but the nestling habits may

leave the bivalve in poorly lit areas anyway.

Mytilimeria lacks photoreceptors, an active

byssus, arenophilic radial mantle glands, and

possesses a very thin shell. These characteristics

fit the bivalves well in their endosymbiont habit.

The enveloping ascidian has coincidentally

assumed the role of stablizing, protecting and

camouflaging the bivalve. In turn Mytilimeria

has developed wide siphonal atria, cryptic col-

oration of siphons to match their host test, and a

physically adhesive periostracum which binds

the bivalve tightly to the tunicate.

Yonge (1952) believed that the byssus of adult

Mytilimeria nuttalli had regressed to the point

of nonfunction, although he did note byssi in

juveniles. This was a reasonable assumption for

adult clams since it is difficult to find even rem-

nants of byssi within the tunicate. Furthermore

there appears to be little need of a byssus for a

bivalve dwelling within a sessile ascidian. Adult

M. nuttalli, however, when placed outside their

70 THE NAUTILUS

April 30, 1981

Vol. 95(2)

hosts will produce a few thin byssal threads

reminiscent of those in Lyonsia. Both of these

genera have developed other extraneous modes

of stabilization. Entodesma, on the other hand,

exposed to the rigors of intertidal, often rocky

shorelines, has evolved a system of numerous,

strong byssal threads and a thick shell and

periostracum.

Coe (1943) in a discussion of functional her-

maphroditism among bivalves noted that most

hermaphrodites are also brooders. In three spe-

cies of Entodesma (saxicola, chiieyisis and

fretalis) numerous ova have repeatedly been

found within the suprabranchial chamber of the

gills. It is uncertain if this represents true

brooding, or is the result of some environmental

or preservation artifact that caused expulsion of

ova into this cavity. Eggs are exceptionally

large in some Anomalodesmata (Morgan and

Allen, 1976), and larvae may have a short larval

existence. Brooding seems reasonable since

many species of Entodesma live in a rigorous

environment in which larvae, even if present in

the plankton for a short time, may quickly be

washed into a zone without appropriate sub-

strata for settlement. If released in a late stage

of development, larvae may be able to settle

quickly out of the water column within a single

tidal cycle and remain within a suitable environ-

ment. Eggs examined in these three species,

however, did not show any signs of develop-

ment, and, indeed, may not have been fertilized.

It may be possible that the suprabranchial

chamber acts as a holding chamber prior to in-

ternal fertilization. In this way gametes may not

be washed away prior to fertilization. The repro-

ductive and life cycles of species of Entodesma

have yet to be examined.

Morrison (1943) described Guianadesma

simiosum and placed this freshwater bivalve in

the Lyonsiidae. Morrison (1943) reported G.

siniiosum as having a small, cylindrical foot,

with a large byssus gland and a large byssal

orifice; being slightly heteromyarian with a

larger posterior adductor; having fused mantle

lobes except for the siphonal and pedal aper-

tures; with papillose siphons; well developed

brown periostracum; small, rhomboidal, inequi-

valve shell; being edentulous; having rounded

anterior end and truncate posterior end; raised

radial striations; umbones about one-third from

anterior end; and internal ligament lacking a

lithodesma. These molluscs were found attached

by byssal threads to rocks in midstream of the

Cuyuni River, Guyana. Specimens personally

examined (ANSP) appeared "Entodesma" like,

as did the shell description offered by Morrison

(1943). Muscle scars were well imprinted on the

shell interior, and the umbonal length ratio was

about 1:3.5. The periostracum appeared clean

(i.e., no adhering sediments) in specimens ex-

amined including the type specimens (NMNH -J.

P. E. Morrison, personal communication). The

gonadal and gill structures, presence of

arenophilic mantle glands, and shell ultrastruc-

ture are presently unknown and these must be

examined prior to final taxonomic categoriza-

tion.

The evolutionary modifications and adapta-

tions within the Lyonsiidae have resulted in

three distinct marine genera, readily separable

and easily characterized, and well suited to the

diverse habitats in which they occur. Because of

the distinct tripartite divergence revealed in

this taxonomic analysis, subgeneric taxa for the

marine Lyonsiidae should be abandoned.

ACKNOWLEDGMENTS

Thanks are extended to the following in-

dividuals for the loan or donation of many speci-

mens used in this study: Dr. J. A. Allen, Univer-

sity Marine Biological Station Millport; Dr. F.

Bernard, Pacific Biological Station; Dr. K. Boss,

Museum of Comparative Zoology, Harvard Uni-

versity; Dr. D. D. Chivers and Dr. W. Lee,

California Academy of Sciences; Dr. G. Davis,

Academy of Natural Sciences of Philadelphia;

R. Dillon, University of Pennsylvania; R. Fay,

Pacific Bio-Marine Labs., Inc.; Dr. R. Fernald,

Friday Harbor Laboratories, University of

Washington; C. Gallardo, Instituto de Zoologie,

Universidad Austral de Chile; Dr. J. H. McLean,

Los Angeles County Museum of Natural His-

tory; Dr. J. Rosewater, National Museum of

Natural History, Smithsonian Institution; and

Dr. R. Virnstein. Harbor Branch Foundation,

Inc.

Vol. 95(2)

April 30, 1981

THE NAUTILUS 71

I am most grateful to Drs. R. T. Abbott, M. R.

Carriker, F. C. Daiber, R. E. Hillman, N. W.

Riser, and J. Rosewater for encouragement and

critical review of manuscript. Thanks also to F.

Prezant for encouragement and help in collect-

ing many of the live specimens used in this study

and P. Savage for typing the manuscript.

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Abbreviations Used in Drawings

aa- anterior adductor muscle

d -digestive diverticula t

e-exhalent siphon

f-foot

fa -fourth pallial aperture

i - inhalent siphon

id - inner demibranch

ip- inner labial palp

k- kidney

ud- outer demibranch

op -outer labial palp

ov - ovary

p;i- posterior adductor muscle

pc- pericardial chamber

pg- pedal gape

r- rectum

t- testis

A NEW GENUS OF TURBINELLIDAE (GASTROPODA: PROSOBRANCHIA),

WITH THE DESCRIPTION OF A NEW SPECIES

FROM THE CARIBBEAN SEA

James F. Quinn, Jr.

Florida Department of Natural Resources

Marine Research Laboratory

100 Eighth Ave., S.E.

St. Petersburg, FL 33701

ABSTRACT

Cyomesus, a new genus, is proposed to receive four species of Turhinellidae

previously assigned to Mesorhytis Meek. 1876, Teramachia Kuroda. 1931. and

Benthovoluta Kuroda and Habe, 1950. All four species are reviewed, and a new

species, Cyomesus aratiunculus, is described from, near the Virgin Islands.

Investigations of the tropical Atlantic and

eastern Pacific deep-sea by the University of

Miami have resulted in one of the most exten-

sive collections of tropical deep-sea mollusks in

the world. Most of this remarkable assemblage

remains to be examined. These collections con-

tain specimens of three of the four western

Atlantic species of Cyomesus, a previously

undescribed genus. Since the species here

assigned to Cyomesu^s have been the subject of

much nomenclatural confusion, a review of all

species is presented. The taxonomic history of

the genus is reviewed and the relationships of

Cyomesus to other genera within the Turhinel-

lidae are briefly discussed.

Specimens on which this paper was based are

housed in the Invertebrate Research Collection

of the Rosenstiel School of Marine and Atmos-

pheric Science, University of Miami (RSMAS),

designated by the abbreviation UMML, the Na-

tional Museum of Natural History, Smithsonian

Institution (USNM), and the Museum of Com-

parative Zoology, Harvard University (MCZ).

Family Turhinellidae Swainson, 1840

Subfamily Ptychatractinae Stimpson. 1865

Cyomesus gen. nov.

Mesorhytis: Dall, 1889a: 172; 1889b; 112; 1890; 317. -John-

son, 1934; 127.-Cernohorsky, 1970; 51; 1972; 218. {Non

Mesorhytis Meek, 1876: 356, 364).

Prodallia Bartsch, 1942; 12 (partim).

Teramachia: Weaver and duPont, 1970: 176 (partim). -

Bayer. 1971: 195. -Abbott, 1974; 243. {Non TeraTnachia

Kuroda. 1931; 45).

Vol. 95(2)

April 30, 1981

THE NAUTILUS 73

Benthmmluta: Rehder, 1972: 7, 8 (parHm). -Cernohorsky,

1973: 126 (parUm).

Type-species -Fasciolaria (Mesorhytis) Meeki-

ana Dall, 1889; herein designated.

Gencfer- Masculine.

Description -SheW fusiform, elongate, of

moderate size; spire extended, 40-50% of total

shell height. Whorls broadly rounded peripher-

ally, constricted anteriorly; siphonal canal rela-

tively short, broad, slightly reflexed. Sculpture

on early whorls of strong axial ribs, usually be-

coming obsolete on later whorls; spiral sculpture

present or absent. Aperture lanceolate, outer lip

slightly flared anteriorly in adult. Columella

slightly flexed, with 3 high, thin, oblique plaits,

posteriormost strongest; parietal wall with very

thin glaze. Operculum small, thin, spatulate,

slightly curved, with terminal nucleus. Radula

triserial; rhachidian multicuspid, with saddle-

shaped base; laterals with elongate base and

distal, clawlike cusp.

Remarks -The species here assigned to

Cyomesus have been placed previously in

Mesorhytis Meek, 1876, Teramachia Kuroda,

1931, and/or Benthovoluta Kuroda and Habe,

1950. Teramachia has usually been accepted as

a member of the Volutidae. The uniserial radula

of the type-species, T. tibiaeformis Kuroda,

1931 (illustrated in Habe, 1952), indicates close

relationship with Calliotectum Dall, 1890, a

volutid (Rehder, 1972; Cernohorsky, 1973).

Since Bayer (1971) showed that Mesorhytis

meekiana Dall, 1889, and Terarmackia chaunax

Bayer, 1971, are turbinellids, Teramachia is

eliminated as an appropriate genus for the pre-

sent group.

Mesorhytis was erected by Meek (1876) for a

fusiform gastropod fossil from the Cretaceous of

Missouri. An examination of the type series of

M. gracilenta Meek, 1876, showed that Cyo-

mesiis differed in having less prominent axial

sculpture, the whorl periphery more anterior,

the columella distinctly twisted to the left

anteriorly (not straight), and the columellar

plaits more lamelliform, with the posterior (not

middle) plait most prominent. However, in view

of the general similarity of Mesorhytis and

Cyomesus, it is quite possible that Mesorhytis is

turbinellid rather than fasciolariid as it has been

regarded by most authors (Meek, 1876; Dall,

1889a, 1889b, 1890; Thiele, 1929; Cernohorsky,

1970, 1972) and may be a precursor of Bentho-

voluta or Surculina Dall, 1908.

Benthovoluta was introduced by Kuroda and

Habe (1950) for Phenacoptygma? kiiensis

Kuroda, 1931. Kuroda (1965) and Rehder (1967)

showed that Benthovoluta was turbinellid in af-

finity rather than volutid. Rehder (1967) also

commented on the relationships of Metzgeria

Norman, 1879, Ptychatractus Stimpson, 1865,

and Surculina Dall, 1908, grouping them

together with Benthovoluta. In a subsequent

paper, Rehder (1972) discussed "Teramachia"

barthelowi (Bartsch, 1942) and concluded that it

should be assigned to Benthovoluta. He went on

to mention Bayer's (1971) discussion of the Car-

ibbean species Mesorhytis meekiana. M. costatus

Dall, 1890, and Teramachia chaunax, and in-

timated that these species constituted a distinct

group of their own, but stopped short of sepa-

rating them from Mesorhytis. Cernohorsky

(1973), apparently unaware of Rehder's (1972)

paper, independently placed Teramachia

barthelowi in Benthovoluta. but, unlike Rehder,

also included T. chaunax. Mesorhytis meekiana,

and M. costatus. The relatively large shell with

rounded whorls, very long, straight siphonal

canal, and low, rounded columellar plaits of Ben-

thovoluta distinguish it from Cyomesus, and, in

my opinion, exclude "Teramachia" barthelowi

from Beyithovoluta.

I thus include the following genera in the

Ptychatractinae in accordance with Rehder

(1967) and Cernohorsky (1973) and with the

changes involving Mesorhytis and Cyomesus

discussed above: Ptychatractus Stimpson, 1865;

Metzgeria Norman, 1879; Mesorhytis Meek,

1876; Benthovoluta Kuroda and Habe, 1950;

Surculina Dall, 1908; Cyomesiis gen. nov.; and

Ceratoxancu^ Kuroda, 1952 (fide Cernohorsky,

1973). Although problematical, the following

fossil genera might also be considered turbinel-

lid: Paleofusimitra Sohl, 1963, Mitridomus

Sohl, 1963, and Fusimitra Conrad, 1855.

Cyomesus meekianus (Dall, 1889)

Fig. 1

Fa-sciolaria (Mesorhytis) Meekiana Dall, 1889a: 172, pi. 36,

fig. 7; 1889b: 112, pi. 36, fig. 7.

Fnsciolari.a (Mesorhytis) meekiana: Johnson, 1934: 127.-

Rehder. 1972: 8.

74 THE NAUTILUS

April 30, 1981

Vol. 95(2)

Mesorhytia Tneekiana: Cernohorsky, 1970: 52; 1972: 218.

Teramachia meekiana: Bayer, 1971: 197, figs. 54 (left), 5.5

D-E.

Benthovoluta meekiana: Cernohorsky, 1973: 127, fig. 2.

Description -See Bayer, 1971.

Lectotype -USNM 86970; herein designated.

Length 15.4 mm; width 5.2 mm.

Type-locality -BLAKE sta. 100, off Morro

Light, Havana, Cuba, 732 m; herein restricted.

Material examined -BLAKE sta. 100, off

Morro Light, Havana, Cuba, 732 m; 1 spec,

USNM 86970 (lectotype); 1 spec, USNM 784568

(paralectotype).- BLAKE sta. 16, 23°irN,

82°23'W, 534 m; 1 spec, MCZ 7243 (paralec-

totype). - BLAKE sta. 20, 23°02.5'N, 83°11'W,

402 m; 1 spec, MCZ 7242 (paralectotype). -

PILLSBURY sta. P-1225, 17°42.5'N, 77°58'W,

457-558 m; 1 spec, UMML 30-8260.

Remarks - Cyomestis meekianus remains a

very rare species, known only from the speci-

mens cited above. The range of this species in-

cludes the three BLAKE stations along the

northwest coast of Cuba and the single PILLS-

BURY station southwest of Jamaica. The

PILLSBURY specimen is the largest known for

this species, measuring 26.0 mm in length.

Cyomesus chaunax (Bayer, 1971)

Fig. 3

Teramachia chaunax Bayer, 1971: 198, figs. 54 (right), 55

R-C. - Rehder, 1972: 8. -Abbott, 1974: 243.

Benthovoluta chayiuix: Cernohorsky, 1973: 127.

Description -See Bayer, 1971.

Holotype -USNM 701216. Length 28.1 mm;

width 8.9 mm.

Type-locality -RIY JOHN ELLIOTT PILLS-

BURY sta. P-904, 13°45.5'N, 61°05.7'W, 201-

589 m.

Material examine;/- PILLSBURY sta. P-904,

13°45.5'N, 61°05.7'W, 201-589 m; 1 spec,

USNM 701216 (holotype).- COLUMBUS ISE-

LIN stations in Tongue of the Ocean, Bahamas:

CI-80, 23°54'N, 77°04'W, 1244 m; 1 spec,

LTVIML 30-8261. -CI-79, 23°5rN, 76°51'W,

1289 m; 2 spec, UMML 30-8262. -CI-151,

23°52.2'N, 76°48.5'W, 1315 m; 1 spec, UMML

30-8263. -CI-363, 23°51.6'N, 76°51.9'W,

1324-1315 m; 1 spec, UMML 30-8264.-

CI-156, 23°44.4'N, 76°48.3'W, 1334 m; 1 spec,

UMML 30-8265. -CI-368, 23°43.2'N,

76°50.5'W, 1352-1342 m; 1 spec, UMML 30-

8266.-CI-252, 23°38.5'N, 76°47.8'W, 1322-

1332 m; 1 spec, UMML 30-8267. -CI-158,

23°30.7'N, 76°56.8'W, 1317 m; 1 spec, UMML

30-8268. -CI-14, 23°33'N, 77°09'W, 1246 m; 1

spec, UMML 30-8269. -CM63, 23°31.6'N,

77°08.3'W, 1342 m; 1 spec, UMML 30-8270.-

CI-47, 23°42'N, 77°08'W, 1372 m; 1 spec,

UMML 30-8271. -CI-54, 23°54'N, 77°13'W,

1298 m; 2 spec, UMML 30-8272. -CI-55,

23°57'N, 77°18'W, 1353 m; 1 spec, UMML

30-8273. -CI-303, 23°54.8'N, 77°18.4'W,

1390-1389 m; 2 spec, UMML 30-8274.-

CI-365, 23°51.2'N, 77°16'W, 1372 m; 1 spec,

UMML 30-8275. -CI-165, 24°04.7'N,

77°22.3'W, 1426 m; 1 spec, UMML 30-8285.-

CI-406, 23°57.3'N, 77°20.8'W, 1408-1399 m; 1

spec, UMML 30-8286.

Remarks -This, the most recently described

species of Cycmiesus, is now the best known. The

present material considerably extends the range

of the species to the north and west. However, it

is recorded from two areas, the Tongue of the

Ocean, Bahamas, and St. Lucia, with no mate-

rial from in between, although U.S. Government

and University of Miami ships have made nu-

merous collections within that area. Specimens

of C. chaunax have not been discovered from

any of the other Bahamian deep-water basins,

although not all of the material collected from

Exuma Sound has been sorted. The TOTO speci-

mens of C. chaunax show that the species is

rather conservative morphologically. Most of

these specimens are somewhat more inflated

than the type but not exceedingly so. One speci-

men is 55 mm long, making C. chaunax the

largest species of the genus.

Cyomesus costatus (Dall, 1890)

Fig. 2

Fasciolaria (Mesorhytis) costatun Dall, 1890: 317, pi. 5,

fig. 5.

Mesorhytis costattis: Cernohorsky, 1970: 52. -Rehder.

1972: 8.

Teramachia costatus: Bayer. 1971: 197.-Abbott, 1974:243.

Benthovoluta costata: Cernohorsky. 1973: 129.

Description -See Dall, 1890.

Holotype-\JSNM 96507. Length 13.8 mm;

width 4.5 mm.

Vol. 95(2)

April 30, 1981

THE NAUTILUS 75

FIGS. 1-5. 1, Cyomesus meekianus (Dull. li;89). Lectotype, USNM 86970. 154 mm. 2, Cyomesus costatus (Dall, 18901-

Holotype. USNM 96507. IS. 8 nun. 3, Cyomesus chaunax (Bayer. 1971). Holotype. USNM 701216. 28.1 mm. 4, Cyomesus

aratiunculus sp. nov. Holotype, USNM 784594. 29.0 mm. 5, Cyomesus barthelowi (Bartsch. 191,2). Holotype. USNM238JM,

27.5 mm.

Type-locality -ALBATROSS sta. 2751,

16°54'N, 63°12'W, 1256 m.

Material examined-See Holotype (only

known specimen).

Remarks -Oi the four Caribbean species of

Cyomesus, C. costatus is the most uncharac-

teristic. However, its strongly convex whorls

are similar to the early whorls of C. meekianus,

and its other characteristics are so similar to the

other Cyomesus species that I have little doubt

C. costatus belongs in this group.

Cyomesus aratiunculus sp. nov.

Fig. 4

Description- Shell elongately fusiform,

strong, coarsely sculptured. Apical whorls lost,

6V2 whorls remaining. Whorls with low, weak

axial folds evident only from above to just below

periphery, separated from each other by some-

what wider interspaces. Numerous (41 on last

whorl) irregular, crowded, unequal spiral

threads covering whorls from suture to tip of

anterior canal. Suture indistinct. Aperture nar-

rowly lanceolate; outer lip simple; columella

twisted to left anteriorly, with 3 oblique,

lamelliform plicae, increasing in size from

anterior to posterior; parietal wall without

callus. Animal unknown.

Holotype -VS'NM 784594. Length 29.0 mm;

width 9.3 mm.

Type-locality -RIV JOHN ELLIOTT PILLS-

BURY sta. P-984, 18°26.4'N, 63°12.6'W, 430 m.

Material examined-See Holotype (only

known specimen).

76 THE NAUTILUS

April 30, 1981

Vol. 95(2)

Remarks -In general shape and size, Cyome-

siis aratiunculus is extremely similar to C.

chaunax and C. meekianus. The axial folds

restricted to the periphery and the persistent

spiral sculpture immediately distinguish C. ara-

tiunculus from the other species.

Cyomesus barthelowi (Bartsch, 1942)

Fig. 5

Prodallia barthelowi Bartsch, 1942: 12, pi. 2, fig. 2.

Teramachia barthelowi: Weaver and duPont, 1970: 177, pi.

75, figs. C, D.-Bayer, 1971: 196-198.

"Teramachia" barthelowi: Rehder, 1972: 7.

Benthovoluta barthelowi: Rehder, 1972: 8. -Cernohorsky,

1973: 127.

Description- See Bartsch, 1942; Weaver and

duPont, 1970.

Holotype -US^M 238444. Length 27.5 mm;

width 8.0 mm.

Type-locality- ALBATROSS sta. 5425, off

Cagayan Island, Sulu Sea, Philippines, 905 m.

Material examined -See Holotype (only

known specimen).

Remarks -I am placing this species in Cyome-

sus. However, the unique axial sculpture of

deeply incised grooves, presence of two instead

of three columellar plicae, and geographic isola-

tion from the Caribbean species may indicate a

need for a separate subgenus to accommodate

C. barthelowi. Soft parts of C. barthelowi must

be examined before a satisfactory solution can

be reached.

ACKNOWLEDGMENTS

I am grateful to Dr. Joseph Rosewater of the

USNM for his cooperation during my visits to

the museum, for making photographs of some

types, and loaning specimens without which this

paper could not have been completed. I thank

Mr. Fred Collier for loaning the syntypes of

Mesorhytis gracilenta contained in the paleon-

tological collections of the USNM. Dr. Gilbert L.

Voss provided access to the collections of

RSMAS, University of Miami. Some of the

specimens contained within these collections

were obtained during the University of Miami-

Deep Sea Biology Program under the direction

of Drs. Voss and F. M. Bayer. This paper con-

stitutes Contribution 135 of that program.

Cruises of R/V COLUMBUS ISELIN to the

Tongue of the Ocean, Bahamas, were supported

by National Science Foundation Grant OCE-

73-06639-A02, Dr. C. Richard Robins, Prin-

cipal Investigator. W. G. Lyons and D. K. Camp

kindly commented on this paper, and Sally D.

Kaicher provided the photographs.

LITERATURE CITED

Abbott, R. T. 1974. American Seashells. 2nd Ed. Van

Nostrand Reinhold Co., New York, 663 pp.

Bartsch, P. 1942, Some deep-sea Philippine volutids. The

Nautilus 56(1):9-13.

Bayer, F. M. 1971. New and unusual mollusks collected by

R/V JOHN ELLIOTT PILLSBURY and R/V GERDA in

the tropical western Atlantic. Bull. Mar. Sci. 21(1):

111-236.

Cernohorsky, W. 0. 1970. Systematics of the families Mitri-

dae and Volutomitridae (Mollusca: Gastropoda). Bull.

Auckl. Inst. Mus. 8:1-190.

1972. A taxonomic evaluation of recent and fos-

sil non-mitrid species proposed in the family Mitridae

(Gastropoda: Mollusca). Rec. Auckl. Inst. Mus. 9:125-194.

. 1973. The taxonomy of Benthovoluta hilgendcrrfi

(von Martens) and allied turbinellid genera (Mollusca:

Volutacea). Rec. Auckl. Inst. Mus. 10:123-131.

Conrad, T. A. 1855. Observations on the Eocene deposit of

Jackson, Mississippi, with descriptions of thirty-four new

species of shells and corals. Proc. Acad. Nat. Sci. Phila.

7(7):257-263.

Da]l, W. H. 1889a. Reports on the Mollusca. Part II. Gastro-

poda and Scaphopoda. Reports on the results of dredg-

ing .. . in the Gulf of Mexico (1877-78) and the Caribbean

Sea (1878-80), by the U.S. Coast Survey steamer "Blake"

. . . Bull. Mus. Com.p. ZooL. Harv. 18:1-492.

1889b. A preliminary catalogue of the shell-

bearing marine mollusks and brachiopods of the south-

eastern coast of the United States. Bull. U. S. Natl. Mus.

37:1-221.

1890. Preliminary report on the collection of

Mollusca and Brachiopoda obtained in 1887-88. Scientific

results of explorations by the U.S. Fish Commission

steamer "Albatross". No. VII. Proc. U. S. Natl. Mus.

12:219-362.

1908. The Mollusca and the Brachiopoda. Re-

ports on the scientific results of the expedition to the

eastern tropical Pacific ... by the U.S. Fish Commission

steamer "Albatross" . . . Bull. Mus. Comp. ZooL, Han.

43:205-487.

Habe, T. 1952. Pholadomyidae, Clavagellidae, Pandoridae,

Juliidae and Condylocardiidae in Japan. In: T. Kuroda

(ed.). Illustrated Catalogue of Japanese Shells, 1(18):

121-132.

Johnson, C. W. 1934. List of marine Mollusca of the Atlan-

tic coast from Labrador to Texas. Proc. Bo.^t. Sac. Nat.

Hist. 40:1-204.

Kuroda, T. 1931. Two new species of Volutacea. Venus

3(l):45-49.

1952. On an interesting new genus of gastropod

Mollusca from the sea of Kii Peninsula. Publ. Seto Mar.

Biol. Lab. 2(2):69-71.

Vol. 95(2)

April 30, 1981

THE NAUTILUS 77

1965. On the generic position of Benthovoluta

(Gastropoda). Venus 24(l):50-.52.

Kuroda, T. and T. Habe. 1950. Volutidae in Japan. In: T.

Kuroda (ed.), lUustrated CntaUigue of Japanese Shells

l(5):31-38.

Meek, F. B. 1876. A report on the invertebrate Cretaceous

and Tertiary fossils of the Upper Missouri Country. Rep.

U. S. Geol. Sum. Ten: 9: Ixiv + 629.

Norman, A. M. 1879. The Mollusca of the fjords near Ber-

gen. Joum. Conchyl. 2:8-77.

Rehder, H. A. 1967. A new genus and two new species in the

families Volutidae and Turbinellidae (Mollusca: Gastro-

poda) from the western Pacific. Par. Sci. 21(2):182-187.

1972. Some notes on the genus Teramachia

(Volutidae: Calliotectinae). Velige.r 15(1):7-10.

Sohl, N. F. 1963. New gastropod genera from the late Upper

Cretaceous of the east Gulf Coastal Plain. Joum. Paleont,

37(4):747-757.

Stimpson, W. 1865. On certain genera and families of zooph-

agous gasteropods. Amer. Joum. Conch. 1:55-64.

Swainson, W. 1840. A Treatise on Malacology: or the nat-

ural classification of Shells and Shellfish. VIII. London,

viii ■¥ 419 pp.

Thiele, J. 1929. Handhiich der systematischen Weichtier-

kunde. Teil 1. Gustav Fischer, Jena, pp. 1-376.

Weaver, C. S. and J. E. duPont. 1970. Living volutes. A

monograph of the Recent Volutidae of the World. Del.

Mus. Nat. Hist., Monogr. 1: xv -H 375 pp.

REMARKS ON MURICODRUPA IREDALE, 1918 (MURICIDAE: THAIDINAE),

WITH THE DESCRIPTION OF A NEW SPECIES

William K. Emerson

American Museum of Natural History

New York, New York 10024

and

Anthony D'Attilio

Natural History Museum

San Diego, California 92112

ABSTRACT

Muricodrupa jacobsoni, a new species known only from Melanesian populations

(Bisynarck Archipelago, Solomon and Fiji Islands), is described and dedicated to

the late M. K. Jacobson. Radular and opercular figures are provided for

Muricodrupa fenestrata (Blainville, 1832). and M. funiculus (Wood, 1828). A lec-

totype of Murex margariticola Broderip is selected and illustrated, and con-

sidered to be a junior synonym of Cronia fiscella (Gmelin, 1 791).

The classification of the numerous species-

group taxa with Morula-like shell characters has

long presented problems to students of murica-

cean gastropods. The thaidid genus Morula

Schumacher, 1817, remains a genus-group

receptacle for numerous, small, non-spinose

forms with denticulate apertures without

regard for the limitations dictated by the

characters of the type species, Drupa uva

Roding, 1798 (cf. Radwin and D'Attilio, 1972).

Recent investigations on the radulae of various

moruloid species, including those of Arakawa,

1962, 1965; Cernohorsky, 1969; Emerson, 1968,

Emerson and Cernohorsky, 1973; Radwin and

D'Attilio, 1971, 1972; Wu, 1965, 1968, and

others, have advanced the morphological know-

ledge of these rachiglossate gastropods. The

basic familial and subfamilial classification of

the Muricacea, however, remains in a state of

flux. Some workers largely ignore the radular

characters and rely mostly on shell morphology

for defining familial-level groups. Such is the

case for the thaidid taxa. Some workers

separate the Thaididae from the Muricidae,

while others recognize subfamilial rank within

the Muricidae for the thaidine taxa (see sum-

mary by Cernohorksy, 1969, p. 293).

The new species described below belongs to a

small group of Indo-Pacific taxa characterized

by shells possessing deeply pitted, squarish in-

terspaces formed by the junction of the axial

and spiral ribs. In the absence of knowledge on

its radular morphology, the present species is

tentatively referred to the genus Muricodrupa

Iredale, 1918, for which the radular dentition of

the type species is described and illustrated.

We name this new species in the cherished

memory of a longtime friend and valued col-

78 THE NAUTILUS

April 30, 1981

Vol. 95(2)

league, Morris Karl Jacobson (1906-1980), in

recognition of his many and varied contributions

to the field of malacology.

Family Muricidae Rafinesque, 1815

Subfamily Thaidinae Suter, 1909

Genus Muricodrupa Iredale, 1918

Muricodrupa Iredale, 1918, p. .38; Thiele, 1929, p. 29.5; Wu,

1968, p. 90, radular drawings of "Muricodrupa elangata

[sic] (Blainville)" pi. 4, figs. 4, 5.

Type species by original designation: Purpura

fenestrata Blainville, 1832, p. 221, pi. 10, fig. 11.

Synonyms: Murex cariosus Wood, 1828, Suppl.

p. 15, Murex pi. 5, fig. 22 [not Linne, 1767, p.

1220]; Purpura "alongee" [vernacular for

elongata] Blainville, 1832, pi. 10, fig. 9, fig. only

[nomen nudum]; Purpura cancellata Quoy and

Gaimard, 1833, vol. 2, p. 563, atlas (2), pi. 37,

figs. 15-16 [not Roding, 1798, p. 143]; Ricinula

elongata Reeve, 1846, Ricinula no. 25, pi. 4,

fig. 25.

Radular characters of type species: Five cusps

on the rachidian tooth, with central cusp narrow

and long, lateral cusps about % the length of the

central cusp, intermediate cusps small and lo-

cated near the laterals (figs. 5a, 5c); lateral

tooth large and normally hooked (fig. 5b).

Opercular characters of type species: Outline

broadly ungniculate, margin thickened on one

side, central area depressed, with irregular rais-

ed, concentric rings on the interior surface (fig.

7b).

Muricodrupa jacobsoni, n. sp.

Figs. 1-4

Description - Shell moderately large for

genus, attaining 35* mm in height, low spired;

nature of protoconch unknown (eroded off speci-

mens); suture weakly defined and interrupted

by varical buttresses; whorls 4*, weakly convex,

shouldered, spire short, blunt. Aperture narrow-

ly ovate, inner lip mostly adherent, outer lip

finely fluted, ornamented with 6 well-defined,

evenly spaced denticles, set slightly back from

apertural margin, with the lowest denticle

above the entrance to canal and the uppermost

denticle below the shoulder area; anal trough

with a prolonged sinus extending above the

shoulder, delineated within on the left side by a

minor denticle and on the right side by a swollen

and more prominent denticle isolated above the

6 lower denticles; canal, broad, mostly open,

tapering and recurved distally, siphonal fasciole

coarsely sculptured with previous canal termin-

ations; pseudo-umbilical pit present. Sculpture

consisting of 6 varices with visibly defined

varical margins, rounded with equal or wider in-

terspaces, varices crossing the angulate

shoulder slightly oblique and forming buttresses

against the previous whorl; shoulder deeply ex-

cavated in the interspaces; varices with low,

scabrous lamellae on varical leading surface;

number of costae increasing by one or two on

the spire; 3 primary spiral cords situated on the

body, along with an occasional secondary cord; a

major cord in concave area below the body;

canal with one major cord, supplemented with

minor or secondary cords; spiral sculpture

crossed by lamellose growth striae, scabrously

ornamented where not abraded.

Shell color - matte white, apertural interior

white in holotype, tinged with pale violet in

paratypes.

Type-locality - Astrolabe Barrier Reef, Yanu-

yanu-i-lona Island, Fiji Islands (19°55'S,

178°35'E), Kauter and Williamson, 1971.

Holotype from type locality, LACMNH no.

71-205; measurements 35.5 mm in height, 16.9

mm in width; fig. 1. Other material examined:

Paratype A, fig. 2, AMNH 201460 (ex-Tulane

University, Department of Geology), Manus

Island, Bismarck Archipelago; 31.5 mm in

height, 16.8 mm in width. Paratype B, fig. 3,

SDNHM Type No. 76523, Nudha Island, Solo-

mon Islands, American Mela Expedition Station

18; 38.5 mm in height, 20.2 mm in width. Para-

type C, Billee Mabry, June-July, 1978, Billee

Mabry Collection, same locality as for Paratype

B; 37.2 mm in height, 17.9 mm in width. Para-

types D and E, Guadalcanal, Solomon Islands;

paratype D, 36.3 mm in height, 17.1 mm in

width; paratype E, fig. 4, 37.8 mm in height,

13.4 mm in width, Thora Whitehead Collection.

DISCUSSION

The new species, together with its species-

group congeners, is characterized by the promi-

nent cavernous excavations between the varical

Vol. 95(2)

April 30, 1981

THE NAUTILUS 79

FIGS. 1-4. Muricodrupa jacobsoni, n. sp.. all x IV2. 1, hutotype, Yanu-yanu-i-loma Island, Fiji Islands, LACMNH 71-205. 2,

paratype A. Manus Island, Bisma7xk Archipelago, AMNH 20H60. 3, paratype B. Nudha Island, Solomon Islands. Billee

Mabry Collection. 4, paratype E, Rove, Guadalcanal Island, Solomon Islands, Thora Whitehead Collection.

and spiral ridges, which form squarish pits. It is

readily distinguished from its closest relatives

by the extended narrow form of the shell, the

blunt spire and broad canal.

The new species has been confused with Mur-

icodrupa funiculiis (Wood, 1828, p. 15, Murex

pi. 5, fig. 17), locality unknown; radula and oper-

culum here illustrated, figs. 6a, b; 8a, b. We con-

sider Muricodrupa decussata (Reeve, 1845,

Murex species 153, pi. 31, fig. 153), "Island of

Bohol, Philippines," type specimens not located

in the BM(NH) teste J. H. McLean and Murico-

drupa triangulata (Pease, 1868, p. 278, pi.

"233", fig. 15, "Insl. Hawaii") to be junior

synonyms of Muricodrupa funiculus (Wood,

1828). Compared to the new species. Wood's

taxon has an essentially triangular form, is

broad at the shoulder relative to height, has a

more spinose shoulder carina, and has three

denticles anteriorly positioned on the columella.

80 THE NAUTILUS

April 30, 1981

Vol. 95(2)

FIGS. 5a-5c. Radular dentition of Muricodrupa fenestrata

(Blaimnlle), greatly enlarged; SW Rarotonga Island. Cook

Islands, ANSP 278974. 6a-6b, Radular dentition of

Muricodrupa funiculus (Wood), greatly enlarged; Rodda

Reef Queensland. Australia, SDSNH 51212.

Kay (1979, p. 238, fig. 831) assigned Murico-

drupa triangulata (Pease) to the synonymy of

Muricodrupa funiculus (Wood). Cernohorsky

(1969, p. 311, pi. 49, fig. 25), however, referred

Pease's taxon to the synonymy of Morula

(Crania) fiscella{Gme\m, 1791, p. 3552, no. 160),

but his figured specimen represents an example

of Muricodrupa funiculus (Wood). Cerno-

horsky's nomenclatural interpretation of the

identity of Murexfiscellum Gmelin was based on

the figure citations by Gmelin (1791, p. 3552) to

Chemnitz's (1788, vol. 10, pi. 160, figs. 1524,

1525) illustrations and on the descriptive text.

Chemnitz's text (op. cit., p. 242) describes the

shell as being "... strongly clathrate with deeply

recessed windows (depressions) which are col-

oured brown", and Cernohorsky (1969, p. 311)

concluded that the ". . . description and figure

[sic] are only applicable to M. fiscella not to M.

margariticola." The figures of Chemnitz, how-

ever, lack squarish windows, whereas the col-

oration and sculpture are much closer to Morula

margariticola (Broderip, 1833, p. 177), as

figured by Cernohorsky (1969, p. 312, pi. 49, fig.

26, and 1972, pi. 128, pi. 36, fig. 8). Cernohorsky

(1978, p. 69, pi. 20, fig. 5) illustrates what ap-

pears to be a specimen of Morula margariticola

(Broderip, 1833) (our concept oi fiscella Gmelin)

under the name (Cronia crassulnata (Hedley,

1915), and he (1978, p. 70, pi. 20, fig. 6) il-

lustrates a specimen of Muricodrupa funiculus

(Wood, 1828) as Cronia triangulata (Pease,

1868), which he suggests may prove to be an ex-

treme form of Cronia fiscella (Gmelin, 1791).

FIGS. 7a- 7b. Opercular characters (7a. outer surface; 7b, in-

ner surface) of Muricodrupa fenestrata (Blaimnlle), greatly

enlarged; Truk Lagoon, Moen Island, Caroline Islands,

SDSNH 7652J,. 8a-8b, Opercular characters (8a. outer sur-

ftwe; 8b inner surface) of Muricodrupa funiculus (Wood),

greatly enlarged; Palmyra Island, Line Islands, SDSNH

ni88.

Vol. 95(2)

April 30, 1981

THE NAUTILUS 81

It is our view that Murex fiscellum (Gmelin,

1791) should be based on the drawings of Chem-

nitz (op. cit.), which lack any indication of

squarish, window-like depressions, and, in the

absence of the type specimens, should represent

the typological concept of Gmelin's species.

Moreover, the descriptive text of Chemnitz (op.

cit.) could reasonably be applied to several other

moruloid species with squarish pits, such as the

type species of Muricodrupa, Purpura fene-

strata Blainville, 1832. Therefore, we interpret

Murex fiscellum Gmelin to be referable on the

basis of Chemnitz's illustrations (op. cit.) to the

common and wide-ranging Indo-Pacific species

subsequently described as Murex margariticola

Broderip, 1833, p. 177; Reeve, 1846, Murex

species 178, pi. 34, fig. 178; syntype here il-

lustrated, fig. 9.

This interpretation agrees with the concept of

Murex fiscellum Gmelin arrived at by Lamarck

(1822, p. 346), Blainville (1832, p. 206', pi. 10, fig.

8), and Reeve (1846, Ricinula sp. 28, pi. 4, fig.

28), who would qualify as the First Revisor

under Article 24 of the International Code of

Zoological Nomenclature of the International

Congress of Zoology.

In summary, Muricodrupa jacobsoni, n. sp. is

most closely related to M. funiculus (Wood,

1828), [synonyms: Murex decussatus Reeve

(1845, Murex species 153, pi. 31, fig. 153); Pur-

pura stellaris Hombron and Jacquinot (1853,

atlas, pi. 22, figs. 13, 14); Coralliophila con-

FIG. 9, Murex margariticola BrodeWp, one of three syntypes

in The British Museum (Natural History), x I'k; this

specimen is selected as the lectotype. It is a junior synonym

u/Cronia iisceWa (Gmelin. 1791).

fragosa H. and A. Adams (1864, p. 432), and

Sistrum triangulatum Pease (1868, p. 278, pi.

23, fig. 15)]. Whereas Cronia fiscella (Gmelin,

1791), [synonyms: Murex margariticola Brode-

rip (1833, p. 177), Purpura thiarella Quoy and

Gaimard (1833, p. 571, pi. 39, figs. 4-6) [not

Lamarck, 1822, p. 246], [?] Thais crassulnata

Hedley (1915, p. 749, pi. 85, fig. 90), and Morula

rhyssa Dall (1923, p. 304, a new name for

Ricinula fiscella Reeve, 1846)], with which the

new species also has been confused, is a distinc-

tive species. The type species of the genus-group

taxon Cronia H. and A. Adams, 1853, Purpura

amygdala. Kiener (1835), apparently has radular

morphology (Cooke, 1919, fig. 33) similar to that

of the type species of Muricodrupa.

ACKNOWLEDGMENTS

We are indebted to the following friends and

colleagues for kindly providing specimens for

study: Billee Mabry, Richard Salisbury, Thora

Whitehead, Emily H. Yokes (Tulane Univer-

sity), Virginia Orr Maes (Academy of Natural

Sciences of Philadelphia), and James H. McLean

(Los Angeles County Museum of Natural His-

tory), who also photographed typological

specimens in the British Museum (Natural

History). The remaining photographs were

taken by Sidney S. Horenstein. William E. Old,

Jr., contributed technical assistance.

LITERATURE CITED

Adams, H. and A. Adams. 1853-1854. The genera of Re-

cent Mollusca. arranged according to their organization.

London, vol. 1, p. xi + 256 [1853], p. 257-484 [1854].

1864. Descriptions of new shells chiefly from the

Cumingian collection. Proc. Zool. Soc. London, pp. 428-

438. (Apr., 1864).

Arakawa, K. Y. 1962. A study on the radulae of the Japa-

nese Muricidae. The genera Purpura, Thais, and Manci-

nella. Venus 22(l):70-78.

1965. A study on the radulae of the Japanese

Muricidae. The genera Drupa, Drupina. Drupella, Cro-

nia, Morula, Morulina, Phry(fiomurex. Cyniia, and Ten-

guella gen. nov. Ibid. 24(2):113-126.

Blainville, H. M. D. de, 1832. Disposition methodique des

especes recentes et fossiles des genres Pourpre, Ricinule,

Licorne et Concholepas de M. de Lamarck. Nouv. Ann.

Mus. Nat., Paris 1:189-263.

Broderip, W. J. In, Broderip, W. J. and G. B. Sowerby, L,

1833. Characters of new species of Mollusca and Conchi-

fera, collected by Mr. Cuming. Proc. Zool. Soc. London,

pp. 173-179. (Jan. 14, 1833).

82 THE NAUTILUS

April 30, 1981

Vol. 95(2)

Chemnitz, J. H. 1788. Neues syst.ematisch£s Conchylien-

Cabinet (continuation of F. H. W. Martini) Niirnberg, vol.

10, xxiv + 376 p.

Cernohorsky, W. 0. 1969. The Muricidae of Fiji, Pt. 2, Sub-

family Thaidinae. Veliger 11(4):293-315.

Cernohorsky, W. J. 1972. Marine shells of the Paeific. Syd-

ney, vol. 2, 411 p.

Cernohorsky, W. 0. 1978. Tropical Pacific marinie shells.

Sydney, vol. 3, 352 p.

Cooke, A. H. 1919. The radula in Thais, Drupa, Morula.

Concholepax. Cronia. lopas. and the allied genera. Proc.

Malacol. Soc. London 13(3 & 4):90-110.

Dall, W. H. 1923. Notes on Drupa and Morula. Proc. Acad.

Nat. Sci. Philadelphia 75:303-306.

Emerson, W. K. 1968. Azumanwrula, new name for Moru-

lina Dall, 1923, not Boerner, 1906. Th£ Nautilus 81(4):

125-127.

Emerson, W. K. and W. 0. Cernohorsky. 1973. The genus

Drupa in the Indo-Pacific. Indo-Pacific Mollusca 3(13):

1-40.

Gmelin, J. F. 1791. Systermi naturae per regno tria nature

. . .. ed. 13. Leipzig 1(6):3021-3910.

Hedley, C. H. 1915. Studies on Australian Mollusca. Pt. 12,

Proc. Linn. Soc. New South Wales 39(4):695-755 (Feb.

26, 1915).

Hombron, J. B. and C. H. Jacquinot, Zoologie, vol. 5. De-

scription des mollusques, . . ., In, Rousseau, L., 1842-

1853 [pis.], 1854 [text]. Voyage au Pole Sud et dans

rOceanie sur les corvetts I'Astrolabe et la Zelee, execute

. . . pendant . . . 1837-1840.

Iredale, T. 1918. Molluscan nomenclatural problems and

solutions. No. 1 Proc. Malacol. Soc. London 13(1&2):

28-40.

Kay, E. A. 1979. Hawaiian marine shells. Reef and shore

fauna of Hawaii, Sec. 4: Mollusca. B. P. Bishop Mus.,

Honolulu, xvii + 653 p.

Kiener, L. C. 1835. Species general et icotiographie des

coquilles vivantes. Genre Pourpre. Paris, vol. 8, pp. 1-151.

Lamarck, J. B. P. A. de M. de. 1822. Histoire naturelle

des animaxix sans vertebres. Paris, vol. 7, 711 p.

Linne, Carl von, 1767. Systema naturae per regna tria

naturae . . ., ed. 12. Stockholm, [Regnum animale], 1(2):

533-1327.

Pease, W. H. 1868. Descriptions of sixty-five new species of

marine gasteropodae. inhabiting Polynesia. Avier. Jour.

Conch. 3(4):271-297, [April 2, 1868].

Quoy, J. R. C. and J. P. Gaimard, [1832-] 1833 [-1835]. Voy-

age d£ decouvertes de rAstrolabe. execute par ordre du

Roi Paris. Zoologie, Mollusca 2:321-686 (1833), atlas

(1835).

Radwin, G. E. and A. D'Attilio, 1971. Muricacean supra-

specific taxonomy based on the shell and radula. Echo,

Western Soc. Malacologists 4:55-67.

1972. The systematics of some New World

muricid species . . . with description of two new genera

and two new species. Proc. Biol. Soc. Wash. 85(28):

323-352.

Schumacher, C. F. 1817. Essai d'un nouveau systeme des

habitations des vers testaces. Copenhagen, iv ■¥ 287 p.

Reeve, L. A. 1845-1846. Conchologia iconica. London,

vol. 3, Monograph of the genus Murex, text with 36 pis.

1846. Conchologia ieonica. London, vol. 3, Mono-

graph of the genus Ricinula, text with 6 pis.

Roding, P. F. 1798. Museum Boltenianum . . . pars secunda

continens Conchylia. Hamburg, vii -i- 199 p.

Thiele, J. 1929. Handhuch der systematischen Wekhtier-

kunde. Jena, l(l):l-376.

Wood, W. 1828. Supplement to the Index testcuxologicus;

or a catalogue of shells, British and foreign. London,

vi + 59 p.

Wu, Shi-Kuei, 1965. Studies of the radulae of Taiwan muri-

cid gastropods. Bull. Inst. Zool, Acad. Sinica 4:95-106.

1968. On some radulae of the muricid gastro-

pods. Venus 27(3):89-94.

NEW RECORDS OF LAND MOLLUSCA IN NEW YORK CITY

Bruce Einsohn

Department of Physical Sciences

Kingsborough Community College

Brooklyn, NY 11235

Cecilioides acicula (Miiller), a small achatinid

snail, has been found in Inwood Hill Park at the

extreme northern end of Manhattan Island in

New York City. This is the first reported occur-

rence of this species in New York State.

Specimens of C. acicula were discovered

along a rocky ridge where the snails were found

attached to the undersides of bricks from the

ruins of what appears to have been a green-

house. At this site nine species of shelled pul-

monates, in addition to the Cecilioides, were

found within a few square feet: Cochlicopa

lubrica (Miiller), Eitx;onulus fulvus (Miiller),

Hawaiia minuscula (Binney), Helicodiscus

parallelus (Say), Oxychilus cellarius (Miiller), 0.

draparnaldi (Beck), Pupoides albilabris

Vol. 95(2)

April 30, 1981

THE NAUTILUS 83

Adams), Vallonia pulchella (Miiller), and Ver-

'igo cf. veyitri.cosa (Morse). Several species of

slugs have also been recorded. Curiously, Zo7ii-

'aides arboreiis (Say), moderately common else-

tvhere in the park, has not been found here.

Vallonia costata (Miiller) was also found in In-

A^ood Hill Park, as well as at other locations in

northern Manhattan. These occurrences consti-

;ute the first record of this species for Manhat-

jan (New York County), but not for New York

[lity. V. costata was not recorded from the New

York Metropolitan Area until some 20 years ago

A'hen Jacobson and Emerson (1961) reported it

Tom Van Cortlandt Park in the Bronx, but that

colony evidently does not exist today. I carefully

searched the environs of Van Cortlandt Park

A'ithout finding V. costata. In the New York

^hell Club Notes for May, 1962 (no. 82) H. S.

Peinberg reported V. costata from the Riverdale

section of the Bronx. I was able to confirm this

'ecord at a site some two miles southwest of

V^an Cortlandt Park in November, 1977. Subse-

quently, I was able to establish the Manhattan

records. V. costata is found under stones and

fallen logs, and in rock crevices. It occurs in

close association with V. pulchella. The animals

of the two species appear quite similar in their

gross aspects, both being white with con-

spicuous black eye spots.

Specimens of Cecilioides acicula and Vallonia

costata, both from Inwood Hill Park, have been

deposited in the American Museum of Natural

History (catalog numbers 200375 and 201470

respectively).

I would like to gratefully acknowledge the

assistance of the late M. K. Jacobson who read

portions of this manuscript and made helpful

criticisms. It was he who first suggested that

Cecilioides might be the correct genus for what

proved to be C. acicula. I would also like to

thank William E. Old, Jr. of the American Mu-

seum who granted me access to the Museum's

collections and library.

LITERATURE CITED

Jacobson, M. K. and W. K. Emerson. 1961. Shells of the New

York City Area. Argonaut Books. Larchmont, N.Y. 142 p.

CORBICULA FLUMINEA, IN LAKE ERIE

Arthur H. Clarke

Ecosearch, Inc.

7 Hawthorn Street

Mattapoisett, MA 02739

On December 17, 1980, 2 living juvenile speci-

mens of Corbicula fluminea (Miiller) were col-

ected in the western end of Lake Erie at Mon-

roe, Monroe County, Michigan, by me and by

two divers, Messrs. Al Melkic and Ted Creese,

rhis is the first record of C. fluminea from the

jreat Lakes-St. Lawrence drainage system,

rhe specimens both occurred on a sand bottom

in 3 feet of water at Sterling State Park, one off-

shore from a point 1000 feet south of the south-

ern end of a rocky dike near the mouth of Sandy

3reek and the other offshore from a point 2000

feet south of the same landmark. The lake level

ivas 2.4 feet above mean low water (MLW) and

the specimens were each found while screening

the substrate from SM^ bottom samples through

a V4-inch mesh screen. No other mollusks were

found in these samples. The specimens were 8.0

and 8.6 mm long, respectively.

C. fluminea probably cannot survive at such

shallow depths in Lake Erie because of winter

freezing and ice-scouring, but other juveniles

from the same 1980 larval settlement probably

occur nearby in deeper water. If water temper-

atures permit, C. fluminea will probably now

become widespread in the region.

One suspects that the abundant bottom-feed-

ing fishes in Lake Erie will keep C. fluminea

84 THE NAUTILUS

April 30, 1981

Vol. 95(2)

populations in the lake itself from becoming too

populous and from exerting an adverse effect on

native unionid populations. (Where dense pop-

ulations of C. fluminea occur native unionids

become rare, perhaps because the filter-feeding

activities of C. fluminea remove unionid sperm

from the water and interfere with unionid repro-

duction). The eventual damage that C. flumiyiea

will cause to water intake systems and other

commercial activities in the region, however,

may be significant.

LIFE CYCLE OF THE FRESHWATER SNAIL CAMPELOMA DECISUM

(VIVIPARIDAE) IN THE LABORATORY

Marc J. Imlay^

John W. Arthur^, Barbara J. Halligan"

and John H. Steinmetz'

ABSTRACT

Campeloma decisum reared in Minnesota Lake Superior water grew con-

sistently well when clam meat or commercial fish food wees provided and a

substrate of sand or mud was present. Food alone, or the substrate alone, was

generally ineffective in promoting growth. Thick substrates were more effective

than thin substrates. Substrate depth wa^ directly correlated with growth,

although some growth occurred when no soft substrate was present. Campeloma

decisum tested in Missouri hard well water grew equally well with or without a

substrate. A population of newborn snails from the St. Croix River, Wisconsin

was reared through three generations in U2 months on a diet of clam meat and

trout chow with St. Croix River mud substrate. Survival of the original snails to

Jfl months was 80%.

Campeloma is an exclusively North American

genus of ovoviviparus snails widely distributed

in lakes and streams of eastern North America.

Campelojna decisum (Say, 1819) plays an impor-

tant role in the fish (Price, 1957) and diving duck

(Thompson, 1973) food chains and has been used

in studying the effects of toxicants in the labora-

tory (Arthur, 1970, Arthur and Leonard, 1970).

Arthur and Leonard (1970) studied the effects

of a range of copper concentrations on survival,

feeding and parturition of young Campeloma

decisum snails. The snails completely devoured

'Columbia National Fisheries Research Laboratory

U.S. Fish and Wildlife Service

Route #1; Columbia, MO 65201

^Environmental Research Laboratory

U.S. Environmental Protection Agency

Duluth, MN 55804

fresh unionid clam meat in copper concentra-

tions of control (2.0 jig/l) up to 8.0 /jg/1 but would

not accept or consume this food at the higher

concentrations tested. Although the control

snails fed at the rate of one clam per 10 snails

per week, there was no measurable growth in 6

weeks. Thus, it was not possible to assess the ef-

fects of copper on the ability of the snails to

grow and complete the life-cycle. It was believed

that experiments to determine why the snails

fed without growing would demonstrate a way

to grow the snails in the laboratory.

A literature review suggested several expla-

nations for why the snails fed without growing.

The following describes several experiments

which tested these ideas and ultimately culmi-

nated in rearing Campeloma decisum through

several generations in the laboratory.

Allison (1942) trapped Campeloma with dead

Vol. 95(2)

April 30, 1981

THE NAUTILUS 85

fish or cloth packets of dog, cat, chicken, ferret

or muskrat dung. Snails came from both up and

down stream, with a maximum number of snails

at the trap on the 10th day. Bovbjerg (1952)

found populations of Campeloma decisum just

downstream from rapids in the presence of silt

and detritus. In the absence of factors that

would orient the snails to food, the snails moved

upstream (positive rheotactic response) but the

hard surfaces associated with riffles or rapids

blocked further upstream movement. Snails

moving upstream did not travel over exposed

surfaces of rocks. Snails also aggregated on the

downstream side of log barriers or boulders.

Thus, the literature reports that Campeloma

decisum. feeds on decayed animal material and

cannot function properly on a bare hard surface.

In the following experiments Campeloma deci-

sum was fed dead clams or other foods under

various conditions of hard, sandy, muddy or

other substrates. Water quality was also varied

to determine the significance of hardness, cal-

cium, or other minerals in growth.

MATERIALS AND METHODS

Effect of Substrate and Food Source

In a study to determine if a soft substrate is

needed for growth of snails, young Campeloma

decisum and various substrates were collected

from the St. Croix River, Douglas Co., Wiscon-

sin where the calcium content was 32-37 mg/1 as

CaCOs. Tests were run for 90 days in flowing

carbon filtered water pumped from Lake Supe-

rior at Duluth. During the tests, calcium was

46-53 mg/1 as CaCOs, temperature 18±1C,

dissolved oxygen 8.2-10.2 mg/1, and pH 7.5-8.0.

Ten or 20 snails as available were randomized

by size and added to each of 48 10-liter tanks.

Substrates provided were either mud or sand,

3.5-4.5 cm deep. Other snails were held in tanks

with only glass substrates. Either one 10-15 cm

long freshly killed unionid clam or 0.5 gram

trout chow (Glencoe starter granules) was pro-

vided every 1-2 weeks. Shell lengths were

measured with vernier calipers (0.1 mm ac-

curacy).

Tests with Missouri Snails in Hard Water

To determine further if a soft substrate was

needed for growth of snails tested in hard

water, young Campeloma decisum were col-

lected from a muddy substrate in the Gasconade

River, Osage Co., Missouri.

Sandy substrate (with some silt and gravel in-

termixed) was collected from a Gasconade tribu-

tary and a layer of this substrate 2.3 cm thick

was added to four aquaria each containing 10

snails and 10.3 liters of Columbia, Missouri hard

well water (Ca, 70; Mg, 27; K, 3.9; SO4, 4.4; CI,

29; EDTA hardness, 272 mg/1).

The water was continuously exchanged at the

rate of 0.50-0.52 liters every 4-8 minutes. Four

additional control aquaria differed in that no

substrate was added to the glass bottom. One

dead 10-12 cm freshwater mussel was fed every

3 weeks to the snails in each of two substrate

and two control aquaria. This experiment ran

from June 19-September 9, 1978 at 18.5-19. 3C.

Campeloma Life Cycle

Adult snails were collected in February, 1970

from the St. Croix River, Douglas Co., Wiscon-

sin and placed on a sieved mud substrate in an

aquarium at the Duluth Environmental Re-

search laboratory. In August 1970, 30 newborn

snails were recovered from this aquarium and

placed in an aquarium with sieved mud sub-

strate 3.5-4.5 cm thick. They were fed trout

chow with clam meat ad libitum. The snails were

provided with flowing Lake Superior water at

18±1C. The mud substrate was exchanged in

March 1971, June 1973, and January 1974.

Growth rates of the young snails were measured

periodically.

RESULTS

Campeloma decisum tested in Duluth, Minne-

sota soft water grew consistently well when

clam or fish food was provided and a substrate

of sand or mud was present (Table 1). For exam-

ple, in one tank with glass substrate and clam

meat growth was 0.3 mm (standard error of only

0.09) in 90 days. With mud substrate and clam

meat the least growth was 0.8 mm. Food alone,

or the substrate alone was generally ineffective

in promoting growth. The most growth with

mud alone was 0.7 mm. Thick substrates were

more effective than thin substrates (Table 2). It

86 THE NAUTILUS

April 30, 1981

Vol. 95(2)

TABLE 1. Growth in 90 days o/Campeloma decisum snails (10-20 mm original lervgth) in varied

substrates and food sources. Duluth soft water. Each number (except overall average) is average

growth (mm) of 10 or 20 snails.

Substrate

provided

None

FOOD SOURCES

Clam

S-

FUh Food

Glass

0.0

0.1

0.2

0.7

0.8

1.0

2.0

"triT

1.1

0.079

2.1

injT

TABLE 2. Growth in 90 days o/Campeloma decisum snails (10-20 mm original length) in varied St.

Croix River mud substrate depths and food sources. Duluth soft water. Each number is average

growth (mm) of 10 snails.

Substrate

provided

Clam

FOOD SOURCE

S-

Flsh Food

Glass

0.0

o.s

0.5

0.7

0.098

1.5

1.1

~r2i

0.10

1.0 nm

0.0

1.2

1.5

1.1

0.11

2.8

1.5

1.8

0.17

5.0 1

0.0

1.8

1.3

1.4

0.15

3.3

3.4

3.2

0.26

25.0 mi

0.0

2.1

2.2

2.5

t:7t

0.17

3.2

3.7

2.6

"TIT

0.17

Vol. 95(2) April 30, 1981 THE NAUTILUS

TABLE 3. Growth of young Missouri snails June Q-Septetnber 19. Mi-ssouri hard water. 18.5-19.3C.

87

Substrate

Food

Initial

No.

Initial

length

im growth

102 days

Final No.

Alive

Sand

Glass

Sand

clam

TABLE 4. Meayi length and number of survivors for several generations o/Campeloma decisum. The

first getierntion produced at least three second generations. The first of these in turn produced a third

generation.

First Generation

Second Generation Second Generation Second Generation Third Generation

N Age length N Age length N Age length N Age length N Age length

(months) (ran) (months) (mm) (months) (fim) (months) (mm) (months) (ran)

9.0 30 3

is seen that substrate depth was directly cor-

related with growth, although some growth oc-

;nirred without any soft substrate. The survival

rate was 80-100% per tank.

Campeloma decisum tested in Columbia,

Missouri hard water grew equally well with or

without substrate (Table 3). A population of

newborn snails from the St. Croix River,

Wisconsin was reared through three genera-

tions in 42 months on a diet of clam meat and

trout chow with St. Croix River mud substrate

[Table 4).

DISCUSSION

The demonstrated synergistic action of food

and natural sand or mud substrate on growth of

Campeloma decisum in the laboratory is prob-

ably related to the preference of this species for

sand or mud substrate in the wild.

Further experimentation is required to deter-

mine if the synergistic property of the substrate

was a mineral such as calcium, a vitamin, sand

grain digestive aid, protection from harmful

wavelengths of light, or a "psychological re-

quirement." It is not known if the lack of

synergistic action of soft substrate and food for

Missouri snails in Missouri hard water was due

to calcium in the hard water or genetic dif-

ferences from the Wisconsin snail population.

Chamberlain (1958) cultured 45 North Carolina

88 THE NAUTILUS

April 30, 1981

Vol. 95(2)

Campeloma decisum "in isolation" in 4.5 inch

fingerbowls containing a natural substrate of

clayey silt with some sand and decaying organic

debris. They grew at about the same rate as in

nature but only two snails were still alive after

12 months. He found that Campeloma decisum

from University Lake, Chapel Hill, North

Carolina were not gravid before two years of

age and until reaching 15.0 mm in length. The

largest snail he collected was 27.3 mm long. The

second year class lost identity as a size class at

20 mm in length. The parturition period was

from mid-March until the end of June.

Medcof (1940) who studied Campeloma deci-

sum from the Speed River, Ontario, also re-

ported that sexual maturity was reached in two

years, and one, two, and three year old snails

were 12, 17 and 23 mm long, respectively. The

parturition period was from March- September.

From Table 4 it may be noted that newborn

snails (August 1970) reproduced in less than two

years (January 1972, about 17 months after

birth) presumably due to early parturition in the

laboratory. The approximate maximum length

(25.1 mm) obtained by snails in our study was

similar to that found by Medcof (23 mm) and

Chamberlain (20-27.3 mm).

ACKNOWLEDGMENTS

Dr. Henry van der Schalie, University of

Michigan Museum and department of Zoology,

and Dr. Carol B. Stein, Ohio State University

Museum of Zoology, identified Campeloma

decisum from Wisconsin and Missouri, respec-

tively. Virginia Vail reviewed the manuscript.

LITERATURE CITED

Allison, L. N. 1942. Trapping snails of the genus Campelo-

ma. Sftertrp 95:131-132.

Arthur, J. W. 1970. Chronic effects of linear alkylate sul-

fonate detergent on Gammarus pseudolimnaeus. Campe-

loma decisum and Physa Integra. Water Research 4:

251-257.

Arthur, J. W. and E. N. Leonard. 1970 Effects of copper on

Gammarus pseudolimnaeus. Physa Integra, and Campelo-

ma decisum in soft water. Journal Fisheries Research

Board of Canada 27:1277-1283.

Bovbjerg, R. V. 1952. Ecological aspects of dispersal of the

snail Campeloma decwum. Ecology 33:169-176.

Chamberlain, N. A. 1958. Life history studies oi Campeloma

decisum. The Nautilus 72:22-29.

Medcof, J. C. 1940. On the life cycle and other aspects of the

snail, Campeloma. in the Speed River. Canadian Journal

of Research 18(sec. D):165-172.

Price, J. H. 1957. A study of the food habits of some Lake

Erie fish, U.S. Fish and Wildlife Sennce Report No. 837,

105 pp.

Thompson, D. 1973. Feeding ecology of diving ducks on

Keokuk Pool, Mississippi River. Journal of Wildlife Man-

agement 37:367-381.

NEWS

Dr. Arthur E. Bogan joined the staff of the

Department of Malacology, Academy of Natural

Sciences of Philadelphia in September 1980. He

came to the Academy having received his doc-

torate from the University of Tennessee, Knox-

ville. His thesis was concerned, in part, with

Unionidae in archaeology. His position, cura-

torial associate, involves management of the

growing computerized collection data base,

generating reports from the data base such as:

Catalog of the Chitm Types (1979; Tryonia,

1:1-60), identification of species, curatorial up-

dating of families, processing new collections

for cataloging. Dr. Bogan joins Drs. Davis and

Robertson in managing the neontological and

paleontological sections of the Department of

Malacology. The collections are supported, in

part, by a continuing grant from the National

Science Foundation.

The Western Society of Malacologists will

hold its 14th annual meeting June 23-26, 1981,

at the San Diego State University. The Ameri-

can Malacological Union will hold its 50th an-

niversary meeting July 19-24, 1981, in Ft.

Lauderdale, Florida (details Jan. issue of The

Nautilus, p. 37). The 1981 convention of the

Conchologists of America will meet in San

Francisco, California Sept. 2-5 at the Miyako

Hotel in the Japan Center.

Vol. 95(2)

April 30, 1981

THE NAUTILUS 89

THE NORTHERN EXTENSION OF THE RANGE OF ANODONTA

SUBORBICULATA SAY (BIVALVIA: UNIONIDAE)

Marian E. Havlik

Malacological Consultants

La Crosse, Wisconsin 54601

ABSTRACT

The naiad mollusk, Anodonta suborbiculata Say, 1831, has apparently never

been reported alive m the Mississippi River main stem north ofFairport Iowa

(River Mik 463). During 1977 two live specimens were collected m Bluff Slough at

La Crosse, Wisconsin. Because of the obvious age difference in these specimens

reproduction m the area seems likely. Three other living naiad species and four

dead naiad species were also collected from this site

The naiad mollusk Anodoyita suborbiculata

Say, 1831, popularly known as the Heel-Splitter

or Flat Floater, has apparently never been

reported alive from the Mississippi River main

stem above Fairport, Iowa (River Mile 463)

(Coker, 1919), nor in the Illinois River north of

Peoria Lake (Danglade, 1914).

Witter (1883), in reporting on the mollusca of

Muscatine County (Iowa), stated that A. subor-

biculata was "common or even abundant, in

Keokuk Lake, and lakes along Cedar (River),

especially the lake on the west bank of Cedar, a

half-mile below Moscow" (Iowa). Studies of the

Mississippi River since the 1920's have not

reported this species (Dr. M. M. Ellis (summariz-

ed by van der Schalie and van der Schalie, 1950),

Dawley (1947), Coon et al. (1977), Havlik and

Stansbery (1978), Fuller (1978), Perry (1979)

and Havlik and Marking (1981)).

Apparently A. suborbiculata was never found

in Wisconsin (Baker, 1928, and H. Mathiak, per.

-omm., Horicon, Wisconsin). Several studies of

iie Mississippi, Minnesota River and Black

Rivers by the author have not revealed this

5pecies.

During June 1977 two live specimens of A.

suborbiculata were taken from Bluff Slough,

^ol 8 of the Mississippi River at La Crosse',

Visconsin. This 90-meter-wide side channel, at

■lississippi River Mile 695, was being investi-

gated by the author as part of an environmental

ssessment for a sewer line to be constructed

-nder the Slough by the city of La Crosse.

The two living specimens, about 5 and 8 years

of age, were in 1.5 meters of water on a sand bar

that also contained some soft to firm mud, about

15 meters downstream from the proposed sewer

line. Because of the obvious age and size dif-

ference, reproduction in the area seems likely,

at least on a limited basis. One specimen is in the

Ohio State University Museum of Zoology, Col-

umbus, Ohio 43210 (OSUM:1977:398:42780).

Other naiad species collected alive at this site

mcluded Anodonta grandis corpulenta Cooper,

1834, Amblema plicata plicata (Say, 1817) and

Fusconaia flava (Rafinesque, 1820). Dead

specimens were found of Lampsilis radiata

luteola (Lamarck, 1819) and L. ventricosa

(Barnes, 1823); sub-fossil specimens were found

of Lasmigona complanata (Barnes, 1823) and

Leptodeafragilis (Rafinesque, 1820). No rare or

endangered species were found.

Very few recent records exist for this species

in the Upper Mississippi River. Two additional

Wisconsin records for A. suborbiculata in the

Mississippi River backwaters have been re-

ported. A single fresh-dead specimen was found

August 1978 at Mississippi River Mile 637.4,

Pool 10, on the shore of an area known as Big

Lake, 3.2 kilometers north of Prairie du Chien,

Wisconsin (James Theler, per. comm. Dept. of

Anthropology, University of Wisconsin-Madi-

son, Madison, Wisconsin). Theler also found

several other fresh-dead A. suborbiculata in the

same general area June 1980. These specimens

are all at The Ohio State University Museum of

Zoology.

90 THE NAUTILUS

April 30, 1981

Vol. 95(2)

Fresh-dead shells of A. suborbiculata were

found in 1976 in a then dried-up, small pond on

the southern tip of Arsenal Island bordering

Sylvan Slough, and in two other locations in

Sylvan Slough in 1977 at Rock Island, Illinois,

Mississippi River Mile 482.8 (Thomas Freitag,

per. comm., Rock Island District, Corps of

Engineers, Rock Island, Illinois).

Four recently-dead shells were found in 1978

in water 0.75 meters deep in about a 2 hectare

pond, about 10.4 kilometers NW of Muscatine,

Iowa (Michael Knott, per. comm., Stanley Con-

sultants, Inc., Muscatine, Iowa).

Apparently this species is more common in the

Upper Mississippi River than formerly believed,

but the favored habitat makes collection dif-

ficult.

ACKNOWLEDGMENTS

I wash to thank Dr. David H. Stansbery and

Dr. Carol B. Stein for their comments on the

early draft of this paper, and Leif Marking, Na-

tional Fishery Research Laboratory, La Crosse,

Wisconsin, for his comments on the final manu-

script.

LITERATURE CITED

Baker, F. C. 1928. The fresh water moUusca of Wisconsin.

Part II. Pelecypoda. Bull. Wisconsin Geological and

Natural History Survey, 70:1-495.

Coker, R. E. 1919. Fresh-water mussels and mussel indus-

tries of the United States. Bull. Bureau of Fisheries 36:

11-89.

Coon, T. G., .J. W. Eckblad, and P. M. Trygstad. 1977. Re-

lative abundance and growth of mussels (Mollusca: Eula-

mellibranchia) in pools 8, 9, and 10 of the Mississippi Ri-

ver. Freshwater Biology 7:279-285.

Danglade, E. 1914. The mussel resources of the Illinois

River. Report U.S. Commissioner of Fisheries for 1913,

Appendix 6:1-48.

Dawley, C. 1947. Distribution of aquatic mollusks in Minne-

sota. Amer. Midland Nat. 38:671-697.

Flowers, W. 1975. Notes on the current status of Wisconsin

Unionidae. Sterkiana 57:40-42.

Fuller, S. L. H. 1978. Fresh-water mussels (Mollusca: Bi-

valvia: Unionidae) of the upper Mississippi River: Observa-

tions at selected sites within the 9-foot channel navigation

project on behalf of the United States Army Corps of

Engineers. Acad. Nat. Sci. Philadelphia. 401 pp.

Grier, N. M. and J. F. Mueller. 1923. Notes on the naiad

fauna of the Upper Mississippi River. II. The naiads of the

upper Mississippi drainage. The Nautilus 36:96-103.

Havlik, M. E. and L. L. Marking. 1981. A quantitative

analysis of naiad mollusks from the Prairie du Chien,

Wisconsin dredge material site on the Mississippi River.

Bull. Amer. Malacol. Union, 1980, pp. 30-34.

Havlik, M. E. and D. H. Stansbery. 1978. The naiad mollusks

of the Mississippi River in the vicinity of Prairie du Chien,

Wisconsin. Bull. Amer. Malacol. Union, Inc. (1977). pp.

9-12.

Perry, E. W. 1979. A survey of Upper Mississippi River

mussels. In: Rasmussen, J. L., editor. A compendium of

fishery information on the Upper Mississippi River.

Second Edition. Upper Mississippi River Conservation

Committee, Rock Island, Illinois, pp. 118-139.

Starrett, W. C. 1971. A survey of the mussels (Unionacea)

of the Illinois River; a polluted stream. Bull. Illinois

Natural History Survey 30:267-403.

van der Schalie, H. and A. van der Schalie. 1950. The mus-

sels of the Mississippi River. Amer. Midland Nat. 44(2):

448-466.

Witter, F. M. 1883. The mollusca of Muscatine County and

vicinity. The Muscatine Conchological Club, Muscatine,

Iowa. S. E. Cassino and Co., Boston, pp. 3-24.

Major Research and Identification

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Vol. 95(2)

April 30, 1981

THE NAUTILUS 91

SOME PERUVIAN HYDROBIIDS, POTENTIAL

SNAIL HOSTS OF PARAGONIMIASIS

Emile A. Malek and W. Lobato Paraense

Department of Tropical Medicine,

Tulane Medical Center, New Orleans, LA, U.S.A.

and Institute Oswaldo Cruz, Rio de Janeiro, Brazil

Paragonimiasis, a lung fluke infection, is com-

mon among humans and/or animals in the Far

East, Southeast Asia, West Africa and the

Americas. According to Abbott (1948) thiarids

(melaniids), pleurocerids or assimineids are the

usual snail first intermediate host in the Far

East, but 3 out of 17 species of lung flukes there

utilize hydrobiids. In West Africa the snail host

is a thiarid. It has been established that hydro-

biids (family Hydrobiidae) act in this capacity in

the Americas. While it has been known for some

time that the amphibious Poniatiopsis lapida^ia

Say is the snail host of Paragonimus keUicotti in

the United States (Ameel, 1934), only during the

last decade did it become known that the small

aquatic Aroapyrgus colombiensis is the snail

host of P. caliensis in Colombia (Malek and

Little, 1971) and that Aroapyrgus costaricensis

(Morch, 1861) is the snail host of P. mexicanus in

Costa Rica (Malek et al., 1975).

Although the etiologic agent of human para-

gonimiasis in Peru and Ecuador is not known, it

is very likley that one or all of P. peruvianus. P.

amazonicus and P. caliensis, which infect ani-

mals in Peru, also causes the disease in humans.

The snail hosts of Paragonimus spp. in Peru and

Ecuador are still not known. However, on ac-

count of similarities in the biology and details of

the life cycle of the lung flukes in Central and

South America, we believe that the snail hosts

of paragonimiasis in Peru and Ecuador are also

small aquatic hydrobiids, as they are in Colom-

bia and Costa Rica.

Among snails collected by the junior author in

Peru in 1960 and 1961 are some small aquatic

hydrobiids which we consider to be potential

hosts of lung flukes in Peru and possibly also in

Ecuador. These hydrobiids are: (1) Aroapyrgtis

"Mlombiensis Malek and Little, 1971, Fig. lA.

rhis species was collected from streams at

lacos, Trujillo, Peru. Potamopyrgus mirandoi

FIG. 1. A, Aroapyrgus colombiensis Malek and Little. 1971,

male and female. B, Littoridina cumingii (Qrbiffny. 1835).

male and female. Some internal organs show through the

transparent shell especially the embryos in the

ovoviviparous female A. colombiensis. In the male, part of

the shell broken to expose verge, bp, brood pouch; e, eye; ec,

egg capsule; em, embryo; g, gill; i, intestine; o, operculum; p,

papilla on verge; r, rectum; t, tentacle; v, verge.

Weyrauch, 1963, described as a new species in

Peru on the basis of the shell only, is probably

this species. (2) Littoridina cumingii (Orbigny,

1835) Fig. IB. This species was collected from

streams near Lima, Peru. Orbigny (1835, 1835-

1846) based his description of the shell on

material collected near Callao and Lima, Peru

and at Valparaiso, Chile. Oiir bases for iden-

tification of these two hydrobiids are the shell,

92 THE NAUTILUS

April 30, 1981

Vol. 95(2)

the operculum, the verge, details of the female

reproductive system and the radula.

Aroapyrgtcs colombiensis has a similar habitat

in Peru as in Colombia, where it is the natural

host of P. caliensis. The purpose of this short

paper is to stimulate parasitologists to look for

natural infections with Paragonimus spp.

among hydrobiids in Peru and Ecuador, and to

attempt to infect them experimentally. It should

be noted that thiarids, in the same habitats with

A. colombiensis in Colombia, are not infected

with the lung flukes.

LITERATURE CITED

.\bbott, R. T. 1948. Handbook of medically important mol-

' lusks' of the Orient and the Western Pacific. Bull. Mvs.

Camp. Zool. Harvard. Univ. 100:245-328.

Ameel, D. J. 1934. Paragonimus, its life history and distri-

bution in North America and its taxonomy (Trematoda:

Troglotrematidae). Amer. Jour Hygiene 19:279-317.

Maiek, E. A. and M. D. Little. I'm. Aroapyrgus colombien-

sis n. sp. (Gastropoda; Hydrobiidae), snail intermediate

host of Paragonimus caliensis in Colombia. Thf Nautilus

85:20-26.

Malek, E. A., R. Brenes and G. Rojas. 1975. Aroapyrgus

costari^ensis. hydrobiid snail host of paragonimiasis in

Costa Rica. Jour. Parasit. 61:355-359.

Orbigny, A. 1835. Synopis terrestrium et fluviatilium Mol-

luscorum in suo per America meridionalem itinere collec-

torum. Mag. Zool. 5:1-44.

1835-1846. Voyage dans rAmerique Meridio-

nale. Paris (Vol. 5. Mollusques).

Weyrauch, W. K. 1963. Cuatro nuevas especies de Hydro-

biidae de Argentina y Peru (Gastropoda; Prosobranchia).

Acta Zoologica LiUoawi 19:243-259.

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BY Gary R. McDonald and

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Vol. 95(2)

April 30, 1981

THE NAUTILUS 93

FRESHWATER NAIADES OF EAGLE CREEK,

A TRIBUTARY OF THE KENTUCKY RIVER (UNIONIDAE)

Ralph W. Taylor

Department of Biological Sciences

Marshall University

Huntington, WV 25701

ABSTRACT

A survey of the freshwate?- Naiades of Eagle Creek, a tributary of the Kentucky

River, was carried out during the summer of 1980. Ten stations were collected at

irregular intervals during the summer. A total of twenty-one species are reported

as currently occurring in the stream. Two species, Pleurobema clava and

Cyclonaias tuberculata, may no longer be present in the stream as they were found

only as dead shells. All other species enjoy wide-spread distribution and good

numbers are present. Anodontoides ferussacianus, Simpsonaias ambigiia and

Elliptio crassidens are reported for the first time as occurring in the Kentucky

River system.

As part of a continuing effort to document

freshwater mussel faunal assemblages of

smaller Kentucky streams, this paper reports

work carried out during the summer of 1980 on

Eagle Creek, a major downstream tributary of

the Kentucky River. Eagle Creek enters the

Kentucky River near the village of Worthville,

Carroll County, Kentucky, at a point some

seven miles from the confluence of the Kentucky

with the Ohio River at Carrollton, Kentucky

(Fig.l). The Kentucky River proper originates

in the mountains of eastern Kentucky which are

located within the Cumberland Plateau. The

headwaters consist of three main branches, the

North, Middle and South Forks. Three addi-

tional major tributaries flow into the Kentucky

River along its 400 mile length. They are: (1) the

above-mentioned Eagle Creek, (2) the Dix River

and (3) the Red River.

. The only previous study concerned with the

"reshwater naiades of this drainage was carried

)ut by Danglade (1922) some 60 years ago. Dur-

ng the summers of 1919-1920, he surveyed the

nussel resources of the mainstem Kentucky

liver with an eye on the commercially valuable

;hells which fed the burgeoning shell-button in-

lustry. In 1920, a single 35 mile stretch of river,

vhich he monitored regularly, produced 87 tons

if desirable shells. A total of 40 species of

nussels (22 with commercial value) was re-

VIG. 1. Map of northern central Kentucky showing collecting

stations (blafk dots) on the Eagle Creek.

ported as occurring in the drainage (Table 1).

These data indicate a productive stream of good

water quality and readily available suitable

habitat. Since the studies of Danglade the river

has been modified. Extensive "improvements"

94 THE NAUTILUS

April 30, 1981

Vol. 95(2)

TABLE 1. Freshwater Naiades of Kentucky River as

Reported by Danglade (collected summers of 1919-1920).

Name as used by Danglade

usage

AlasntidontB marginata

Alasmidonta minor

Anodonta grandis

Anodonta imbecillis

Cyprogenia irrorata

LuRipsilis alata

Loapstlis anodontotdcK

Uinps i 1 i s f a 1 1 ac i osa

Lampsilis graolis

Lamps i lis ligament) na

Lompsilis lutcola

Lampsilis aultiradiata

LanpsiliK parva

Lampsilis recta

Lampsilis ventricosa

Obliquaria reflexa

Obovaria lens

Plagiola donacifomis

Plagiola clcgans

Plcurobcffla clava

Ptychnbranchus phaseolu!

Quadrula coccinea

Quadrula cylindrica

Quadrula granifera

Quadrula heros

Quadrula kirtlandiana

Quad ru la 1 ac)i rymosa

Quadrula pustulata

Quadrula pustulosa

Quadrula rubiginosa

Quadrula sol ida

Quadrula subrotunda

Quadrula undulata

Strophitus cdentulus

Symphynota complanata

Symphynota costata

Tn togonia tuberculata

Truncilla rangiana

Truncil la triquetra

Unio gibbosus

Alasmidonta marginata Say, 181S

Alasmidonta viridis iRaf.. 1820)

Anodonta g. grandis Say, 1$29

Anodonta imbecillis Say, IS29

Cyprogenia stegaria (Kaf., 1820)

Potamilus alatus (Suy, 1817)

Lampsilis teres form anodontuides (Lea, 1B31)

Lampsilis teres form teres (Raf., 18201

Leptodea fragilis (Kaf., 1820)

Actinonaias ligamentinu carinata [Barnes. 1823

Lampsilis radiata luleola (Lam., 1819)

Lampsilis fasciola Raf.. 1820

Toxolasma parvus (Barnes, 1823)

Ligunia recta (l.am., 18191

Lampsilis ventricosa (Barnes, 1S23)

Obliquaria reflexa Haf . . 1820

Obovaria subrotunda (Raf., 1820)

Truncilla donaciformis (Lea, 1827)

Truncilla truncata Haf., 1820

Pleurobema clava (Lam., 1619)

Ptychftbranchus fasciolaris (Raf., 1820)

Pleurobema sintoxia (Raf., 1820)

Quadrula cylindrica cylindrica (Say, 1817)

Cyclonaias tuberculata (Raf., 1820)

Megalonaias nervosa (Raf,, 1830)

Fusconaia maculata kirtlandiana (Lea, 1834)

Quadrula quadrula (Raf., tS20)

Quadrula iiodulaLa (Raf., 1820)

Quadrula pustulosa pustulosa (I.ea, 1831)

Fusconaia flava (Raf.. 1820)

Pleurobema cordatum (Haf., 1820)

fusconaia maculata maculata (Raf. , t82U)

Amblema plicata plicata (Say, 1817)

Strophitus undulatus undulatus (Say. 1817)

Lasmigona complanata (Barnes. 1823)

Lasmigona costata (Raf.. 1820)

Tritogonia verrucosa (Raf., 1820)

Epioblasma torulosa rangiana (Lea. 1039)

EpiobJasma triquetra (Raf.. 1820)

El liptio dilatiita (Raf., 1820)

METHODS

Ten stations, where good naiad populations

existed, were established and visited at ir-

regular intervals throughout the summer of

1980. Shells were hand picked from the shal-

lows. Additionally fresh dead valves, deposited

as middens by muskrats and raccoons, are in-

cluded in Table 2. Specimens found only as dead,

badly eroded shells are indicated as such. The

material collected was returned to the labor-

atory, cleaned, identified and catalogued in the

Marshall University Malacological Collections.

Dr. David H. Stansbery of the Ohio State

University Museum of Zoology very kindly con-

firmed identifications of some specimens.

Voucher specimens have been placed with

O.S.U.M. All names included herein are those

used by Stansbery (1979).

Collecting Site Localities

1. Scott Co. -Co. Rd. 620 at Porter Rd. near

Salem Church.

2. Scott Co.-Pokeberry Rd., % mi. W of 1-75

near village of Sadieville.

TABLE 2. List of species found at each location. Eagle

Creek. Kentucky 1980 Survey. (C) = common. (M) = moderate-

ly common, (R) = rare.

for navigational purposes have been made, and

additionally the stream has suffered from man's

other activities in the last 80 years (i.e., mining,

industry, agriculture and sewage).

Eagle Creek, on the other hand, remains

essentially unchanged today. There are no

dams, no industries and only limited human

sewage input along the Ca. 80 mile length of the

stream. Eagle Creek originates in the Bluegrass

region of central Kentucky just north of Lex-

ington and flows in a northwesterly direction

through rolling knobs past horse and tobacco

ferms to the Kentucky River. No towns of ap-

preciable size exist within the drainage of this

creek. The creek for the most part never ex-

ceeds 15 m in width or 2 m in depth.

Anodonta g. grandis Say, 1829 (C) XXXXXXXXX

Anodontoides fcrussacianus (Lea, 1834) (R) X

Strophitus u. undulatus (Say, 1817) (C) X X X X X X X

Alasmidonta viridis (Raf., 1820) (C) X X X X X X

Sinpsonaias ambigua (Say. 1825) (M) X X

Lasmigona complanata (Barnes. 1823) (C) X X X X

Lasmigona costata (Raf., 1820) (R) X

Tritogonia verrucosa (Raf., 1820) (C) X X X X

Quadrula quadrula (Raf., 1820) (M) XXX

Amblema p. plicata (Say. 1817) (M) X X X X

Fusconaia flava (Raf.. 1820) IM) X X X X

Cyclonaias tuberculata (Raf., 1820)« (R) X X

Pleurobema clava (Lam., 1819)* (fi) X

Elliptio c. crassidens (Lam.. 1819) (R) X

Elliptio dilatata (Raf., 1820) (C) X X X X X X

Ptychobranchus fasciolaris (Baf., 1820) (M) X X

Leptodea fragilis (Raf.. 1820) (M) X X X X

Potamilus alatus (Say. 1817) (C) X X X X X

Toxolasma parvus (Barnes, 1823) (R) X

Lampsilis r. lutcola (Lam., 1819) (C) XXXXXXXX

Lampsilis ventricosa (Barnes. 1823) (C) X X X X X

•Found only as badly eroded dead shells

Vol. 95(2)

April 30, 1981

THE NAUTILUS 95

3. Owen Co. -Co. Rd. 1883, 1 mi. NW of Jet.

with Co. Rd. 2018, 2 mi. W of village of Nat-

lee.

4. Owen Co. -Co. Rd. 1739, behind Mussel

Shoals Baptist Church, 1.5 mi. NE of Jet.

with St. Rd. 845.

5. Owen Co.- Jet. of St. Rd. 330 at St. Rd. 845

under bridge, area locally known as Lusby's

Mill (old milldam still present).

6. Grant Co. -Co. Rd. 1132, 1.5 mi. N of Jet.

Calendar Rd., 3 mi. N of village of Jones-

ville.

7. Grant Co. -Co. Rd. 1132, 1.5 mi. S of Jet.

with St. Rd. 467 at Ford's Mill Rd.

8. Gallatin Co. - St. Rd. 467, 4.2 mi. E of village

of Sparta, 1.2 mi. W of Gleneoe.

9. Gallatin Co. -St. Rd. 467, 1.2 mi. ENE of vil-

lage of Sparta at Louisville and Nashville

Railroad crossing.

10. Owen Co. -St. Rd. 35, under bridge at

Sparta.

RESULTS

Twenty-two species of freshwater naiades

were found in Eagle Creek (Table 2). Two

species, Cyclonaias tuberculata and Pleurobema

clava. were found only as badly eroded dead

shells and may be assumed to be either very rare

or no longer present in this stream. Anodon-

tx)ides fertcssacianus. Simpsonaias ambigua.

Lasmigona costata. Elliptio crassidens and Tox-

olasma panms were found only rarely. All other

species were found widely distributed and in

fairly good numbers throughout most of the

stream. Anodonta g. grandis was found at every

station and Lampsilis r. luteola was found at

every station except Station No. 1.

Anodontoides fenissacianics, Simpsonaias am-

bigua and Elliptio crassidens are reported

herein for the first time as occurring in the Ken-

tucky River system.

Specimen Shells

Offering microscopic and miniature (to '/» inch) shells

from the Florida Keys, with accurate locality data Also

unsorted grunge: write for list.

Margaret Teskey

P.O. Box 273

Big Pine Key. H. 330J,3

CONCLUSIONS

The Kentucky River around the turn of the

Twentieth Century was a stream of relatively

high quality and supported a freshwater naiad

population of considerable commercial value

(Danglade, 1922). Whether that is still the case

remains to be seen. Future investigators may

wish to take a second look at the Kentucky and

see what effects habitat modifications (i.e, pollu-

tion, damming, etc.) have had. One must assume

that as in other comparable streams the impact

has been great. I would be very surpised if any

single location in the Kentucky still supported

mussels in commercial quantities. I would also

be surprised if many of the species reported by

Danglade were still in the river, even in limited

numbers. Among this doubtful group would be

Quadmla cylindrica, Actinonaias I. carinata,

Lampsilis teres, Pleurobema clava, Epioblcbsma

t. rangiana and Epioblasm,a triquetra.

The future outlook for our larger streams is

not one of total dispair. It may well be that if

and when the larger streams are cleaned up, to a

point where they again afford suitable habitat

for naiades, lesser tributaries such as Eagle

Creek may produce the restocking material for

these larger waterways.

The large number of species and good num-

bers of individuals in Eagle Creek indicate a

stream of rather high quality that is under little

or no environmental stress. Conservation ef-

forts by state and federal agencies, aimed at

protecting these small stream refugia, may be

the key to the continued existence of freshwater

naiades in North America.

LITERATURE CITED

Danglade, Earnest. 1922. The Kentucky River and Its

Mussel Resources. U.S. Bureau of Fisheries Doc. 934:1-8.

Stansbery, David H. 1979. Naiad MoUusks of the Ohio River

Drainage System. The Ohio State University Museum of

Zoology, 1-p mimeo.

PHILLIP W. CLOVER

COLLECTOR & DEALER IN

WORLD WIDE SPECIMEN

SEA SHELLS p. o. Box 83

Glen Ellen, CA 95442

FREE SHELL LISTS

SPECIALISTS IN

CYPRAEA. CONUS, VOLUTA

margineCla, Mif RA, MUREX

96 THE NAUTILUS

April 30, 1981

Vol. 95(2)

ANEW SPECIES OF CROSSLANDIA (NUDIBRANCHIA: DENDRONOTACEA)

FROM THE GULF OF CALIFORNIA

Leroy H. Poorman'

Museum Associate

Los Angeles County Museum of

Natural History

Members of the dendronotacean nudibranch

family Scyllaeidae have been reported through-

out the equatorial and temperate seas for over

two centuries. Seba (1743) first published an il-

lustration of one of these species as Pullus

Ranae Piscatricis Quartae. He thought is was

the young of a fish and figures it in an inverted

position. Several years later, Linnaeus (1758)

named this species Scyllaea pelagica. thus

establishing the binomial. Linnaeus, however,

continued the error of describing the animal up-

side down.

Presently, Scyllaeidae contains three genera:

Scyllaea Linnaeus, 1758, Crosslandia Eliot,

1902, and Notobryon Odhner, 1936. Character-

istics of the genera are detailed in Odhner (1936:

1096-1103).

Crosslandia daedali Poorman and Mulliner,

new species

Description -Body long, about 25 mm in

length, narrow and deep; produced forward in a

long neck and posteriorly in a short tail (Fig. 1).

Wide winglike lobes extended laterally along the

middle one-half of each side; lobes irregularly

notched and digitate (Fig. 2). Head blunt, with

an abbreviated vellum on upper portion of the

buccal opening. Rhinophores retractile in hollow

of flaring rhinophore sheaths; conical, perfoliate

with 22 leaves. Numerous fimbriating retracta-

ble branchial tufts irregularly placed on the in-

side surface of the lobes and the dorsal area be-

tween (Fig. 2). A caudal crest extended over the

tail section.

Color of animal greenish brown-orange; longi-

tudinal fine chestnut brown lines with some

white lines on sides and undersides of lobes; a

and

David K. Mulliner

Research Associate

San Diego Museum of Natural History

Balboa Park, San Diego, CA 92112

FIG. 1. Sketch of a living Crosslandia daedali (25 mm in

length) crawling over Padina; lateral mew, anterior to the

right. Dramng try A. D'Attilio.

> 15300 Magnolia Street, Sp. 55, Westminister, CA 92683.

FIG. 2. Dorsal view o/Crosslandia daedali, shoacing the bran-

chiae on the inner surface of the body lobes and various inter-

nal organs, a, jaw plates: b. pharyngeal bulb: c, gaglion; d,

liver mass: e, three-part hermaphroditic gland: f, stomach:

g, heart: h, ana.'t: i, branchial tufts. Drawing by A. D'Attilio.

Vol. 95(2)

April 30, 1981

THE NAUTILUS 97

narrow light-colored border along the thin edge

of the rhinophore sheaths, along the sides of

neck, around edge of lobes and crest of tail; ir-

regular black to brown blotches on some ani-

mals. Brilliant blue small round spots medially

along sides of body, about 6 in number, about 5

spots medially on the dorsum, most spots with

fine black borders. A row of 4-6 flesh-colored,

sharply conical tubercles along median line of

each side of the animal.

Jaw plates (Fig. 3) large and hinged dorsally

with the muscles attached at the bend and

FIG. 3. Lateral mew of the jaw o/Crosslandia daedali. Draw-

ing by A. D'Attilio.

covering the large tessellated stiff cheeks. The

radula with 15 longitudinal rows of teeth denti-

culated on both sides (Figs. 4 and 5); central

tooth slightly flattened, smaller than the

laterals. The radula formula 15x25«1.25.

The hermaphrodite gland (Fig. 6) of three

masses, two posterior, one on each side of a liver

mass located in the mid-dorsal region; the third

mass located anterior on the right side of the

animal. The genital opening beneath the rhino-

phore sheath on the right side. The spermatheca

X)nnecting directly into the vagina. The large

ampulla connected by a long convoluted tube to

;he genital orifice. The liver in two large masses

interior and posterior. The stomach armed with

14 plates in a constricting ring. The anus located

nidpoint of the side below the right lobe.

Type-locality -Tmajas, Bahia de Bacochibam-

)o, Sonora, Mexico (27°56'N; 110°59'W).

Material examined -Eoloty^e, San Diego

Natural History Museum, Department of Ma-

ine Invertebrates, Type Series No. 514. Col-

FIG. 4, Sketches of various views of assorted radiilar teeth.

Draunngs by A. DAttilio.

lected at Tinajas, Bacochibampo Bay, Sonora

Mexico (27°56'N; 110°59'W); 4 December 1975,

by Roy and Forrest Poorman. Paratypes, col-

lected with the holotype specimen, are deposited

in the malacology (or marine invertebrate) col-

lections of the San Diego Natural History

Museum (SDNHM Type Series No. 515), the Los

Angeles County Museum of Natural History

(LACM 1910), and the United State National

Museum (USNM 795112).

Additional material was collected at Tinajas,

Sonora, Mexico, on 23 October 1976. Also, 4

specimens were collected at Bahia de Algo-

dones, Sonora, Mexico, and 1 specimen was col-

lected on the east side of Punta Cuevas, Bahia

de San Carlos, Sonora, Mexico.

Etymology -This species is named in recogni-

tion of the Greek, Daedalus. When the animal is

at rest, it attaches to Padina with the posterior

part of the foot. With its lateral lobes extended

98 THE NAUTILUS

April 30, 1981

Vol. 95(2)

FIG. 5. Scanning electron micrographs of the lateral teeth of

Crosslandia daedali. Top and middle., approximately 6S5 x .

Bottom, approximately ISOOx. Microscopy by Robert Petty-

john.

FIG. 6. Sketch of the viscera o/ Crosslandia daedali. a, liver

mass; b, stom,ach; c, hermaphroditic gland. Drawing by A.

D'Attilio.

and head and neck raised, it appears to reach

outward from the stem. Just so must the legend-

ary Daedalus have looked as he fastened on his

feathers and paused before launching into his

winged flight.

DISCUSSION

Crosslandia da£dali has been found only on

the Sonoran shores of the Gulf of California, in

the Guaymas area. It is the first record of the

genus from the Eastern Pacific. Its known con-

gener, C. viridis Eliot, 1902, has been reported

only from Zanzibar, the Red Sea and Japan.

There are distinctive internal anatomical

features which distinguish these two species. In

Crosslandia daedali the masticatory edge of the

jaws is smooth and flexible, bending outward

and forming stiff cheeks which are attached full

length. By contrast, a slit separates the bottom

one-third of the jaw plate at the bend in C.

viridis. The spermatheca of C. daedali is attach-

ed directly to the vagina, whereas in C. viridis it

is connected by a long tube.

Externally, the new species consistently

Vol. 95(2)

April 30, 1981

THE NAUTILUS 99

shows a narrow, light-colored border along the

sharp edges of the body and all the appendages.

This is not apparent on Crosslandia viridis.

Crosslandia daedali consumes small hydroids

growing on the surface of the algae. The nudi-

branchs graze slowly over the surface or attach

to the stems with a small central portion of the

foot, resting with the head and neck extended

and the lateral lobes projecting at an angle of

about 45° from the vertical. Because of coloring

and irregular shape, these animals are mime-

tically camouflaged, resembling another piece of

torn algae.

ACKNOWLEDGMENTS

We thank Mrs. Laura Shy for field assistance;

Mr. Robert Pettyjohn for doing the scanning

electron microscopy; Mr. Anthony D'Attilio (De-

partment of Marine Invertebrates, San Diego

Natural History Museum) for the anatomical

drawings; and especially Dr. Hans Bertsch

(formerly Curator of Marine Invertebrates at

the San Diego Natural History Museum) for his

editorial assistance in putting this paper

together.

LITERATURE CITED

Eliot, C. N. E. 1902. On some nudibranchs from Zanzibar

Proc. Zool. Soc. London 2:62-72; pis. 5-6; text figs. 2-5.

Linnaeus, C. 1758. Systema naturae, tenth edition

Odliner. N. H. 1936. Nudibranchia Dendronotacea. A revi-

sion of the system. Me7n. Mus. Roy. d'Hist. Nat. Belgigue

2nd ser. 3:1057-1128; 1 pi.; 47 text figs.

Seba, D'Albert. 1743. Locupletissimi rerwn naturalimn

thesauri accurata descriptio et iconihus artificionissi-

mis. Amstelodami.

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THE

NAUTILUS

ISSN 0028-1344

Vol. 95

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THE

NAUTILUS

Volume 95, number 3 - July 10, 1981

ISSN 0028-1344

CONTENTS

William K. Emerson

Two New Indo-Pacific Species oiMorum (Gastropoda: Tonnacea) 101

William K. Emerson, George L. Kennedy, John F. Wehmiller, and Everly Keenan

Age Relations and Zoogeographic Implications of Late Pleistocene Marine

Invertebrate Faunas from Turtle Bay, Baja California Sur, Mexico 105

Dorothea S. Franzen

Catinella vagans (Pilsbry) and a New Species of Catinella (Succineidae Pulmonata)

from the Shore of Lake Waccamaw, North Carolina 116

Barbara W. Myers and Anthony D'Attilio

The Morphology and Distribution of Ocenehra grippi (Muricidae: Ocenebrinae) 124

Hugh J. Porter and Glenn Safrit

The Marine Faunal Zones of North Carolina, with New Molluscan Records 127

R. S. Harvey

Recolonization of Reactor Cooling Water System by the Asiatic Clam

Corbicula fluminea 131

Roy S. Houston and Edward B. Hatfield

The Reproductive System of the Western Atlantic Anachis avara

(Gastropoda: Columbellidae) 136

Robert M. Severns

Growth Rate Determinations of Achatinella lila, A Hawaiian Tree Snail 140

Amy Lyn Edwards and Celeste Marie Humphrey

An Electrophoretic and Morphological Survey oi Busycon Occurring in

Wassaw Sound, Georgia 144

James F. Quinn, Jr.

The Gastropods, Calliostoma orion Dall, 1889 (Trochidae) and Heliacus (GyrisctLs)

worsfoldi N. Sp. (Architectonicidae), from the Bahama Islands 150

Publications received ii Recent deaths ii

THE NAUTILUS

July 10, 1981

Vol. 95(3)

PUBLICATIONS RECEIVED

Roth, Alexander, Jr. 1980. Molluscan Melange: How to

Prepare Your Molluscs for Eating. 148 pp., illus. Aljemasu

Enterprises, P. 0. Box 7867, Tamuning, Guam 96911.

Paperback, $6.95. A charming book containing many new

and old recipes for scallops, oysters, escargots, squid, and

various lesser mollusks. The culinary information is far

better than the malacological accounts.

Roth, Alexander, Jr. 1980. Mollusks of the Southem Ma-

rianas Islandx. 110 pp. Aljemasu Enterprises, Guam. An

informal checklist of mollusks found in Guam. Contains a

phylogenetic listing of most families of mollusks. List is

marred by inclusion of numerous species guessed to be

"probable on Guam" which doubtlessly will never extend

their ranges to that archipelago.

Farmer, Wesley M. 1980. Sea-Slug Gastropods. W. M.

Farmer Enterprises, Inc., P. 0. Box 26653, Tempe, AZ

85282. 177 pp. Technical coverage of Pacific coast nudi-

branchs, aphysiids, sacoglossates, one Titiscania (no

Lamellaria sea slugs) and Onchidella, with drawings

of animals, radulae and ranges. Author recommends

reader obtain set of 60 pencils in order to color the draw-

ings! Index consists only of list of authors with the species

they have described. Unfortunately the preface is poorly

written, but does not detract from the usefulness of the

book.

Breisch, Linda L. and Victor S. Kennedy. 1980. A Selected

Bibliography of Worldwide Oyster Literature. Publication

no. UM-SG-TS-80-11, Sea Grant Program, Univ. Mary-

land, 1224 H. J. Patterson Hall, College Park, MD 20742.

Contains titles and references to 2837 published articles,

810 reports, and 134 theses, with subject indices to each.

Waller, Thomas R. 1981. Functional Morphology and Devel-

opment of Veliger Larvae of the European Oyster, Ostrea

eduiis Linne. Smithsoiitan Contributions to Zoology, no.

328, 70 pp., 152 SEM figs. Many new structures dis-

covered.

Dell'Angelo, Bruno and Angelo Tursi. 1978. Guida biblio-

grafica ai Chitoni (Polyplacophora): 1970-1978. Oebaiia,

vol. 4, pp. 79-151. [living and fossil].

Kaas, Piet and Richard A. van Belle. 1980. Catalogue of

Living Chitons (MoUusca: Polyplacophora). 144 pp. Dr. W.

Backhuys, Publ., Oudorpweg 12, Rotterdam RC 3062,

Netherlands. Hardback. About $20.00 U.S. (no bibliog-

raphy, see above).

Bruce, J. I. et al., editors. The Mekong Schistosome. Mala-

cological Review. Chapter on snail host, Triatla aperta.

$26.00. Malacological Review, P. 0. Box 420, Whitmore

Lake, MI 48189.

RECENT DEATHS

Joshua L(ongstreth) Baily, Jr. died on April

18, 1981, in Mission Hills, California, at the age

of 92. He was born Jan. 29, 1889, in Philadel-

phia, PA. He graduated from Haverford College

(A.B., 1912; A.M. 1913) and Johns Hopkins

(Sc.D., 1938). A Quaker, he served in the

American Red Cross in World War I. He was a

past-president and charter member of the

A.M.U. and later in life moved to California

where he was associated with the San Diego

Society of Natural History where his collection

and library are now housed. A biobibliography

appears in Festimis, vol. 8, no. 5, p. 63 and in

American Malacologists, 1st ed., 1973, p. 195.

Ralph H(amilton) Humes died on April 17,

1981, in Leesburg, FL, at the age of 79. He was

born Dec. 25, 1902, in Philadelphia, PA. He was

a well-known sculptor and an active collector

and student of Florida and Cuban tree snails of

the genus Liguus for many years. His collection

was given to the Everglades National Park

museum. A short biography appears in Ameri-

can Malacologists, 1st ed., p. 312. He is survived

by his wife, Janet C. Humes, 2616 Azalea Pt.,

Leesburg, FL. 32748.

Vol. 95(3)

July 10, 1981

THE NAUTILUS 101

TWO NEW INDO-PACIFIC SPECIES OF MORUM

(GASTROPODA: TONNACEA)

William K. Emerson

American Museum of Natural History

New York, New York 10024

ABSTRACT

Morum (Oniscidia) macdonaldi, n. sp. (type locality Kwajalein Atoll, Marshall

Islands) and M. (0.) joelgreenei, n. sp. (type locality, GulfofDavao, Mindanao

Island, Philippines) are described. The former taxm represents the first Microne-

sian record for the genus Morum in the western Pacific Ocean. Nineteen living

species o/ Morum (sensu lato) are now known (IS in the Indo-Pacific, two in the

eastern Pacific, and four in the western Atlantic). Some of these taxa are poorly

known and require additional study.

Although the genus Morum (sensu lato) was

more widely distributed during the Tertiary

with species known from Europe, India, In-

donesia, New Zealand, Japan, and the Americas

(from Florida to Peru), the surviving members

of the subgenera Oniscidia and Herculea are

best represented in the western Pacific Ocean.

Here most of the species live in the waters off

the Old World continent, ranging from southern

Japan, the Ryukyu Archipelago, Taiwan, to the

Philippines, and are found in the southwestern

Pacific waters in New Guinea, New Caledonia,

and eastern Australia. One species (Morum

pon.derosum). however, occurs in the south-

central Pacific at Pitcairn Island; it is also

recorded from the Ryukyu Archipelago, New

Caledonia, and off Queensland, Australia. With

the discovery of the new species described

lerein from the Marshall Islands, the genus is

low known from Micronesia. In contrast, the

discovery of another new species in the Philip-

aines is not unexpected, as many new and other-

A'ise interesting mollusks have been recently

recovered in this archipelago by industrious col-

ectors.

In addition to the two species described below,

he following Recent species of Morum are

mown, 1. Indo-Pacific, M. (Oniscidia): cancella-

um (Sowerby, I, 1824); exquisitimi (Adams and

leeve, 1848); grande (A. Adams, 1855); macan-

Irewi (Sowerby, III, 1889); praeclarum Melvili,

919; bruuni Powell, 1958; teramachii Kuroda

and Habe, in Habe, 1961; uchiyamai Kuroda

and Habe, in Habe, 1961; watsoni Dance and

Emerson, 1967; kurzi Petuch, 1979; M. (Hercu-

lea) ponderosum (Hanley, 1858). 2. Eastern

Pacific, M. (Morum) tuberculosum (Reeve,

1842); M. (Oniscidia) veleroae Emerson, 1968. 3.

Western Atlantic, M. (Morum) oniscus (Linne,

1767); M. (Oniscidia): dennisoni Reeve, 1842);

strombiformis (Reeve, 1842); matthewsi Emer-

son, 1967.

One or two of these nominal species are per-

haps best considered a nomen iyiquirendwm, un-

til additional specimens can be obtained. A few

others require anatomical study in order to

determine their biological validity.

Family Cassidae Swainson, 1832

Genus Morum Roding, 1798

Type species by monotypy: Morum purpureum

Roding, 1798 [ = Strombus oniscus Linne, 1767],

Recent, western Atlantic. Morum s.s. is repre-

sented by a few Plio-Pleistocene to Recent, New

World species with knobbed, subcylindrical

shells.

Subgenus Oniscidia Morch, 1852

Type species by monotypy: Oniscia cancellata

Sowerby, I, 1824, Recent, Indo-Pacific (See

I.e. Z.N. Opinion 1040, 1975). Represented by

several Eocene to Recent, largely world-wide

species with extended spires and cancellate

102 THE NAUTILUS

July 10, 1981

Vol. 95(3)

FIGS. 1-3. Morum (Oniscidia) joelgfeenei n. sp. x 1. I, Holotype, dorsal, parietal and apertural vieu's. 2, Paratype A. dorxal

and apertural views. 3, Paratype B. dorsal and apertural inews.

FIGS. 4-6. Morum (Oniscidia) macdonaldi, n. sp., x 2. 4, Holotype. dorsal, parietal, and apertural in,ews. 5, Paratype A, dor-

sal and apertural views. 6, Paratype B. dorsal and apertural views; note immature apertural chararters.

FIG. 7. Morum (Oniscidia) kurzi Petuch, 1979. x 2; Delaware Mws. Nat. Hist. no. 126S93: holotype, dorsal and apertural views.

All photographs try S. S. Horenstein.

sculpture of broad axial ribs and narrower spiral

cords.

Morum (Oniscidia) joelgreenei,

new species

Figs. 1-3

Description- Shell trian^larly ovate, moder-

ately stocky with a wide shoulder, attaining 46 +

mm (holotype, fig. 1); spire extended; proto-

conch of 3V2 smooth whorls, erect and papillate;

5+ postnuclear whorls cancellated, with 10

moderately weak spiral cords, crossed by 10

conspicuous, spinose axial ridges (varices) per

Vol. 95(3)

July 10, 1981

THE NAUTILUS 103

whorl; juncture of spiral cords and varices with

a sharp, hooked spine; spines most prominent at

the shoulder; intervarical areas with 8 to 10

evenly spaced axial lamellae; parietal shield

large with outer margin raised and covered with

numerous pustules; parietal pustules linear near

the aperture, pimplelike on the outer margin;

outer lip thickened, crenulated and toothed; 9

primary teeth form linear bifid projections on

the inner labial margin, secondary teeth con-

fined to postmarginal surface; anal sulcus shal-

low; siphonal canal short, recurved, open.

Coior- Nucleus shiny, light- tan; postnuclear

whorls with whitish base color, overlaid with

flecks of reddish brown; 4 widely interrupted

brownish spiral bands on body whorl (1 band on

shoulder, 2 on either side of midbody area, 1

near the base); darkest coloration of bands on

side facing apertural face of each varical spine

and on edge of outer lip; bands more defused in

Paratype B; parietal shield glazed, buff color

with posterior surface tinged a pale lavender-

white; pustules white; outer lip glazed, buff col-

or with dark-brown blotches (4 major blotches

formed at labial base of spiral bands and 2

secondary blotches between each spiral band).

Material examined - E.o\QtyTpe A.M.N.H.

203719 (fig. 1), 46.4 mm in length, 29.8 mm in

width; Paratype A, A.M.N.H. 201362 (fig. 2),

39.4 mm in length, 26.1 mm in width (both ex-

Joel Greene collection from type locality);

Paratype B, (fig. 3), 35.3 mm in length, 22.8 mm

in width (William Bledsoe collection, from

Panglao, Bohol Island, Philippines, from tangle

nets, in 146 meters, June 1980).

Type locality -Davao Gulf, Mindanao Island,

Philippines, netted in 200 meters in 1980 by

Filipino shell fishmen.

Distribution -Known only from Davao Gulf

and Bohol Strait.

Etymology -'Named for Joel Greene, an avid

collector and a purveyor of shells.

Remarks -This species is reminiscent of the

western Atlantic species Morum (Oniscidia)

dennisoni (Reeve, 1842; Dance and Emerson,

1967, p. 93-94, pi. 12, figs. 5-7), but differs in

details of the sculptural ornamentation and in

the coloration of the aperture and parietal

shield. Morum (0.) exquisitum (Adams and

Reeve, 1848), a species also known only from

Philippine waters (Emerson, 1977, p. 83, 84,

figs. E, F, J), has a more robust shell, with

stronger and more numerous axial ribs, and a

purplish pink parietal shield and outer lip.

Morum (0.) kurzi Petuch (1979, p. 7, figs.

10-13), recently described from the Philippine

Islands, has a smaller shell with coarser sculp-

ture and an orange-colored parietal shield and

outer lip (fig. 7). The Sino-Japanese species, M.

(0.) macandrewi (Sowerby, III, 1889; Habe,

1964, p. 67, pi. 20, fig. 4), has coarser sculpture,

stronger banding, with a white parietal shield

and a white outer lip bordered with numerous

dark blotches on the outer labial rim.

Morum (Oniscidia) macdonaldi,

new species

Figs. 4-6

Description- Shell somewhat pyriform,

broadly shouldered, small for group, attaining

17-1- mm in length (holotype, fig. 4); spire weak-

ly extended; protoconch of 3 whorls, erect and

papillate; A+ postnuclear whorls cancellated,

with 12 strong spiral cords, crossed by 16 promi-

nent axial ridges (varices); juncture of spiral

cords and varices with a blunt, weakly hooked

spine, spines most conspicuous at the shoulder;

intervarical pits with 6 to 10 weakly raised

striae; parietal shield small, largely confined to

columella wall, with outer margin raised and

covered with numerous small pustules, mostly

pimplelike; outer lip narrowly thickened, crenu-

lated and toothed with about 10 major denticles

on the inner labial surface; 3 minor denticles

near anterior end of siphonal canal; anal sulcus

weakly notched; siphonal canal short, gently

recurved, open.

Coior- Nucleus shiny, pinkish-tan; post-

nuclear whorls with creamish tan base color, 4

discontinuous purplish-browTi bands on body

whorl (1 band on shoulder, 2 on either side of

midbody area, and 1 near the base; bands less in-

terrupted on paratype with juvenile aperture

(fig. 6); darkest coloration of bands on the aper-

tural sides of varical spines and at base of outer

lip; parietal shield poorly glazed, with white

pustules; labial margin white, not blotched.

Material examined -Holotype A.M.N.H.

104 THE NAUTILUS

July 10, 1981

Vol. 95(3)

203713, 17.3 mm in length, 10.8 mm in width

(fig. 4); Paratype A, A.M.N.H. 203714, 16.1 mm

in height; 9.5 mm in width (fig. 5); Paratype B,

A.M.N.H. 203715, 15.8 mm in length, 10.2 mm

in width (fig. 6); Paratype C, A.M.N.H. 203716,

15.9 mm in length, 10.1 mm in width (all ex-D. J.

MacDonald collection); 2 Paratypes, D. J. Mac-

Donald collection.

Type locality-West reef of Kwajalein Atoll,

between the islands of Kwajalein and Ninni,

Marshall Islands, in about 15 meters, on sandy

rubble imder coral boulders, along the ocean

side dropoff of the fringing reef (^es^e D. J. Mac-

Donald, February 23, 1981).

Distribution -Known only from the type

locality.

Ety7nology -Named for the collector, D. J.

MacDonald. He recognized the uniqueness of

this discovery and submitted specimens to

Robert W. Morrison, who in turn kindly trans-

mitted the material to me for study.

i?emarA-s- Somewhat resembling a tiny,

immature Morum (0.) macandrewi (Sowerby,

III, 1889), this distinctive species is the first

representative of the genus reported from the

Marshall Islands. The molluscan fauna of these

atolls is well known (e.g. Dietrich and Morris,

1953; Brost and Coale, 1971). The difficulties of

collecting on the ocean side of the reefs and the

diminutive size of the shells undoubtedly have

contributed to the failure to find specimens in

the past. No specimens were obtained inside the

lagoon. Mr. MacDonald reports examining

about a dozen specimens, including two living

ones discovered at night on patches of sand near

coral rubble. None of the six specimens recorded

here were live- taken, but several were obtained

in a well-preserved condition, as is the case of

the holotype and the figured paratypes.

ACKNOWLEDGMENTS

I am indebted to the following collectors for

their generosity in submitting specimens for

study: William Bledsoe of Los Angeles, Califor-

nia, Joel Greene of San Francisco, California,

Robert W. Morrison of Sarasota, Florida, D. J.

MacDonald of Kwajalein Atoll, and Carl C.

Withrow of St. Petersburg, Florida. Virginia 0.

Maes and Robert Robertson of the Academy of

Natural Sciences of Philadelphia, Russell

Jensen of the Delaware Museum of Natural

History, and Joseph Rosewater of the U.S. Na-

tional Museum of Natural History, kindly pro-

vided information on material in their respec-

tive institutional collections. I thank my col-

leagues, Sideny S. Horenstein and William E.

Old, Jr., for technical assistance.

LITERATURE CITED

Adams, Arthur. 1855. Descriptions of new genera and spe-

cies of gasteropodous [sic] Mollusca. Proc. Zool. Soc.

Londmi for 1853, 21(259):182-186 (May 16, 1855).

Adams, Arthur and Lovell Reeve. 1848[-50]. Mollusca. In.

A. Adams, The Zoology of the Voyage of H.M.S. Sama-

rang; under the Command of Captain Sir Edward Belcher.

London, p. x +87.

Brost, F. B. and R. D. Coale. 1971. A Guide to Shell Col-

lecting in the Kwajalein Atoll. Charles E. Tuttle Co., Rut-

land, Vermont, 157 pp.

Dance, S. P. and W. K. Emerson. 1967. Notes on Morum

dennisoni (Reeve) and related species (Gastropoda: Ton-

nacea). The Veliger 10(2):91-98.

Dietrich, R. V. and P. A. Morris. 1953. Mollusks from

Kwajalein. The Nautilus 67(1):13-18.

Emerson, W. K. 1967. A new species of Morum from Brazil,

with remarks on related species (Gastropoda: Tonnacea).

The Veliger 9(3):289-292.

1968. A new species of the gastropod genus

Morum from the eastern Pacific. Jour. Conchyl. 107(1):

53-57.

1977. Notes on some Indo-Pacific species of

Morum (Gastropoda: Tonnacea). The Nautilus 91(3):

81-86.

Habe, Tadashige. 1964. Shells of the Western Pacific in

Color, 2. English ed. Hoikusha, Osaka, 233 pp.

Hanley, Sylvanus. 1858. Description of a new Oniscia.

Proc. Zool. Soc. London 26(142):255-256.

International Commission on Zoological Nomenclature.

1975. Opinion 1040 Oniscidia Morch, 1852 (Mollusca):

Placed on the Official List. Bull. Zool. Nomeri. 32(3):

139-140.

Kuroda, Tokubei and Tadashige Habe, In, T. Habe. 1961.

Colored Illustrations of the Shells of Japan, 2, Hoikusha,

Osaka, Appendix, p. 1-41.

Linne, Carl. 1767. Systema naturae per regna tria naturae.

Editio duodecima. reformata, pt. 2, p. 533-1327.

Melvill, J. C. 1919. Description of Morum praeclarum, sp.

nov., with remarks on the Recent species of the genus.

Proi: Mnlnc. Soc. London 13(3-4):69-72; Addendum,

Itnd. 13(5-6): 145.

Morch. 0. A. L. 1852. Calalogus conchyliorum . . . de Yoldi.

Regis Daniae. Copenhagen. Fac. 1, 170 p.

Petuch, E. J. 1979. Twelve new Indo-Pacific gastropods.

Occ. Pap. Delaware Mus. Nat. Hist. Nemmiria no. 23,

21 p.

Vol. 95(3)

July 10, 1981

Powell. A. W. B. 1958. Mollusca of the Kermadec Islands.

Pt. 1. Rirordx Auckland Inst, and Mus. 5(l-2):65-85,

pis. 9-11.

Reeve, L. A. 1842. Conchologia Systematica, or Complete

System of Conchology. London, vol. 2.

Roding, P. F. 1798. Musmm Btilteniariuni . . . pt. 2, Con-

chylia. Hamburg, vii+109 p.

Sowerby, G. B., I. 1824. The Genera of Recent and Fossil

THE NAUTILUS 105--

Shells. London, vol. 1, Oniscia pi. 233.

Sowerby, G. B., IH, 1889. Descriptions of fourteen new

species of shells from China, Japan, and the Andaman

Islands . . . Proc. Zool. Sac. London for 1888, p. 565-570.

Swainson, William. 1829-33. Zoological illustrations, or

figures and descriptions of new, rare, or interesting ani-

mals . . ., ser. 2, vol. 3, pis. 1-136.

AGE RELATIONS AND ZOOGEOGRAPHIC IMPLICATIONS OF LATE

PLEISTOCENE MARINE INVERTEBRATE FAUNAS FROM TURTLE BAY,

BAJA CALIFORNIA SUR, MEXICO

William K. Emerson', George L. Kennedy^,

John F. Wehmiller^, and Everly Keenan^

ABSTRACT

Two Pleistocene marine terraces at Turtle Bay, northwestern Baja California

Sur, Mexico (27.7° N. lat.) have been dated at approximately 120.000 and 95,000

years B.P. on the basis of amino-acid racemization in fossil mollusks. These ages

imply a correspondence to the early and middle-to-late parts, respectively, of

marine oxygen-isotope stage 5. Faunal differences between the upper {2k-27 m),

120,000-B.P. terrace and the lower (12 m). 95,000-B.P. terrace conform to the age

relations and faunal-temperature aspects docum.ented previously in other

localities on the Pacific coast of North America. Faunal assemblages from, these

terraces contain both extralimital northern and southern species, an enigmatic

situation not uncommon in East Pacific Pleistocene deposits. However, nearly

50% of the species from the upper tei'race are warm-water (subtropical and

tropical) taxa, whereas only 5% are cool-water (warm teynperate) taxa. Converse-

ly, the lower terrace fauna is composed of 21 % extralimital northern taxa, and. on-

ly a minor (9%) southern, warm-water element.

INTRODUCTION

Pleistocene marine invertebrate faunules

from two marine-terrace deposits at Turtle

Bay*, northwestern Baja California Sur, Mexico

(Figs. 1, 2), contain distinct warm- and cool-

water elements (Emerson, 1980). These faunal

'Department of Invertebrates. American Museum of

Natural History, New York, New York 10024

-U.S. Geological Survey, Menlo Park, California 94025

'Department of Geology, Llniversity of Delaware, Newark,

Delaware 19711

^Turtle Bay (27°41'N., 114°52'W.) is also known as Bahia

Tortugas, the port of which is Bahia San Bartolome or Puer-

to Bartolome.

differences, in comparison with similar faunal

differences known to represent discordant ages

elsewhere (Kern, 1977; Kennedy, 1978; Lajoie et

ai, 1979), suggest that the warmer and cooler

water assemblages at Turtle Bay might also

represent different ages. To test this hypoth-

esis, we examined the extent of amino-acid

racemization in mollusks from each assemblage,

and derived estimates of both relative and ab-

solute ages. We also considered the zoogeo-

graphic implications of the temporally distinct

assemblages (Emerson, 1980).

Amino-acid racemization methods can serve

as both relative and semi-quantitative tools for

106 THE NAUTILUS

July 10, 1981

Vol. 95(3)

FIG. 1. Index map of Baja California, Mexico, showing

Pleistocene localities (numbered 1 to 11), Turtle Bay (locality

9), and geographic place names representing the modem

range endpoints of some components of the Turtle Bay

faunas.

dating Quaternary mollusks (see Hare et aL,

1980, for recent review and references). Recent

studies of Pleistocene mollusks from both the

Atlantic and Pacific coasts of the United States

have shown that D/L values increase with age in

Pleistocene samples with known stratigraphic

relations. In addition, the temperature depen-

dence of amino-acid racemization has been docu-

mented with D/L data from three roughly coeval

(~120,000-yr.) uranium-series-dated localities

over a broad latitudinal range on the Pacific

coast (24° N. to 35° N.) (Wehmiller and Emer-

son, 1980). The ~120,000-yr. amino-acid

isochron thus generated allows interpolation of

amino-acid enantiomeric ratios (D/L values) at

intermediate temperatures, such as for the

localities at Turtle Bay.

Sebastian Vizcaino Bay

iTurtle'tJ ■

'^Ir^ Bay

B-3007 ^»,B-3024 (SaioSTM)

Cape ^"^V^-'

Tortolo I 'B-3026 i6to9M

B-3048 (6 M) localed i 9 7 Km

southeast of Turtle Bay

Thurloe Head

FIG. 2. Sketch map (not to scale) showing the approximate

location offossiliferous terrace remnants in the Turtle Bay

area.

The fossils used herein are part of a collection

made in 1956 by the late E. C. Allison from six

localities in the vicinity of Turtle Bay (Fig. 2)

(see "Register of Localities" for collection data).

These collections are now in the University of

California Museum of Paleontology (UCMP),

Berkeley. Specimens for amino-acid analysis are

from two of these localities, one containing a

warm-water assemblage (UCMP loc. B-3024)

and the other a cool-water assemblage (UCMP

loc. B-3007). Locality B-3024 is on a 24 to

27-m-high terrace along the inner, bay side of

Cabo Tortolo, a peninsula forming the south-

west margin of Turtle Bay; locality B-3007 is on

a 12 m-high terrace along the northwest margin

of the bay, round its mouth. Although terrace

remnants are present at several elevations

around Turtle Bay (Ortlieb, 1979; Emerson,

1980), we herein refer to localities B-3024 and

B-3007 as the upper and lower terraces, respec-

tively.

PROCEDURE

We analyzed a total of 13 samples of the

venerid bivalve mollusks, Saxidomus nuttalli

Conrad, 1837, Chione undatella (Sowerby,

Vol. 95(3)

July 10, 1981

THE NAUTILUS 107

1835), and C. califomiensis (Broderip, 1835), to

determine the extent of racemization of their

component amino acids. Multiple analyses, in-

cluding repeats of the same shell, were neces-

sary to discriminate the slight differences in age

expected between the two localities. Amino-acid

analyses were performed according to the pro-

cedures of Kvenvolden et al. (1972), Frank et al.

(1977), Wehmiller et al. (1977), and Wehmiller

and Emerson (1980). Capillary column gas chro-

matography was performed on either NTFA-

isopropyl derivatives or NTFA-( -^ )-2-butyl

derivatives of the total amino-acid mixture. The

NTFA-( -)- )-2-butyl derivatives were analyzed

with a Perkin-Elmer Sigma 2 gas chromato-

graph, using a 100-m glass capillary column

coated with OV225, programmed as follows: in-

crease from 115° to 140°C at 1.5°/min, 36 min

isothermal; increase at 2°/min to 165°C, 150

min isothermal. Chromatographic conditions for

the NTFA-isopropyl derivatives are found in

Wehmiller and Emerson (1980). When both pro-

cedures were used, sample extracts were split

and derivatized after all the hydrolysis and

desalting steps. Excellent baseline resolution

for at least seven amino acids is possible by the

combination of these two procedures. The enan-

tiomeric ratios (D/L) reported herein represent

mean values of peak-height ratios from at least

two chromatograms.

Table 1 lists the enantiomeric ratios of seven

amino acids in the Turtle Bay samples. These

data generally satisfy the criterion of reproduci-

bility and are consistent, within typical analyt-

ical uncertainty, with relative intergeneric and

intrageneric racemization (Lajoie et al., 1980).

The only significant deviations occurred in the

glutamic acid data for Saxidomus from locality

B-3007. In these samples, the glutamic acid D/L

values were too high in comparison with the

ratios of other amino acids, particularly leucine.

'' DISCUSSION

Enantiomeric ratios for the Turtle Bay

samples (Table 1) imply a small but significant

difference in age between the two sample locali-

ties. Differences in enantiomeric ratios between

each locality, however, are slight and fall barely

outside the range of normal analytical scatter,

Table 1, Amino Acid Enantiomeric (D/L) Ratios From Ciiione and Saxidomus

From Turtle Bay, Baja California Sur, Mexico

(UCMP localities B-3007 and B-3024)

Sample

Species

.oc. LEU GLU »AL ALA PRO PHE ASP iCal. Method

i-3007 ,57 .53 .50 .83 .64 .70 nd ..8 B

.56 .51 .50 .87 nd .58 .76 <.8 P

.56 .57 .47 .87 nd .58 .76 nd P

.52 .55 .53 .91 nd .49 .75 nd P

.53 .55 .53 .91 nd (.6) nd nd P

1-3007 .65 .61 .51 nd nd .61 .62 < 8 P

.62 .58 .49 .97 nd .65 .59 < .& p

.64 .63 .53 .94 nd .65 .69 < 8 P

.63 -52 .47 .91 nd .60 .60 <.8 P

.58 .63 .55 .93 nd .57 ,69

.60 .59 .58 .94 nd .59 .66

.71 .64 .61 .89

.69 .62 .59 .94

.61 .55

.61 .57 .55 .91

.63 .57 .56

70 ,76

nd .59 .70 .

1 ,0 nd .66 ,64 ■

nd ,62 .73

72 ,70 nd

e-3024 .73 .62 .51 .92 .84 .75 nd

.71 .63 .54 .93 nd .65 ,67

.69 .58 .51 .99 nd .66 .58

.64 .59 .45 .86 .78 .74 nd

.67 .57 .48 .94 nd .60 .69

.64 .58 .50 .94 nd .59 .65

Notes for Table 1:

Amino acid abbreviations:

LEU

GIU

VAL

ALA

Leucine

Glutamic Acid

Valine

Alanine

PRO Proline

PHE Phenylalanini

ASP Aspartic Acii

Kal , S Calcite

nd not determined

Methods: B - (t)-2-butyl derivative on OV 225 column.

P - isopropyl derivative on Chirasil Val column.

Samples labelled "R" represent second fragrant cut from a shell valve.

Samples split for analysis by two chromatographic methods represent

single fragments, the hydrolyzate of which was split after desalting

for separate derivatization.

Samples 79-64-la and 79-64-lb are the two valves of a single articulated

specimen of Chione,

especially for the Saxidomus data. Although the

ratios from each locality overlap slightly, the dif-

ference in mean D/L values is 2-5% for Sax-

idomus and 6-10% for Chione, depending on

which amino acid is compared. According to

Miller and Hare (1980), these differences would

be significant at the 90-95% confidence level. It

might be argued, however, that the amino-acid

results do not reflect any age difference, but are

instead due to typical analytical scatter (in the

case of Saxidomus), or species-level effects on

racemization kinetics (in the case of Ckmie).

Because of our accumulated observations on nu-

merous samples of both species of Chione and

two species of Saxidomus (Lajoie et al, 1980;

unpublished data), we believe the best interpre-

tation is of a real age difference.

Figure 3 plots D/L leucine values against local

mean annual air temperature for three uranium-

series dated localities along the Pacific coast, at

Cayucos, San Diego (Nestor Terrace), Califor-

nia, and at Magdalena Bay, as well as D/L leu-

cine values for Bird Rock Terrace at San Diego.

108 THE NAUTILUS

July 10, 1981

Vol. 95(3)

1.0-

.9-

.8-

.7-

LLi

-J .5-

^ ^-

Q

3

.2-

.1-

0-

LOC:

SD

TB MB

1

10

12 14 16 18 20 22 24

PRESENT MEAN ANN. TEMP., "C.

FIG. 3. Comparison of D/L leucine values from Turtle Bay

samples mlh 120.000-yr. B.P. isochron of D/L leucine vs.

present mean annual temperature (after Wehmiller and

Emerson. 1980). Calibration localities, connected by solid

line, are: Cayucos (C, 35.3°N. lat); Nestor Terrace CN, at

San Diego. SD, 32.7° N. lat): Magdalena Bay (MB, 2J,.8°N.

lat). Data for Bird Rock Terrace (BR, at SD), which is

known to be younger than the Nestor Terrace (Kern. 1977),

imply a leucine kinetic model age of 80.000 ±10.000 years

(Wehmiller et al., 1977). The plotted D/L leucine values for

Turtle Bay (TB>. 0.57 ± 0.03 for loc. B-3007 and 0.65 + 0.03 for

lac. B-302It. are mean values of all data, factored to account

for intergeneric differences in Chione, Protothaca, and Sax-

idomus (Lajoie et al, 1980), and for differences produced by

the two analytical methods used in this study (Wehmiller

and Emerson, 1980:32, footnote). The present mean annual

temperature at Turtle Bay is 20.9°C. (Hastings, 1961,). The

leucine mjudel age for loc. B-3007 is 95.000 ±15,000 years, us-

ing 120.000 years as the "calibration" age for loc. B-3021, and

a slightly cooler Effective Quidernary Temperature for

B-3007.

The age of Bird Rock Terrace, which occurs be-

low the 120,000-B.P. Nestor Terrace, is esti-

mated at 80,000± 15,000 B.P. by amino-acid

dating (Wehmiller et al, 1977) and from its

geologic relation to the Nestor Terrace (Kern,

1977). Both the faunal characteristics and rela-

tive extent of racemization of the Nestor/Bird

Rock Terrace pair resemble those of the upper

and lower terraces at Turtle Bay and invite com-

parison along these lines.

The data points plotted in Figure 3 are mean

values of all the D/L leucine determinations in

Chione, Protothaca, and Saxidomus from each

locality. These data have been factored slightly

to allow comparison of results obtained from dif-

ferent genera^ and by the two analytical

methods mentioned previously (see Wehmiller

and Emerson, 1980:32, footnote).

The Turtle Bay data are plotted at a mean an-

nual air temperature of 20.9° C (Hastings, 1964).

The data point for the upper terrace (loc.

B-3024) lies just below the smooth 120,000-yr.

(early stage 5) isochron drawn through the three

uranium-series-dated calibration points. The

separation between the isochron and locality

B-3024 data point is analytically only marginally

significant, and can not be considered as reliable

evidence for an age significantly less than

120,000 B.P. because of uncertainties in their

local Effective Quaternary Temperature his-

tories^. For example, if the difference in the

assigned temperatures of Magdalena Bay and

Turtle Bay was 0.3°C greater than that used

herein, the B-3024 data point would lie on the

isochron. Small differences in effective-tem-

perature histories create an inherent uncertain-

ty in amino-acid dating, especially in cases

where only small increments of time are being

resolved.

The data point for the lower terrace (loc.

B-3007) plots well below the 120,000-yr. iso-

chron and cannot be considered contemporane-

ous unless unreasonably large effective-temper-

ature differences are invoked. Assuming an

equal effective Quaternary temperature history

for both terraces (and an age of 120,000 B.P. for

the upper terrace), the age estimate for the

lower terrace would be approximately 85,000 ±

15,000 B.P., using the leucine kinetic model of

age estimation (Wehmiller et aL, 1977). Because

localities younger than 120,000 B.P. probably

have had a slightly cooler (0.3-0. 5°C.) effective-

temperature history (Wehmiller et aL, 1976;

Wehmiller et al.. 1977: fig. 16, table 1), the age

^Protothaca and Chione are assumed to have equivalent

kinetics; Saxidomus data have been converted to "equiva-

\ent-Protothaca" values (Lajoie et al.. 1980).

i^The Effective Quaternary Temperature (EQT) is the

temperature representing the average rate constant, and in-

tegrated temperature history, for a fossil sample (see

Wehmiller el al. 1977; Kvenvolden et at. 1979; Wehmiller

and Emerson, 1980; Wehmiller. 1981).

Vol. 95(3)

July 10, 1981

THE NAUTILUS 109

estimate for the lower terrace is herein revised

to approximately 95,000 B.P. (see Wehmiller et

ai, 1977:68, for discussion of similar tempera-

ture modeling of the Bird Rock Terrace age

estimate).

In summary, the early and middle-to-late

stage 5 amino acid age estimates for the upper

and lower terraces at Turtle Bay are based on

small differences in analytical results that could

also be due to factors other than age. Neverthe-

less, the simplest, and we believe the best, inter-

pretation is of a real difference in age (within a

single interglacial stage) between the two ter-

race remnants at Turtle Bay (Iocs. B-3024,

B-3007). Implications of an apparent difference

in the age and faunal character of the terraces

at Turtle Bay and elsewhere along the Pacific

Coast (Kern, 1977; Kennedy, 1978) are discuss-

ed below.

Faunal comparisons of

Turtle Bay assemblages

The upper Pleistocene terrace deposits from

Turtle Bay have yielded 138 species of metazoan

invertebrates, mostly mollusks (Emerson,

1980). When these fossils were collected, they

were believed to represent a single period of

deposition. Although most of the terrace de-

posits around Turtle Bay are horizontal in atti-

;ude, some are clearly deformed or faulted

Mclntyre and Shelton, 1957; Minch et ai,

1976), and the differences in elevation were at-

;ributed to this post-depositional deformation.

The fossiliferous terrace remnants in the vicini-

:y of Turtle Bay (Fig. 2) actually represent

several terrace levels: at 4.5 to 6 m (UCMP Iocs.

3-3027, B-3050, B-3048), at 6 to 9 m (loc.

3-3025), at 12 m (loc. B-3007), and at 24 to 27 m

,loc. B-3024) (elevations determined by E. C.

\.llison, see Fig. 2 and Emerson, 1980). How-

'ver, Ortlieb (1979:Fig. 1) recorded terrace

elevations in the Turtle Bay area at 5, 12, 20,

uid 50 m.

Two of the terrace localities (UCMP loc.

3-3024, B-3025) contain warm-water (sub-

ropical and tropical) species and were cor-

elated with marine oxygen-isotope substage 5e

'^Sangamon interglaciation) (Emerson, 1980)

'n the basis of faunal comparisons with other

dated assemblages (Kennedy, 1978). Four other

assemblages from Turtle Bay (Iocs. B-3027,

B-3050, B-3007, and B-3048) lack these warm-

water species and were not assigned to any in-

terglacial or isotopic stage on the basis of their

faunal composition (Emerson, 1980).

Emerson (1980) reported 83 positively identi-

fied species (53 gastropods, 28 bivalves, 1

chiton, and 1 echinoid) from locality B-3024 and

34 taxa (16 gastropods, 17 bivalves, and 1 echi-

noid) from locality B-3007 (Tables 2-5). In all, 20

species (12 gastropods and 8 bivalves), about

20% of the total number of taxa, are common to

both localities. No extinct species have been

recognized in these faunas.

Comparison of the modern geographic ranges

of the species from the upper and lower terraces

(Iocs. B-3024 and B-3007, respectively) show

basic differences in the zoogeographic composi-

tion of each fauna. Combined, the faunas con-

tain 25 tropical (Table 2), 17 subtropical (Table

3), and 8 warm-temperate (Table 4) species. The

warm-water fauna of the upper terrace contains

19 gastropods and 5 bivalves that have modern

northern endpoints of range south of Turtle Bay

(Table 2). An additional 14 species (6 gastro-

pods, 7 bivalves, and 1 chiton) occur only as far

north as the Isla Cedros-Bahia de Sebastian

Vizcaino area, and three other species (two gas-

tropods and one bivalve) range only as far north

as Bahi'a de Todos Santos in Baja California

Norte (Table 3). Thus, the assemblage from the

upper terrace contains distinct tropical and sub-

tropical elements representing nearly one half

(49%) of the fauna. On the other hand, the as-

semblage from the lower terrace contains only

three southern species (one gastropod, one bi-

valve, and one echinoid) that do not occur today

as far north as Turtle Bay (Tables 2, 3). The two

mollusks are common to both localities.

Table 4 lists warm-temperate species with

southern endpoints of range north, or in the

vicinity, of Turtle Bay. This northern element is

represented by only four species (three gastro-

pods, one bivalve) on the upper terrace and by

seven species (two gastropods and five bivalves)

from the lower terrace. Of these, two gastro-

pods and one bivalve are common to both

localities. The northern species from the upper

110 THE NAUTILUS

July 10, 1981

Vol. 95(3)

Table 2. Southern (tropical) Faunal Elements

From Turtle Bay Localities B-302't and B-3007

Table 3- Southern (subtropical) Faunal Elements

From Turtle Bay Localities B-3024 and B-3007

[Names in brackets for species not collected at

locality B-302'i, but recorded from SDSNH 062't

(=locanty B-3024; Emerson, 198O].

Species with modern northern endpoints of range

that occur south of, or in the vicinity (■•') of

Turtle Bay.

Mollusca: Gastropoda

Bulla punatulata

Cancellaria oassidiformis

Cantharus elegans

Ceritkium maculosum

Columbella major

*Conus fergxisoni __

Conus perplexus

IConus purpurasaens'^

[ Cypraea annettae']

[ Cypraea arabicula'^

Hormospira maculosa

Nerita saabriaosta

Oliva incraasata

Oliva polpasta forma davisae

Phyllonotus erythrostomus

Strombus graoilior

\_Strombus granulatusj

Thais biserialis

Trigonostoma goniostoma

Bivalvia

[ Araopsis solida ]

Chione picta

Ostrea angelica

Semele flavesoens

Trachyaardium panamense

Echi nodermata : Echinoidea

Eucidaris thouarsii

Col lect ing Stations

B-302l( B-3007

X

1

X

1

X

x_

X

1

X

1

X

[Names in brackets are species not collected at

locality 6-302*4, but recorded from SDSNH 062*4

('locality B-302I4, Emerson; 1980].

Species with modern northern endpoints of range

occurring on the west coast of Baja California,

north of Turtle Bay in the Isla Cedros-Bahia de

Sebastian Vizcaino area, unless otherwise indicated.

Chione gnidia

Dosinia ponderosa

Megapitaria squalida

Protothaoa grata

Tellina simulans

Polyplacophora

[Stenoplax magdalenensis]

06^*4

Species also recorded from SDSNH loc.

(Chace, 1956; Emerson, I98O, table 1).

2

Northern endpoint of range: Bahia Todos Santos.

Northern endpoint of range: 2*4 km north of Bahia

San Quint in.

Northern endpoint of range; Cabo Colnett.

Species also recorded from SDSNH loc. 062*4

(Chace, 1956; Emerson, I98O, table 1).

terrace represent less than 5% of the assem-

blage, in comparison with 21% for the lower ter-

race assemblage.

The remaining 46 species, all mollusks (Table

5), have modern ranges that overlap the latitude

of Turtle Bay. Many of these species terminate

their ranges to the north at Point Conception,

California (41%), and to the south on the west

coast of Baja California Sur (65%).

Amino-acid racemization data are not avail-

Vol. 95(3)

July 10, 1981

THE NAUTILUS 111

Table '4. Northern (warm temperate) Fauna I

Elements From Turtle Bay localities B-302'4 and

B-3007

[Names in brackets for species not collected at

locality B-302'(, but recorded from SDSNH 062^4

("locality B-302'(; Emerson, 1980). Same usage

in Table 5].

Species with modern southern endpoints of range

that occur north of, or in the vicinity (•'■) of

Turtle Bay.

Col lect i ng Stat ions

B-302'4 B-3007

X X

1

Mollusca: Gastropoda

Cypraea spadiaea

*Lottia gigantea

"Olivella biplioata

Bi val via

*Chaoeia ovoidea

"Glans oarpentepi

"Milneria minima

Sasddomus nuttalli

*Transennella tantilla

Species also recorded from SDSNH 1 oc . 062'i (Chace,

1956; Emerson, I98O, table 1).

Table 5. Other Species (non-ext ral i mi ta 1 )

From Turtle Bay Localities B-302't and B-3007

Species with modern northern and southern

endpoints of range occurring north and south,

respectively, of Turtle Bay. Species with

northern endpoints of range extending no

farther north than Point Conception, California

indicated by an asterisk (*) ; species with

southern endpoints of range terminating on

the west coast of Baja California Sur indicated

by a number sign (#).

Mollusca: Gastropoda

If Alia carinata

*ttAstraea undosa

[Siipsa aali foimiaal

ttCaeoum crebricinctum

ttCaecum dalli

ttCollisella limatula

ItConus satifomiaus

1

X

Col lect ing St

6-3024 B

[Crepidula onyx"] x

Cimoibulujn spinosum x

*Elephantulum aarpenteri x

#Fartulum ocaidentale x

iFissurella volcano x

*tiHaliotis fulgens x

\_Hipponix antiquatus'} x

iHipponix tumens x

"ItNassarius tegula x

"Neverita reolusiana x

"ttllopinsia norxn-si

"ttPseudomelatoma peniaillata x

-■■•tfPteropurpura festiva x

"§Serpulorbis squamigems

■-■tt[.Tegula aureotinota'] x

'■'■ttTeguta eiseni x

"UTegula gallina x

UTrivia solandr-i x

"/fTmnaatelta oatiformica

Bi val vi a

'"ttArrriantis oallosa x

Anomia peruviana x

"Chione oalifomiensis x

iCorbula luteola x

*Crassinella pacifioa x

Cryptomya aalifomiaa x

{.Diplodonta orbellus'\ x

"ttOonax aalifomiaus x

HEpiluoina aalifomiaa

Felaniella serioata x

ttUinnites giganteus

"tlLepovimetis obesa x

Luainisoa nuttallii x

#Macoma indentata x

UMaaoma nasuta

Parviluaina approximata

\_Penitella fitohil x

Kenitella penita

"#Semele deaisa x

Tagelus aalifomianus x

Species also recorded from SDSNH loc.

0621) (Ch?ce, 1956; Emerson, I98O, tablel).

at ions

-3007

X

112 THE NAUTILUS

July 10, 1981

Vol. 95(3)

able for most of the Turtle Bay assemblages,

and so any temporal correlations must be made

on the basis of fauna! or geomorphic evidence.

E. C. Allison, who collected these fossils, be-

lieved loc. B-3025 to be on a tilted remnant of

the 24 to 27 m terrace represented at loc.

B-3024. Locality B-3025 was previously referred

(Emerson, 1980) to isotopic substage 5e, owing

to the presence of four extralimital tropical and

subtropical mollusks in its fauna {Conus regu-

lariti, Oliva polpasta forma davisae. Thais

biserialis, and Ostrea angelica). The remaining

six taxa in the small fauna all have modern geo-

graphic ranges that overlap the latitude of Tur-

tle Bay. The presence of an extralimital south-

ern element and the geologic setting suggest

that localities B-3024 and B-3025 are probably

coeval and referable to the warm-water phase of

the Sangamon Interglaciation (Emerson, 1980).

Assemblages from the remaining Turtle Bay

localities -B-3027 (northwest of the bay on the

outer coast), B-3050 (inner northeastern margin

of the bay), and B-3048 (southeast of the bay on

the outer coast) (see Fig. 2) -are dominated by

species still living in the region, but include both

extralimital northern and southern taxa. Extra-

limital southern species present at these

localities are Thais biserialis, Trachycardium

panamense, and Protothaca grata, each of which

occurs in loc. B-3024, and the latter two in loc.

B-3007. Three northern extralimital species also

occur in loc. B-3050 (Lottia gigantea, Saxidomus

nuttalli, and Tresus nuttallii), two of which are

present in loc. B-3024. Because of the small size

of these other faunas and the presence of both

extralimital northern and southern species, we

hesitate to assign precise ages to them at this

time. Further amino-acid racemization deter-

minations on elements of these faunas would

probably resolve the question of their ages.

In summary, it is difficult to imagine that

faunas (from Iocs. B-3024 and B-3007) with such

striking differences in their zoogeographic com-

position could have been deposited contem-

poraneously, and the amino-acid data presented

herein support their temporal difference.

Although both assemblages contain both extra-

limital northern and southern species, indicative

of a shift in the geographic ranges of a few com-

ponent species subsequent to deposition, the

overall faunal composition of each assemblage

reflects different hydrocHmatic conditions.

Thus, nearly half (49%) of the assemblage from

the upper terrace is made up of warm-water

(subtropical and tropical) faunal elements, in

comparison with only 9% of these elements on

the lower terrace. In contrast, 21% of the taxa

from the lower terrace are northern, cool- water

(warm temperate) species, in comparison with

only 5% of the taxa from the upper terrace

(Tables 2-4).

Comparison with other faunas

from Baja California Sur

Late Pleistocene megainvertebrate faunas

from the west coast of Baja California Sur have

been reported from only three areas in addition

to Turtle Bay (lat. 27°4rN.) (Fig. 1): (1) Laguna

Ojo de Liebre (Scammon Lagoon, lat. 27°57'N.)

-24 molluscan species from "raised beaches

near Scammon's Lagoon" (Jordan, 1924); (2)

Laguna de San Ignacio (San Ignacio Lagoon,

lat. 26°45'N.)-88 species of mollusks (Hertlein,

1934; including taxa cited previously by Jordan,

1924); and (3) Bahia de Magdalena (Magdalena

Bay, lat. 24°30'N.)-442 species-group taxa,

mostly mollusks (Jordan, 1936; incorporating

previous records of Dall, 1918, Smith 1919, and

Jordan, 1924). The Magdalena Bay fauna is the

largest Pleistocene fauna described from

anywhere in Baja California.

No amino-acid or radiometric dates are avail-

able for the faunas at Scammon Lagoon or San

Ignacio Lagoon. However, at Magdalena Bay,

uranium-series dates on both corals and

echinoids indicate an average age of 1 16,500 ±

6,000 B.P. for Magdalena Terrace (Omura et ai.

1979). These radiometric dates suggest that

Magdalena Terrace is correlative with a high-

stand of sea level at approximately 125,000 to

120,000 B.P., equivalent to the early, warm-

water phase of the last interglacial stage (sub-

stage 5e) of the marine oxygen-isotope record

(Shackleton and Opdyke, 1973). The uranium-

series date on the Magdalena Terrace has been

used subsequently by Wehmiller and Emerson

(1980) to calibrate the southern temperature

Vol. 95(3)

July 10. 1981

THE NAUTILUS 113

range of the 120,000-yr.

Fig. 3.

isochron shown in

Amino-acid racemization data suggest that

the fauna from the upper terrace at Turtle Bay

(loc. B-3024) and that from Magdalena Bay

(CAS loc. 754 of Jordan [1936] = loc. F-6 of

Omura et al. [1979]) probably were deposited

contemporaneously. Faunal comparison (Table

6) of these two assemblages suggests a slightly

warmer hydroclimate at Magdalena Bay, not

totally unexpected because of its more southerly

location (Fig. 1). Both the absolute number and

the percentage of tropical and subtropical taxa

are greater at Magdalena Bay than at Turtle

Bay. although both sites supported similar

faunas rich in these elements. Conversely, the

number of warm-temperate (i.e.. extralimital

northern) taxa at Turtle Bay is greater than at

Magdalena Bay.

Comparison of the fauna from the lower ter-

race at Turtle Bay (loc. B-3007) with the noncon-

temporaneous fauna at Magdalena Bay shows

greater discrepancies (Table 6). Thus, although

three-fourths of the non-extralimital species at

Turtle Bay also occur at Magdalena Bay, only

three of the seven warm-temperate taxa occur

there. Moreover, two of the three tropical and

subtropical species are common to both

localities.

Table 6. Comparison of Positively Identified Species in

Turtle Bay Faunas with Those of the Magdalena Bay Faunas.

Comparison with more

northern localities

The temporal and faunal relations of the up-

per and lower terraces at Turtle Bay invite com-

parison with other terrace pairs on the Pacific

coast. The best known of these pairs is at Point

Loma in San Diego, California, where Nestor

and Bird Rock Terraces occur in superposition.

The upper terrace (Nestor) has been dated by

uranium-series methods on corals at 121,000 +

10,000 B.P. (Ku and Kern, 1974), and the lower

terrace (Bird Rock) by amino-acid methods

(Wehmiller et al.. 1977) and geologic evidence

(Kern, 1977) at approximately 80,000 B.P. Thus,

the terraces at Point Loma can be correlated to

the early and late phases of marine oxygen-

isotope stage 5 and correspond to the ages ob-

tained herein for the terrace pair at Turtle Bay.

Although it is inappropriate to make a direct

species comparison of the San Diego and Turtle

Bay faunas because of the distance separating

them (~600 km) and of the different deposi-

tional settings, their zoogeographic relationship

can be examined. The fauna of Nestor Terrace

contains both extralimital northern and south-

ern species, but is dominated by southern

species; this observation suggests seasonal

temperatures warmer than those now prevail-

ing in the San Diego area (Kern, 1977). The

fauna of lower and younger Bird Rock Terrace

contains few (4%) extralimital northern ele-

ments, but lacks extralimital southern species;

this observation suggests marine temperatures

lower than those of the San Diego area (Kern,

1977).

The similarity of the radiometric and amino-

acid age estimates for these widely separated

terrace pairs (southern California and northern

Baja California Sur), as well as their similar

zoogeographic compositions, is strong evidence

that near-shore marine waters were successive-

ly warmer and cooler than those of today during

the early and middle-to-late parts, respectively,

of marine oxygen-isotope stage 5 (130,000-

80,000 B.P.).

Provincial assignments of

Turtle Bay assemblages

The original usage of a single provincial

114 THE NAUTILUS

July 10, 1981

Vol. 95(3)

designation for a geographically prescribed area

(Valentine, 1961; Addicott, 1966) must now be

tempered by the recognition of more than one

marine-terrace level (and associated fauna) at

elevations previously believed to represent con-

temporaneous deposition (Kennedy, 1978,

1979). In the San Diego, California area, for ex-

ample, assemblages from late Pleistocene ter-

race deposits that previously were considered

coeval are now referable, on the basis of radio-

metric and amino-acid age estimates, to three

temporally distinct episodes of deposition (Ku

and Kern, 1974; Kern, 1977; Masters and Bada,

1977; Wehmiller et aZ., 1977; Lajoie et aL, 1979;

Demere, 1980; and Karrow and Bada, 1980).

The recognition of several possible terrace ages

that relate to highstands of sea level during dif-

ferent glacial minima requires that provincial

faunas be identified by their respective ages

(Kennedy, 1978). Establishment of a geochro-

nology that is related to the deep-sea isotopic

chronology of glacial minima and maxima

(Shackleton and Opdyke, 1973) facilitates the

assignment of an isotopic-stage number to the

modern or Pleistocene provincial name most

representative of that fauna (Kennedy, 1978).

Valentine (1961:393) proposed the Magdale-

nan Province for late Pleistocene molluscan

assemblages characterized by tropical and sub-

tropical faunas at Magdalena Bay and elsewhere

along the coast of Baja California Sur, the Gulf

of California, and the adjacent mainland of Mex-

ico. The Magdalenan Province is here restricted

to faunal assemblages that are referable to the

130,000- ~120,000-B.P. highstand of the sea,

correlative with the early part of marine oxy-

gen-isotope stage 5 (substage 5e). The warm-

water assemblages at Turtle Bay (loc. B-3024

and probably loc. B-3025) are herein assigned to

the Magdalenan Province. Other warm-water

faunas from along the southern Baja California

coast at San Ignacio Lagoon (Hertlein, 1934)

and at Scammon Lagoon (Jordan, 1924) prob-

ably also can be assigned to the Magdalenan

Province. However, provincial assignments

based entirely on faunal inferences should be

tempered by some means of absolute dating,

especially if their faunas are small and contain a

mixture of northern and southern species.

The cooler water, middle-to-late stage 5 as-

semblage at Turtle Bay (loc. B-3007) is not as

readily assigned a Pleistocene provincial desig-

nation because the more northerly Verdean and

Cayucan Provinces also have been restricted to

early stage 5 faunas (Valentine, 1980). Until

more of the known localities along the Baja

California coast are dated, either biochemically

or radiometrically, and can be shown to repre-

sent either early or late stage 5 time, provincial

delineation will remain difficult. Fossil localities

with faunas that still need provincial assignment

include those at Cedros Island (Hertlein, 1934),

and in Baja California Norte at San Quintin

(Jordan, 1926), Punta Cabras (Addicott and

Emerson, 1959), Punta China (Emerson, 1956),

and Punta Descanso (Valentine, 1957). A fauna

at Camalii has been assigned already to the

Pleistocene Verdean Province by Valentine

(1980).

Register of Localities

University of California Museum of Paleon-

tology, Berkeley, California. All fossils were col-

lected by E. C. Allison. For locality data of

Magdalena Bay localities, see Omura et ai,

(1979).

UCMP loc. B-3007. Terrace deposit at an ele-

vation of about 12 m, N. 30°E. of peak on south

side of entrance to Turtle Bay. Collected June

18, 1956.

UCMP loc. B-3024. Terrace, traceable for

several hundred meters, at an elevation of 24 to

27 m, along the southwestern part of Turtle Bay

in back and south of small fishing camp. Col-

lected June 26, 1956.

UCMP loc. B-3025. Terrace at an elevation of

6 to 9 m southeast of loc. B-3024 and possibly

equivalent to the terrace at loc. B-3024, because

it appears to be tilted in that direction. Collected

June 26, 1956.

UCMP loc. B-3027. Terrace at an elevation of

4.5 to 6 m immediately behind long sandy beach

along southwestern part of peninsula northwest

of Turtle Bay. Collected June 27, 1956.

UCMP loc. B-3048. Terrace at an elevation of

approximately 6 m that extends along the open

coast adjacent to a long sand-gravel beach about

Vol. 95(3)

July 10, 1981

THE NAUTILUS 115

9.7 km southeast of Turtle Bay. Collected July 2,

1956.

UCMP loc. B-3050. Terrace at an elevation of

4.5 to 6 m along the northeast side of Turtle

Bay. Collected July 3, 1956.

ACKNOWLEDGMENTS

Fossils from Turtle Bay used for amino-acid

analysis were kindly loaned by Joseph H. Peck,

Jr., of the University of California Museum of

Paleontology, Berkeley. Technical assistance

was provided by William E. Old, Jr., of the

American Museum of Natural History, New

York. Amino-acid research at the University of

Delaware, Newark, was supported by U.S.

Geological Survey Grants 14-08-0001-G592

and 14-08-0001-G680. The manuscript was

critically reviewed by Kenneth R. Lajoie, Leslie

F. Marcus, and Louie N. Marincovich, Jr.

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CATINELLA VAGANS (PILSBRY) AND A NEW SPECIES OF

CATINELLA (SUCCINEIDAE PULMONATA) FROM THE

SHORE OF LAKE WACCAMAW, NORTH CAROLINA

Dorothea S. Franzen

Illinois Wesleyan University

Bloomington, Illinois 61701

ABSTRACT

Pihhry (19Jf8), on the bases of differences of shell features as well as of the

reproductive systems, recognized two "varieties" of CatineWa (Quickella) vagans.

The type locality ofC. vagans is Cape May Point, New Jersey; locality of the sec-

ond "variety" is Lake Waccamaw, North Carolina. The observations of Pilsbry

(ibid), as well as my own, are sufficient reasons for recognizing these two popula-

tions as distinct species of Catinella.

In 1900 Pilsbry described Succinea campestris

vagans from Cape May Point, New Jersey; this

species is now known as Catinella vagans

(Pilsbry). Later Pilsbry mentioned and figured

(1948, p. 844, Fig. 456C) a specimen from the

shores of Lake Waccamaw, North Carolina,

Vol. 95(3)

July 10, 1981

THE NAUTILUS 117

which varied in certain details from the type

series. The observations of Pilsbry (1948:843-

845) as well as my own are sufficient reasons for

recognizing these two populations as distinct

species.

Shell characteristics, patterns of pigmenta-

tion of body and mantle, structural details of

radulae and jaws, and the anatomy of reproduc-

tive systems are criteria for identification of

genera and species of Succineidae. Geographic

distribution, geographic barriers, microhabi-

tats, adaptation to environmental conditions,

time of maturing and mating seasons also are

significant factors to be considered in the

recognition of species, especially in the family

Succineidae.

Catinella vagans (Pilsbry)

Succinea campestris vagans Pilsbiy, 1900. The Nautilus,

14(7):74.

Quickella- vagans (Pilsbry) 1948. Land Mollusca of North

America, vol. 2, Ft. 2:843-845; Figs. 44.3d, A56A. B, C.

Because of beach erosion, the type locality on

Cape May Point, New Jersey, as known at the

time Pilsbry described Succinea campestr-is

vagans no longer exists. On June 7, 1979, I ob-

tained a number of Catinella vagans from two

localities in the vicinity of what is now known as

Cape May Point, New Jersey, namely: (1) D. S.

Franzen Field No. 494, shore of pond, city of

Wildwood pumping station, on New Jersey

Highway 47, northwest of Rio Grande, Cape

May County, New Jersey. A colony of C. vagans

was living under fine litter on the wet, flat shore

of the pond. Some C vagans were crawling on

grass blades. The edge of the pond supported

growths of predominately willow (Salix) and

poison ivy (Rhus). (2) D. S. Franzen Field No.

495, Cape May County Park located between

U.S. Highway 9 and the Garden State Parkway

Lake Shore Road, city of Cape May Court

House, Cape May County, New Jersey. Several

C. vagans were on the wet, sandy loam soil of a

small bay of the shore of the freshwater lake.

Trees growing along the shore included willow

(Salix), sweet gum (Liquidamber). maple (Acer)

and oak (Quercus). A third locality: D. S.

Franzen Field No. 499, June 13, 1979. Burton's

Pond located on south edge of Angola, Route

Delaware 24E, Sussex County, Delaware. Only

two C. vagans were found living on twig litter on

the wet bank of the pond. The small number

might be attributed to the last spring's flooding

of the flood plain. The bank supported growths

of willow (Salix) and bulrush (Scirpus). Typha

and Saggitaria grew at the edge and in shallow

water of the pond.

The following is a description of Catinella

vagans as now known from the vicinity of Cape

May Point, New Jersey:

Shell-(F\g. lA, B) Shell globose-ovate,

amber-colored, translucent, fragile, imper-

forate, composed of 2-1/4 to 3 inflated, sharply

incised whorls; height 7.6 mm to 10.8 mm; width

5.0 mm to 6.4 mm (Table 1); nuclear whorl ap-

pressed, spire short; whorls increase rapidly

resulting in a tumid ultimate whorl. Ovate aper-

ture occupies seven tenths to eight tenths of

height of shell (Table 1). Surface of nuclear

whorl finely granular, sometimes mottled whit-

ish because of worn periostracum; striations

fine on penultimate whorl, gradually becoming

moderately coarse towards the aperture; sharp-

ly edged peristome fragile; callus on ultimate

whorl may not be visible. Amber-colored col-

umella follows inner border of peristome curv-

ing as it ascends into the ultimate whorl.

Head. Body and Mantle Surfaces -'"The

cream-white body and head are sparsely pep-

pered with minute dots" (Pilsbry, 1948, p. 845).

The series of Catinella vagans from the three

FIG. 1. A, Catinella vagans (Pilsbry) (Height 10.5 mm).

B, Catinella vagans (Pilsbry) (Height 9.5 mm). Both shells

from D. S. Franzen Field No. JtH; Pond, city of Wildwood

pumping station. Cape May County, New Jersey.

TABLE 1. Dimeyisions of shells o/Catinella vagans (Pilsbry). The measureynents are of the fine largest shells of the first two

localities and of the two shells obtained from the third localitii. In the J,th column of measureTnents are listed the ratios of the

width nfthe shell over its height. In the last 3 columns are listed the ratios of height of aperture over height of shell, width of

aperture over width of shell, width of aperture over height of aperture.

localities included in this study exhibit varia-

tions in pigmentation from those of Pilsbry's

description. The following is a description of a

representative pigmented C. vagans (Field No.

D. S. Franzen 494). Surface of head light cream-

colored, irregularly tuberculate. Pigmentation

of dorsal surface of head consists of a median

band Hanked on either side by two bands, con-

vergent at anterior end of the head, spreading

and then converging at level of base of the

superior (posterior) tentacles, spreading again

to extend over the remainder of the head region;

some bands extend a short distance onto the

dorsal, white body surface; on either side of

these bands another band extends from the

anterior end of the head, over the superior ten-

tacles to continue over the remainder of the

head region.

Lateral body wall cream-colored, coarsely and

irregularly tuberculate. On either side a broad,

pigmented band, consisting of a series of dorso-

ventral bands, extends from the labial palyp to

posterior tip of body. The semi-lunar genital

aperture, about 1.0 mm in length, surrounded

by a white lip, is situated on right-hand side of

body immediately posterior to the head region.

On either side a pedal groove, extending from

labial palyp to posterior end of body, separates

foot from lateral body wall; pedal groove is

paralleled by a less pronounced suprapedal

groove. Shallow vertical grooves incise supra-

pedal and pedal grooves and pigmented band,

produce scallops along margin of foot especially

when animal is in a somewhat contracted state.

Sole of foot is cream-colored, unpigmented.

Anterior and posterior inner margin of mantle

collar outlined by bands of fine flecks. Free edge

of mantle collar, white. Pigmented band along

anterior dorsal margin of mantle flecked from

left side to mid-dorsal area, becoming solid black

on right hand side and terminating as a band of

flecks. Across dorsal surface of mantle dark

streaks extend from anterior band to area of the

cream-colored nephridium where a black band

outlines its anterior margin. Posterior to ne-

phridium are scattered patches of pigment. Col-

or of liver is golden brown.

Variations - Color of head varies from almost

white to a dark cream. Patterns of pigmentation

of head, body and mantle collar are constant,

varying only in intensity. Band paralleling man-

tle collar ranges from very narrow to one which

Vol. 95(3)

July 10, 1981

THE NAUTILUS 119

includes a broad, dark blotch. Pigmentation of

mantle assumes various patterns: (1) Narrow

streaks of pigment extend over the mantle to

anterior margin of nephridium; posterior mar-

gin of nephridium outlined by an irregular,

broad band. (2) Mantle pigment is in form of a

network of streaks becoming broader and more

blotched over the nephridium. (3) Very narrow

band parallels mantle collar from which broad,

netted bands extend for one-third the distance

from mantle edge to anterior margin of nephrid-

ium; several heavy blotches located in interven-

ing space; anterior margin of nephridium par-

tially outlined by a narrow, lightly pigmented

band. "The mantle over the lung is translucent

whitish with some faint gray spots (seen under

magnification to be composed of minute flecks

of pigment); several next to the thickened edge

being larger and longer ... The thick mantle

edge . . . not dotted" (Pilsbry, 1948, p. 845).

Reproductive System~{Fig. 2) Albumin gland

(AG) somewhat larger than prostate gland, tri-

angular in form, composed of fine acini, is

enclosed within a thin, transparent, unpig-

mented sheath. Seminal vesicle (SV) composed

of a long lobe and of a shorter, narrower lobe

closely adherent to the longer lobe, is enclosed

within a thin, sparsely flecked sheath. The light-

ly to moderately pigmented hermaphroditic

duct (HD) joins the seminal vesicle to form the

fertilization sac (FS) from which diverge the

oviduct (OD) and the sperm duct (SD); the latter

leads into the prostate gland. The oval prostate

(PG) enclosed by a thin, transparent, unpig-

mented to sparsely flecked sheath, is composed

of acini slightly coarser than those of the

albumin gland. The vas deferens follows the

penis (P) along its dorsal surface; as it ap-

proaches the distal end of the penis it enlarges

to form the epiphallus (EP) which enters the un-

sheathed penis terminally; the penis enlarges

immediately into a cylindrical form. The cylin-

drical penial appendage (PA), approximately the

length of the penis, arises from the proximal end

of the penis. Fibers of the broad retractor mus-

cle (PRM) attach to the epiphallus, penis and

penial appendage. Pilsbry (1948, p. 845) states

:he penial appendage "is free from the retractor

FIG. 2, Reproductive organs o/Catinella vagans iPilshry).

P. penis:EP. epiphallus: PRM, penial retractor muscle; PA.

penial appendage: SP. spermatheca: HD. hermaphroditic

duct: AG. albumin gland: GA. genital atrium: VA. vagina:

SPD. spennathecal duct: OD. oviduct: PG. prostate gland:

SD. sperm duet: OD. oviduct: FS. fertilization sac: SV.

seminal vesicle.

muscle." His Fig. 456A shows a few fibers at-

tached to the penial appendage. The duct (SPD)

of the globular spermatheca (SP) is short and

stout, sometimes dilated as it approaches the

vagina (VA); the vagina is short.

Radula and Jaw- Radulae of three individuals

of Catinella vagans examined have 91, 96, 97

rows of teeth, respectively. There are few tenth

on the anterior-most rows; the number in-

creases rapidly posteriorly. The number of

marginals and laterals of representative rows of

a radula are recorded in Table 2. Although there

is an individual variation of the radulae and,

also, of the rows of teeth of a radula, the ratio of

marginals to laterals approximates 1:1.

The characteristics of the teeth of C. vagans

are described as follows and illustrated in Fig. 3,

A. The central tooth (C) bears a long, broad,

basal plate with a posterior serrated margin

flanked on either side by a rounded boss. The

pointed mesocone, variable in length, extends

downward as far as to the lower third of the

basal plate. A short, pointed ectocone flanks the

mesocone on either side. The laterals (R-L-1;

R-L-10) have a pointed mesocone varying in

120 THE NAUTILUS July 10. ^^^^

TABLE 2. Formulae of representative of teeth o/Catinella vagans (PiUbi-y).

Station

Vol. 95(3)

Field No. 494

Pumping Station,

City of Wildwood,

Cape May County,

New Jersey

Slide

A

No . of Rows

of Teeth

91

FIG 3 A, Representative radula teeth of CatmeWa vugans

(Pilshry) Row 76: C, central tooth: 1-R-L. first left lateral:

10-R-L. tenth riqht lateral: 1-R-M. first right marginal:

8-R-M, eighth right marginal. Row 71: 6-R-M. sixth right

marginal. B, A jaw o/Catinella vagans (Filslrry).

length from a very short structure to some ex-

tending downward to the level of the posterior

margin of the basal plate. A small, pointed en-

docone is present. The ectocone, undivided m

the more medial teeth, is divided into two cusps

in the more lateral teeth. The distinction be-

tween laterals and marginals is not always clear

because sometimes a tooth whose ectocone is

divided into three cusps is flanked on either side

by one whose ectocone is divided into two cusps.

The marginals (1-R-M; 8-R-M) smaller than the

laterals, have a basal plate which is broader than

long, true especially of the outermost marginals.

The small endocone is sharply pointed; the

pointed mesocone extends to and below the mar-

gin of the basal plate. The ectocone is divided

generally into three, sometimes into two or four

cusps of varying lengths.

The features of the teeth of C. vagarui compare

with those of species of the genus, namely (1)

the ratio of the laterals to the marginals approx-

imates 1:1 and (2) the basal plate of the mar-

ROK

25

39

62

70

M L C L M

U - 13 - 1 - 13-14

12 - 15 - 1 - 15-12

13 - 15 - 1 - 15-12

13 - 14 - 1 - 14-13

ginals is broader than long. Such features of the

genus were noted by Quick to be true of Cati-

nella (Succinea) armaria ("B.-Ch.") (Quick,

1933, Fig. 4, p. 296) and by Franzen ofCatinella

parallela Franzen (Franzen, 1979, p. 66, Table

2; p. 67, Fig. 3A).

The amber-colored jaw is illustrated in b ig.

3B. Anteriorly the collar has a median fold

flanked on either side by a larger fold. Poster-

iorly the margin of the collar has a fold on either

side of the median indentation.

Catinella waccamaivensis n. sp.

Quickella nigans (Pilsbry) 1948. Vol. II, Pt. 2. pp. 844-845.

Fig. 456C.

Description of Holotype-SheW: Fig. 4, A, B.

Shell light amber-colored, glossy, translucent,

thin, very fragile, imperforate, elongate-ovate,

composed of three tumid whorls; suture sharply

incised; height 7.1 mm, width 4.6 mm, height of

aperture 4.9 mm, width of aperture 3.3 mm.

Height of ovate aperture equals 69% of total

height of shell (Table 3). Sharply edged peri-

stome very fragile; light amber columella fol-

lows inner border of peristome, curves as it

ascends into the ultimate whorl. Nuclear whorl

knoblike; spire short; whorls increase rapidly in

size resulting in an elongate, tumid ultimate

whorl. Nuclear whorl finely granular; longi-

tudinal striations fine on penultimate whorl, in-

creasing gradually towards the aperture. Sur-

face coated with fine grains of sand and soil.

Ho/oi^pe;- Catalogue No. FMNH 200983;

Paratype No. FMNH 200984 Molluscan Collec-

tion, Field Museum of Natural History, Chicago,

Illinois. Additional paratypes in the private col-

lection of the author.

Description of paratypes -SheW: (Fig. 4, C, D)^

Shells of mature snails, attaining a height ot 7.5

Vol. 95(3)

July 10, 1981

THE NAUTILUS 121

FIG. 4. A, B, Holotype o/Catinella waccamawensis ». sp.

(Height 7.1 mm). C, D, Paratj/pe o/Catinella waccamawensis

n. sp. (Height 6.5 mm). Type locality. Lake Waccarmw. Co-

lumbus County. North Carolina.

mm, are comprised of 2-1/2 to 3 inflated whorls.

Dimensions of the holotype and six paratypes,

the median of the series, are recorded in Table

3. The height of the largest shell is 7.5 mm, its

width is 5.9 mm. The aperture occupies from

65.5 to 75.0 percent of entire height of shell.

Other ratios are to be noted in Table 3. The

shells are extremely fragile, break readily, mak-

ing accurate measurements difficult.

Head, Body and Mantle Surfaces -Surface of

head and body wall cream-colored, lightly pig-

mented, finely, irregularly tuberculate. Pigmen-

tation of dorsal surface of head consists of bands

of fine flecks anteriorly forming a triangle, nar-

rowing between the superior (posterior) tenta-

cles into a single band; pigmentation posterior

to tentacles diffused over the dorsal body sur-

face; the triangle flanked on either side by a

band. Surface of both pairs of tentacles flecked.

Retractor muscles of superior tentacles black.

Lateral body wall lightly pigmented with fine

flecks forming an indistinct band.

Genital aperture, situated on anterior right-

hand side of body, lunate, about 0.5 mm in

length, surrounded by a white lip. On either side

a pedal groove, continuous from labial palyp to

posterior lip, separates foot from lateral "body

wall; pedal groove paralleled by less pronounced

suprapedal groove. Shallow, vertical grooves in-

cise pedal and suprapedal grooves, the lateral

body wall and the pigmented band, produce

shallow scallops along margin of the foot

especially when animal is in a somewhat con-

tracted state. Sole of foot is light cream-colored

and unpigmented.

Mantle collar is lightly flecked overall. On the

mantle a narrow, finely-flecked band parallels

the mantle collar from which bands extend to

anterior margin of the nephridium. Nephridium

white, partially outlined by a narrow, dark band

and covered by flecks of pigment. The liver is

light golden brown in color. Pigmentation of

other paratypes is variable in intensity and

distinctness in pattern.

TABLE 3. Dimensions of shells ijfCatinella waccamawensis n. sp. The measurements are of the seven measure-able shells ob-

tained from the type locality. In the ith column of m£asurements are listed the ratios of the width of the shell over its height. In

the last 3 columns are listed the ratios of height of aperture over height of shell, width of aperture over width of shell, width of

aperture over height of aperture.

122 THE NAUTILUS

July 10, 1981

Vol. 95(3)

Reproductive Syfttem- (Fig. 5) The albumin

gland (AG) triangular in form, composed of fine

acini, enclosed within a thin, transparent, un-

pigmented sheath; seminal vesicle (SV) enclosed

within a thin, transparent, lightly flecked

sheath, elongate, bilobed, one lobe small and

closely adherent to the larger lobe. The lightly

pigmented hermaphroditic duct (HD) and the

seminal vesicle join to form the fertilization sac

(FS) from which a duct divides into the oviduct

(OD) and the sperm duct (SD) which leads into

the prostate gland (PG). The oval prostate

gland, enclosed by a thin, transparent unpig-

mented sheath, is composed of fine acini slightly

larger than those of the albumin gland (AG).

FIG. 5. Reproductive organs o/Catinella waccamawensis n.

sp. P, penis; PA. penial appendage: EP. epiphnlliis: PRM.

penial retractor muscle; SP, sperrnatheca; HD. hermaphro-

ditic duct; SV, seminal vesicle; GA. genital atrium; VA.

vagina: SPD, spermathecal duct; PG, prostate gland: OD.

oviduct; AG, albumin gland; FS, fertilization sac.

Length of albumin gland exceeds that of the

prostate gland. As the vas deferens approaches

the penis it follows the penis along its dorsal sur-

face, enlarges to form the epiphallus (EP) to

enter the distal end of the unsheathed penis

which enlarges immediately into a cylindrical

form (P). The penial appendage (PA) whose base

is almost half the length of the penis, originates

subterminally near where the penis joins the

genital atrium (GA); appendage expands into a

large pouch-like structure; anterior-posterior

dimension of the appendage is almost thrice the

diameter of the penis. Fibers of the broad, stout

penial retractor muscle (PRM) insert mainly on-

to the base of the penial appendage; lesser fibers

insert onto the penis and onto the epiphallus.

The globular spermatheca (SP) is connected to

the vagina (VA) by a stout, short spermathecal

duct (SPD). The short vagina (VA) expands as it

opens into the genital atrium (GA).

Radula and Jaw^-Radulae of two paratypes

of Catinella waccamawensis n. sp. were stained

and mounted; the number of rows of teeth, 72

and 73. There are few teeth on the anterior-

most rows; the number increases rapidly poster-

iorly. The number of marginals and laterals are

recorded in Table 4. Although there is an in-

dividual variation of the radulae and, also, of the

rows of teeth of a radula, the ratio of marginals

to laterals approximates 1:1. The characteristics

of the teeth are described below and illustrated

in Fig. 6A.

The central tooth (C) bears a long, broad,

basal plate with a posterior serrated margin

flanked on either side by a prominent, rounded

boss. The pointed mesocone extends downward

TABLE 4. Formulae of representative rows of teeth o/Catinella waccamawensis n. sp.

Vol. 95(3)

July 10, 1981

THE NAUTILUS 123

FIG. 6. A, Represe7itative radula teeth o/Catinella wacca-

mawensis n. sp. Row J,5: C. central tooth; 1-L-L. 1st left

lateral: 9-L-L. 9th left lateral; 1-L-M. 1st left marginal;

6-L-M. 6th left marginal; 8-L-M, 8th left marginal. B, A jaw

o/Catinella waccamawensis n. sp.

to about the lower fourth of the basal plate. A

short, pointed ectocone flanks the mesocone on

either side. The laterals have a large, long,

pointed mesocone flanked medially by a short

endocone, laterally by a single ectocone: 1-L-L,

9-L-L. The basal plate of the outermost laterals

is shorter than of the more medial laterals. The

marginals, smaller than the laterals, have a

basal plate broader than long; this is especially

true of the outermost marginals. The small en-

docone is pointed; the larger, pointed mesocone

extends beyond the basal plate. The ectocone of

the innermost marginals is divided into two, of

the outermost into three cusps; 6-L-M, 8-L-M.

Features of the teeth of C. waccamawensis n.

sp. compare with those of species of the genus,

namely, the ratio of the laterals to marginals ap-

proximates 1:1 and the basal plate of the mar-

ginals is broader than long. This is true, also, of

C. vagans (Pilsbry) as noted above.

The amber-colored jaw is illustrated in Fig.

6B. Anteriorly the collar has a median, bluntly

pointed fold flanked on either side by a lower,

rounded fold. The posterior margin of the collar

is indented medially.

Type Locality - Habitat -Lake Waccamaw,

Columbus County, North Carolina, North shore

Comparison of Catinella waccamawensis n. sp. with Catinella vagans fPilsbry)

Pigmentation of body:

General

Head

Dorsal body wall

Lateral body wall

Mantle

Nephridium

Liver

Reproductive system

Penial appendage

vagans f Pilsbry)

pouch -like, anterior-posterior

dimension about 3X diamter of penis

cylindrical, approximately

length of penis

124 THE NAUTILUS

July 10, 1981

Vol. 95(3)

of Lake Waccamaw at intersection of Lake

Shore Drive and McRae Lane (3.7 mi. from junc-

tion of U.S. Highway 74 and 76, east end, with

Route 214). Date of collection, July 15, 1978. The

shore is flat for about twenty feet from shore

line to the abruptly rising bank; area shaded by

pine (Pinus), willow (Salix), birch (Betula) and

cypress (Taxodium) trees. Catiyiella wacca-

mawensis n. sp. was found living on wet, sandy

ground, moist boards and dead leaves along the

shore of the lake.

Distinctive Features - SheW: Comprised of

2-1/2 to 3 inflated, sharply incised whorls; max-

imum height of shells of this series, 7.5 mm,

width, 5.9 mm. The median of the height of

aperture over height of shell, .69 (69%). Nuclear

whorl knoblike, surface finely granular.

Pigmentation -Figmentation of animal is gen-

erally very light. The bands of pigment on the

head form a characteristic triangle, a single

band courses between the superior tentacles;

pigmentation on dorsal body wall is diffuse, not

in distinct bands. Pigmentation of lateral body

wall is not in form of distinct bands. Pigmenta-

tion of edge of mantle varies from a narrow

band to absence of a recognizable band. Ne-

phridium is white, not distinctly outlined with a

black band. Liver is a golden color.

Reproductive System -Pcma\ appendage is a

large pouch-like structure whose base is almost

half the length of the penis. Penis is cylindrical

in form. Seminal vesicle is bilobed, one lobe

small and closely adherent to the larger lobe.

Comparison of the features of Catinella wac-

camawensis n. sp. with those of Catinella vagans

(Pilsbry) are shown in the outline on previous

page.

ACKNOWLEDGMENTS

National Science Foundation Grants-in-Aid

No's. NSF G18000 and NSF GB2715 provided

laboratory equipment. Dr. A. Byron Leonard

read the manuscript and offered helpful sugges-

tions. Sue Hobbs, Phil Dietz and R. S. Prezant

assisted me in the collection of Catinella vagans

from the various localities.

LITERATURE CITED

Fninzen, Dorothea S. 1979. Catinella parallela. A New

Succineiciae (Pulmonata) from Midwestern United States.

The Nautilus 93(2-3):63-69. Figs. 1-3, Tables 1, 2.

Pilsbry, Henry A. 1900. Land Snails of Cape May, New

Jersey. The Nautilus 14(7):73-75.

1948. Land MollMSca of North America (North

of Mexico). Acad. Nat. Sci. Philadelphia Monograph 3.

vol. 2, pt. 2: pp. xlvii and 521-1113, .585 figs.

Quick, H. E. 1933. The Anatomy of British Succineae. Proc.

Mai. Soc. London 20(6):295-318, pi. 23-25, tables 1-5.

figs. 1-18.

THE MORPHOLOGY AND DISTRIBUTION OF

OCENEBRA Gi?/PP7 (MURICIDAE: OCENEBRINAE)

Barbara W. Myers and Anthony D'Attilio

Department of Marine Invertebrates

Natural History Museum

San Diego, CA 92112

ABSTRACT

Ocenebra grippi (Da//, 1911) ranges frorn Monterey, California, to Punta Ban-

da, Baja California Norte, Mexico. The radula is illustrated for the first time,

and features of the shell morphology and ontogeny are clarified.

Recent collections by scuba diving have yield-

ed specimens that give information about the

radular and shell morphology and range of an

obscure muricid species.

References and Synonymy - Eupleura grippi

DalK 1911: 87. Dall, 1921: 100; pi. 5, fig. 1.

Vol. 95(3)

July 10, 1981

THE NAUTILUS 125

Oldroyd, 1927: 28; pi. 32, fig. 6. Abbott, 1974:

188; fig. 1964. Ocenehra grippi (Dall). Radwin &

D'Attilio, 1976: 121; pi. 20, fig. 2.

Material Examined-l) 1 specimen, dead,

tidepool. La Bufadora, Baja California Norte,

Mexico. Leg. G. Radwin, 26 February 1972.

(SDNHM 6i784)

2) 2 specimens, 60 feet, Ocean Beach, Cali-

fornia. Leg. C. Snell, May, 1965. (SDNHM

23584)

3) 2 specimens, 55 feet, Pt. Conception, Cali-

fornia. Leg. C. Snell, July, 1966. (SDNHM

55806)

4) 3 specimens, 30 feet, Monterey Bay, Cali-

fornia. Leg. D. Myers, October. 1978. (2 speci-

mens SDNHM 73668)

Radular Morpfwlogy -WiWiam Healey Dall

described a single, old and worn muricid shell as

Eupleura grippi by which name the species had

been known for years. Radwin and D'Attilio

(1976) reassigned E. grippi to the genus Oeene-

bra based on shell morphology. Investigation of

the radula further substantiates this generic

placement (Fig. 4). Eupleura has a longer cen-

tral cusp than Oeenebra. The axes of the three

major middle cusps of Eupleura appear to

radiate distally, whereas in Oeenebra these axes

are nearly parallel. This is the first published il-

lustration of the radula of 0. grippi.

Shell Morphology. Variability and Ontogeny -

On the basis of the single holotype specimen, the

variability and shell sculpture of the species

could not be adequately described. Dall's

specimen had only obscure varices and worn

nodes at the shoulder. The spiral sculpture was

nearly obsolete. The apertural lip was abnor-

mally thickened, had eight denticles and the

canal was open.

The diverse characters of this uncommon spe-

cies were elaborated by Radwin and D'Attilio

(1976): five to six rounded axial ribs; nodes at

the periphery may be well-developed (Fig. 1);

spiral sculpture is of scabrous cords separated

by sharply cut grooves (Figs. 2 and 5a); color

ranges from brown to yellow with some

specimens banded at the shoulder (Fig. 1). The

canal is often in varying degrees of closure

(Figs. 1, 3 and 5b), an ontogenetic characteristic

of the Ocenebrinae (D'Attilio, 1978). The pro-

toconch is distinctive, consisting of one and a

quarter nuclear whorls (Fig. 5c). The Monterey

FIGS. 1-3. 1, Oeenebra grippi (Dull. lull). Ventral i-tru: alujiviiiy tiudta nt jjn tjjl if r if. dfiituits and cluaed

siphonal canal. 15 mm x 9 mm. Monterey specimen. 2, 0. grippi (Dull. 1911). Dorsal view showing scabrous

cords. 17 mm x 10 mm. Monterey specimen. 3, 0. grippi (Dall. 1911). Ventral view showing open siphonal canal.

18 mm X 10 mm. Monterey specimen.

126 THE NAUTILUS

July 10, 1981

Vol. 95(3)

FIG. 4. Radular dentition o/Ocenebra grippi (Dall. 1911),

collected at. Ocean Beach, California. Greatly enlarged:

drawing try Anthony D'Attilio.

specimens showed further variation, having on-

ly five denticles instead of six to ten as stated by

Radwin and D'Attilio (1976) and the apertural

lip margin is crenulate (Figs. 1 and 5b).

The illustration of the holotype (Dall, 1921)

was reproduced in Oldroyd (1927) and the same

figure appears in Abbott (1974). This figure does

not show any apparent spiral sculpture. The

photograph in Radwin and D'Attilio (1976: pi.

20, fig. 2) is unfortunately rather dark and does

not show the spiral sculpture.

Range -The type locality for this species is

San Diego, California, dredged at 90 feet. The

northernmost reported range for 0. grippi has

been Point Conception, California (Radwin and

D'Attilio, 1976: 121). Three specimens of this

species were collected by David Myers in Octo-

ber, 1978, in Monterey Bay, California in 30 feet

of water. This Monterey Bay finding extends

the range from Southern California approxi-

mately 200 miles into the Oregonian Faunal

Province as defined by McLean (1978). Further

the bathymetric range now extends from 90 to

30 feet. In addition one beachworn specimen has

been found intertidally at Punta Banda, Baja

California Norte, Mexico, 60 miles south of its

previously known southern occurrence. Further

collecting along the Baja California coast of

Mexico is needed to clarify the significance of

the Punta Banda specimen.

ACKNOWLEDGMENTS

I wish to thank Dr. Hans Bertsch for his

critical comments and suggestions in developing

this paper and further for his editorial review of

the final draft. I also wish to thank David Myers

for supplying me with his three specimens of 0.

grippi for study.

FIG. 5. 0. grippi (Dall. 1911), a, Detail of spiral sculpture.

b, Detail of apertural lip showi.ng crenulation, denticles and

closed siphonal canal, c, Detail of proloconch. Drawings by

Anthony DAttilio.

LITERATURE CITED

Abbott, R. T. 1974. Americnn Sea^shelta. 2nd Edition. Van

Nostrand Reinliold, New York, 663 pp., 24 pis., 6405

figs.

Vol. 95(3)

July 10, 1981

THE NAUTILUS 127-

Dall, W. H. 1911. A new California Ef/p/cura. The Nautilus

25(8):87. (December, 1911).

1921. Summary of marine shell bearing mullusks

of the northwest coast of America . . . Bull. U. S. Nat.

Mus. 112:1-217, 22 pis.

D'Attilio, A. 1978. Notes on the siphonal canal in Muricidae.

TheFestivus 10(6):47-48. (June, 1978).

McLean, J. H. 1978. Marine shells of southern California.

Los Angeles County Museum, of Natural History. Science

te>Q

Series 2J,. (Revised Edition): 104 pp., 54 text figs. (20

March 1978).

Oldroyd, I. 1927. The Marine Shells of the West Coast of

North America. Stanford Univ. Press, vol. 2, pt. 2, 304

pp.. pis. 30-72.

Radwin, G. E. and A. D'Attilio. 1976. Murex shells of the

world, an illustrated guide to the Muricidae. Stanford

Univ. Press, 284 pp., 32 pis., 198 figs.

THE MARINE FAUNAE ZONES OF NORTH CAROLINA,

WITH NEW MOLLUSCAN RECORDS

Hugh J. Porter and Glenn Safrit

Institute of Marine Sciences

University of North Carolina

Morehead City, NC 28557

ABSTRACT

Northern range extensions o/Charonia variegata and Cooperella atlantica into

North Carolina marine waters are reported for the first time. The occurrence in

these waters of Anomalocardia auberiana, Astraea phoebia, Lima scabra, Pinc-

tada imbricata and Spondylus aniericanus, previously based on few specimeyis, is

further substantiated. Faunal zones are redefined in relationship to the North

Carolina, marine moUuscan fauna.

The purpose of paper is to clarify and substan-

tiate several North Carolina range records in

the molluscan literatui'e which are based on few

specimens; to add several new North Carolina

range records; and to discuss the relationship of

these records to a reevaluation of faunal zones

within North Carolina waters, an area where

Cape Hatteras is considered a significant boun-

dary.

All records were collected within the past 14

years and unless specified, are based on adult

specimens. Records catalogued in the Univer-

sity of North Carolina, Institute of Marine

Sciences Mollusk Collection are indicated by a

UNC-IMS number, an asterisk (*) designating

live-taken specimens.

Anomalocardia auberiana (Orbigny, 1842).

Published range: South half of Florida to Texas

(Abbott, 1974). Dall (1902) records the northern

range of A. brasiliayia Gmelin as Wilmington,

NC. Subsequent use of North Carolina as the

northern range of this species, as recorded in

Porter (1974), is likely based on former account.

Narchi (1972) states that the North Carolina

record of A. brasiliana, in error, is for A.

cuneimeiis Conrad, a synonym of A. auberiana

(Orbigny), (see Abbott, 1974). DATA: Live spec-

imen washed up on Bogue Banks beach, Car-

teret County (34°41.4'N; 76°47.6'W).

Astraea phoebia Roding, 1798. Published

range: Southeast and northwest Florida to

Brazil (Abbott, 1974). Menzies, et al. (1966) list

the species in their North Carolina report but

give no locality data. Later North Carolina

range references (Porter, 1974) are probably

based on the Menzies et al. report. See also

Porter (1974) and Schwartz and Porter (1977)

for recent North Carolina records of the species.

DATA (11 specimens south of Cape Lookout-

Beaufort Inlet area): Juvenile, UNC-IMS#4174

(34°17.5'N; 76°10.8'W; 46 m depth); UNC-IMS

#3381 (34°16.5'N; 76°42.0'W; 91 m depth);

128 THE NAUTILUS

July 10, 1981

Vol. 95(3)

UNC-IMS#4035. 1-4035.2* (34°20.0'N;

76°42.0'W; 24 m depth); juvenile, UNC/IMS

#4036 (34°23.0'N; 76°39.0'W; 24 m depth);

UNC-IMS#6145* (34°15.6'N; 76°35.5'W; 32 m

depth); UNC-IMS#6343* (South of Cape Look-

out; 23-30 m depth); UNC-IMS#7105. 1-7105.4

(34°21.8'N; 76°35.0'W; 20-26 m depth). Speci-

mens were found at 20-91 m depth generally in

rocky or shelly substrate.

North Carolina is also the northern range of a

related species A. tecta americana (Gmelin,

1791) [see Porter, 1974; record based on one

specimen from south of Beaufort Inlet - UNC-

IMS#4039* (34°23.0'N; 76°39.0'W; 33 m

depth)].

Charonia variegata (Lamarck, 1816). Publish-

ed range: Southeast Florida to Brazil (Abbott,

1974); however, Merrill and Petit (1969) record

a fresh juvenile fragment off Cape Romain, SC.

A Scheltema (1971) larvae record off the North

Carolina coast (unlisted by Scheltema but in-

dicated in Figure 6) is listed by Porter (1974).

DATA (Seven specimens from south to south-

east of Cape Lookout, NC): juvenile, UNC-

IMS#4366 (34°9.9'N; 76°10.6'W; 35 m depth);

Ross specimen* (34°23.5'N; 76°35.0'W; 24 m

depth); Dixon specimen (34°14.0'N; 76°35.0'W;

26-32 m depth); Safrit specimen (34°11.0'N;

76°31.0'W; 31 m depth); UNC-IMS#7106, 7107,

and 7131 (34°21.8'N; 76°35.0'W; 20-26 m

depth). Specimens were found at 20-35 m depth

frequently in rocky or shelly substrate. No shell

or living specimens were noted in 1978 by the

junior author during dives on "Ten Fathom

Rock" (34°21.8'N; 76°35.0'W) but a living

specimen was collected in June 1978, on "210

Rock" (34°14.0'N; 76°35.0'W) during a dive

organized by Dr. R. Searls; no later records

have been reported.

Cooperella atlantica Rehder, 1943. NEW

RANGE RECORD. Published range: Southeast

Florida to Brazil (Abbott, 1974). DATA (10

specimens from southeast of Cape Lookout to

southeast of New River Inlet, NC): UNC-IMS

(34°10.0'N; 77°04.0'W; 27 m depth); four

specimens (three living), UNC-IMS#5386

(34°12.9'N; 76°13.2'W; 37 m depth); UNC-

IMS#6374 (34°11.8'N; 76°36.2'W; 37 m depth);

two specimens, UNC-IMS#6463* (34°12.rN;

76°35.7'W; 37 m depth); UNC-IMS#3832

(33°55.9'N; 76°31.9'W; 35 m depth); UNC-IMS*

(34°17.0'N; 76°46.0'W; 20-26 m depth). This

species in North Carolina waters may be re-

stricted to depths between 20 and 37 m, the lati-

tude restriction, 33°55.9' to 34° 17.0', related (?)

to a lack of samples at above mentioned depth,

north and south of these latitudes.

Lima scabra (Born, 1778). Published range:

South Carolina to Brazil (Abbott, 1974), though

Emerson and Jacobson (1976) list North Caro-

lina to West Indies. Records near Cape Look-

out, NC date back to Stimpson (1860) and Coues

(1871); later records, probably based on the

aforementioned, are listed in Porter (1974).

Jacot (1921) implies, probably correctly, that the

Stimpson and Coues records are Lima inflata

Lamarck (synonym of L. pellucida C. B.

Adams), a species known living in the Beaufort

Inlet and Cape Lookout area. DATA (four speci-

mens from south of Cape Lookout to southeast

of Cape Fear, NC): UNC-IMS#2704 (33°28.5'N;

77=27.5^; 26 m depth); UNC-IMS#6104*,

7132.1*, and 7132.2* (34°14.0'N; 76°35.0'W;

26-32 m depth). Living specimens were attach-

ed to under surface of rocks. Many living speci-

mens were seen attached under rocks on "210

Rock" June, 1978-1980 (personal communica-

tion-S. Ross) and by junior author.

Pinctada imbricata Roding, 1798. Published

range: South Carolina to Brazil (Abbott, 1974);

however, Jacot (1921) found a recent-living

specimen in the vicinity of Beaufort, NC. Other

authors (Porter, 1974), listing North Carolina

within the range for this species, are suspected

to have as their source data the Jacot report.

DATA (two specimens from Cape Lookout

Bight and Pine Knoll Shores Beach, NC): UNC-

IMS#7870* (34°37.5'N; 76°33.3'W; beach);

Rowland and Giles specimen* (34°41.7'N;

76°52.2'W; beach). The Howland and Giles

specimen was attached to Sarga^sum sp. sea-

weed. Specimens collected by Jacot and more

recently by Ryan (UNC-IMS#7870) may also

have been brought into North Carolina waters

by Sargassum or other drifting objects upon

which they may have set. During winter months

it is believed that P. imbricata might be found

Vol. 95(3)

July 10, 1981

THE NAUTILUS 129

on any beach in North Carolina wherever Snr-

gassum is washed ashore.

Spondylus americanus Hermann, 1781. Pub-

lished range: North Carolina to Brazil (Abbott,

1974); Porter (1974) lists previous North Caro-

lina records and UNC-IMS holdings. DATA (15

specimens from southeast of Cape Lookout to

east-southeast of Cape Fear, NC): UNC-

IMS#4415* (34°18.5'N; 76°10.8'W; 46 m depth);

four specimens (three recent), UNC-IMS#3400

(33°52.(yN; 76°32.0'W; 57 m depth); UNC-

IMS#4417 (33°26.0'N; 77°00.9'W; 76 m depth);

UNC-IMS#2596* (34°08.1'N; 76°11.4'W; 67-72

m depth); UNC-IMS#4537* (34°09.4'N;

76°08.0'W; 70-119 m depth); two specimens,

UNC-IMS#5007 (34°09.6'N; 76°10.1'W; 46-57

m depth); Safrit specimen* and UNC-IMS#7130

;34°21.8'N; 76°35.0'W; 21 m depth); UNC-

[MS#7108.1*-7108.3(34°11.0'N; 76°31.0'W; 31

n depth). Specimens were found in North Caro-

ina waters between 21 and 119 m depth. Recent

iving specimens have been noted on nearshore

^orth Carolina shipwrecks (pers. comm. - D.

^oe). COMMENTS: Molluscan species occur-

•ing within the shallow marine waters of North

Carolina have been considered members of

■ither the Virginian (Boreal subprovince), Caro-

inian, and/or the Caribbean Faunal Provinces

Abbott, 1968). Cape Hatteras is usually con-

idered to be the southern boundary of the

■^irginian and northern boundary of the Caro-

inian and Caribbean faunas. Faunal overlap-

ping is common. Basically, these faunal prov-

ices or regions are acceptable when consider-

ig most groups of marine organisms (Briggs,

974). The North Carolina marine faunas fall in-

0 the following redefined provinces:

Boreal: species having reproducing popula-

lons from Labrador south to North Carolina.

Virginian: species having reproducing

opulations north and south of North Carolina

'aters. This group may correspond to the "Tem-

erate" or "Virginian" group of Bousfield (1960).

efined as ranging from the Gulf of St. Law-

3nce to northern Florida and the Gulf of Mex-

0.

Carolinian: species having reproducing popu-

tions from Florida north to North Carolina.

i.bbott, 1968, and Briggs 1974). In North Caro-

lina waters, the Carolinian species may be

restricted to estuarine and nearshore waters of

less than 20 or 25 m depth; further north, the

species live at depths from 26-156 m (Merrill et

al. 1978).

Caribheayi: species seldom found north of

North Carolina and probably not capable of

reproducing within North Carolina waters. Ma-

jor populations occur offshore in deep water

habitats influenced by the warm Gulf Stream

(Abbott 1968 and Briggs 1974).

Anomalocardia auberiana, Astraea tecta

americana and Charonia mriegata are mem-

bers of the Caribbean Province and not capable

of sustaining North Carolina populations. As

such, they are considered as accidental strays

within the North Carolina fauna.

Astraea phoebia, Cooperella atlantica, Lima

scabra and Spondylus americanus are believed

to be members of the Carolinian Province.

Cooperella atlantica is widely distributed in san-

dy habitats within the area sampled and have oc-

curred there for several years. Astraea phoebia,

L. scabra and S. americanus frequently are

found in rocky offshore areas. The fauna at "210

Rock", studied intensively during recent years,

is believed to be mainly self-reproducing (per-

sonal communication - R. 0. Parker). LInusually

cold winters in 1977 and 1978 have caused sig-

nificant mortalities at this rock (pers. comm. -

R. Searls); however, the 1978 to 1980 presence

of large living specimens of Charonia variegata

and Lima scabra indicates that these two

species, at least, are capable of surviving off

North Carolina at "210 Rock" even under

periods of unusually cold \\inter stress. Read

(1967) in his thermal tolerance study of Lima

scabra from Puerto Rico, primarily concerned

with upper temperature limits, lists a winter

adaptation temperature of 26.2°C for the

species, a temperature considerably higher than

that occurring at "210 Rock". That Charonia

variegata also seems capable of surviving winter

temperatures as low as 6°C, may suggest that it

likewise is capable of sustaining a population

within North Carolina waters.

ACKNOWLEDGMENTS

Specimens collected by the junior author were

I

130 THE NAUTILUS

July 10, 1981

Vol. 95(3)

taken during dives connected with ecological

studies of North Carolina rock outcroppings

sponsored by: Dr. Richard Searls, Duke Univer-

sity, Durham, NC (grant support: Duke Univer-

sity and North Carolina Board of Science and

Technology) and the Atlantic Estuarine Fish-

eries Center (AEFC), National Marine Fisheries

Service (NMFS), Beaufort, NC (Project Leader -

Mr. R. 0. Parker). Astraea specimens collected

by Mr. E. Pond (UNC-IMS #4035, 4036, 4039)

were from a study supported by NC Board of

Science and Technology, Grant 456. Catalogued

UNC-IMS specimens used in this study not col-

lected by the authors were donated by: Dr.

Charles E. Jenner, Department of Zoology,

University of North Carolina at Chapel Hill,

Chapel Hill, NC; Mr. Bill Laughinghouse,

Morehead City, NC; Mr. Steve W. Ross, Depart-

ment of Zoology, University of North Carolina

at Chapel Hill, Chapel Hill, NC; and Dr. William

J. Woods, Swansboro, NC.

Thanks are given to the following individuals

who loaned specimens to the authors for use in

this paper: Mr. Billy Corbett, Wilson, NC

(Anomalocardia auberiana); Mr. Bob Dixon,

NMFS, NOAA, Beaufort, NC (Charonia varie-

gata); Ms. Jean Giles, National Park Service

Ranger Station, Harkers Island, NC and Ms.

Patricia A. Howland, Morehead City, NC (Pinc-

tada imbricata); and Dr. Edward Ryan, Biology

Department, East Carolina State University,

Greenville, NC (Pinctada inibricat a -\3iter

donated as UNC-IMS#7870).

Specimens of Cooperella atlantica in the UNC-

IMS Collection were compared by the senior

author with identified specimens in the

molluscan collection at the Delaware Museum of

Natural History. Our specimen of Charonia

variegata (UNC-IMS#4366) was identified by

Mr. Russell Jensen of the above institution.

Acknowledged also are Dr. A. F. Chestnut

(Director) and Dr. W. E. Fahy of the University

of North Carolina, Institute of Marine Sciences

and Dr. Arthur S. Merrill, NMFS, NOAA,

Northeast Fisheries Center, Woods Hole, MA,

who critically reviewed this paper.

LITERATURE CITED

Abbott. R. T. 1968. Seashdia of North America. A guide to

field identification. Golden Press, New York.

1974. Aytwrican Seashells (second edition). Van

Nostrand Reinhold Co., New York.

Bousfield, E. L. 1960. Canadian Atlantic Sea Sheila. Nat.

Mus. Canada, Ottawa.

Briggs, J. C. 197i. Marine Zooyeography. McGraw-Hill Book

Co., New York.

Coues, E. 1871. Notes on the natural history of Fort Macon,

N. C. and vicinity. Proc. Acad. Nat. Sci. Philadelphia

23:120-148.

Dall, W. H. 1902. Synopsis of the family Veneridae and of

the North American recent species. Proc. U. S. Nat. Mus.

26:335-412.

Emerson, W. K. and M. K. Jacobson. 1976. The American

Museum, of Natural History Guide to Shells. Land, fresh-

water, and marine, from Nova Scotia to Florida. Alfred

A. Knopf, New York.

Jacot, A. P. 1921. Some marine molluscan shells of Beau-

fort and vicinity. Jour. Elisha Mitchell Sci. Soc. 36:

129-144.

Menzies, R. J., 0. H. Pilkey, B. W. Blackwelder. D. Dexter.

P. Ruling and L. McCloskey. 1966. A submerged reef off

North Carolina. Int. Rev. ges. Hydrobiol. 51:393-431.

Merrill, A. S., R. C. Bullock and D. R. Franz. 1978. Range

extension of moUusks from the middle Atlantic Bight. The

Nautibis 92:34-40.

and R. E. Petit. 1969. Mollusks new to South

Carolina: II. The Nautilus 82:117-122.

Narchi, W. 1972. Comparative study of the functional mor-

phology ol Anomalocardia brasiliana (Gmelin, 1791) and

Tivela mactroides (Born, 1778) (Bivalvia, Veneridae).

Bull. Mar. Sci. 22:643-670.

Porter, H. J. 1974. The North Carolina Marine and Estua-

rine Mollusca, an Atlas of Oecurrenee. Univ. of North

Carolina, Inst. Mar. Sciences, Morehead City, NC.

, C. Johnson and Anne B. McCrary. 1977. Marim

Invertebrates. Introduction. In: J. E. Cooper, S. S. Robin

son, and J. B. Funderburg(Eds.). Endangered and Threat-

ened Plants and Animals of North Carolina, N. C. State

Mus. Nat. Hist., Raleigh, NC.

Read, K. R. 1967. Thermal tolerance of the bivalve mollusc

Lima scabra Born, in relation to environmental tempera-

ture. Proc. Malac. Soc. bond. 37:233-241.

Scheltema, R. S. 1971. Larval dispersal as a means of gene-

tic exchange between geographically separated popula-

tions of shallow-water benthic marine gastropods. Biol.

Bull. 140:284-322.

Schwartz. F. J. and H. J. Porter, 1977. Fishes, macroin-

vertebrates, and their ecological interrelationships with a

calico scallop bed off North Carolina. NOAA, Fishery

Bull 75:427-446.

Stimpson, W. 1860. A trip to Beaufort, North Carolina.

Amer. Jour. Sci. and Arts. (Series 2) 29:442-445.

Vol. 95(3)

July 10, 1981

THE NAUTILUS 131

RECOLONIZATION OF REACTOR COOLING WATER SYSTEM

BY THE ASIATIC CLAM CORBICULA FLUMINEA^

R. S. Harvey

Savannah River Laboratory

E. L du Pont de Nemours and Company

Aiken, South Carolina 29801

ABSTRACT

Recolonization rates for the Asiatic dam Corbicula fluminea ranged fro7n 3 0 to

5.6ynetric tons per year in cooling water basins for a nuclear production reactor

at the Savannah River Plant. However, a 10-month cleaning cycle for each basin

(Jlow area. 6100 m^} keeps the depth of the stlt/clam layer low. With this deaniZ

Jrequmcy. CorhicnX^ are not reaching heat exchangers at sufficient size or in suffi-

cient numbers to restrict flow. Data are presented on the sue/age distribution L

dams recolonizing cooling water basins between cleanings.

The Savannah River Plant (SRP), built and

operated for the Department of Energy by E. I.

du Pont de Nemours and Company, was estab-

lished in 1950 to produce plutonium-239 and

tritium for national defense (Harvey and Ran-

dall, 1974). SRP occupies an 800-km2 area of the

Atlantic Coastal Plain near Augusta, Georgia,

and is bordered on the south for 35 km by the

Savannah River. The Savannah River is the

arincipal source of cooling water for the nuclear

•eactors used to produce the plutonium and

;ritium.

The Asiatic clam Corbicula fluminea was first

■eported in the Savannah River near Augusta

Georgia, in 1973 (Fuller and Powell, 1973)!

--abeled as a pest species by many industries,

"orbicula are noted for their ability to restrict

low in water supply pipes and to clog ducts and

creens. The affected industries are widespread

nd include water and sewage plants, power

.•enerating plants, and irrigation systems (Goss

nd Cain, Jr., 1975; McMahon, 1977). By 1975,

ufficient numbers of Corbicula were present in

ooling water from the Savannah River to clog

le heat exchangers (Fig. 1) of P-Area nuclear

roduction reactor, one of three (P, K, and C) at

RP. Clams were also found in the K- and C-

•eactor cooling water systems.

he information contained in this article was developed dur-

i the course of work under Contract No. AT(07-2)-l with

e U. S. Department of Energy.

The cooling water for P Reactor comes from

two sources: the Savannah River and a cooling

water reservoir, Par Pond (Fig. 2). The cooling

water for K and C Reactors is pumped directly

from the river through a system of pipes into

large basins. Juvenile clams apparently enter

the system with the river water and are trans-

ported 8 to 10 km through pipes before reaching

the basins. Corbicula have been recently (1981)

found in Par Pond.

At K and C Areas, large volumes of river

water are discharged into three 32-megaliter

basins (Fig. 3) where some settling occurs

before the water is pumped through heat ex-

FIG. 1. Heat exchanges- openings are clogged by the Asiatic

Clam Corbicula fluminea.

132 THE NAUTILUS

July 10, 1981

Vol. 95(3)

FIG. 2. Prnduclion Areas and coaling water .soKrcf.s- on the Savannah River Plant.

Vol. 95(3)

July 10, 1981

THE NAUTILUS 133

1 Process 1

T Cooling T

^ Water to \

Process

Cooling

Water to

Heat Exchangers"

105-K

?>=o

Cooling Water

Basins

^^^r-i^^

^

o

?lver I

IWoter Header

-CX}

Tie Line Header

f

FIG. 3. K-Area cool

By-Pass Header

t7ig water system.

changers in the reactor area. The floor area of

each basin is approximately 6100 km^. Due to in-

frequent cleanings and unexpected accumula-

tions of Corbicula, the silt/clam substrate levels

in P-Area basins were about 90 cm deep when

heat exchanger pluggage occurred. The sub-

strate levels in K-Area basins in 1976 were ap-

proximately 75 cm. The deposited silt and flow

of river water provides suitable substrate and

Qutrients for Corbicula growth and reproduc-

:ion. Silt and clams must be removed at regular

ntervals to prevent heat exchanger pluggage

irising from high populations of clams in the

msins. Current practice is to clean the basins

?very ten months.

A model has been developed to determine the

•growth rate of Corbicula in the cooling water

)asins at SRP (Pool and Tilly, 1978); their sur-

vival in chlorinated water has also been studied

Tilly, 1973). The objective of this paper is to

•haracterize and provide a measure of the Cor-

icula population recolonizing the K-Area cool-

ag water basins between cleanings (October

976-August 1977).

Method

At present, the clams are controlled by clean-

mg the reactor basins, pump wells, and emer-

gency cooling system every ten months. Each

cleaning occurs during reactor shutdown and in-

volves draining the basins. The walls are washed

down with fire hoses and the silt on the floor is

removed. The emergency cooling system is also

flushed completely at this time.

When the basins were cleaned, clams sus-

pended in basin water were sampled with a

760-M plankton net, 0.5 m in diameter and 1.5 m

long, with a digital flowmeter mounted in the

mouth of the net. The net was hand-held near

floor drains as water levels dropped from 1.0 to

0.7 m. The sample was examined and clams

were measured with the aid of a dissecting

microscope.

Quantitative samples from the walls, floors,

and pump wells were washed through a U.S.'

Standard Number 10 sieve to collect the Cor-

bicula present. Shell lengths of 100 clams from

each sample were measured with a caliper

across the widest part of the shell parallel to the

hinge; this measurement was then used to deter-

mine the approximate age of each specimen

(Gardner, et al., 1976).

Results and Discussion

Flow was maintained on at least one of the

three cooling water basins at all times. Under

normal flow conditions, water is pumped from

the pump wells to heat exchangers in the reac-

tor area. Basins 2 and 3 were both drained on 1

September 1977, and were dry, when sampled

six days later, except for small areas exposed to

leakage. Basin 1 was drained on 28 September

1977, and was sampled during and immediately

after draining. Basin 2, located between the

other basins, contained essentially no silt and

too few clams for a meaningful sample. About

50% of the floor area of Basin 3 was covered

with silt up to 12.5 cm deep with an average

depth of about 7.5 cm. Clam mortality, based on

5 sample areas (each 100 cm^), ranged from 20

to 80% depending on the moisture of the sub-

strate. Earlier notification would have permit-

ted samples from Basin 3 during draining and

would have made results more comparable with

those from Basin 1. Mortality was only 5% for

134 THE NAUTILUS

July 10, 1981

Vol. 95(3)

Corbicula collected from pump wells in Basins 2

and 3, and for those collected from Basin 1.

About 40% of the floor area of Basin 1 was

covered with silt up to 5.0 cm deep with an

average depth of 2.5 cm.

Clam concentrations on the floors of Basins 1

and 3 (Table 1) were generally comparable ex-

cept for the fifth sample from Basin 3 which was

taken from a large mound of clams piled up by

receding water. By using mean concentrations

of Corbicidalm^ and appropriate percentages oi

floor area covered by silt, clam populations in

Basins 1 and 3, ten months after cleaning, were

estimated to be 2.7 and 10.2 million, respective-

ly (calculation excluding sample 5).

Size/age distribution data (Table 2) show that

Corbicula in Basin 1 were smaller and younger

than those in Basin 3. A higher percentage of

juveniles and fewer one- and two-year old Cor-

bicula in Basin 1 than in Basin 3 may be due tc

TABLE 1 . Corbicula aoneentrations in K-Area cooling water basins.

Sample 5 was collected from a mound of clams accumulated by

receding water. The sample is not representative of clam

concentrations in the basin.

TABLE 2. Size distribution of Corbicula in the K-Area cooling water basin.

Shell Length/ Age Class (Percent of Population)

13.6 - 18.5 mm 18.6 - 28.0 rm

(2 yr) (3 yr)

6.8

0.0

Shell lengths are <1 mm (151 specimens)

Vol. 95(3)

July 10, 1981

THE NAUTILUS 135

the source of cooling water. Basins 2 and 3 are

supplied from the river water header; Basin 1 is

supplied from a tie line header which has a sec-

tion of pipe with stagnant water. This would

suggest that the juveniles might be produced or

raised in the tie line.

The silt substrate in the pump wells of Basins

2 and 3 generally contained higher concentra-

tions of Corbicula (Table 1) than were found in

basin floor samples. The reason is not known.

Size/age distribution data for clams from the

pump well (Table 2) are comparable to those

observed for clams in Basin 3.

Wall scrapings in the K-Area basins did not

yield any Corbicula. Samples (lOO-cm^ areas)

were collected at various depths and washed

through a U.S. Standard Number 10 sieve.

Corbicula larvae, generally smaller than 250

pi, were not found in the K-Area basins. Shell

lengths of 151 juveniles collected from 400 kilo-

liters (kL) of water during the draining of Basin

1 ranged from 380 to 1000 m (1 kL = 264.18

gallons; 1 fi = 0.001 mm). These specimens were

collected in a 715-(j plankton townet as the

water level dropped from l.O to 0.7 m. This col-

lection represents a concentration of about 0.4

clams/kL or 12,618 clams per basin volume.

An analysis of the size/age distribution data

(Table 2) shows that Corbicula grow about 600

to 1100 /i/month during the first year. On this

basis, the juveniles collected from Basin 1 were

probably produced in late August or early

September 1977, just prior to the draining of the

basin. The Corbicula spawning season begins

when the water temperature reaches 16 to 17°C

and continues until temperature falls below this

(Gardner et al., 1976), thus allowing a spawning

season in the Savannah River usually from April

•through November. However, the origin of

these clams can only be speculated. They could

have entered the basins as larvae or as juveniles

by transport through distribution pipes, or they

could have been produced as larvae by adult

Corbicula living on the floor of Basin 1.

An experiment in October 1977 estimated the

transport of Corbicula from the raw water

system into Basin 1. Immediately after the basin

A'as drained, the walls and floor were washed

A'ith fire hoses to remove all clams. The basin

was refilled on 6 October 1977, and the water

was allowed to stand for two hours for the clams

to settle before draining for the second time.

Four Carbicula juveniles with shell lengths

about 0.5 mm in length were found in a 129-kL

plankton townet sample (mesh 715 fj.) collected

from Basin 1 as the water level dropped from

1.0 to 0.7 m. This calculates to about 0.03

clams/kL or 946 clams/basin volume. When the

basin was completely drained, the basin floor

contained very little silt and only a few clams

near the inlet header and near the effluent

drain. Six l-m^ floor samples yielded Corbicula

concentrations of 0, 0, 4, 12, 2, and O/m^. One

specimen was less than 1 year old, seven were

about 1 year old, and ten specimens were ap-

proximately 2 years old. This experiment

demonstrates how quickly a clean basin can be

restocked with both juveniles and sexually

mature clams from the river water header.

Summary

The ten-month cleaning cycle is effective in

preventing the buildup of silt/clam substrate in

K-Area basins. The level in 1976 was about 75

cm; in both 1977 and 1978, silt/clam levels were

<15 cm. Although clams are recolonizing Basins

1 and 3 at rates of 3.0 and 5.6 metric tons/year,

clams apparently are not reaching the heat ex-

changers at sufficient size or in sufficient

numbers to restrict the cooling water flow. A

higher percentage of juvenile clams in Basin 1

(78%) than in Basin 3 (9.4%) may be due to

Basin 1 receiving water from the tie line header

which has a section that is not routinely flushed

to remove clams.

LITERATURE CITED

Fuller, S. L. H. and C. E. Powell. 1973. Range Extensions

of Corbicula manilensis (Philippi) in the Atlantic Drain-

age of the United States. The Nautilus 87(2):59.

Gardner, J. A., Jr., W. R. Woodall, Jr., A. A. Staats, Jr.

and J. F. Napoli. 1976. The Invasion of the Asiatic Clam

Corbicula manilensis (Philippi) in the Altamaha River,

Georgia. The Nautilus 90(3): 117.

Goss, L. B. and C. Cain, Jr. 1975. Power Plant and Service

Water System P>.)uling by Corbicula. the Asiatic Clam. In

Proceedings of Biofouling Workshop, Electric Power Re-

search Institute and Maryland Power Setting Program,

John Hopkins University, Baltimore, Maryland, June

16-17, 1975.

136 THE NAUTILUS

July 10, 1981

Vol. 95(3)

Harvey, R. S. and D. Randall. 1974. Measuring the Environ-

mental Effects of Thermal Discharges. DuPont Innovn-

ti„n 6(1): 1.

McMahon, Robert F. 1977. Shell Size - Frequency Distribu-

tions of Corbicula manilensis (Philippi) from a Clam-

Fouled Steam Condenser. The Nautilus 91(2):54-59.

Pool, A. C. and L. J. Tilly. 1978. A Model to Determine

Growth Rate of Corbicula. USERDA Report DP-MS-

77-79, E. 1 du Pont de Nemours and Company, Savannah

River Laboratory, Aiken, SC.

Tilly, L. J. 1973. Clam Survival in Chlorinated Water.

USAEC Report DP-1398, E. I du Pont de Nemours and

Company, Savannah River Laboratory, Aiken, SC.

THE REPRODUCTIVE SYSTEM OF THE WESTERN ATLANTIC

ANACHIS AVARA (GASTROPODA: COLUMBELLIDAE)

Roy S. Houston

Department of Biology

Loyola Marymount University

Los Angeles, California 90045

and

ABSTRACT

Edward B. Hatfield'

Jackson Estuarine Laboratory

RFD 1, Adams Point

Durham, New Hampshire 03824

The reproductive system of specimens o/Anachis avara (Say, 1822) from. Bis-

cayne Bay, Florida, is described from dissections and histological sections, and

found similar to that of its southern counterpart, A. brasiliana. In this case it ap-

pears that the reproductive systems are of little taxonomic value at the specific

level.

Few investigations have been made regarding

the functional anatomy of reproductive systems

in the Columbellidae. Marcus and Marcus

(1962b) studied the genitalia of eight species

from Brazil. In a later study, Marcus and Mar-

cus (1964) compared the external shell charac-

teristics and the genital system of Anachis

pulchella (Blainville 1829) with those species

previously investigated. Houston (1976) de-

scribed the reproductive systems of several

species from the Gulf of California.

Anachis avara (Say, 1822) is a small proso-

branch of the family Columbellidae reported by

Radwin (1977a) to have a geographical range

from the Gulf of Maine to Miami, Florida. In

Brazil and Uruguay this species is replaced by

A. bra^siliana (von Martens, 1897) one of the

eight species studied by Marcus and Marcus

(1962b). Abbott (1974) considered brasiliana to

be a subspecies of avara. Recently, Radwin

(1977a, 1977b) placed these species in the genus

Costoanachis Sacco, 1890. However, in this

' Present address: P. 0. Box 94, Freedom, N.H. 03836.

study, we treat Costoanachis as a subgenus of

Anachis.

It is the objective of this study to determine if

there are differences in the reproductive anat-

omy, which are useful in distinguishing A reac/its

avara from A. brasiliana. In addition, the major

anatomical and functional aspects of the genita-

lia of A. avara will be discussed, in relation to

other neogastropods.

Methods and Materials

Both sexes of Anachis avara were collected

from the shallow subtidal of Biscayne Bay,

Florida. Gross anatomical features of the

reproductive system were determined by means

of dissections of living and preserved material.

In addition, stained serial sections were used to

elucidate the histological details. Through the

use of standard histological techniques, the

animals were infiltrated with paraffin and sec-

tioned at 8 microns. The sections were then

stained with Weigert's Hematoxylin and

Vol. 95(3)

July 10, 1981

THE NAUTILUS 137

Gomori's Trichrome following the procedure of

Gomori (1950).

Results

The Male Duct

Posteriorly, both the testis (t) and digestive

gland share the visceral mass. The testis is com-

posed of numerous acini which are surrounded

and separated from each other by a thin layer of

loose connective tissue. Mature spermatozoa oc-

cur within each acinus. They are arranged in an

orderly fashion with their heads embedded in

the acinar epithelium and their tails extending

into the center of the lumen.

These acini lead to acinar ducts which ulti-

mately join to form the testicular duct (td) (Fig-

ure lA). Anteriorly, the testicular duct runs

along the columnar region of the whorls next to

the digestive gland until it becomes highly con-

voluted. This coiled region, now the posterior

vas deferens, appears to function as a seminal

vesicle (sv) for it is densely packed with sperm.

The lumen is lined with low columnar epithelium

which have round basal nuclei. In addition, the

cytoplasm contains light blue granules which

may be secretory in nature. Furthermore, this

duct is approximately 2.5 mm long and attains

the same diameter throughout its length. As the

seminal vesicle approaches the posterior region

?rnm ,

IG. 1. Genitalia of Anachis avara: A- male. B- female,

■ampulla: bc-lmrsa copulatrix; cg-capsule gland; go-

ynadal oiiduct; gp-ge>i>tal pore: o-ovary: om-openiitg into

■nntle cavity: p-peois; ^A-penial duct: to- renal oviduct; sv-

mvinal vesicle; i-testis: td-testicnlar duct; vd-uas deferens;

■i-vestibv.le.

of the mantle cavity, it straightens out for a

short distance then opens into a large thin-

walled ampulla (a). This structure corresponds

to the seminal vesicle of Brasilian columbellids

studied by Marcus and Marcus (1962b). From

this sac there is communication with the mantle

cavity (om) by means of a short ciliated duct.

This duct is 70^ long and its entrance into the

sac is guarded by a sphincter.

Anteriorly the sac or ampulla leads to a thick-

walled muscular ciliated duct, the anterior vas

deferens (vd). This tube runs along the right

body wall until it joins the penis (p). The penis,

which is located just posterior to the right

cephalic tentacle, is extremely long and dorso-

ventrally flattened. Furthermore, it is wide at

the base and then tapers to a point. The wall of

this organ is composed of an outer layer of circu-

lar muscle cells. Inside are two layers of longi-

tudinal muscle fibers from which arise addi-

tional fibers that form a latticework around the

haemal sinuses. Finally, the entire structure is

covered with a single layer of ciliated squamous

cells. The penial duct (pd) is centrally located

and appears as a convoluted tube which opens at

the tip of the penis. Histologically the penis can

be divided into two regions. At the base it is

lined with glandular cells interspersed with

ciliated tall columnar cells. The basal round

nuclei of the gland cells are highly basophilic and

have two nucleoli. The ciliated cells, in turn,

have oval nuclei which are centrally located.

Anteriorly, the lumen of the penial duct is lined

entirely by secretory epithelium. As in other col-

umbellids (Marcus and Marcus, 1962b; Houston,

1976), the tip of the penis is tucked in a pouch in

the posterior mantle wall.

The Female Duct

The bright yellow ovary (o) lies along the outer

side of the visceral mass and is separated from

the digestive gland by a thin layer of connective

tissue. In addition, there is a tenuous layer of

connective tissue surrounding the ovary itself.

As in the testis of the male, the ovary is com-

posed of numerous acini which collectively fun-

nel into the gonadal oviduct (go) (Figure IB).

Several cell types comprise the acinar epithe-

138 THE NAUTILUS

July lU, 1981

Vol. 95(3)

Hum. These include low columnar cells, secre-

tory cells, primoidal germ cells and developing

oocytes. Within the acinar lumina are oocytes

that are attached to the epithelium by a pedun-

cle. Also, there are large numbers of oval secre-

tory droplets that stain bright red with

Gomori's.

The short thin-walled gonadal oviduct is lined

with nonciliated low columnar epithelium and in

mature females it is packed with oocytes. As

this tube leaves the visceral mass it becomes

ciliated and becomes the renal oviduct (ro). Here

it straightens out and runs anteriorly along the

right side of the body wall, just ventral to the

nephridium and dorsal to the pericardial cavity.

Anterior to the pericardial ca\aty the oviduct

enters the posterioventral region of the large

capsule gland (eg).

In cross section this organ has a lumen which

appears as a dorsoventral slit that divides it into

right and left lobes. The lumen is lined with

ciliated, tall, columnar epithelium interspersed

by ducts arising from clusters of subepithelial

gland cells. It is interesting to note that two sub-

epithelial cell types, each with their respective

staining properties, occur within the gland.

The posterior one-fourth of the gland is com-

posed mainly of polygonal cells with small round

centrally located nuclei. Moreover, the cyto-

plasm stains bluish-gi-een with Gomori's. The

rest of the capsule gland is made up of elongated

clusters of teardrop-shaped cells that stain deep

red. In addition, within the lumen are masses of

secretory droplets of the same color.

Anteriorly, the lumen of the capsule gland is

continuous with a large deeply folded vestibule

(ve). It is rather thin-walled and lined with

ciliated, low, columnar epithelium. Ventral to

and communicating with the vestibule is the

highly muscular bursa copulatrix (be). This

organ is lined with ciliated, low, columnar

epithelium like that of the vestibule, except the

cilia are shorter and not as numerous. The vesti-

bule and bursa copulatrix both join anteriorly in

the form of a short ciliated vagina which ter-

minates at the genital pore (gp).

DISCUSSION

As far as one is able to determine, the

reproductive system of Anachis avara is like

that of A. hrasiliana as described by Marcus and

Marcus (1962b). It is therefore apparent that, in

this case, the reproductive system is of little tax-

onomic value at the specific level. Differences in

reproductive anatomy, do occur among higher

categories.

Marcus and Marcus (1962b) concluded there

are two morphological divisions among the Co-

lumbellidae, based on their reproductive

systems. One group contains species in which

the males have a seminal vesicle and no prostate

gland; and females that have an albumin gland

and bursa copulatrix. The other group contains

species in which males do not have a separate

seminal vesicle but have a prostate gland. More-

over, the females lack an albumin gland and

bursa copulatrix, but they have a gonopericar-

dial connection. In following this scheme, Ana-

chis avara and A. hrasiliana would belong to the

former group.

It is worth noting that Anachis avara and the

columbellids studied by Houston (1976) appear

to have generalized reproductive systems with

specific regions performing more than one func-

tion. Thus, compartmentalization is not to the

degree as in other neogastropod groups. These

include: the Muricidae, Nassariidae and Buccin-

idae studied by Fretter (1941), and the Turridae

examined by E. H. Smith (1967). In these groups

the separate organs each appear to assume one

function.

In male columbellids the coiled posterior vas

deferens appears to function both as a seminal

vesicle and for resorption of sperm. This condi-

tion also occurs in those species that appear to

have a separate seminal vesicle. Furthermore,

the penis probably has a dual function. In addi-

tion to being an intromittent organ, the pres-

ence of glandular tissue indicates it may assume

a prostatic function. The bursa copulatrix in

females receives the penis during copulation

(Houston, 1976). Moreover, it functions as a

depository for spermatozoa, although no sperm

were present in females of Anachis avara.

Observations by Marcus and Marcus (1962b) in-

dicate that in some species of columbellids, the

bursa is divided into two sacs. One sac serves as

Vol. 95(3)

July 10, 1981

THE NAUTILUS 139

a site for sperm ingestion, while the other is

ased for storage.

The albumin gland oiAnachis avara and other

solumbellids is not externally separated from

the capsule gland, but occupies the posterior

region of the latter. This also appears to be the

:ase for some species of olivids (Marcus and

Marcus, 1959). This arrangement differs from

ather families of neogastropods where a short

iuct separates the two glands. Some of these

families are: Muricidae, Nassariidae and the

Buccinidae (Fretter, 1941), the Terebridae (Mar-

cus and Marcus, 1962a), and the Turridae (E. H.

Smith, 1967). In addition. Ponder (1970) found

^his to be true for the volute, Alcithoe arabica

Gmelin, 1791). Also, a later study by Ponder

1972), showed this to be the case for the Mitri-

lae. More recently, Fretter (1976) indicated

;hat a deep constriction separates the capsule

md albumin glands in the marginellid, Vol-

mrina taeniolata Morch, 1860.

Therefore, it appears that two major morpho-

ogical types of genital systems occur through-

out the neogastropods. One specialized type

vith high compartmentalization and numerous

iccessory organs, each apparently performing a

:)articular function; and a second generalized

ype with low compartmentalization and fewer

iccessory structures which assume multiple

unctions. Whether one type is more advanced

han the other is difficult to determine.

Recently, Radwin (1977a) mentioned that the

]olumbellidae exhibit a high degi'ee of adaptive

adiation in shell morphology. Since they have

nvaded numerous habitats, possibly they would

lave evolved specialized organ systems to adapt

0 these habitats. This does not appear to be the

ase in their reproductive anatomy. On the

ther hand, since the Columbellidae originated

uring the Eocene and radiated as recently as

he Miocene (Radwin, Op. cit.). it is possible

lere has not been enough time for specialized

ystems to evolve. If there was ample time for

pecializations to occur, they could possibly have

een lost. In any case much work is needed on

le functional and ecological interrelationships

f reproductive systems.

ACKNOWLEDGMENTS

I am most grateful to the late George Radwin

for his invaluable criticism of the manuscript. In

addition, thanks are extended to Dr. Evelene

Marcus for her encouragement during this

study.

LITERATURE CITED

Abbott, R. Tucker. 1974. American Seashells. Van Nostrand

Reinhold, N.Y. 663 pp.

Fretter, Vera. 1941. The genital ducts of some British steno-

glossan prosobranchs. Joum. Mar. Biol. Assoc. U.K. 25:

173-211.

1976. The anatomy and feeding of the volutacean

prosobranch Volvarina taeniolata Morch, Joum. of Mol-

luscan Studies 42(3):327-336.

Gomori, G. 1950. Gomori's one step trichrome stain. Aracr.

Joum. Cliyxical Path. 20:661-664.

Houston, Roy S. 1976. The structure and function of neo-

gastropod reproductive systems: with special reference

to Columbella fu.scata Sowerby, 1832. The Veliyer 19(1):

27-47.

Marcus, Ernst and Eveline du Bois-Reymond Marcus. 1959:

Studies on "Olividae." Bol. Fac. Filos. Cien. Univ. Sao

Paulo. Zool. 22:99-188.

1960. On Haatula cinerea. Bol. Fac. Filos Cien.

U)iiv. Sao Paulo. Zool. 23:2.5-66.

1962a. On Leucozonia nassa. Bol. Fat. Filos.

Cien. Univ. Sao Paulo. Zool. 24:11-30.

1962b. Studies on Columbellidae. Bol. Fac.

Filos. Cien. Sao Paulo. Zool. 24:355-402.

1964. On the dove-shell Anachis pulchella (Blain-

ville). Anais da Academia Brasileira de ciencias 36(3):

359-366.

Ponder, Winston E. 1970. The morphology of Alcithoe ara-

bica (Gastropoda: Volutidae). Malacol. Rec. 3:127-165.

1972. The moqjhology of some mitriform gas-

tropods with special reference to their alimentary and

reproductive systems (Neogastropoda). Malacologia 11(2):

295-342.

Radwin, George E. 1968. A taxonomic revision of the family

Columbellidae (mollusca: Gastropoda) in the western

Atlantic exclusive of the genus .Astryis. Ph.D. disserta-

tion. The George Washington University. 237 pp.. 18 pis.

1977a. The family Columbellidae in the western

Atlantic. The Veliger 19(4):403-417.

1977b. The family Columbellidae in the western

Atlantic. Part Ila. • The Pyreninae. The Veliger. 20(2):

119-1.33.

Smith, Edmund H. 1967. The reproductive system of the

British Turridae (Gastropoda: Toxoglossa). The Veliger

10(2):176-187.

140 THE NAUTILUS

July 10, 1981

Vol. 95(3)

GROWTH RATE DETERMINATIONS OF ACHATINELLA LILA,

A HAWAIIAN TREE SNAIL

Robert M. Severns^

Natural Sciences Division

Hilo College

Hilo, Hawaii 96720

Hawaiian tree snails of the family Achatinel-

lidae are described by Pilsbry, et al. (1912-

1914). The species studied in this paper is

Achatinella lila, the habitat of which is the sum-

mit area of the Koolau mountains on the Island

of Oahu. Little is known about the biology of

these snails, therefore this study was under-

taken to determine their growth rates.

Materials and Methods

The altitudes of the colonies range from 2,500

feet to 2,800 feet. The colonies were all located

on ohia trees (Metrosiderns polymorphus) and

the surrounding low shrubs and vines. Speci-

mens were taken from three colonies, each of

which was characterized by a distinctive overall

color: brown, yellow, or green. All of the snails

were banded with either yellow or brown.

A total of 56 animals was collected -20 from

the predominantly yellow colony, eight from the

predominantly green colony, and 28 from the

predominantly brown colony. The green and the

yellow colonies were from the same immediate

area and altitude, the brown from a slightly

lower elevation.

Because A. lila had not been kept in captivity

successfully before, some details of the means of

doing so are presented here. The collected snails

were reared in cages which were 30x 18 inches

on the base and 20 inches high, and made of

screen on a pine frame. Three cages were con-

structed to permit isolation of the individual col-

onies so that no cross-breeding among colonies

could occur. Because the cages were kept at a

high humidity, there was a possibility that

disease-causing bacterial colonies might form.

To avoid this, the cages were placed in a slight

draft and partial sunlight. The snails feed

'Present address: 2535 Alaula Way, Honolulu, Hawaii

96822.

naturally on algae and fungus species growing

on the surface of smooth-leafed plants. As per-

manent substrate for the snails, Hawaiian bird

nest ferns (Asplenium nidum) were kept potted

in the cages. The ferns required minimal sun-

light and provided a large smooth leaf surface

for grazing snails. The snails do not eat the

ferns.

The snails were fed a mixture of lettuce and

dried milk. By blending the lettuce leaf and the

dried milk with water, a paste that could be lap-

ped up by the snails from the surface of the

substrate plants was made. This mixture was

marginally acceptable by two of the varieties,

while the third, the green variety, seemed to do

well.

All three varieties formed a growth scar while

adjusting to the artificial nutrient mixture. This

scar is a convenient mark with which to measure

growth. Two scars were present on the shell at

the end of the first month after collection. The

first scar was formed after birth and marked the

end of the nuclear whorl. The other scar was

formed as a result of the nutritional changes

described above. Several snails were born to the

colonies during the initial period of captivity,

and these shells showed none of the scarring due

to the artificial food.

The artificial food was replaced eventually by

natural food (fungus and algae found on the

bark and leaf surfaces of forest trees) to insure

the life of the snails born in captivity and to

allow growth to continue at as near normal rate

as possible. The snails were fed in captivity and

observed for several months.

Growth measurements were taken on a total

of 32 shells. Six of these were born in captivity

and placed in individual size classes to the near-

est 0.5 mm. The rest were grouped in 1.0 mm

size classes, beginning at 11.0 mm (see Table I).

Growth was measured along the suture (Fig-

Vol. 95(3)

July 10, 1981

Table I .

THE NAUTILUS 141

Shell Sa:e Suture Growth Average suture Number of Suture Growth

apex to base per sire class growth per size days of rate per day

(iron) . (mm) . class (mm) . observat ion (mm) .

2.3

2.4

1.7

1.6

4

20

39

47

52

72

81

0.086

0.070

0.056

0.049

0.035

0.029

0.028

0.029

0.027

0.021

0.020

0.025

0.020

'Bom in captivity.

ure 1) of the shell, beginning at the scar formed

from change in diet when the animals were

taken into captivity. A thin piece of thread was

used to measure the suture growth. Calipers

were used to measure the overall length of the

shell. An average of growth rate for each size

class was calculated, and this was then divided

by the number of days since scarring had occur-

red to give an estimate of daily growth rate.

This measurement was compared with the total

length of the shell from apex to base. Figure 2

shows the relationship of these two measure-

ments. The procedure was repeated with ani-

mals which had been born in captivity and whose

shells showed no scarring. The average growth

rates of the latter series of snails also were com-

142 THE NAUTILUS

July 10, 1981

Vol. 95(3)

FIG. 1. The ahell measurements used in

the paper: A, the apex of the shell. B, the

base of the shell. G, the growth along the

body whorl of the shell. L, the length of

the shell from apex to base, and S, the

scar formed by the change in nutrition

from the natural food to the artificial

food.

pared with the length of the shells determined

from apex to base. This series of young in-

dividuals provided the growth rate data for the

beginning of the curve.

Results

Table I presents growth data from the snails.

The first column lists the different size classes

into which the snails were put according to their

shell length (Figure 1). The second column

shows the individual growth measurements of

the snails in each size class. These measure-

ments were averaged in those size classes with

more than one individual (third column). The

fourth column shows the growth period in num-

ber of days. The growth, or average growth, of

the snails during the observed growth period

was then divided by the number of day of obser-

vation giving a value in millimeters which

represents the average growth per day of the

shells. This latter value was plotted against shell

length to obtain the curve (Figure 2), which

shows changes in the growth rate as the snail

matures.

This growth rate curve shows a rapid decrease

in growth rate as the shell length increases. The

shell length at which the growth rate begins to

level off is approximately 9 mm. The length of

GROWTH RATES OF ACHATINELLA LILA (Pilsbry)

.09

1 .08

. .07

a

— .06

° .05

g .04

.01

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Length, aoex to base, (mm)

FIG. 2. Growth rates 0/ Achatinella \\]a. (Pilsbry).

Vol. 95(3)

July 10, 1981

THE NAUTILUS 143

the shell eventually almost doubles to 17 mm but

with a much slower growth rate. The smaller

and younger snails grow much faster than the

larger snails.

Three-millimeter shells, which is the size at

birth, have a growth rate of .086 mm/day. At 5

mm the daily growth rate has declined to .049

mm/day and at 8 mm to .029 mm/day. The

growth rate then decreases from .028 mm/days

to .020 mm/days for shells 11 mm to 17 mm re-

spectively (Table I).

DISCUSSION

With the data collected and calculated, it

became clear that age approximations for each

shell class could be figured. Table II follows the

progression of data from the size class to the age

in days of the shell at that size class.

In column 1 the size classes of shells, meas-

ured apex to base, are listed. Choosing one of

these classes, 15 mm, the suture of the shell was

measured from the end of the nuclear whorl

around the whorls to the end of the body whorl.

This is shown in column 2 as 53 mm. Next, the

suture of the preceding size class, 14 mm, was

measured and subtracted from the length of the

suture of the shell of the class of 15 mm shells.

Thus an increase of 4 mm in suture length is

then listed in column 3. The next step involves

utilizing the data from the last column of Table

I, the daily growth rate of the shell along its

suture. The daily growth rates of the preceding

class, 14 mm, and of the 15 mm size class, .021

mm and .020 mm respectively, were averaged to

obtain .021 mm, representing the growth rate

from one class to the next. Finally, in column six

the number of days to advance from one class to

another was figured. This was obtained by divid-

ing the suture length difference of column 3, 4

mm, by the average growth rate between size

classes, .021 mm/day. The final column is the ac-

cumulated number of days from birth of the

snail to the size class being observed; class 15

mm is 1,404 days old or 3.85 years old.

It can be seen from the data, then, that the

oldest and largest of the snails studied is 17 mm

in length, and has reached an estimation age of

5.27 years. This suggests that the life span of

the snails can be five years.

ACKNOWLEDGMENTS

I would like to thank Mr. Richard Davis of

Kaneohe for supplying A. lila. Dr. Yoshio Ron-

do of the Bishop Museum for his kind advice on

raising the snails, Dr. James Rutherford of the

U. of Hawaii, Hilo for his encouragement, and

[All measurements in mm unless indicated.)

5.27 years

565/1925 days

144 THE NAUTILUS

July 10, 1981

Vol. 95(3)

especially to Dr. H. F. Little of the U. of Hawaii,

Hilo for his editorial assistance.

Special thanks go also to Mrs. La Vanda War-

ren secretary of the Natural Sciences Division

at t-he U of Hawaii, Hilo for her help in typing

and other secretarial skills during the project.

LITERATURE CITED

Pilsbry, Henry A. and Cooke, C. Montague. 1912-1914.

Achalinella'lila. Manual ofConcMogy 22:139-140.

AN ELECTROPHORETIC AND MORPHOLOGICAL SURVEY OF BUSYCON

AN ELECiRUPHUK^^^^^ ^^ W ASS AW SOUND, GEORGIA

Amy Lyn Edwards and Celeste Marie Humphrey

Skidaway Institute of Oceanography

University of Georgia

P.O. Box 13687

Savannah, Georgia 31406

ABSTRACT

Sixty-seven specmiens of right-handed knobbed whelks _ collected m Wassaw

Sound Georgia were examined for genetic and morphological vartatwrt m order

toZrmiJths validity of the ta^a Busycon carica (Gmehn, 1 791) and Busycon

eliceans (Montfort, 1810). Starch gel ^^^^ff^^^^^^^^^.^V^VpG^^

^sterns; of these, six were used for data collection: SOD LAP, MDH, PGI,and

6.PGD They were all found to be moncmorphic. Four shell characters, tumidity

knobhiness, aperture coloration, and the ratio of aperture lerujth to overall shell

length were also examined. No assocmtion between these characters wo.s found

and the sample was normally distributed. Only 3U% oj tke specirnens could be

classified as belonging to B. carica or B. eliceans exclusively Therefore from thts

electrophoretic and morphological evidence, we determined the sampk to have

been taken from a single population o/B. carica and use of the taxon eliceans in

this locale is unnecessary.

The knobbed whelk, Busycon carica (Gmelin,

1791), is a large (125 to 225 mm) carnivorous

gastropod common in estuaries from Cape Cod,

Massachusetts, to Cape Canaveral, Florida (Ab-

bott, 1974). The name Busycon elicean.^ (Mont-

fort,' 1810) refers to a similar form commonly

found in the southern part of the range of B.

carica, from North Carolina to Cape Canaveral

(Pulley, 1959). Bus-ycon carica and Busycon eli-

ceans were classified by HolUster (1958) as a pair

of sympatric species, and later reclassification

placed the taxon B. eliceans as a subspecies of B.

carica (Abbott, 1974).

The adult forms of B. eliceans have previously

been separated from B. carica on the basis of

three morphological characters: presence of

tumid ridge, prominent spines as opposed to low

tubercles, white aperture coloration with yellow

to brown suffusions as opposed to the orange

aperture color in B. carica. In this paper all

spines, knobs, and tubercles are referred to as

degrees of knobbiness.

Both described forms of the knobbed whelks

are found in Wassaw Sound, Georgia. We exa-

mined individuals from this area in order to

determine their morphological and genetic

variation and to see if separation of these in-

dividuals into populations of B. carica andB. eli-

ceans is applicable. Protein electrophoresis was

employed to determine genetic differences be-

Vol. 95(3)

July 10, 1981

THE NAUTILUS 145

tween individuals for comparison with their

morphological characteristics. Electrophoresis

has been successfully used to distinguish closely

related molluscan taxa (Chambers, 1978; Skibin-

ski et at, 1977). The morphological traits ap-

plied are those typically used by malacologists

for species distinction. The niche, historical age,

habitat and abundance of the animal led us to

believe that electrophoretic techniques might

detect considerable genetic variation.

Large differences in shell form, coloration

and sculpture exist among local populations,

members within a single population and even in

single individuals (Pulley, 1959; Stanley, 1979).

Busycon is a wholly North Atlantic genus that

has flourished in this region since the lower

Miocene epoch (Hollister, 1958). Busycon are

found in abundance from intertidal flats where

their prey, oysters (Crassostrea virginica) and

clams (Merceyiaria mercenaria) are numerous to

approximately the 26 fathom contour offshore

(Walker, in prep.). The genus seems to be made

up of localized populations of slow-growing long-

lived animals, and gene flow between different

populations could be slow or even negligible

(Pulley, 1959). Individuals are continually

migrating between adjacent intertidal flats as a

result of prey availability and on and offshore

seasonally (Walker et ai, 1980).

The estuarine habitat is not homogeneous in

structure or in physical, chemical or biotic char-

acteristics. Fluctuations of salinity, turbidity,

water depth and temperature greater than

those in the open sea are encountered (Vern-

berg, 1972). Considerable controversy exists

concerning the relationship between environ-

mental stability and genetic variability. Based

on theoretical argument, Valentine (1976) and

Levins (1968) conclude that unstable environ-

ments should be inhabited by organisms having

higher genetic variability than organisms in-

habiting stable environments. Levinton (1973)

contributed experimental support to these

hypotheses by demonstrating that, for different

species of bivalve molluscs, varying and hetero-

geneous environments did support species that

were more polymorphic than those in non-vary-

ing, geologically permanent environments.

Lewontin (1958) demonstrated a loss of chromo-

somal polymorphism in a population of Droso-

phila pseudoobscura raised for many genera-

tions in a constant environment and concluded

that heterogeneous environments retard the

loss of genetic polymorphism. Increased hetero-

zygosity has also been correlated with increased

benthic ecosystem diversity and with the stabil-

ity of trophic resources (Selander, 1976; Valen-

tine, 1976; Ayala and Valentine, 1977). Busycon,

being a geologically old genus, living as it does

in a temporally heterogeneous estuarine envi-

ronment and experiencing spatial heterogeneity

through its migratory behavior, appears to fit all

the criteria necessary for the maintenance of

electrophoretically and morphologically poly-

morphic populations.

Methods and Materials

All specimens of Busycon were collected from

Wassaw Sound, Georgia, in April, 1980 and kept

frozen until used. Tissue samples were dissected

from partially thawed specimens, ground and

then run on starch gels. Morphological measure-

ments taken for comparison with electrophore-

tic findings were: overall length, aperture

length, width, presence or absence of a tumidity

across the back of the siphonal canal, direction

of knobs on the whorls, extent of knobbiness,

and color of the aperture. Measurements of shell

width, overall length and aperture length were

taken using metric calipers. Presence or

absence of a tumidity (Fig. 1) and direction of

FIG. 1. TTie presence (A) or absence (B) of a tumidity (a)

across the back of the siphonal canal 0/ Busycon.

I

146 THE NAUTILUS

July 10, 1981

Vol. 95(3)

knobs on the shoulder of the whorls (Fig. 2) were

recorded. Color hues were determined by eye

according to predetermined standards. Examin-

ation of radula dentition was made.

The Hunter-Markert zymogram technique

combines electrophoresis with histochemical

staining methods (Brewer, 1970). The electro-

phoretic frequencies observed were converted

to allelic frequencies for genetic inferences. The

enzymes studied by this method were chosen by

the availability of appropriate staining tech-

niques and not with regard to the functions they

specify.

Horizontal starch gel electrophoresis was

used following the procedure of Schaal and

Anderson (1974). Ground tissue samples absorb-

ed on 3 by 6 mm filter paper wicks were set in

the gel and 55 ma currents were passed across

the gel by a model IP-2717 Heathkit power sup-

ply for five hours.

Initial samples of liver, kidney, heart, and

FIG. 2. Direction oj'hwbs on the shoulders of the whorLs. A.

Jorwardly directed, B. recurvetl spines.

radula retractor muscles were run on starch

gels using six different buffer systems at vary-

ing pH regions. These gels were stained for 23

enzyme systems. Lithium Hydroxide, Tris-HCl

and JRP buffer systems (John Avise, personal

communication), Dehydrogenase and Tris-

citrate buffer systems (Schaal and Anderson,

1974), and Poulik Discontinuous buffer system

(Poulik, 1957) were examined in conjunction

with the following stains: Isocitrate Dehydro-

genase, Lactate Dehydrogenase, Malate Dehy-

drogenase (MDH), 6-Phosphogluconate Dehy-

drogenase (6-PGDH), Glucose-6-Phosphate De-

hydrogenase, Alcohol Dehydrogenase, Xanthine

Dehydrogenase, a-Glucose Phosphate Dehydro-

genase, Sorbital Dehydrogenase, Phosphoglu-

cose Isomerase (PGI), Phosphoglucomutase

(PGM), Glutamate Oxaloacetate Transaminase,

Leucyl Amino Peptidase (LAP), Hexokinase,

Nucleoside Phosphoralase, Creatine Kinase,

Peptidase, Alkaline Phosphatase, Acid Phos-

photase. Adenylate Kinase, Esterase o-Naph-

thylacetate. Superoxide Dismutase (SOD), Malic

Enzyme and General Protein (Schaal and An-

derson, 1974; John Avise, personal communi-

cation). The systems that produced the most

clearly defined bands in the initial experiments,

were chosen for data analysis. SOD, LAP and

MDH stains were used in conjunction with the

Tris-citrate buffer system, PGM and 6-PGDH

were used with the JRP buffer system, and PGI

was used with the Dehydrogenase buffer

system.

Results

A summary of the morphological observations

shows that of the 67 specimens examined, 64

were females (determined by lack of penis and

presence of enlarged nidamental glands), 34

possessed recurved spines, 14 had both recurved

spines and spines directed forward, and 19 had

all forward directed spines. Thirty shells dis-

played tumid ridges and 37 lacked them. There

were 20 pale yellow, 23 yellow, 21 orange and

three red apertures observed. The denticulation

on the rachidian varied from four to eight while

the laterals all had two large cusps on the

marginal and central ends separated by two,

three or four small denticles. Other workers

Vol. 95(3)

July 10, 1981

THE NAUTILUS 147

have found varying male to female ratios for

these snails 1:11 (Walker, in prep.), 1:1, 1:2, 3:1

and 2:1 (Magalhaes, 1943).

Contingency Chi-square tests were used to

determine independence of the morphological

traits; direction of knobs, presence of tumidity,

and aperture coloration, while "goodness of fit"

tests were used to ascertain normality of the

population (Bhattacharyya and Johnson, 1977;

Mendenhall, 1968). There is considerable varia-

tion in the size and degree of knobbiness (Hollis-

ter, 1958; Magalhaes, 1943) leaving these char-

acteristics undiagnostic. Direction of knobs was

determined to be independent of both the pres-

ence of tumidity, and aperture coloration at the

0.05 confidence level: knobs/tumidity, x^ = 0.71,

d.f. = 2 (Table 1); knobs/aperture coloration, x^

= 7.66, d.f. = 6 (Table 2). Tumidity and aper-

ture coloration were not shown to be occurring

independently at the 0.05 confidence level; x^ =

11.71, d.f. = 3 (Table 3). Additional testing of

these data by both Cramer's contingency coeffi-

cient and Pearson's coefficient of mean square

contingency indicated no strong associations

between variables and leaves the above men-

TABLE 1. Contingency Table using the Chi-square "good-

ness of fit" test for the Null Hypothesis that the two variables.

Tumidity and Direction of Knobbation, are independent of

each other. Expected frequencies are listed in parenthesis

next to observed frequencies, k' = 0.71, d.f. = 2, at 0.05 con-

fidence level.

TABLE 3. Contingency Table using the Chi-square "good-

ness of fit" test for the Null Hypothesis that the two variables.

Tumidity and Aperture Coloration, are independent of each

other. Expected frequencies are listed in parenthesis next to

observed frequencies, x' = 11.71. d.f. = 3, at 0.05 confidence

level.

tioned dependence uninterpretable. These

values were 0.17 and 0.39 respectively. The

sample ratios (N = 67) of overall length to aper-

ture length were found to be normally distrib-

uted at the 0.05 confidence level; x^ = 7.65, d.f.

= 7 (Table 4).

The denticulation on the rachiglossate radula

varied greatly but bore no correlation to the size

of the individual. There was also no observed

correspondence between an increased number

of denticles on the rachidian and lateral teeth.

The numbers observed for rachidian denticles

were: 20 individuals with four denticles, 27 with

five, 13 with six, three with seven and one with

eight denticles. The denticulation on the lateral

teeth varied less; there were four individuals

with four, 46 with five, and 14 with six. Some of

the radulas are illustrated in Figures 3 to 8. The

variations observed in knobbiness, aperture col-

148 THE NAUTILUS

July 10, 1981

Vol. 95(3)

FIGS. 3 to 8. Examples of obsemed variation in radular of

Busycon. Rachidian tooth (a) and lateral (b) teeth: in-

dividuals J,2(Z), 53(4), 5.4(5), 52(6), UC!) and j,9(6).

(1948). Variation in the ratio of overall length to

aperture length compared to the variation Ma-

galhaes (1948) measured in spire height (Fig. 2).

Although the zymograms produced clearly

discernible banding patterns, all of the six en-

zymes analyzed (N = 67) were monomorphic. In-

traspecific monomorphism in electrophoretic

banding patterns seems to be typical throughout

the Busycon genus, based on preliminary data

(Jerry Harasewyzh, personal communication).

DISCUSSION

The purpose of this study was to determine

which genetic and morphological differences

within the local Busycon could be identified and

to relate such variation to the taxonomy of the

genus. The sample exhibited interpopulation

normality while displaying characteristics at-

tributed to two different taxa, Busycon carica

and B. eliceans. These findings led to questions

involving the validity of these taxa.

Hollister (1958) separated B. carica from a

dextral sympatric species, B. eliceans, in the

adult form by the presence of a tumid ridge that

runs across the back of the siphonal canal and a

more rugged and knobbed shell in the latter.

More recently, Abbott (1974) has reassigned B.

eliceans as a subspecies under B. canca using

tumidity, knobbiness and aperture coloration

for distinction. He has listed B. carica as having

no tumidity, low knobs and yellow-orange to red

aperture coloration; while the subspecies eli-

ceans has a tumidity, rugged knobbed shoulders

and a white aperture with yellow and brown suf-

fusions (this coloration corresponds to our pale

yellow color designation). In the sample studied,

no correlation between the presence of a tumid

ridge and the direction of knobbiness was

observed, and the colorations corresponding to

the presence of a tumidity were not those listed

in the literature. Of the 44.75% of the popula-

tion that possessed tumidities, 50% had yellow

apertures, 33.3% had orange apertures, 10.0%

had pale yellow apertures and 6.7% had red

apertures.

We detected no polymorphism in the enzymes

that we studied; however, it is important to

remember that electrophoretic measurements

give minimum estimates of variation (Selander,

1976). So, although no evidence of polymorph-

ism was found, it is not possible to draw final

conclusions about the inherent genetic variabil-

ity of the population from this data. However,

since the same techniques have been used to ex-

amine electrophoretic variation in other marine

invertebrates, conclusions can be drawn by com-

paring our data with the results of previous

work. Monomorphism such as we detected is ex-

tremely unusual, particularly in marine inverte-

brates which are among the most variable

groups studied, exhibiting 5% to 50% poly-

morphic loci and 5% to 15% heterozygosity

(Selander, 1976). Specific studies on five marine

gastropod species showed a 17.5% polymorphic

loci and 8.3% heterozygosity in 17 studied loci

(Selander, 1976). Therefore our results are a

radical departure from previous work on similar

groups and are consistent with the hypothesis

that we observed a population of a single

species, particularly since intraspecific mono-

morphism of electrophoretic banding patterns

seems to be typical of Busycon (Jerry

Harasewych, personal communication).

A subspecies as defined by Mayr (1963) is "an

Vol. 95(3)

July 10, 1981

THE NAUTILUS 149

aggregate of local populations of a species in-

habiting a geographic subdivision of the range

of the species and differing taxonomically from

other populations of the species" (p. 672). It has

been suggested that species be divided into taxo-

nomic subspecies if more than 75% of the indi-

viduals can be recognized as belonging to one or

the other taxa (Mayr, 1969). In this study the

percentage of specimens that could be recogniz-

ed as being of one or the other defined sub-

species (Abbott, 1974) was only 34.3%, not suffi-

cient to support a subspecies division. We are

left to conclude that the observed specimens in

this particular area represent a population of a

single species.

Reasons for the observed variation within this

species may be related to environmental adapta-

tion. Vermeij (1978) identifies factors that con-

tribute to the production of morphological varia-

tion in gastropods. Calcification efficiencies,

predation pressures, and lack of certain sub-

strate constraints may induce greater morpho-

logical diversity toward the southern end of the

species range, accounting for increased thick-

ness and knobbiness of southern shells (Vermeij,

1978).

Clinal variation, often used to classify

populations within a species (Mayr, 1970), could

also explain the morphological variation observ-

ed in B. carica; however, the word cline refers

to a specific character (such as knobbiness), and

a species may contain many clines. So although

useful as a component of species structure, the

character of the word makes it undesirable as a

taxonomic divider.

The description of a species should be exten-

sive enough to include the variations in the dif-

ferent parts of its range (Pulley, 1959). In the

population we observed there were no indica-

tions that its variation necessitates the separa-

tion of individuals into either two separate

species or subspecies. Therefore we conclude

that the population in Wassaw Sound, while in-

:luding individuals whose characteristics might

classify them as either B. carica orB. eliceans, is

1 single population and that the subspecies

aame eliceans is unnecessary in the taxonomy of

:he Busycon from this locale.

ACKNOWLEDGMENTS

We are indebted to the following persons: Dr.

John Avise, Dr. David Gillespie, Bretton Kent,

Dr. James Porter and Dr. Grace Thomas for

critical examination of the manuscript; Charles

Aquadro and Dr. John Avise for assistance and

use facilities; Randy Walker for assistance with

field work; and the University of Georgia Ma-

rine Extension Service where the major part of

this work was carried out. This work was par-

tially funded by Georgia Sea Grant #NA 79-

AA-D-00123.

The U.S. Government is authorized to produce

and distribute reprints for governmental pur-

poses not withstanding any copyright notation

that may appear hereon.

LITERATURE CITED

Abbott, R. T. 1974. American Seaskells. 2nd Edition, Van

Nostrand Reinhold Co., New York. 663 p.

Ayala, F. J. and J. W. Valentine. 1977. Genetic Variation

and Resource Stability in Marine Invertebrates. In Marine

Organisms, Genetics. Ecology and Evolution. Ed., Bruno

Battaglia and James Beardmore. Plenum Press, New

Yorli. 23-51.

Avise, J. Personal Communication. University of Georgia,

Genetics Department, Athens, Georgia 30602.

Bhattacharyya, G. K. and R. A. Johnson. 1977. Statistical

Concepts and Methods. John Wiley and Son, New York.

639 p.

Brewer, G. J. 1970. Introduction to Isoenzyme Techniques.

Academic Press, New York. 186 p.

Chambers, Steven M. 1978. An electrophoretically detected

sibling species of "Goniobasis floridensis" (Mesogastro-

poda: Pleuroceridae). Malacologia 17(1):157-162.

Dobzhansky, T.. F. J. Ayala, G. L. Stebbins and J. W. Valen-

tine. 1977. Evolution. W. H. Freeman and Co. 572 p.

Harasewych, J. Personal Communication. University of Del-

aware, College of Marine Studies, Newark, Delaware

19711.

Hollister, S. C. 1958. A review of the genus Busycon and

its allies. Palentog. Amer. 4:49-126.

Levins, R. 1968. Evolution in Changing Environments.

Princeton University. Press. Princeton, N.J. 120 p.

Levinton, J. 1973. Genetic variation in a gradient of environ-

mental variability: Marine bivalvia (Mollusca). Science

180:75-76.

Lewontin. R. C. 1958. The adaptations of populations to

varying environments. In Cold Spring Harbor Symposia

on Quantitative Biology 22:395-408.

Magalhaes, Hulda 1948. An ecological study of snails of the

genus Busycon. at Beaufort, N.C. Ecological Monographs

18:377-409.

Mayr, E. 1963. Animal, Species and Evolution. Belknap

Press of Harvard Univ. Press. Cambridge, Mass. 797 p.

150 THE NAUTILUS

July 10, 1981

Vol. 95(3)

1969. Principles of Systematic Zoology. Mc-

Graw-Hill, New York. 428 p.

1970. Populations, Species and Evolution.

Belknap Press of Harvard Univ. Press. Cambridge, Mass.

453 p.

Mendenhall, W. 1968. The Design and Analysis of Experi-

ments. Duxbury Press. Belmont, Calif. 465 p.

Poulik, M. D. 1957. Starch gel electrophoresis in a dis-

continuous system of buffer. Nature 180:1477-1479.

Pulley, T. E. 1959. Busycon perversum (Linne) and some

related species. Rice Institute Pamphlet 46:70-89.

Schall, B. A. and W. W. Anderson. 1974. An outline of tech-

niques of starch gel electrophoresis of enzymes from the

American oyster, Crassostrea virginica Gmelin. Georgia

Marine Science Center, Technical Report Series. Unpub-

lished manuscript.

Selander, R. K. 1976. Genetic variation in natural popula-

tions. From: F. S. Ayala (Ed.), Molecular Evolution.

Sinauer Assoc. Inc. Sunderland Mass. 21-45.

Stanley, S. M. 1979. Macroevolution: Patterns and Process.

Freeman and Co., San Francisco. 332 p.

Skibinski, D. 0. F., J. A. Beardmore and M. Ahmad. 1977.

Genetic aids to the study of closely related taxa of the

genus Mytilus. In Marine Organisms, Genetics, Ecology

and Evolution. Ed., Bruno Batteglia and James Beard-

more, Plenum Press, New York. 469-486.

Valentine, J. W. 1976. Genetic strategies of adaptation.

From: F. S. Ayala (ed.). Molecular Evolution. Sinauer

Assoc. Inc. Sunderland, Mass. 78-94.

Vermeij, G. J. 1978. Biogeograpky and Adaptation; Pat-

terns of Marine Life. Harrard Press, London. 331 p.

Vernberg, W. B. and F. J. Vernberg. 1972. Environmental

Physiology of Marine Animals. Springer-Verlag, New

York. 346 p."

Walker, R. L. Intertida! populations of whelks (Busycon

spp.) in Wassaw Sound, Georgia. In preparation.

Walker, R. L., M. A. Fleetwood and K. R. Tenore. 1980.

The distribution of the hard clam, Mercenaria mercenaria

(Linne) and clam predators in Wassaw Sound, Georgia.

Georgia Marine Science Center Technical Report 80-

859 pp.

THE GASTROPODS, CALLIOSTOMA ORION DALL, 1889 (TROCHIDAE)

AND HELIACUS (GYRISCUS) WORSFOLDI N. SP.

(ARCHITECTONICIDAE), FROM THE BAHAMA ISLANDS

James F. Quinn, Jr.

Florida Department of Natural Resources

Marine Research Laboratory

100 Eighth Ave., S. E.

St. Petersburg, PL 33701

ABSTRACT

Heliacus (Gyriscus) worsfoldi n. sp., is described from the northwestern

Bahamas. Calliostoma orion Dall, 1889. is redescribed and the radula and jaws

are illiistrated by SEM micrographs. Calliostoma orion lives in and. feeds upon

the tube sponge. Spinosella vaginalis. Heliacus worsfoldi, the first record of the

subgenus Gyriscus in the western Atlantic, is associated with a species of Zoan-

thus or Parazoanthus.

The use of SCUBA equipment by shell collec-

tors has opened an immense area of heretofore

inaccessible ocean bottom for examination. This

is especially true of the deep fore-reef zone of

coral reef tracts such as occur in the Bahama

Islands. Numerous specimens of gastropods col-

lected near Freeport, (Jrand Bahama Island,

were loaned to me for identification by Mr. Jack

Worsfold. Among these specimens are some

representing two species with unusual biological

associations.

Type-specimens are deposited in the collec-

tions of the U. S. National Museum of Natural

History, Washington, D.C., the Academy of

Natural Sciences, Philadelphia, Pennsylvania,

and the Florida Department of Natural Re-

Vol. 95(3)

July 10, 1981

THE NAUTILUS 151

sources, Marine Research Laboratory, St.

Petersburg, Florida, abbreviated USNM,

ANSP, and FSBC I respectively. Additional

specimens are in the personal collections of

Messrs. Jack Worsfold and Bob Quigley, Free-

port, Grand Bahama Island.

Family Trochidae Rafinesque, 1815

Genus Calliostoma Swainson, 1840

Calliostoma orion Dall, 1889

Figures 1-13

Calliostoma orion Dall, 1889a: 367, pi. 28, fig. 2; 1889b:

162.-Pilsbrj', 1889; 383, pi. 48. fig. 18.-Johnson, 1934:

70. -Clench and Turner, 1960: 54, pi. 35, figs. 1, 2.

Description -SheW medium in size, height to

about 16 mm, turbinate, imperforate, delicately

sculptured by numerous spiral rows of small

beads, teleoconch whorls 8-8 V2; color straw or

bone white, often with nebulous areas of light-

brown, always with fine, spiral brown lines. Pro-

toconch small, white, IV2 whorls. Early teleo-

conch whorls flat-sided, last 3 distinctly convex.

Spiral sculpture of 20-26 fine cords ornamented

by small, sharp, spirally elongate tubercles;

cords generally alternate in size. Base almost

flat, sculptured by 28-40 smooth spiral cords,

generally every fourth larger and colored

brown; cords made somewhat undulate by ir-

regular growth lines. Aperture subquadrate;

outer lip thin, simple; columella short, thick,

straight, white. Operculum thin, multispiral,

light amber in color.

Radula typically calliostomatine (Figures 3, 4).

FIGS. 1 and 2. Calliostoma orion Dall. 1889. 1, Apertural

view, USNM 784595, U.8 mm high. 2, Basal view of same

specimen.

Rachidian slender, base pyriform, with long,

slender, finely denticulate cusp. Laterals 5;

bases pyriform, becoming rhombic on distal 2

(Figure 5); cusps long, slender, becoming very

slender on outer laterals, finely denticulate on

both sides. Marginals numerous, about 25-30

per half-row; inner marginal large, massive,

usually with 6-8 large, strong teeth on proximal

margin of tip, finely denticulate on distal mar-

gin, with prominent buttress opposite toothed

margin (Figure 6); succeeding inner marginals

of similar, although less massive, structure

without buttress (Figures 4, 6, 7); outer margin-

als very slender, whisker-like, with fine teeth

along both sides of tip, occasionally smooth.

Jaws chitinous, subrectangular, rounded an-

teriorly and posteriorly, fringed anteriorly

(Figures 10, 11). Two major plates joined dor-

sally by pair of smaller, elongate, corrugated

plates (Figures 9, 10). Outer surface of jaws

comprised of small, elongate, hexagonal or

diamond-shaped scales (Figure 12); inner sur-

face vaguely reflecting outer texture (Figure

13).

Holotype-VSNU 214272. Height 4.5 mm;

maximum diameter 4.2 mm.

Type-locality -BhAKE station, off Havana,

Cuba, 146 m.

Material examined -BLAKE station, off

Havana, Cuba, 146 m; 1 spec, USNM 214272

(Holotype).-Off Tamarind, Lucaya, Grand

Bahama Island, Bahamas, on sponge, 15-43 m,

J. Worsfold collector; 1 spec, USNM 784595; 1

spec, USNM 784597; 2 spec, ANSP 353315; 1

spec, FSBC I 22163; 1 spec, FSBC I 23777.-

Little San Salvador, Bahamas, on sponge, 34 m,

J. Tyler collector; 1 spec, USNM 706809.-

Providencia Island, Colombia, N. A. Roberts,

leg.; 1 spec, ANSP 316567.

Distribution -Known from the eastern and

northwestern Bahamas, northern Cuba, and the

western Caribbean off Nicaragua, at depths of

15-43 m and 146 m.

Remarks -Until now Calliostoma orion has

been known from only two shells: the holotype,

a juvenile, collected from 146 m off Havana; and

a second specimen found at Arenas de la Chor-

rera in sand dredged from 5-27 m off Sante Fe,

Cuba (Clench and Turner, 1960). Both speci-

152 THE NAUTILUS

July 10, 1981

Vol. 95(3)

FIGS. 3-7. SEM micrographs of radida o/Calliostoma orionDaH, 1S89 (FSBC 1 22163). 3, Composite

micrograph ofradula; 75 x. 4, Segment showing laterals and marginals; note deritieulatwn of prox-

imal and distal edges of marginals: SOOx. 5, Detail of outer two laterals; apparent fusion of several

teeth is an artifact of mounting; J,12 x . 6, Detail of tip of first inner marginal showing heavy buttress;

638 x. 7, Marginal f rem, middle of marginal half-row; 600 x.

mens are bone white in color with the character-

istic spiral brown lines very faint. The speci-

mens from Providencia and Little San Salvador

Island are also albinistic. However, all

specimens examined from Grand Bahama Island

are rather richly colored, with brown clouds

Vol. 95(3)

July 10, 1981

THE NAUTILUS 153

E /■/ « , f "'T'"^''"' * "■' '""■" '-'.'■ Calliostoma orion Dall. 1889 (FSBC 1 22163). 8, Anterior

)rnge oj left lateral plate; S75x. 9, Surface detaU of dorsal conr^cting plates; S75>.. 10, Left latZal

pla e and u,o dorsal plates, external surface; 60.. 11, Right lateral pMe, ^nt^nalsurfaJ;6oTl2

Lateral plate external surjace microsculpture of elongate hexagonal and tetragonal scales; 150 x' 13

Lateral plate internal surface microsculpture: 150 X. . • lo.

superimposed on a straw-colored background,

and numerous, distinct brown spiral lines.

In outline, Calliostoma orion is extremely

similar to C. marionae Dall, 1906. The upper

whorls are flat-sided, forming an evenly conical

spire, but the last 2 or 3 whorls are convex, with

the base remaining almost flat throughout. The

whorl periphery becomes less angular as growth

154 THE NAUTILUS

July 10, 1981

Vol. 95(3)

progresses. Calliostoma orion also differs from

C. maricmae in having beaded sculpture and no

umbilicus, as well as being considerably smaller.

The very small, sharply-pointed beads on the up-

per part of the whorls and the shape of the shell

immediately separate C. orion from other im-

perforate species, such as C. euglyptum (A.

Adams, 1854) and C. sarcodum Dall, 1927, with

which it may be confused.

The radula and jaws are very similar to those

described and illustrated for the subgenus Cal-

liostoma as restricted by Clench and Turner

(1960). In this subgenus there are five marginals

with long, slender cusps, a massive inner margi-

nal followed by a number of teeth of less massive

but similar structure, and an outer series of very

slender marginals. The radula of C. orion differs

primarily in the shape of the first marginal

tooth, especially the buttressed tip and slender

rhachis which are more similar to those in the

subgenera Kombologion Clench and Turner,

1960, and Elmerlinia Clench and Turner, 1960.

Until radulae of more species of Calliostoma are

examined using SEM, I refrain from assigning

C. orion to a subgenus.

This species, as far as is known, occurs only on

deep reefs of the northern and western Carib-

bean islands. It is not uncommon in depths from

15 to 43 m (50-140 ft) and is always found in the

tube sponge, Spinosella vaginalis (Lamarck,

1814), in the Bahamas (J. Worsfold, personal

communication). A number of recent papers

have documented the feeding of Calliostoma

species on coelenterates (Lang, 1970; Salvini-

Plawen, 1972; Francis, 1973; Miller, 1973; Per-

ron, 1975; Perron and Turner, 1978), bryozoans

(Perron, 1975), and dead animal flesh (Keen,

1975; Perron, 1975), in addition to the herbi-

vorous or detrital diets previously thought

characteristic of all trochids. An examination of

the contents of the intestine of a specimen of C.

orion revealed numerous spicules of Spinosella

vaginalis (straight oxeas), cellular material of

indeterminate origin, and small calcareous frag-

ments. In view of the previous observations of

oppc feeding of Calliostoma spp. and

the f.. "< sponge spicules in the fecal

material don, it is probable that this

species does in fact feed on Spinosella, the first

such observation for Calliostoma.

Family Architectonicidae Gray, 1850

Genus Heliacus Orbigny, 1842

Subgenus Gyriscus Tiberi, 1867

Heliacus (Gyriscus) worsfoldi n. sp.

Figures 14, 15

Description- Shell small, height to 7.3 mm,

solid, turbinate, umbilicate, with high spire;

whorls rounded, sculptured by spiral rows of

beads; color of shell whitish to light mauve, with

8-10 axially elongate blotches of light-brown

around periphery; umbilicus purplish brown

within, columella stained with purplish brown.

Protoconch anastrophic, prominent, glassy,

brown, 0.84 mm in greatest diameter. Teleo-

conch whorls 4, subtubular, with 5 or 6 beaded,

spiral cords above periphery and 8 or 9 (rarely 7

or 10) on base; axial sculpture of low, rounded,

flexuous threads. Umbilicus narrow, about 15%

of greatest shell diameter, lightly wrinkled by

growth lines. Aperture circular; outer lip thin,

crenulated by external sculpture; columella con-

cave, lip slightly reflected, smooth. Operculum

thin, circular, multispiral, light-brown in color;

external surface concave, with concentric over-

lapping foliations; nucleus central; inner side

with prominent, clockwise-spiraled central plug.

A color slide (ex J. Worsfold) of the ventral

view of a specimen with animal expanded shows

the foot deeply bifid anteriorly and broadly

FIGS. 14 and 15. Heliacus (Gyriscus) worsfoldi Quinn, n.

sp. 14, Apertural view ofholo'type. USNM 78J,593. 7.S mm

high. 15, Basal view of sarne specimen.

Vol. 95(3)

July 10, 1981

THE NAUTILUS 155

rounded posteriorly. Color of foot light mauve,

with numerous spots of opaque white. Tentacles

long, tapering gradually to rather bluntly round-

ed tips; color Hght mauve, with zig-zag markings

of darker purple. Radula not preserved.

Holotype -USNM 784593. Height 7.3 mm;

maximum diameter 6.2 mm.

Type-locality -Off Settlement Point, Grand

Bahama Island, 12.2 m, J. Worsfold and B.

Quigley, collectors.

Paratypes -USNM 784596, 2 spec; FSBC I

23778, 2 spec; ANSP 353241; 2 spec; J. Wors-

fold and B. Quigley collections, 43 spec; all

specimens with same data as holotype.

Remarks -Heliacus worsfoldi is the third

known species of the subgenus Gyriscus, which

was established by Tiberi (1867) for Gyriscus

jeffreysianus Tiberi, 1867, described from off

Sardinia, Italy. One of the three syntypes of H.

jeffreysianus is in the USNM and has been re-

iescribed by Merrill (1970). Specimens of the

new species are superficially very similar to

those of H. jeffreysianus but are smaller, have a

smaller protoconch [range 0.810-0.875 mm, x =

D.84 mm for H. worsfoldi; 0.95 mm for H. jef

'reysianus (Merrill, 1970)], have fewer primary

spiral cords (5 or 6, not 7), lack intercalarj'

secondary spiral threads, have a proportionally

larrower umbilicus (H. ivorsfoldi: 15% of maxi-

Tium shell diameter; H. jeffreysianus: 20%), and

ire a different color. Powell (1965) described

lyriscus asteleformis from off the northern tip

)f North Island, New Zealand, from a depth of

)0 fathoms. Powell's species differs from H.

riirsfoldi in being larger, proportionally

iroader, uniformly buff-colored, in having more

lumerous and more finely beaded spiral cords.

md a larger umbilicus.

All of the specimens of H. worsfoldi were col-

?cted together on a specimen of the antipath-

rian, Cirripathes sp., which was largely en-

insted by a species of Zoanthus or Parazoan-

'lus. Previously, architectonicids have been

bserved in association with scleractinian corals

ilobertson, Scheltema and Adams, 1970) and

ne zoanthiniarians Zoanthus and Palythoa

Robertson, 1967; Marche-Marchad. 1969), and

owell (1965) reported Heliacus (Gyriscus)

steleformis from the ca\ity of a sponge.

Robertson (1981) has recently reviewed the gas-

tropods symbiotic with zoanthiniarians, of which

assemblage Heliacus was a major constituent. It

is therefore probable that H. worsfoldi is also

svTnbiotic with the zoanthid, although the possi-

bility of an association with antipatharians can-

not yet be dismissed.

ACKNOWLEDGMENTS

I am grateful to Mr. Jack Worsfold who

brought the two species to my attention and

who kindly donated the tj'pe material. Sally D.

Kaicher made the excellent photographs, and

W. G. Lyons and D. K. Camp reviewed the

manuscript. Lana Tester provided SEM serv-

ices.

LITERATURE CITED

Clench, W. J, and R. D. Turner. 1960. The genus Calliosto-

ma in the western Atlantic. Johnsonia 4(40):l-80.

Dall. W. H. 1889a. Reports on the Mollusca. Part II. Gastro-

poda and Scaphopoda. Reports on the results of dredg-

ing .. . in the Gulf of Mexico (1877-78) and the Caribbean

Sea (1878-80), by the U. S. Coast Sur\-ey steamer "Blake"

. . . Bull. Mils. Comp. ZooL, Han: 18:1-492.

1889b. A preliminary' catalogue of the shell-

bearing marine mollusks and brachiopods of the south-

eastern coast of the United States. Bull. U. S. Natl. Mus.

37:1-221.

Francis, L. 1973. Intraspecific aggression and its effect on

the distribution of Anthopleura elegantissima and some

related sea anemones. Biol. Bull. 144:73-92.

Johnson, C. W. 1934. List of marine Mollusca of the Atlan-

tic coast from Labrador to Texas. Proc. Bost. Soc. Nat.

Hist. 40:1-204.

Keen, A. M. 1975. On some western American species of

Calliostoma. The Veliger 17:413-414.

Lang, J. C. 1970. Inter-specific aggression within the scler-

actinian reef corals. Unpubl. Ph.D. Dissertation, Yale

University. 80 pp.

Marche-Marchad, I. 1969. Les Architectonicidae (Gastro-

podes prosobranches) de la cote occidental d'Afrique.

Bidl. Inst. Found. Afr. Noire, Serie A. 31:461-486.

Merrill, A. S. 1970. The family Architectonicidae (Gastro-

poda: Mollusca) in the western and eastern Atlantic. Un-

publ. Ph.D. Dissertation, Uni\'ersity of Delaware, 338 pp.

Miller, A. C. 1973. Obser\'ations on the associations and

feeding of six species of prosobranch gastropods on antho-

zoans in Discovery Bay. Jamaica. Echo 5:35-36.

Perron. F. E. 1975. Carnivorous Calliostoma (Prosobran-

chia: Trochidae) from the northeastern Pacific. The Veli-

ger 18:52-54.

Perron, F. E. and R. D. Turner. 1978. The feeding behavior

and diet of Calliostoma occidentale, a coelenterate-associ-

I

156 THE NAUTILUS

July 10, 1981

Moll. Stud. 44:

ated prosobranch gastropod. Joum.

100-103.

Pilsbry H A 1889. Trochidae, Stomatiidae, Pleurotoman-

idae.'Haliotidae. In: G. W. Tryon, 1879-1913, Manual

ofConchology, Series 1, vol. 11. Philadelphia, 519 pp.

Powell A W. B. 1965. New Zealand molluscan systematics

with 'descriptions of new species: Part 5. Rec. Auckl. Inst.

Mus. 6(2):161-168.

Robertson, R. 1967. Heliacus (Gastropoda: Architectonici-

dae) symbiotic with Zoanthiniaria (Coelenterata). Science

156:246-248.

Vol. 95(3)

1981. Gastropods symbiotic with zoanthid sea

anemones. Bull. Amer. Malacol. Union for 1980: 69 (ab-

stract).

Robertson, R., R. S. Scheltema and F. W. Adams. 1970. The

feeding, larval dispersal, and metamorphosis of Philippta

(Gastropoda: Architectonicidae). Pacific Science 24:55-65.

Salvini-Plawen, L. v. 1972. Cnidaria as food sources for

marine invertebrates. Cahiers Biol. Mar. 13:385-400.

Tiberi, N. 1867. Diagnose du nouveau genre mediterraneen

Gyriscus. Joum. de Conchyl. 15:303.

SECOND, REVISED AND IMPROVED PRINTING - July 15, 1981

GUIDE TO THE NUDIBRANCHS OF CALIFORNIA

INCLUDING MOST SPECIES FOUND FROM ALASKA TO OREGON

By Gary R. McDonald and

(Edited By R. Tucker

James W. Nybakken

Abbott)

Destined to be the "bible" tor tidepool and stuba biologists, the

Guide to the Nudihranchs of Catiiornia will equally serve those

researchers from Alaska and Pacific Canada to Oregon. The extensive

information on the specialized foods and habitats of each species will

aid not only in identification but also in ecological analyses.

Unique among similar guides, this book has the advantage of ex-

tensive keys, authoritative information and convenient phylogenetic

organization. This Iwok will be welcomed by marine biologists,

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oceanography.

Years in the making, this compact account gives the scientific

essentials to all the known nudihranchs snails of California, including

the higher classification and descriptions oi each genus with their

type-species. With top quality in photography and understandable,

concise morphological descriptions, identifications ot species are

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Dr. Joseph Rosewater

Division of Mollusks

U.S. National Museum

Washington, D.C. 20560

Dr. G. Alan Solem

Department of Invertebrates

Field Museum of Natural History

Chicago, Illinois 60605

Dr. David H. Stansbery

Museum of Zoology

The Ohio State University

Columbus, Ohio 43210

Dr. Ruth D. Turner

Department of Mollusks

Museum of Comparative Zoology

Cambridge, Mass. 02138

Dr. Gilbert L. Voss

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THE

NAUTILUS

Volume 95, number 4 - October 29, 1981

ISSN 0028-1344

CONTENTS

Joseph Rosewater

Malacological Journey into Cuba, 1980 159

Paul M. Tuskes

Population Structure and Biology oi Liguus Tree Snails on Lignumvitae Key, Florida 162

Harald A. Rehder

A New Species of Volutocorbis (Volutidae), from Somalia 169

G. Thomas Watters

Two New Species oi Acanthochitona from the New World

(Polyplacophora: Cryptoplacidae) 171

Eugene Coan

What is Venericardia morsel Dall? 177

Eliezer Rios and Luis Roberto Tostes

A New Brasilian Pyrene (Prosobranchia: Columbellidae) 178

Mark D. Baxa

Ano(k»ita Species of Lake McConaughy, Western Nebraska 180

Robert Robertson

Protandry with Only One Sex Change in an Epitnninm (Ptenoglossa) 184

Roland Houart

ChicoreusfChicmmirex) turschi. a New Muricidae from New Guinea 186

Antonio J. Ferreira, M.D.

Laminoplax. a New Genus of Chitons and the Taxonomic Position oi Hnnleyn rialli

Kaas, 1957 (Polyplacophora: Afossochitonidae) 189

Emile A. Malek and Jean-Paul Chaine

Freshwater Snails of the Senegal River Basin, West Africa 193

Tom and Beatrice Burch

Tellina oahuana and niauai in Hawaii 198

1982 (ZEOL. 96) SUBSCRIPTIONS ARE NOW DUE:

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THE NAUTILUS

October 29, 1981

Vol. 95(4)

The first ntnckulogiral work hy an Aint-rtrnn

published in America,

Thomas Say's CONCHOLOGY

1819

A beautiful f(wMmile copy of the third

edition of Say's fundemerifal work from

Nicholson's British Encyclopedia

Philadelphia 1819

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tains 2(1 pages and four lithograph plates of Say's new

land and freshwater species of mollusks. This is the

expanded version of the first (1816) and second (18 IS)

edition. 32 pages, paperbound.

The preface, by R. Tucker Abbott, tells the history of

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exciting and nostalgic anthology of stiell collecting in the Nineteenth

Century ISBN 0-915726-02-X , Cloth $13 95

Arakawa. K Y SHELLS ON STAMPS OF THE WORLD 1979 234 pp , 15

color pis , text tigs lllus Catalog and classitlcations.

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color, living animals, habitats ISSN 0-91582606 4 Paperback $ 8 95

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1979 130 pp . 98 pis , 3 in color Monographs of Marine Mollusca no

1, with buchram looseleal binder ISSN 0162-8321 $26 00

Wagner. R J L Abbott, R Tucker STANDARD CATALOG OF SHELLS

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lists, maps, hundreds ot figs , some in color 15,000 entries

ISBN 0-915826-03-8 Buchram postbinder $40 00

McDonald and Nybbaken, 1980 GUIDE TO THE NUDIBRANCHS OF

CALIFORNIA 112 color plates, 64 pp .

ISBN 0 915826 08-1 Soil $13 50

D S FRESHWATER SNAILS OF AFRICA AND THEIR

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THE NAUTILUS 159

MALACOLOGICAL JOURNEY INTO CUBA, 1980

Joseph Rosewater

Division of Mollusks

National Museum of Natural History

Smithsonian Institution, Washington, D.C. 20560

The Smithsonian and the Academia de Cien-

cias de Cuba have joined in an exchange pro-

gram whereby scientists of both institutions

may visit the other and conduct research of

mutual interest. Several Smithsonian scientists

have done this: Raymond Manning and Mere-

dith Jones (Crustacea and Worms), were early

participants (1978). Storrs Olson (Birds) trav-

eled to Oriente Province in October 1980 for a

joint ornithological expedition; Porter Kier

(Fossil Echinoids) visited during late October

1980 and worked in the Geological Institute col-

lections. Early in 1980 I indicated an interest in

participating in the exchange program. It was

my feeling that a Smithsonian malacologist

should visit Cuba, renew acquaintances with old

colleagues, meet new ones, and begin to re-

establish what was a very active program of

cooperative research.' Another very important

reason for wanting to visit Cuba was the hope of

examining old and new collections of research

interest and to carry out field work. As it turned

out I accomplished all but some hoped-for field

work in Pinar del Rio, that mecca for Cuban

land Mollusca. I boarded the plane at National

Airport, left Washington at 7:30 a.m. on

November 10, 1980, and arrived in Toronto,

Canada, my Cuban disembarkation point, at

10:30 a.m. The Havana bound A ir Canada flight

left Toronto at noon and arrived at 3:30 p.m.

Upon arrival in Havana the passengers from

the Air Canada DC-8 were gathered into the

terminal to await passport examination, a pro-

cess which occupied at least an hour. My wel-

'For early accounts of Cuban visits see The Nautilus, vols.

25:3 (Webb, 1911); 26:2 (Henderson, 1912); 26:99, 111

(Wheeler, 1913); 27:136 (Henderson, 1914); 28:4, 49, 133

(Ramsden, 1914, 191.5); 31:41 (Henderson, 1917); 35:118

(Remington, 1922); 38:.56 (Emery, 1924); 40:37, 88 (Hand,

1926, 1927), and 62:78 and 7o!l (.Jao.bson, 1949, 1956)

[editor].

coming party patiently waiting outside the cus-

toms shed consisted of Dr. Fernando Gonzalez

Bermudez, director of the Instituto De Zoologia,

Academia De Ciencias De Cuba, Jose Fernandez

Milera, Curator of Mollusks, and others. After

warm greetings, and since it was then nearing

5:00 p.m., I was driven into the city to the

residence for visiting scientists at no. 212 Prado

(now Paseo San Marti) where I was to be housed

and fed during my stay.

The residence, once the house of an important

official, is beautifully furnished in Spanish

motif, replete with marble floors, stairways and

statues. Rooms are large, well-furnished and

air-conditioned. Three meals a day are served in

the large well-attended dining room. While

there I met scientists from France, Germany

and other Latin American countries, for Cuba

has cooperative research agreements with many

countries.

On the following morning I was picked up at

9:00 a.m. and driven to the Zoological Institute

on the west side of Havana. The road traversed

the Malecon, the famous Havana waterfront

road that runs from the harbor entrance (Morro

Castle) past the entire city proper. As those who

have visited Havana already know, the down-

town area boasts many large tourist hotels, one

of the most prominent being "The Rivera". Upon

arriving at the Zoological Institute a meeting

was held during which I was introduced to staff

concentrating on various malacological prob-

lems: Jose Milera, who as I mentioned, is in

charge of the Institute's mollusk collections;

Jose Espinosa, who is collaborating with

Hortensia Sarasua on systematic revisions of

Cuban prosobranchs; Isabela Cortes Vico, of the

Institute's Department of Terrestrial Ecology,

who is working on problems concerning the es-

tablishment of an escargot resource utilizing the

large land snail, Zachrysia guanensis castanea;

160 THE NAUTILUS

October 29, 1981

Vol. 95(4)

and Renzo Rodriguez of the same department,

who is working on cuituring Polymita to ensure

its preservation in the face of destruction of the

habitat and heavy collection pressure. Both of

the latter workers are very anxious to contact

U.S. scientists who can counsel them or provide

references which would help with an under-

standing of the ecology, dynamics of reproduc-

tion, and trophic niches of Zachrysia and

Polymita.^ At present both are being cultured in

the laboratory and have passed through several

generations. Various types of commercial food

have been accepted by the snails, the most

satisfactory results so far having been with

Zachrysia feeding. The Polymita seem to offer

more of a problem and Rodriguez is presently

performing dissections on the digestive system

to determine just what the animals are eating.

He certainly would welcome suggestions or ref-

erences on Polymita digestive system anatomy.

The address at which they can be reached is:

Departamento de Ecologia Terrestre, Institute

de Zoologia, Academia de Ciencias de Cuba,

Calle 212 #17A09, esq. 19, Atabey, Municipio

Playa, Ciudad Habana, Cuba.

Other malacological research currently being

done in Cuba, so far as I could learn, is concern-

ed with matters of public health and disease vec-

tors. I made inquiries about fisheries research,

but learned nothing and suggest that informa-

tion may be obtained by contacting the fisheries

directly. I am quite certain that mollusks are be-

ing studied by other Cuban governmental in-

stitutes such as Oceanology in connection with

their research, but learned nothing definite.

After discussing the above, the program was

reviewed for the balance of my visit, consisting

of laboratory and field studies on Cuban Littor-

inidae. Also detailed were several extracurricu-

lar activities, such as an evening tour of old

Havana; an evening at the International Ballet

which was then having its season in Havana;

dinner at a roof-top restaurant downtown; and a

much anticipated visit to the Museo Felipe Poey

(which did not take place because the latter was

^Sec Thi Xinililiix. '■Sonif Habits ot" A Culian Snail

Pdhpniln pirln Born" liv A. Iv Andrews. VXVZ. vol. 4(1. pp.

22-27 le.iiu.r!.

being renovated). My approval of the proposed

program was solicited and since the work por-

tion, at least, was what I had hoped for - approv-

al was freely given! There followed a toast (with

Cuban banana brandy) to the success of the pro-

gram. The afternoon was spent reviewing the

work of the malacology section and in examin-

ing collections.

The next day, November 12, was spent at the

malacology section with Milera examining, sort-

ing and naming Cuban Littorinidae. Due to a

number of nomenclatorial, distributional and

ecological problems, it was agreed that we

should co-author a study of that family in Cuba.

As I was interested in tracking down as many

of our colleagues as possible, I asked about

Alfredo de la Torre, son of Carlos, and was told

he works at the Institute de Geologia. Miguel

Jaume, formerly Director of the Museo Felipe

Poey, now retired, resides at Calle 42, #3307,

Playa 13, Havana, Cuba. He visited me one day

at the Institute, is a hearty 73, and was most in-

terested in hearing about and being remem-

bered to his colleagues in the U.S. I am sure he

would welcome letters directed to the above ad-

dress. He is busily engaged in a large biblio-

graphic study on Cuban mollusks.

Field work with Milera, Renzo and a driver,

occupied four of the six full days I spent in Cuba.

On Thursday, November 13, we traveled via

Matanzas to Cardenas, about 150 km east of

Havana. There we spent two days completing 15

stations around the Varadero peninsula. Milera,

who is an excellent field man, took me to

habitats where the maximum number of Lit-

torina species would be found. Inclement

weather and higher than normal tides seemed to

have stimulated some of the Littorina to seek

"higher ground", such as L. nebulosa, which we

found to be clustered near the tops of pilings

under estuarine conditions. On occasion there

would be 100 or more on the top of a single pil-

ing, more, claimed Milera, than he had ever

noted previously! While near Varadero we col-

lected on the shore near Xanadu, former du-

Pont Estate, which has been maintained in

lieautiful condition. The house is now a very

elaborate restaurant.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 161

Litforina ziczac. L. angusfior. L. lineolata,

Tectarius muricatus. Nodilittorina tuberculata,

and Echininus nodulosus all were collected on

hard reef substrate, the latter three species

often being found at highest shore levels. Lit-

torina mespillum. the brown-spotted form, was

found in rocky tide pools (a first for me). LH-

torina meleagris was collected at lowest tide

line, and L. angulifera was rare on mangrove

and sea walls. In all, I collected 10 species of Lit-

torinidae on the trip. Two more are known to

live in Cuba, the possibly introduced Littorina

flava. which lives only in the vicinity of Cien-

fuegos, and Littorina te>isellata. also an inhabi-

tant of the south coast.

On Saturday, November 15, we traveled to

the vicinity of Guira de Melena on the south

coast of Cuba where we again collected Lit-

torina nebulosa and Melampus cqffeus both of

which were living in great profusion in man-

grove and clustered on pilings at Playa Cajio.

There were many Truncatella in the litter. At-

tempts to collect at the port of Batabano were

largely thwarted by high winds and rain.

On Sunday, November 16, 1980, having

evidenced interest in seeing Hemingway's

home, I was taken there by Milera and party.

The Hemingway estate is located in a suburb of

Havana, in the town of San Francisco de Paula,

overlooking the city. It is kept as a museum with

ground, furniture and contents as they were

when the author and his wife lived there. We

collected some land snails on the grounds. From

there we traveled to nearby Cojimar, a little

fishing village that inspired Hemingway to write

"The Old Man and the Sea". Collections were

made there also (it was there that L. meleagris

was found plentifully at low tide). The Cubans

seem devoted to Hemingway, who made his

home there for many years.

While I may have had vague concerns about

traveling to Cuba, by the time I had to leave,

these had vanished. As those of you who have

been there know, the country is a malacological

paradise at least for marine and land mollusks.

For those unfamiliar with Cuba, I recommend

(to U.S. naturalists at least) they read Thomas

Barbour's 1945 book, "A Naturalist in Cuba". It

relates a great deal about the fauna and flora.

and gives one a taste for the island. As a

member of our malacological "fraternity" I felt I

was genuinely accepted there, and left feeling

that we have reestablished some of the old

cooperative research interest with the Cubans,

and that I accomplished much that I had hoped

in going there.

In many ways Cuba's contact with much of the

rest of the malacological world -certainly

ours -was largely severed 25 years ago. That

means they have to catch up on much recent

literature. For instance, Milera's laboratory

lacks most of Johnsonia, Occasional Papers on

Mollusks, The Nautilus. Malacologia, The

Veliger. etc. They do not have Abbott's second

edition of "American Seashells". I have obtained

Abbott's book and have sent it to them and he

has donated "American Malaeologists" and the

Supplement. We are sending our reprints. Our

International Exchange Service will supply

quite a few volumes of the The Nautilus that re-

main from a number Abbott gave the exchange

two years ago. Cuban malaeologists wish to re-

establish contact with their U.S. colleagues and

to exchange literature with them. I know Jose

Fernandez Milera and his colleagues would like

to hear from other malaeologists. His address is:

Departamento de Malacologia, Instituto de

Zoologia, Academia de Ciencias de Cuba, Calle

212 #17A09, Esq. 19, Atabey, Municipio Playa,

Ciudad Habana, Cuba. It is my understanding

that mail, so directed, will now go through safe-

ly, if not rapidly. Milera tells me he would be

delighted to exchange specimens (prepared

and/or preserved as you want them) for

literature.

It may be of interest to U.S. malaeologists

that it is possible t\)r them to visit Cuba, and, in

fact, I was encouraged to spread this good news

to my colleagues. A Cuban Visa may now be

legally obtained by U.S. citizens and travel is by

way of Canada or Mexico via the airlines of

those countries. Your travel agent should be

able to provide the necessary information. Staff

of the Instituto de Zoologia, and especially

Milera, recommended your contacting them if

you would like to have their guidance and helj.) in

collecting and studying Cuban muliusks.

162 THE NAUTILUS

October 29, 1981

Vol. 95(4)

I departed Cuba on Air Canada at 5:00 p.m.,

Monday, November 17. It was 32° F and snow-

ing when I arrived in Toronto and I was afraid

the many living mollusks, for which I had an im-

port license, would die of the cold shock. They

survived, however, and following a night in

Toronto I continued on to Washington the next

day to conclude a fruitful and interesting trip.

POPULATION STRUCTURE AND BIOLOGY OF LIGUUS TREE SNAILS

ON LIGNUMVITAE KEY, FLORIDA.

Paul M. Tuskes

1444 Henry Street

Berkeley, California 94709

ABSTRACT

Two named color forms o/Liguus fasciatus are native to Lignumvitae Key. The

two color forms, simpsoni and lignumvitae constitute about 90% of the total

population. The form simpsoni grows larger than lignumvitae in the dense ham-

mock, but the opposite is true along the hammock edge. Individuals of both forms

from the hammock edge, are significantly larger than individuals of the same

form and age class from the central portion of the hammock. A population

estimate suggests that there are about 28,500 snails on the Key in age classes 2

through 6 years. Three introduced forms of L. fasciatus; dryas, delicatus, and

subcrenatus make up the remainder of the population. About 178 of the Key's 280

acres appears to be suitable Liguus habitat. Experiments examining the proba-

bility of dispersal via rafting showed that Liguus died after short exposures to sea

water.

A great deal of work has been published re-

garding the taxonomy of tropical tree snails in

the genus Liguus. Much of the taxonomic work

regarding Florida Liguus, done by Simpson,

Clench, McGinty, and Pilsbry, was summarized

by Pilsbry (1946) in his monograph on North

American land molluscs. With the exception of a

recent paper by Voss (1976), most articles re-

garding Liguus biology have been popularized,

presenting interesting but generalized informa-

tion (Doe, 1937; Jones, 1954; Davidson, 1965).

There is still a great deal to be learned regard-

ing various aspects of their biology, but it has

become increasingly difficult to find pristine col-

onies of Liguus. Many colonies have been ad-

versely influenced by human activity either

through modification of the colonies' composi-

tion (by the introduction and establishment of

new forms), or the modification of the hammock

habitat by lumbering or real estate develop-

ment. The purpose of this study was to examine

the population structure and evaluate the status

of the Liguus population on Lignumvitae Key.

In addition, an effort was made to examine the

likelihood that Liguus are able to traverse great

distances across seas by rafting.

Lignumvitae Key was privately owned and,

because of its isolation, was never developed

commercially. The Key is now a Florida State

Botanical Preserve which can only be reached

by boat. It is unique in that the Key's hardwood

forest, or hammock, has for the most part re-

mained intact, with some trees well over 500

years in age. The height and diameter of these

trees are matched by only a few stands of ham-

mock left on the northern portion of Key Largo.

The Key has an elevation of about 5 m making it

among the highest in the 200 km long chain of

Vol. 95(4)

October 29, 1981

THE NAUTILUS 163

islands which extend from the southern tip of

Florida to within about 130 km of Cuba. In addi-

tion to its forest, the Key has a number of fresh

water springs.

METHODS

Three study sites were established on the Key,

each measuring 25 by 25 m. The first site was

located on the east side of the Key about 300 m

N.W. of the boat dock. The second site was just

north of the main trail near the center of the

Key, while the third site was on the west side of

the Key, about 350 m N.W. of site 2.

Dead snails were collected in order to deter-

mine the areas and degree of mortality. Trees 4"

or more in diameter were identified and

counted. The age class of a snail was based on

how many growing seasons the snail had ex-

perienced. An annual growth line appears on

the shell of each snail caused by the deposition of

new shell at the thickened lip formed the previ-

ous year. This interface is marked by a furrow

which is often a different color. The annual

growth line is quite prominent on most shells

and usually can be distinguished easily from

lines formed by interrupted growth during the

growing season. Measurements of length were

made with vernier calipers and rounded to the

closest 1/10 of a mm. These measurements were

taken in November after the snails had finished

their seasonal growth.

A Lincoln Index was conducted on 4 different

occasions at each site to estimate the population

density. For each index the snails received a

distinctive mark. Individuals in age class 1

(snails in the first growing season) were not in-

cluded in the recapture study for two reasons:

(1) their small size precludes them from being

observed and thus recaptured with the same

probability as snails which are 2 years or older,

and (2) snails in this age class are very fragile

and might be subjected to a great deal of dam-

age if included in the study.

To examine the effects of exposure to salt

water on Liguus two experiments were con-

ducted using 90 snails in age classes 2 to 5 col-

lected on North Key Largo. These snails were

divided into 3 color groups of 30 individuals,

each of which contained 22 lineolatus, 6 cas-

taneozonatus, and 2 elliottensis. Snails in the

first group were allowed to attach to 3 Dogwood

branches, 10 to a branch. The branches were

placed in a protected lagoon and the response of

the snails observed. The branches floated in

water about 1 m deep. Snails which fell off the

floating branches were retrieved, rinsed with

fresh water, and returned to Key Largo. The

second group of snails was placed on a piece of

plywood and left floating in the same Lagoon

(on Plantation Key, Oct. 5, 1978) for 2 hours.

The third group served as the control and was

placed in a screen covered box on a dock within

4 m of the snails being tested. Both experiments

were conducted under calm weather conditions,

with only 2 cm ripples caused by light wind. A

thin film of sea water covered the upper surface

of the plywood board, but at no time were the

board or snails submerged.

RESULTS

The plant survey indicated 16 tree species

were distributed among the 3 study sites, with 8

species contributing over 60% of the individuals.

Table 1 indicates the species composition for

each site and the relative frequency of each tree

TABLE 1. List of tree species found in each study site, and the %

occurrence of trees with a 4 inch or greater diameter at each site.

164 THE NAUTILUS

October 29, 1981

Vol. 95(4)

species at a site. Because of the dense canopy,

little direct sunlight reaches the hammock floor

during the warm wet summer, thus, most of the

iloor is covered with leaf litter, bare soil or ex-

posed coral rock. Plants in the understory occur

near clearings and along trail cuts. Species in

the understory associated with the study sites

are wild coffee Psyehotra nervosa, white indigo

Rnndia acuteata, crabwood Gymnnthes lucide,

cheesewood Morinda royoc, and white stopper

Eugenia axillaris.

The average of the 4 Lincoln Indices for each

site was determined to be 21, 28, and 25 individ-

uals for sites 1, 2, and 3 respectively, with a

pooled average of 24.7 individuals per plot.

Thus, based on the size of a plot and the acreage

of the island suitable as Liguus habitat, it is

estimated that there are about 28,500 snails in

the 2nd to 6th year age classes on the Island.

A comparison of individuals in the hammock

with those at the hammock edge indicated that

the length of individuals of the same color form

and age class inside the hammock was signifi-

cantly less (t-Test, P>0.5) than those from the

edge (Table 2). Though there was no statistical

difference between the two color forms, individ-

uals of simpsoni at all age classes averaged 1 to

3 mm larger than lignumvitae in the hammock,

but the reverse was true at the hammock edge

(Table 2, Fig. 1). Corresponding with the dif-

ference in growth in the hammock, compared to

the hammock edge, a difference in the distri-

bution of age classes was noted, with the ham-

mock edge having a greater proportion of 2 to 3

year old snails (58 to 65%) than the other por-

TABLE 2. Average size as related to age class and occurrence in

the hammock. A t-test was conducted between members of the same

age class which occurred in different portions of the liammock.

* t-test not conducted imless n was > 5.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 165

60

55

5 0

4 5

E

E 4 0

g" 3 5

01

to

<u

>

<

3 0

25

2 0

1 5

1 0

1 2 3 4 5 6

Age Class (yrs)

FIG. 1. Average length of snails from the hammock edge and

central portion of the hammock. Open symbols represent

snails from the edge of the hammock, closed syynbols repre-

sent snails from the central portion of the hammock.

Triangles = simpsoni; circles = lignunivitae.

tions of the hammock (33 to 41%) as indicated by

Figure 2.

Empty shells which were collected at the

study sites during October were examined to

determine the cause of death. Of the 61 dead

siynpsoni found, 47.0% of the shells were intact

and therefore placed into the unknown cate-

gory, 27.7% of the damaged shells were attri-

buted to mammals and 24.4% to birds. A total of

35 dead lignumvitae were found, 31.3% of which

were placed in the unknown category, 22.8%

were attributed to birds, and 45.7% to mam-

mals. Considering the number of dead shells col-

lected and the present population density, the

shells must have represented the accumulation

of a number of years. It is possible that damage

may have occurred after the death of the snail,

which resulted in attributing their death to

other causes. From October 1978 to August

1980, 29 additional dead snails were found in the

study sites (8 lignumvitae, 21 sinipwni). All 29

shells represented recent mortalities with 6

simpsoni and 2 lignumvitae appearing to have

been predated, the remainder of the shells were

intact.

Observations were made in an effort to ex-

amine the likelihood that Liguus are able to

traverse great distances across seas on floating

trees. In the first experiment 10 snails were

placed on each of 3 cut Dogwood branches as

described in the methods. Within 1 minute after

the snails and branches came into contact with

sea water, the snails released their grip from the

branches and sank to the bottom. Thirty addi-

tional snails which were placed on plywood and

floated in the lagoon withdrew into their shells

upon contact with sea water. All 30 snails died

from their 2 hour exposure to a thin film of sea

water within 36 hours. No mortality was ob-

served among the control group.

DISCUSSION

Liguus become active in the spring following

the first warm rains in April or May. It is at this

time that the majority of the eggs deposited in

the ground the previous fall begin to hatch. The

snails feed almost exclusively on lichens, fungi,

and algae which grow on the bark of trees. Al-

though snails may be seen on any species of tree

on the Key, they show a marked preference for

smooth barked trees such as Jamacian Dog-

wood, Blolly, and Mastic. Lysiloma and Dog-

wood are two tree species preferred by Liguus

in south Florida, but of the two only Dogwood

occurs throughout the Keys. Lysiloma does not

occur commonly any further south than Planta-

tion Key, about 15 Km northeast of Lignum-

vitae Key.

During the course of the field work, five

named color forms of L.fasciat us were found on

the Key. The two endemic forms, simpsoni and

ligiumivitae. constitute about 90% or more of

the Liguus population. The remainder of the

population consisted of two forms endemic to

adjacent Lower Matecumbe Key, delicatns and

suhcrenatus, both introduced to Lignumvitae

KW; THENAl'TimS

50

Vol. 95(4)

Age Class

Ham moc k (

edge

central

FIG. 2. Agf c/f/.s-.s- distribution varied between the central portion and the edge of the hammock. The

number of two-iiear-old individuals is unexpectedly low. and perhaps related to the unusually dry

sutnmer and cold winter on the Key two years ago. Drought effects the hatch and sunnval of young

snails.

Key around 1955 by C. C. Von Paulsen, accord-

ing to Mr. A. L. Jones. One specimen of the

form dryas, also said to be introduced by Von

Paulsen, was found.

From April to August the snails remain active

and rather mobile, especially during and after a

rain. In July and August mating occurs and by

early October the snails have come down out of

the trees to lay their eggs. The construction of

the nest and deposition of eggs requires 1 to 3

days, during which time 5 to 30 eggs will be

deposited in the soil near the base of a tree. The

eggs may vary in color from light to dark brown,

and measure about 7.5x4.0 mm. Weber (1953)

and Voss (1976) give additional information re-

garding nest construction. The time of these

events will vary from (jne Key to the next, as

does the behavior of any one individual in a

population.

Population Size and Structure

The frequency of thunder storms in the area

decreases sharply in October, reducing the

movements of the snails. It is at this time that

the mark-recapture study was conducted. Four

Lincoln indices were conducted at each study

site, and the values averaged. The average

estimates for the three sites were then pooled

giving a value of 24.7 individuals per plot. Thus,

based on 178 of the Keys 280 acres being suit-

able Liguus habitat, the population estimate for

the Key is about 28,500 individuals in the 2 to 6

year age classes. Frequently as many as eleven

first year snails were observed in a study plot,

and it is not known how many additional in-

dividuals were hidden by foliage. Though no spe-

cific data was collected on this age class in the

mark-recapture study (for reasons given in the

methods) they could have contributed an addi-

tional 35 to 45% to the population.

On Lignumvitae Key snails in their first or

second growing season continued to grow until

November, while older individuals stopped

growing in September; for this reason measure-

ments of length were taken in mid-November

after all individuals had reached their maximum

length. Individuals collected from the hammock

edge were significantly larger than those from

Vol. 95(4)

October 29, 1981

THE NAUTILI'S KIT

the middle of the hammock (Table 2). By plot-

ting size against age class it becomes evident

from the slope of the line that the major dif-

ference is attributed to growth during the first

two seasons (Fig. 1). A difference also exists

between the two color forms with the average

size of simpsoni exceeding that of lignumvitae

in the central hammock but with the opposite

being true along the hammock edge. Thus, it is

possible that the two forms represent different

biologically adapted types, as indicated by the

differential growth rates under similar condi-

tions. It should be noted that physically, condi-

tions on the hammock edge are quite different

than in the rest of the hammock. Typically the

edge is less humid, has greater light penetra-

tion, is exposed to winds, and has an abundance

of food on the trees as compared with the inner

portions of the hammock on this Key. Although

the size difference between the two color forms

from the same portion of the hammock was not

always statistically significant, this may be due

to sample size as the averages show a consistent

difference (Fig. 1).

An unexpected difference in age class distri-

bution was found to occur between the ham-

mock and the hammock edge (Fig. 2). In the cen-

tral hammock the majority of the individuals

were of the 4-6 age class, while along the ham-

mock edge the majority were in the 2-3 age

class. This difference might be attributed to a

higher rate of survival among newly hatched in-

dividuals because of greater food availability

and less competition from older snails. Mature

snails in this area must have a higher mortality

rate, or a tendency to move away from the edge

into the hammock.

At least three observations on Lignumvitae

Key differ sharply from those made by Voss

(1976) on two Liguus populations on the

mainland north of Homestead, and near Miami.

Voss indicates that the growth rate of the snails

is linear with respect to age. On Lignumvitae

Key it is clear that the most rapid growth occurs

in the first year and decreases at about the time

individuals become sexually mature (3 or 4 years

old). Thus, on the Key, shells of 4, 5, and 6 year

old snails are not growing in length as fast as 1

year old snails (Fig. 1). Secondly, Voss found

that almost all individuals die after apparently

breeding only once at the age of 4. He found on-

ly 1 individual which was 5 years old, and meas-

ured perhaps only 3 individuals greater than 50

mm in length. On Lignumvitae Key about 21%

of the Liguus population (2-6 yr.) were of the

age class 5 and 6, with the vast majority of the

individuals 4 years old or older being well over

50 mm (Table 2, Fig. 1). Thus Liguus on the Key

exhibit a different pattern of growth, live sub-

stantially longer (which results in more repro-

ductive attempts), and grow considerably larger

than those which Voss examined at Timm's and

Brickell Hammocks. Voss failed to mention

which forms of fasciatus he observed and

measured during his study. My own observa-

tions in Timm's Hammock revealed at least 14

named forms of fasciatus to be well established

there in 1978. Although some of the observa-

tions by Voss differ from the ones reported

here, this is to be expected as he was dealing

with different forms oi L. fasciatus living under

biological conditions very different than those

on Lignumvitae Key.

Sources of Mortality

All of the empty shells on the ground at the

start of the study were collected and placed into

1 of 3 categories depending upon the condition

of the shell. Of the 96 dead shells found, about

64% were simpsoni. with the remainder being

lignumvitae. The type of damage differed

markably between the two color forms, but the

significance of this is not clear because it is not

known how much of the damage observed oc-

curred after the death of the snail. During the

observations made in 1980, 8 lignumvitae and

21 simpsoni were found dead in the study area,

21 of the shells showed no sign of damage, but

individuals of each color form had been attacked

by raccoons. The damage caused to a shell by

raccoons typically results in the upper portion of

the shell being crushed and on occasion tooth

holes may be seen on the remaining portion of

the shell. Shells damaged by birds usually have a

hole punched in the lower 2/3 of the shell, and it

is more likely that a portion of the snail remains

in the shell than if it were attacked by a raccoon.

Shells which were placed in the unknown cate-

168 THE NAUTILUS

October 29, 1981

Vol. 95(4)

gon,' may have died in any number of ways, but

in all cases the shell remained intact. Causes of

death in this group might include predation by

land crabs of the genus Coenobita. carniverous

snails, ants, or old age. Although Eisner and

Wilson (1970) suggest that body fluids offascia-

tus may ser\-e to deture attacking ants. I have

observed LiffuiLs being attacked and killed by

the fire ant, Solonopsis geminata (Fab.) on 3 oc-

casions. Thus. Liguus may be protected from

some species of ants, but not all.

Habitat Stability

In a mature hammock, such as Lignum\itae

Key, the Liguus population is probably rela-

tively stable barring severe cUmatic conditions

or other catastrophic events. A balance appears

to have developed in which light intensity and

moisture (influenced by canopy densitj- and cli-

matic predictability) interact to influence the

rate at which the snaUs' food regrows after be-

ing grazed. This combined with the relative

numbers of smooth-barked trees must deter-

mine the over-all carrj-ing capacity'. An ex-

amination of the Dog^vood trees on the Key

reveals those in the central hammock to be

polished or almost so. This condition results

from the continual scraping of the radula on the

bark of the trees over a great many generations.

A tree which has been polished by Liguus ap-

pears quite different from one which has been

recently occupied and merely had the majority-

of the food eaten off the bark. In hammocks

disturbed by fire where the Liguus population

was sharply decreased, the food regrows rapidly

due to increased light and reduced grazing

pressure by the snails. During the second and

third years following a fire, large individuals are

found. These have a high reproductive success

such that the density may exceed that reached

prior to the fire. As a result of the population in-

crease, the available food is soon consumed.

This caus^-'s a shortage for most members of the

population which results in stunted growth and

lower fecundity. In time the lower fecundity and

lack of food results in a general decline in the

population. Numerou.s oscillations may follow as

the balance is established between food avail-

ability and the density ot Liguus. Based on the

mean size of indi\iduals on the Key and the pop-

ulation density, the Lignumxitae Key Liguus

population is probably oscillating about a point

near the present carrying capacity of the island.

Thus, this population is probably relatively

stable in relationship to the conditions within

the hammock as it presently exists on the Key.

Dispersal of Liguus

Pilsbr\\ (1946) stated that "All naturalists who

have considered the subject agree that our

Liguus were derived from Cuban stocks of the

polymorphic L. fasciatus (Miiller), brought to

Florida sealed to floating trees and cast ashore

by high winds or hurricanes." Although the ori-

gin of our Liguus may not be in dispute, the

means by which they arrived here is by no

means clear. The mode by which Pilsbry sug-

gested that L iguus arrived in Florida cannot be

discounted, but the likelihood of an event such

as he described appears to be much lower than

one might expect. AestivatingLi^i/^ do form a

tenacious seal by which they attach themselves

to a tree during the winter, but the hurricane

season is during the summer and fall while the

snails are active and not in aestivation. In addi-

tion, the mucus which seals the snail softens and

becomes non-adhesive when moistened for ex-

tended periods.

To examine the possibility' that non-aestivat-

ing snails could sunive the journey which

Pilsbrj- described, several tests were run. First,

it was obsen'ed that the density of some trees,

such as Lignum\itae and Ironwood, is greater

than that of sea water and therefore they do not

float. Other tree species, such as Gumbo-limbo,

Dogwood, and Poisonwood, barely remain afloat

in calm water. Thus, it appears that many

species of trees in the hammocks are not

suitable as rafts for Liguus.

None of the 30 snails on Dogwood branches

remained attached for more than a minute after

the branches were placed in sea water. The

snails placed on a board, which was floated for 2

hours, never came into contact with water

greater than 3 mm deep, and were usually out of

the water, but moist. Again, the snails withdrew

into their shells upon contact with sea water,

Vol. 95(4)

October 29, 1981

THE NAUTILUS 169

but this time the shell remained setting on the

flat surface of the board. No individuals exposed

to these conditions during the 2 hour test were

alive 36 hours later.

This sensitivity to sea water may explain why

many of the forms of Liguus endemic to the

Keys occurred on only one or two Keys, while

forms in the Everglades tend to be more wide-

spread. It appears that aestivating or non-aesti-

vating snails have an exceedingly low probabil-

ity of surviving a 130 Km trip in a hurricane to

reach the southern-most portion of Florida.

ACKNOWLEDGMENTS

I wish to thank Mr. Archie Jones and Dr.

Barry Roth for reviewing the manuscript, and

Dr. Roy Snelling for identifying the ants. I

would also like to thank Kevan O'Kane, and Jim

Stevenson of the Florida Department of Natural

Resources for their cooperation, and Steve

Sparks and Kevin Sunderland for assistance.

Special thanks to park ranger Ms. Jeanne Parks

for all of her assistance and cooperation.

LITERATURE CITED

Davidson, T. 196.5. Tree .snails, gems of the Everglades. Nat.

Geogr. Mag. 127:372-387.

Doe. M. F. 1937. Tree snails of south Florida. Nature Mag.

29:82-84.

Eisner. T. and E. 0. Wilson. 1970. Defensive liquid dis-

charge in Florida tree snaWs (Liguusfaseiatus). The Nauti-

lus 84:14-15.

Jones, A. L. 1954. How Florida Tree Snails Live. Everglades

Nat. Hist. Mag. 2:59-62.

Pilsbrj', H. A. 1946. Land Mollusca of North America (north

of Mexico). Acad. Nat. Sri. Ph Had. Monogr. No. 3, Vol. 2.

pt. 1, p. 37-102.

Voss. R. S. 1976. Observations on the ecologj- of the Florida

tree snail Liguus fasriatus (Muller). The Nautilus

90:6.5-69.

Weber, J. A. 1953. Nests of the Florida tree snail. Ever-

glades Nat. Hist. Mag. 1:63-65.

A NEW SPECIES OF VOLUTOCORBIS (VOLUTIDAE) FROM SOMALIA

Harald A. Rehder

National Museum of Natural History

Smithsonian Institution

Washington, D.C. 20560

Through the kindness of Dr. Harry G. Lee of

Jacksonville, Florida, I received for examination

a small series of a species of Volutocorbis from

Somalia. I recognized immediately that the

specimens were unlike any described species of

the genus.

With Dr. Lee's permission I am describing this

species as new and am pleased to name it in

honor of Mrs. Rosavittoria Todaro, from whom

Dr. Lee received the specimens. They were col-

lected by Abdulkadir Ma'allin "Javane", from

whom Mrs. Todaro obtained the specimens.

Volutocorbis rosai-ittoriae new species

(Figs. 1-5)

Description: Shell of medium size for genus.

heavy, biconic, with the spire sharply conical,

about V4 total length or slightly more. Proto-

conch mamillate. consisting of about IVs

smooth, rounded whorls, the top sometimes ob-

liquely flattened. Postnuclear whorls 5V4-6, first

one with axial ribs that become nodulose below

suture after first "4 whorl, with a second spiral

row of nodules, separated from the first by a

rounded groove; the subsutural row of nodules

in later whorls margins a channeled subsutural

shelf and may divide and form an upper flat-

tened, less nodulose cord; in later whorls the

number of spiral rows of nodules increases with

the addition of finer spiral cords, the number of

such spiral elements numbering about 45 in

paratype #3; the number of axial ribs and riblets

170 THE NAUTILUS

October 29, 19S1

Vol. 95(4)

FIGS. 1-5. Volutocorbis rosavittoriae n. up. x 1. 1, Hulofype. dorsal vieu: 2, Hutotype. apertural rieu: 3, Paratype nu. 1.

4, Pnratype no. 2. 5, Paratype no. 3.

also increases so that in the same parat^^^e there

are 16 riblets in the first postnuclear whorl and

about 50 in the last whorl. The last whorl is

usually slightly angled at the shoulder by a

strong row of pointed nodules, and the entire

surface is rendered rough and filelike by the

numerous spiral cords and threads made finely

nodulose by the crowded axial riblets. The color

is pale tan or dark straw-color with white spiral

lines or bands. Aperture narrow, pointed at both

ends, outer lip broadly thickened inside with

16-22 teeth of various sizes that extend as spiral

ridges into the aperture; parietal callus thin,

margined above and on lower half, with 7-10

spiral folds on thickened internal lower half, the

lowest fold usually strongest; lower part of

outer lip flattened near broad, open siphonal

canal.

Range: South coast of Somalia from off Kisi-

mayu (Chisimaio) to Brava.

Type locality: Off Kisimayu, southern

Somalia.

Measurements (in mm):

Holotype USXM 784653

Paratype #1 USNM 784654

Paratype #2 Colin. H. G. Lee

Paratype #3 USNM 784654

Remarks: This species is distinct from other

known species of Volutocorbis in possessing a

stout, thick shell with strong, fine spiral and ax-

ial sculpture. In size, general shape, and in the

thickness of the outer lip it is closest to V.

semirugata Rehder and Weaver, 1974, but that

species is much smoother, with more strongly

shouldered whorls.

Since receiving the four specimens that form

the basis of this description, Dr. Lee has learned

that this species has been collected in some

numbers off Brava on a species of Xenophora.

probably pallidula (Reeve). Of 100 specimens of

the latter species 29 had specimens of Volutocor-

bis rosavittoriae affixed to them.

NOW AVAILABLE

MONOGRAPHS OF MARINE MOLLUSCA, no. 2. The Family Buccinidae. Part 1; The Genera iVa^-

saria, Trajana and Neoteron. 50 pp. By Walter 0. Cernohorsky. $7.50. Postage free if order is ac-

companied by payment. Foreign subscribers please add $1.00 for postage. American Malacologists,

Inc., P.O. Box 2255, Melbourne, FL. 32901-0328. U.S.A.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 171

TWO NEW SPECIES OF ACANTHOCHITONA FROM THE NEW

WORLD (POLYPLACOPHORA: CRYPTOPLACIDAE)

G. Thomas Watters

Department of Zoology'

University of Rhode Island

Kingston, Rhode Island 02881

A systematic revision of the New World Cryp-

toplacidae has revealed the presence of two new

species: Acanthochitona imperatrix (command-

ing chiton) from tropical west America and

Acanthochitona andersoni from southeast

Florida and the Caribbean. Because of the wide-

spread confusion in the literature concerning

this family, additional notes on related species

have been extracted from the revision to help

clarify the taxonomic position of the species in-

volved.

Abbreviations used in the text:

AMNH- American Museum of Natural History,

New York.

ANSP- Academy of Natural Sciences of Phila-

delphia.

DMNH- Delaware Museum of Natural History,

Greenville.

MCZ- Museum of Comparative Zoology, Har-

vard University.

USNM-U.S. Museum of Natural History,

Washington, D.C.

Acanthochitona imperatrix new species

(Plate la, b, c; Plate 4b)

Description: Holotype 8.9 mm in length,

curled. Tegmentum of intermediate valves

about twice as wide as long, flattened, not

carinate. Beaks prominent. Jugum very wide,

flat, smooth, and distinctly raised above the

latero-pleural areas. Jugal macresthetes widely

spaced, arranged in longitudinal rows, each

associated with 0-2 micresthetes. Latero-pleural

areas sculptured with numerous teardrop-

shaped, close-set pustules, each moderately

elevated and concave. Each pustule bears one

centrally located macresthete. 0-5 micresthetes

(commonly 0) accompany each macresthete and

are generally confined to the area anterior to

'Present address: Museum of Zoology, Ohio State Univ.,

Columbus, OH 43210.

the macresthete. Mucro central and prominent

with a concave postmucronal slope. Tegmentum

uniformly peach-colored, the jugum lighter.

Alternating spots of cream and maroon occur

along the posterior borders of the valves and

flank the jugum on the holotype.

Apophyses extensive. Slit formula 5-1-2. Ar-

ticulamentum colored cream, tinged with green

towards the beaks.

The dorsum of the girdle is velvety, armed

with dense, very minute spicules. These spicules

are monomorphic (i.e. -composed of one tj^pe of

element as opposed to bimor-phic, composed of

two distinct types of elements), round in cross-

section, smooth, and slightly bent. Girdle dor-

sum peach-colored, ventral side slightly darker.

Marginal fringe and sutural tufts well-

developed, composed of numerous long, slender

spicules.

Type locality: 8 fathoms (14.6 m) off San

Diego, California; lat. 24°22'30" S, long.

110°19'30" W; taken with tangles on broken

shell bottom, April 30, 1888, by the U.S. Fish

Commission. Holotype: USNM 218762. Para-

types: USNM 225346 - Sta. 2826, 9.5 fathoms

(17.4 m) off La Paz, Baja California Sur; lat.

24°12'00" S, long. 109°55'00" W; taken with

oyster dredge on shelly bottom, April 30, 1888,

by the U.S. Fish Commission. ANSP 153484

-Seymour Bay, Isla Santa Cruz (Indefatigable

Island), Galapagos Islands, by Pinchot Expedi-

tion, Pilsbry.

Range: Subtidally to at least 17 m, from

southern California to the Galapagos Islands.

Remarks: A. G. Smith and Ferreira (1977) il-

lustrated and described a specimen of this

species (ANSP 153484) but did not name it.

Their specimen was composed of a head, tail,

and three intermediate valves without the gir-

dle. The specimen is labeled as 'A. galapagana

Pils. MS, A. G. Smith TYPE". This name was

172 THE NAUTILUS

October 29. 1981

Vol. 95(4)

PLATE 1. Figs, a, b, and e: Acanthochitona imperatrix new species. Paratope ANSP 153i8i, Seymour Bay,

hla Santa Cruz. Galdpago's Islands, (a): valve ? VII. 3.9 mm diameter, (b): valve VIII, 2.8 mm diameter, (c): valve

VIII. profile. Fig. d: Acanthochitana communis (Risso. 1826). USXM 218733. Tierra del Fuego. Argentina;

calve VII, 5.2 mm diameter. Fig. e, f, and g: Acanthochitona angelica Dall, 1919. AMNH 7U~13. Maria

Mngdalena Island. Tres Marias hlawlx. (e): valve VII. 3.8 mm diameter, (f): valve VIII. 2.7 mm diameter, (g):

■ nlri- VIII. profile. Fig. h, i, and j: Acanthochitona avicula (Carpenter. 186U), AMNH 130977. Agua de Chale.

Buj'j Culij'omia. Mexico, (h): valve VII. 3.J, mm diameter, (i): valve VIII. 2.3 mm diameter, (j): valve VIII, profile.

never introduced and Dr. Ferreira (written

comm.) is not familiar with it. Subsequently I

located two conriplete specimens at the U.S. Na-

tional Mu.seum (TSNM 225346 and 218762), the

latter of which I nave desi^ated as holotjpe.

Acanthochitona imperatrix is one of several

species in a New World complex composed of

forms characterized by broad, rectangular, in-

termediate valves bearing teardrop-shaped

pustules and a centrally located, prominent

Vol. 95(4)

October 29, 1981

THE NAUTILUS 173

mucro. In addition to A. imperatrix. the com-

plex contains A. angelica Dall, 1919, A. avicula

(Carpenter, 1864), A. communis (Risso, 1826),

and A. spiculosa (Reeve, 1847). A second com-

plex, composed of A. astriger (Reeve, 1847), A.

exquisita (Pilsbry, 1893a), A. hemphilli (Pilsbry,

1893a) (rhodea (Pilsbry, 1893a) is this species),

A. hirudin ifonnis hirudiniformis (Sowerby,

1832) (coquimboensis (Leloup, 1941a) and tabo-

geyisis A. G. Smith, 1961, are this species), and

A. kirvxiiniformis peruviana (Leloup, 1941a), is

differentiated by having long, pentagonal

valves, oval to teardrop-shaped pustules, and a

low, posteriorly acentric mucro. The third New

World complex will be discussed under the fol-

lowing remarks of Acanthochitona andersoni

new species.

The superspecies that contains A. imperatrix

antedates the closing of the western Tethys Sea

and probably stems from A. communis or its im-

mediate ancestor. Acanthochitona communis

(pi. Id; pi. 4a) is a widely distributed species

throughout the Mediterranean, the eastern

Atlantic from Spain to Great Britain and the

Azores (Malatesta, 1962), the Cape of Good

Hope and the Falkland Islands (Leloup, 1941a),

Tierra del Fuego (USNM 218733). and the

southern Caribbean (as A. bonairensis Kaas.

1972). The dorsal girdle elements of A. com-

munis are bimorphic while those of .4. impera-

trix are monomorphic; furthermore, A. com-

munis does not possess the very wide, flat,

distinctly raised jugum of A. imperatrix.

Acanthochitona angelica Dall, 1919. (pi. le. f,

g; pi. 4e) differs in having bimorphic girdle

elements, both of which are bent and striated;

those of .4. imperat7-ix are straight and smooth.

The jugum of A. angelica may be longitudinally

striated and is never as wide as in A. impera-

trix. A. G. Smith (1977) inexplicably sxTiony-

mized A. angelica with .4. avicula despite ob-

\ious differences between the two species and

A. angelica has not been recognized as distinct

in recent years (Putnam, 1980, and Kaas and

Van Belle, 1980). The dorsum of the girdle of .4.

angelica is velvety, composed of minute

spicules, while those of A. avicula are coarse

and thorn-like. In addition, the pustules of A.

angelica are never as large and elongated as

those of A. avicula. A. G. Smith and Ferreira

(1977) introduced A. jacquelinae, a sjTionym of

A. angelica.

Acanthochitona avicula (Carpenter, 1864) (pi.

Ih, i, j; pi. 4c, d) differs from A. imperatrix in

possessing a striated jugum and large, bent,

distally striated spicules among the smaller,

smooth elements on the dorsum of the girdle.

Acanthochitona avicula variety diegoensis

(Pilsbry, 1893b) is a common variant; the lec-

tot\-pe, herein designated, is ANSP 349330 from

San Diego, California (pi. 4d).

Acanthochitona spiculosa (Reeve. 1847) (pi.

2a, b, c; pi. 4f, g) from the Caribbean and south-

eastern U.S. also has a striated jugum and bent

dorsal elements. The A. pygmaea of Abbott

(1954, 1974), Kaas (1972), Warmke and Abbott

(1964), Kaas and Van Belle (1980). and others, is

A. spiculosa. Acanthochitona pygmaea (Pilsbn,',

1893b) is based upon a juvenile of A. spiculosa:

the lectot\'pe, herein designated, is ANSP 35783

from Key West. Florida (pi. 4g). The "spiculosa"

of these same authors (and of most collections)

is A. astriger. a common West Indian species

which has been confused with A. spiculosa ever

since E. A. Smith (1890) first misidentified his

specimens. Acanthochitona astriger (pi. 2d: pi.

4h) never possesses a striated jugum and has

longer, more pentagonal valves than A.

spiculosa. The complicated synonymy of these

two species will be presented at a later time.

Synonymy:

Acanthochitona species? A. G. Smith and Ferreira. 1977.

rWipcr 20:82. 97. fig. 22.

Acanthochitona andersoni new species

(Piate 2e, f. g; Plate 4i)

Description: Maximum size 12 mm in length.

Tegmentum of intermediate valves longer than

wide, pentagonal in outline. Beaks prominent.

Jugum wide, smooth except for growth lines.

Jugal macresthetes widely and irregularly

placed, generally absent from the central por-

tion of the jugum. Each macresthete is accom-

panied by 1-5 micresthetes. Mucro posteriorly

acentric, ven,- prominent; postmucronal slope

steep and concave. Lateropleural areas sculp-

tured with widely spaced, convex, "D"-shaped

pustules which radiate from the beak. Each

171 THENAl'TILrS

October 29, 1981

Vol. 95(4)

iL__Ij

F'LATK 2. Fiys. a, b, <uiil c: At-aiithochitoiia spiculosaffieCT'c, IHJ,7), Walters collection, Windley Key, Florida,

tat: valve VII, 2.8 mm diameter, tbi: valve VIII. 1.9 mm diameter, (c): valve VIII, profile. Fig. d: Acanthochitona

astrij^er (Reeve, ISJ,7I. Bullock collection, Magueyea Island, La Parguera, Puerto Rico; valve VII. S.3 mm

diameter. Figs, e, f, and. g: Acanthochitona andersoni new species, Paralype DMNH 9538S, Picquet Rocks,

Bimini, Baltamas. te): valve VII, 1.7 mm diameter, (j): valve VIII, l.J, mm. (g): valve VIII, profile. Figs, h, i, and

j: Acanthochitona arragonites ^Carpewte?-, 18,57>, Watters collection, Bahia deKino, Sonora. Mexico, (h): valve

VII, 2.!, mm diameter, (i): valve VIII, 1.8 mm diameter, (j): valve VIII, profile.

pustule bears one macresthete located towards

the prepustular edge. The 2-7 micresthetes per

pustule are limited generally to the prepustular

slope. Tegmentum mottled brown, yellow,

green, or uniformly white; pustules may be col-

ored differently from the rest of the tegmen-

Uim. One paratype (DMNH 95383) is uniformly

blackish-brown with occasional white pustules.

Apophyses moderately extensive. Slit formula

5-1-2, with interslits in some specimens.

Vol. 95(4)

October 29, 1981

THE NAUTILI'S T

Articulamentuni translucent white, the color of

the tegmentum showing through.

The entire girdle is velvety, armed with dense,

bimorphic spicules on the dorsum. Both types

are flattened in cross-section, bent, and smooth,

but differ in size. Girdle variously colored green,

white, dark-brown, tan, or mottled with these

colors. Sutural tufts and marginal fringe well-

developed but composed of only a few long,

stout elements colored translucent white.

Type locality: Sta. 2, rocky cove, south shore

of point, 1 km south of Calliaqua, St. Vincent,

Lesser Antilles. Holotype: ANSP 332171.

Paratypes: ANSP 220834 - 30 fathoms (54.6 m),

on wreck, off Destin, Florida; ANSP 220833 - 30

fathoms (54.6 m), off Boynton Beach, Florida,

Bales; Bullock collection - West Summerland

Key, Florida; USNM 103424 - Key West,

Florida, from U.S. Fish Commission; USNM

181248 - Key West, Florida, April 15-27, 1884;

USNM 663398 - Key West, Florida, Weber;

MCZ 204125 - Dry Tortugas, Florida, 1940, E.

Koto; USNM 735327 - Sta. 52-60, on coral,

center of Nicchehabin Reef, East Allen Point,

Ascension Bay, Quintana Roo, Mexico; Bredin -

Smithson. Inst. Expedition, April 10, 1960,

Rehder & Bousfield; USNM 736249 - Sta. 85 &

95, Suliman Point, Ascension Bay, Quintana

Roo, Mexico; Bredin - Smithson. Inst. Expedi-

tion, April 17 & 19, 1960, Schmitt et al.; USNM

736058 - Ascension Bay, Quintana Roo, Mexico;

Bredin - Smithson. Inst. Expedition; Bullock

collection - Galeta Point, Canal Zone; ANSP

325808 - 1 mile west of Haulover, North Bimini,

Bahamas; ANSP 325864 - 1 mile east of Turtle

Rocks, southwest of concrete ship, 18 feet (5.4

m), Bimini, Bahamas, 1957-58, Robertson;

DMNH 95383 - 10.6 m on Strornbus gigas, Pic-

quet Rocks, Bimini, April 17, 1973, Watters;

MCZ 238906 - Goat Key, Andros Island,

Bahamas, Patterson; MCZ 390 - Tobago Island,

Clarke; Bullock collection - St. Jorisbaai,

Curasao.

Range: Subtidally to at least 55 m, from Quin-

tana Roo to southeastern Florida and the

Bahamas, the Lesser Antilles, and the Nether-

lands Antilles.

Remarks: This new species is not uncommon

in collections but is often misidentified as other

species, particularly as A. pyginaea <=A. npicu-

losa) and A. hale^^ae Abbott, 1954. It is part of

distinct complex containing A. arragonites

(Carpenter, 1857) and A. balesae. The species of

this complex are recognized by the vermiform

body and convex, "D"-shaped pustules. All other

New World Acanthochitona have concave, tear-

drop-shaped or oval pustules.

Acanthochitona andersoni is closely related to

A. arragonites (pi. 2h, i, j; pi. 4k), its cognate

from the eastern Pacific, but can be differenti-

ated by the dorsal girdle elements: in A. ander-

soni they are bimorphic, both types being flat-

tened in cross-section, smooth, and bent, but of

two distinct sizes; in A. arragonites they are

monomorphic, round in cross-section, finely rib-

bed, and bent.

Acanthochitona balesae (pi. 3a, b, c; pi. 4j) dif-

fers from A. andersoni in having the dorsal

elements monomorphic, flattened in cross-

section, strongly ribbed, and bent. The pustules

PLATE 3. Figs, a, b, and c: Acan-

thochitona balesae .4 W<o/^ 195J,. Bullock

collect inn, Miigueyes Island, La Par-

guera, Puerto Rico, (a): va I ve III. 1 . 9 mm

diameter, (b): valve VIII. 1.6 mm

diameter, (c): valve VIII, profile

I

176 THE NAUTILUS

October 29, 1981

Vol. 95(4)

PLATE 4. (a): Acaiithuchitona communis (Rititio. lS-^6). Bullock collection, Azores Islands. 12 mm in length, (b): Acaii-

thochitdna impt'ratrix ricir .spfcicx. Holotype USNM 218762. off San Diego. California, 8.9 mm in length, curled, (c): Acan-

thochitona avicula (Carpenter. 18t!J,). Waiters collection. Ensenada. Mexico. 15 mm in length, (d): Acanthochitona avicula

(Carpenter. 186J,I. Lectotype of A. avicuia. variety dKgoens\s(Pilshry . 1893). ANSP 3i9330. off San Diego. California. 19 mm in

length, (e): Acanthochitona angelica Dall. 1919, Holotype USNM 1103US, Bahia de Los Angeles. Baja California, Mexico, 11

mm in length, curled, (f): Acanthochilona spiculosa (Reeve. 181,7). Walters collection, northwest West Summerland Key,

Florida, 11 mm in length, (g): Acantliochitona spiculosa (Recce. 18U7). Lectotype of A. pygmaea (Pil^bry. 1893), ANSP 35783,

Key West. Florida. 9 mm in length, (h): Acanthochitona ix^in^ar (Reeve. 181,7). DMNH !,5:i81. Water Island. Virgin Island.'!. 11

nmi in length, (i): Acanthochitona andersoni new species. Holotype ANSP 332171 . Calliaqua. St. Vincent. 11 mm in length, (j):

Acanthochitona halesac/lWjn;/. 19.5i, USNM 535y.')0. Bonefish Key. Florida. 10 mm m length, (k): Acanthochitona arragonites

(Carpenter. 1857). Walters collection, Salinas, Ecuador, 1, mm in length.

of the intermediate valves ot'/l. nrrnniniilt's and

A. andersdvi tend to radiate from the beak: in

A. hdli-siw (hey arc })aralie! to the ju^-um. E\-

amination of museum collections has shown that

A. bcih'sae is widely distributed in the Caribbean

and is more variable than was previously real-

ized. Kaas's,4. inierfi..'<s<t and A. elongatu (both

1972) are this species. The lectotyyje of A.

baU-sae. herein designated is ANSP 349331 from

Bonefish Key, Florida.

ACKNOWLEDGMENTS

I would like to thank Dr. R. C. Bullock for his

guidance and criticisms of this paper and the

family review, and Dr. A. J. Ferreira for the

loan of specimens and information. The staff of

Vol. 95(4)

October 29, 1981

THE NAUTILUS 177

the museums cited herein are to be thanked for

their time and the loan of specimens. This

research was made possible by a grant from

Sigma Xi and a scholarship from the National

Capital Shell Club.

The latter species is named in honor of Mr.

Burton Anderson of Hollywood, Florida, who in-

troduced me to malacology.

LITERATURE CITED

Abl)ott, R. T. 1954. American Seashells. Van Nostrand Co..

Inc. New York, xiv + 541 pp., text figs., 40 pis.

1974. American Seashells. Van Nostrand &

Reinhold Co. New York. 663 pp., text figs., 24 pis.

Carpenter, P. P. 1857. Catalogue of the Reigen Collection of

Mazatlan MoUusca in the British Museum. Warrington.

552 pp.

1864. Supplementary report on the present

state of our knowledge with regard to the Mollusca of the

West Coast of North America. Rep., British Assoc, for

Advancement of Science for 1863: 517-686.

Dall, W. H. 1919. Descriptions of some new species of

chitons from the Pacific coast of America. Proc. U.S.

Natn. Museum 55:499-516.

Kaas, P. 1972. Polj'placophora of the Caribbean region.

Studies on the Fauna of Curasao and Other Caribbean

Islands 41(137):1-162, 247 text figs., 9 pis.

Kaas, P. and R. A. Van Belle. 1980. Catalogue of the Living

Chitons. Backhuys. Rotterdam. 144 pp.

Leioup, E. 1941a. A propos de quelques acanthochitons peu

connus ou nouveaiLx, II ■ Region Atlantique. Bull. Mus.

Roy. Hist. Natur. Belg. 17(43):1-15, 5 figs.

1941b. A propos de quelques acanthochitons peu

connus ou nouveaux. III ■ Region Pacifique. cotes Ameri

caines. Bull. Mus. Roy. Hist. Natur. Belg. 17(61):l-9.

5 figs.

Malatesta, A. 1962. Mediterranean Polyplacophora, Ceno-

zoic and Recent. Geologica Romana 1:145-171, 23 figs.

Pilsbry, H. A. 1893a. Notes on the Acanthochitonidae with

descriptions of new American species. Nautilus 7:31-32.

1893b. Polyplacophora, (in) Tryon, Manual of

CoKcMoff?/ 15:5-133, pis. 1-17.

Putnam, B. F. 1980. Taxonomic identification key to the

described species of polyplacophoran mollusks of the west

coast of North America (North of Mexico). Pacific Gas &

Electric Company Dept. of Engineering Research Report

411-79.342: 165 pp., 68 figs.

Reeve, L. 1847. Conchologia Iconica, or Illustrations of the

Shells of Molluscous Anirnals 4. London. 28 pis., 194 figs.

Risso, A. 1826. Histoire Naturelle des Prineipales de

VEurope Meridionale et particulierement de relies des

Environs de Nice et des .Alpes Maritimes 4. 439 pp., 4 pis.

Smith, A. G. 1961. Four species of chitons from the Panamic

province (Mollusca: Polyplacophora). Proc. Calif Acad,

Sci. 30:81-90, pis. 8, 9."

1977. Rectification of west coast chiton nomen-

clature. Veliger 19:215-258.

Smith, A. G. and A. J. Ferreira. 1977. Chiton fauna of the

Galapagos Islands. Veliger 20:82-97, 4 pis.

Smith, E. A. 1890. Notes on zoology of Fernando Noronha.

J. Linn. Soc. London 20:483-503.

Sowerby, G. B. 2nd. 1832. (in) Broderip and Sowerby, Char-

acters of new species of Mollusca and Conhifera collected

by Mr. Cuming. Proc. Comm. Sci. Corres. Zool. Soc. Lon-

don for 1832: 25-33, .50-61, 104-108, 113-120, 124-126.

Warmke, G. and R. T. Abbott. 1961. Caribbean Seashells.

Livingston Publ. Co. Wynnewood, Penn. 346 pi)., 44 pis.

WHAT IS VENERICARDIA MORSEI DALL?

Eugene Coan

Research Associate

Department of Invertebrate Zoology

California Academy of Sciences

San Francisco, CA 94118

While I was preparing my review of the north-

west American Carditidae, I examined the type

material of Venericardia (Cyclocardia) morsei

Dall, 1918: 234, described from "Sagami,

Japan." The type material (USNM 274075), in

contrast, is labeled as coming from another

locality, "Kii, Japan." I concluded that, of

eastern Pacific species, V. (C.) morsei was

closest to but separable from Cyclocardia

crehricodata (Krause, 1885) (Coan, 1977: 379).

Habe (1978: 99-100: figs. 5-8) has recently ex-

pressed the view that the type material of Vene-

ricardia morsei. which he illustrates for the

first time, is conspecific with Cyclocardia

crassidens (Broderip & Sowerby, 1829), a

species characteristic of the eastern Pacific, par-

178 THE NAUTILUS

October 29, 1981

Vol. 95(4)

ticularly the Arctic and Bering seas. He also

said that no additional specimens have come to

light in recent years from either, well-studied

Japanese locality.

I concur with Habe that the type material is

probably not Japanese, but I cannot agree that

it is conspecific with Cydocardia crassidens.

After examining carditids in the U.S. National

Museum of Natural History, I am of the opinion

that instead it is closer to Cydocardia borealis

(Conrad, 1832) of the western Atlantic, par-

ticularly to USNM 445701 from Mt. Desert,

Maine.

The type lot of Venericardia morsei contained

opposite valves of similar size from two in-

dividuals. The right valve is here designated the

lectotype and measures 25.2 mm in length, 27.5

mm in height, and 7.9 mm in thickness. This

specimen remains in USNM 274075. The left

valve, which measures 24.5 mm in length, 27.9

mm in height, and 7.0 mm in thickness, is

unusual in that it appears to be the product of

hinge transposition. This paralectotype has

been renumbered USNM 784633.

LITERATURE CITED

Broderip, William John and George Brettingham Sowerby I.

1829. Observations on new or interesting Mollusca con-

tained, for the most part, in the Museum of the Zoological

Society. Zoo/. Jmim. 4(15):359-376; pi. 9 (post-Jan, 1829).

Coan, Eugene V. 1977. Preliminary review of the north-

west American Carditidae. The Veliger 19(4):375-386;

19 figs, (on pis.) (1 April 1977)

Conrad, Timothy Abbott. 1832. American Marine Concho-

logy. no. 3:29-40; pis. 6-8 Philadelphia (Conrad) (May

1832).

Dall, William Healey. 1918. Notes on Chrysodomus and

other niollusks from the North Pacific Ocean. Proc. U.S.

Nation. Mms. 54(2234):207-234 (5 April 1918).

Habe, Tadashige. 1978. Notes on the type specimens of

three Japanese shells described by W. H. Dall and held in

the National Museum of Natural History, Smithsonian

Institution, U.S.A. The Venus 37(2):98-100; 8 figs. (July

1978).

Krause, Arthur. 188.5. Ein Beitrag zur Kenntniss der Mol-

lusken-Fauna des Beringsmeeres. I. Brachiopoda et

Lamellibranchiata. Arch. Naturg. 51(1X1):14-41; pi. 3.

A NEW BRASILIAN PYRENE (PROSOBRANCHIA: COLUMBELLIDAE)

Eliezer Rios

Oceanographic Museum

University of Rio Grande

RS Brazil g6200

and

Luis Roberto Tostes

Rio de Janeiro, Brazil

In September 1978, the fisherman, Dorismun-

do Pinto, collected off Marica, Rio de Janeiro

State, 80 meters in depth, entangled in a lost

net, 8 specimens of a Columbellidae which we

believe is a species new to science.

For the time being, we have placed this

species within the genus Pyrene and the

subgenus Conella due to its characteristics and

because it was not possible to save the radula.

Pyrene ledaluciae new species

Description: Shell fusiform, biconic, 24.4 x

12.1 mm, spire high, conic, forming an apical

angle of about 60°. Protoconch smooth,

mammilliform, light-brown in color, with two

whorls. Teleconch with six whorls, slightly con-

vex. Suture well-impressed, but not channeled.

Aperture ovate, long (3/5 of total shell length),

violet internally. Operculum corneous, oval,

yellow, with terminal nucleus. Outer lip not

thickened, acute, with 12 denticles or lirae, the

front 9 separated from the last 3. Outer surface

bright, ornamented with microscopic spiral

striae, more prominent on the spire and scarcely

visible on the body whorl. Color brown with

whitish yellow stains irregularly spotted.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 179

FIG. 1. Immaluft ijuratype and holotype (21t.lt

mm) of Pyrene (Conella) ledaluciae Rios and

Tostes. new species, from off Marica, Rio de

Janeiro State, Brazil.

FIG. 2 and 3. Protoconch and operculum o/Pyrene

ledaluciae Rios and Tostes, new species.

Periostracum not apparent. Siphonal canal

short, straight and open.

Only 2 species of the subgenus Conella -

ovulata (Lamarck, 1822) and C. cnmloides (C. B.

Adams, 1850) - are known in the Western At-

lantic, both living in Florida and the Caribbean

Sea. Our species is distingijished from the

former by the protoconch, spire, aperture and

form of denticles. It differs from the latter by

the general shape, spire and aperture.

The holotype and a young specimen have been

cataloged in the Malacological Laboratory of the

Rio Grande Oceanographic Museum under no.

20.518. Paratype no. 1 is in the Malacological

Collection of the junior author under no. 1781;

paratype no. 2 is in the National Museum of Rio

de Janeiro under no. 3.900; paratype no. 3 is in

the American Museum of Natural History of

New York under no. 183.263.

The authors wish to thank Dr. R. Tucker Ab-

bott and Prof. Paulo Sa Cardoso (Maceio,

Alagoas, Brasil) for their valuable suggestions,'

and thank Eng. Thierry J. Rios for the photos.'

Measurevients (mm):

holotype

paratype 1

paratype 2

paratype 3

length

24.4

27.2

21.6

24.6

width

12.1

12.2

12..5

12.0

length of width of

aperture aperture

13.1 3.3

14..5 3.8

14.5 3.1

14.2 3.4

This species is named after the wives of the

authors, Leda Rios and Luci Tostes.

LITERATURE CITED

Abbott, R. T. 1974. Am.erican Seashells. Van Nostrand

Reinhold Co., 663 pg., 24 color pL, 2nd ed.

Radwin, G. E. 1977. The Family Columbellidae in the West-

ern Atlantic, the Pyrenidae (part lib). The Veliqer 20(4)-

328-344.

Rios, E. C. 1975. Brazilian Mamie Mollusks Iconography.

Museu Oceanografico da Furg, 331 pg., 91 pi.

PHILLIP W. CLOVER

:OLLECTOR & DEALER IN

ifORLD WIDE SPECIMEN

iEA SHELLS p. o. Box 83

Glen Ellen, CA 9S442

O

FREE SHELL LISTS

SPECIALISTS IN

CYPRAEA. CONUS, VOLUTA

margineLla, Mif RA, MUREX

Specimen Shells

Offering microscopic and miniature (to '/. inch) shells

from the Florida Keys, with accurate locality data. Also

unsorted grunge: write for list.

Margaret Teskey

P.O. Box 273

Big Pine Key, Fl. 3301,3

180 THE NAUTILUS

October 29, 1981

Vol. 95(4)

ANODONTA SPECIES OF LAKE McCONAUGHY,

WESTERN NEBRASKA

Mark D. Baxa

School of Life Sciences

University of Nebraska

Lincoln, Nebraska 68588

ABSTRACT

This is the first report of bivalves from Lake McConaughy. the largest reservoir

in Nebraska. Two. or possibly three, species of the geyius Anodonta (Bivalvia,

Unionidae) were found live from fourteen sites, over an area of l.JtOO square

meters, in deaths ranging from three to five meters of water.

Lake McConaughy is formed by Kingsley

Dam, completed in 1941, across the North

Platte River in southwestern Nebraska. The

reservoir is located in Keith County, thirteen km

north of Ogallala, Nebraska, and thirty-six km

northwest of the Colorado-Nebraska state line,

at approximately 101° north longitude, and

41.5° west latitude. The lake is thirty-five km

long, six and a half km wide for some distance

above the dam, and is forty-six m deep near the

dam (Fig. 1). It has a shoreline of 170 km and a

surface area, when full, of 14,165 ha. Since the

dam was put into operation in 1941, Lake Mc-

Conaughy's greatest storage was in July of

1951, at 23.6 X 10** m^ and its lowest in October

of 1956 at 4.72 X 10« m^ (CNPPD, 1965b).

Lake McConaughy, Nebraska's largest reser-

voir, is the backbone of Central Nebraska Public

Power and Irrigation District, the state's largest

irrigation project. The primary purpose of this

reservoir is to supplement the irrigation needs

of the agricultural community below the dam;

consequently water levels fluctuate dramatically

throughout the year, with significant effects on

the fauna of the lake.

Comparative ecological studies on tempera-

ture, oxygen concentration, water chemistry,

and fluctuating water levels as factors influenc-

ing the fish population of Lake McConaughy

have been the focus of continuing studies by the

state's fishery department (Taylor, 1979). Little

work, if any, has been conducted in identifica-

LAKE McCONAUGHY

FIG. 1. Mii/i III Litki' Mi'CiDiiiiif/hn shinrhni irtili'r ili-plh ntnl ili:<lrihiitiiii) nf Cdllprliiin silc^. each

rcpri'sfiiliini II iiiir-liiuiilreil xijiinri' niiicr unilcrwnler ijuiulnil.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 181

tion or collection of the freshwater inverte-

brates which inhabit this reservoir. I have found

no mention in the literature of any malacological

studies conducted on the Lake McConaughy

reservoir, and, according to experts in this field,

little research has been carried out on this sub-

ject in the area of western Nebraska. This paper

is the first report on the collection and identifi-

cation of two species of unionacean clams con-

ducted in the McConaughy reservoir during

August of 1980.

MATERIALS AND METHODS

Fourteen collection sites were selected at

random within the reservoir (Fig. 1). Because of

the vast surface area of the lake, and depth of

the water, a small boat and scuba equipment

were utilized in collecting the specimens from

the lake substrate. Survey materials included

red survey flags, tape measures, compasses,

and depth gauges of U.S. Diver 100 meter ac-

curacy. At each site, one 10 x 10-meter quadrat

was established, with the survey flags placed at

one meter intervals to outline the 100 square

meter quadrat. The specimens were removed

and placed live in a tank aboard the boat, and

marked by collection site number. In excess of

thirty-five man-hours were spent searching the

lake bottom.

The specimens were taken to the Cedar Point

Biological Station, operated by the University of

Nebraska, located at Lake Keystone, Keith

County, to be identified and preserved for fur-

ther reference. The shells are now in the collec-

tion of Dr. D. H. Stansbery, Director of the

Museum of Zoology, Ohio State University, Col-

umbus.

For each specimen, a complete description of

the physical environment (i.e., relative turbid-

ity, depth, and composition of the substrate)

from which it was collected was recorded, as

well as the length and weight of each specimen.

From these records, the data was compiled by

collection site and species collected (Table 1). To

obtain further data on the numbers and habitats

of the unionacean clams, area divers were en-

listed to complete a modified data log of the

number of bivalves observed, location of the

observation, and composition of the substrate

where the bivalve was observed during routine

dives.

DISCUSSION AND RESULTS

Sixteen specimens were collected during this

study, all belonging to the genus Anodonta, a

unionacean clam common to North America.

The majority of the specimens were collected in

3 to 5 m of water, and none under 2 m. Most

were on a sand-silt substrate.

Specimens were identified by Dr. D. H. Stans-

bery, Ohio State University as^. imbecillis, A.

gratidis. and A. grandis dakota. They are

described below.

One specimen (MDB14) was found to be A. im-

becillis Say, 1829. It was 9.1 cm long, and was

collected in five meters of water (Figure 1). This

species is widespread from Mexico in the south-

west, throughout the central and lower Missis-

sippi River system, in Lake Erie, and tributaries

and in rivers (including impoundments) to the

Atlantic coast from Florida north to at least

Maryland. It is a member of the subgenus /Ano-

donta, the old world Anodonta species, as are

several other North American species (Burch,

1973).

The remaining 15 specimens belong to the A.

gr-andis Say, 1829, complex of the subgenus

Pyganodon. These are the new world ylworfow^a,

and a few species of this subgenus are found in

Asia. This species is common throughout the

Mississippi River basin, and most of the eastern

United States (Burch, 1973). Twelve of them are

A. grandis grandis Say, 1829.

Three of the larger bivalves taken from the

base of the dam (MDB8, MDB4, JEF15), were

identified as A. grandis dakota Frierson, 1910.

This clam is distinguished from A. grandis gran-

dis by a straw-colored periostracum, beaks (or

umbo) low, double-loop umbonal sculpture, ray-

less, no central swelling of the disc, and the

posterior extreme frequently being near the

base line (Frierson, 1910). It was described as a

new species from specimens found in Clear

Lake, Deuel County, South Dakota, 1909; Frier-

son reported A. grandis grandis from the same

lake. It is not known at this time whether A.

182 THE NAUTILUS

October 29, 1981

Vol. 95(4)

TABLE 1. Dislrihiitioti unit slulixlics i>J xpeciea colli'i-tcd nt Luke McConaughy. Keith County.

AVA;vi.sA'«.

grandis dakota is 1) a distinct species, or 2) a

subspecies of A. grandis, or 3) an environmental

form of A. grandis grandin (Stanshery, pers.

comm.). However, consistently finding both A.

g. grandis, and A. g. dakota in the same lake

argues against environmental forms, if one

assumes that conditions are uniform throughout

the reservoir. Note that although I found A. g.

grandis in some relatively shallow, fluctuating

environments, some were found in sites with A.

g. dakota; it is not likely that the environmental

conditions of MDBS and MDBS (Table 1, Fig. 1)

are appreciably different.

Lake McConaughy was formed in 1941 from

95(4)

October 29, 1981

THE NAUTILUS 183

the North Platte River (part of the Missouri

River drainage) and has been repeatedly

stocked with game fish from sources both in the

I'nited States and Canada by the Nebraska

Game and Parks commission (Nebraska Game,

Forestation, and Parks Commission, 1958-T9).

Since Anodonta spp. are known from the

eastern part of the Missouri drainage and

Wyoming, but may also be carried as parasitic

larvae by stocked fish (Pennak, 1958), it is im-

possible to determine the source of the clams.

Other lakes do not occur naturally along the

Platte, and the North Platte River formerly

went dry in late summer. Therefore, it seems

likely that Anodonta abundance has greatly in-

creased since the completion of Lake " Mc-

Conaughy. The presence of Ayiodonta in the

Sandhills Lakes northwest of Lake Mc-

Conaughy seems unlikely because of their

jnusual chemistry (McCarraher, 1977), and lack

3f outlets. I do predict their presence in com-

Darable reservoirs in the region (e.g. in Kansas

md Colorado).

The specimens ranged in length from 8 to 21

•m, with a live weight averaging 450 g. The dis-

;ribution was skewed to large clams; none under

\ cm were found. While this could indicate the

ibsence of small individuals from Lake Mc-

^onaughy, I believe it is due to the difficulty of

ocating small clams in the poor visibility of the

>ottom (usually under 3 m). The substrate of

.ake McConaughy is sand, but a thin layer of

ilt is found in the deeper waters toward the

am. 12 of the clams were found on the sand-

ilt; only 4 clams (A. g. grandis and A. im-

ecillis) were collected on sand-rock substrates

Fable 1).

Of the larger clams collected (MDB4, JEF6,

[DB8, JEF9) the majority were found in deeper

-aters located in the coves at the base of the

im (Fig. 1). This area should be the most stable

1 terms of water level fluctuations due to the

LCt that it is closer to the dam and should

lerefore maintain a higher, more constant level

" water.

No Anodonta individuals were found in depths

ss than 2 m, despite searching at least 400 m^.

his result is confirmed by area divers, who re-

ported seeing 70 additional clams, all in depths

of 3 to 5 m. Therefore, Anodonta appears to be

confined to the perimeter waters (3-5 m deep) of

this reservoir. Since the study was conducted in

August of the year in which the lake was high

until quite late in the season, it is likely that

these depths represent early summer level's, and

that minimum depths of perhaps slightly under

2 m are experienced at those sites only at lowest

storage. This suggests that Anodonta is uncom-

mon in the shallow (rarely 2 m deep for any ex-

tended period of time) North Platte River.'

No other mollusks were observed; presumably

they are rare or absent.

ACKNOWLEDGMENTS

I wish to thank Dr. K. Keeler for her support

and direction in this project; J. Ferguson, my

diving partner; Dr. D. H. Stansbery for identi-

fying specimens; and J. Palmer for editing and

tyT3ing this manuscript. A special thanks to the

Cedar Point Biological Station operated by the

University of Nebraska for the use of its

facilities and equipment during this project, and

especially to its Director, Dr. J. Janow, Jr.,' and

his wife, Karen, for the most memorable sum-

mer of my life.

LITERATURE CITED

Burch. J. B. 19T3. Biota of Freshwater Ecosystems. Identi-

fication Manual #11 Freshwater Unionacean Clams (Mol-

lusca: Pelecv-poda) of North America. U.S. Enmromnental

Protection Agency Publication. Washington, D.C.

Central Nebraska Public Power. 1965a. Central Nebraska

District, Lake McConaughy. Cevtral Public Power Dis-

trict Publication. North Platte, Ne.

Central Nebraska Public Power. 1965b. Statistics of the

Lake McConaughy Reser\'oir. Central Public Power Dis-

trict Publication. North Platte. Ne.

Frierson, L. S. 1910. Description of a new species of Ano-

donta. The Nautilus 23(9):113-114.

McCarraher. D. B. 1977. Nebraska's sandhills lakes. Ne-

braska Game and Parks Commission, Lincoln, Ne.

Nebraska Game, Forestation, and Parks Commission. Fish

Stock- Pu'corck. 1958-1979. North Platte Regional Office

North Platte, Nebraska.

Pennak, W. 1958. Study of Freshwater Invertebrates. Uni-

versity of Colorado Press, Denver.

Taylor. M. W. 1979. Modelling the influence of eutrophica-

tion on the cold-water fishen,' habitat of Lake Mc-

Conaughy, a "two-story" reservoir. Nebraska Game and

Parks Commission Publication. Lincoln, Ne.

184 THE NAUTILUS

October 29, 1981

Vol. 95(4)

PROTANDRY WITH ONLY ONE SEX CHANGE IN AN

EPITONIUM (PTENOGLOSSA)

Robert Robertson

Academy of Natural Sciences

Nineteenth and the Parkway

Philadelphia, PA 19103

ABSTRACT

KefHirts conflict on whether ptenoglossam'i undergo more than one sex change,

although since 1926 they were always reported (with few supporting data) to be

protandric. Small individuals of the West Indian wentletrap Epitonium albidum

(Orbigny, lBi2) (shell length <8 mm) were found, to be males (with spermato-

zeugmata in their gonads), and large individuals (shell length >7 mm) were

females (with oocytes and ova). Hermaphroditic individuals ranged in shell length

from 5 to 8 mm.. The data support the idea ofprotandry with only one sex change

in E. albidum. Males and females attain larger sizes in the British Virgin Islands

than at Barbados.

The Epitoniidae ( = "Scalariidae" or "Scalidae")

and Janthinidae, two ptenoglossan families,

have at various times been considered to have

separate sexes, or to be simultaneous herma-

phrodites or to be protandric hermaphrodites.

Cuvier (1808:129) believed that the sexes are

separate in Janthina. but Quoy and Gaimard

(1832:247) believed Janthina to be her-

maphroditic. Pruvot-Fol (1925), who studied

histologic sections of two Janthina animals.

thought that they are simultaneous hermaphro-

dites and that they possibly self-fertilize.

Ankel (1926:196) stated that "Scala" [ = Epito-

nium] and Janthina are protandric. The meager

data published subsequently (Table 1) support

this conclusion, but there is disagreement on

whether there is more than one sex change.

Fretter and Graham (1962:377-378) summa-

rized the situation well.

Ankel (1936:149) stated that in "Scala"! = Epi-

TABLE 1. Authors since Ankel (1926) who have coticluded that pteyioglossans are protandric.

Author

Species studied^

Only one

sex change

More than one

sex change

Ankel, 1930:

496-502, fig. 3

Ankel, 1936:

149-150, fig. 128

Laursen, 1953: 8-14

(Jraham, 1954

Bulnheim, 1962:

302-304

Bulnheim, 1968:

234

Breyer, 1980

Robertson, 1981

Robertson, this paper

Janthijui pallida

Epitonium ctathrus

Janth ma spp.

J(Uilhin(i janthina

Upalia funiculata

Efiiton I N ni linctuni

Epitonium liiiclutn

Epitonium millecostntum

Epilon ium albidum

+

'Nomenclature ijroughl up-to-date.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 185

toninmj clathrus (Linn., 1758) there is sex rever-

sal accompanying each breeding season (it is not

stated when the breeding season occurs, or how

long the Epito7iium lives).

The purpose of this paper is to determine from

a large series of specimens whether the West In-

dian wentletrap Epitonium. albidum. (Orbigny,

1842) is protandric and whether it undergoes

more than one sex change.

MATERIALS AND METHODS

Epitonium. albidum. a symbiont with the ac-

tiniarian Stoichactiit heliunthus (Ellis and

Solander, 1786) (Robertson, 1963:52-53), was

studied at Virgin Gorda Feb.-Mar. 1972 and

Barbados Mar.-April 1980. The shell length of

each specimen was recorded, and the shell was

cracked or dissolved (in weak hydrochloric acid

or in Bouin's solution). Gonads were examined

with a Wild dissecting microscope at 50x . Sper-

matozeugmata (ciensely packed in the gonad, es-

pecially to the right of the stomach) and oocytes

and ova could readily be distinguished. Individ-

uals termed hermaphroditic had spermatozeug-

mata proximally in the gonads and oocytes and

ova distally.

RESULTS

The data are given in Fig. 1. Ninety-three in-

dividuals were sexed-39 from the British Vir-

gin Islands and 54 from Barbados. Fifty-three

animals, ranging in shell length from 1 to 8 mm,

were males, and twenty-nine animals, ranging

in length from 7 to 16 mm, were females. Eight

animals, ranging in length from 5 to 8 mm, were

hermaphrodites, and three additional animals,

ranging in length from 2 to 4 mm, were im-

mature. An animal 8 mm long was seen to shed

spermatozeugmata and was later sexed as a

female (it was categorized as a hermaphrodite).

The sex ratio was 59% male, 9% hermaphrodite

and 32% female.

The largest Barbados males were 6 mm long,

while the largest British Virgin Island males

were 8 mm long. British Virgin Island females

ranged up to 16 mm; one Barbados female was

14 mm, and the others were 11 mm or less in

length. (According to Clench and Turner (1951:

is-

14-

13-

12-

11-

10-

9-

8-

7-

6-

5-

4-

3-

2-

1-

0-

1-

0-

Mill .

; s 9 10

■ I ■

; I 9 10 n 12 13 14 IE I

5 S ; J mm

5 = 93

I

1 2 3 4 5 6 7 « mm

^. H immature

2 3 4 mm

SHELL LENGTh

FIG. 1. Shell lengths vf imninture. itiale, hi-nnaphriiclilp and

frmale itidiridiials (j/'Epitonium idbkiumj'rotii Barbadiis and

Iht' British \'irqtn Isliinds.

260-261), E. albidum attains a length of about

21.5 mm.)

CONCLUSIONS

The data given here on Epitonium albidum

support the concept that at least this species is

strictly protandric, that is, it first becomes male

and later becomes a female between shell

lengths of 5 and 8 mm. All the individuals longer

than 8 mm were females. There is no evidence

that these females ever change back into males.

The proximally (anteriorly) located spermato-

zeugmata of the hermaphroditic individuals in-

dicate that these were changing from the male

to the female phase and not vice versa.

The above conclusions are consonant with

those on Janthina by Ankel (1926, 1930) and

Graham (1954), and other species i)i Epitonium

by Breyer (1980) and Robertson (1981). The

statements by Ankel (1936) and Bulnheim (1962,

1968) about epitoniids alternating their sex

more than once require substantiation.

186 THE NAUTILUS

October 29, 1981

Vol. 95(4)

Male and female Epitnnium nlbidum attain

larger sizes in the British Virgin Islands than at

Barbados.

ACKNOWLEDGMENTS

I am grateful to Dr. Finn Sander, Director,

Bellairs Research Institute of McCJill University,

Barbados, for the provision of excellent facili-

ties. The following kindly criticized the manu-

script: Dr. George M. Davis and Virginia Orr

Maes.

LITERATURE CITED

Ankel, W. E. 1926. Sperrtiiozeugmenbildung durch

atypische (apyrene) und typische Spermien bei Scala

und Janthina. Verhandl. Deutsch. Zool. Gesellsch.. 31

Jnhresi-ersamml. Kiel, Zool. Anzeiger Supplhd. 2:

193-202.

1930. Die atypische Spermatogenese von Jan-

thina (Prosobranchia. Ptenoglossa). Zeitschr. Zellforsch.

mikroskop. Anal ll(3-4):49 1-608, pi. 6-7.

1936. Prosobranchia [in] G. Grimpe and E.

Wagler (eds.), Die Tierwelt der Nord- und Ostsee IX. bi,

Lief. 29:1-240. Leipzig, Al<ad. Verlagsgesellsch.

Breyer, A. 1980. Life history o( Epitonium tinctum (Proso-

branchia: Mesogastropoda). Western Sac. Malacol Ann.

Kept. 12:9.

Bulnhoim. H.-P. 1962. I'ntersuchungen zum Spermatozo-

endimorijhismus von Opalia rrenimarginata (Gastropoda,

Prosobranchia). Zfi^r/i?-. Zellforsch. 56(3):300-343.

1968. Atypische Sperniatozoenbildung bei Epi-

tonium tinctum: ein Beitrag zum Problem des Sperma-

tozoendimorphismus der Prosobranchia. Helgolander

iciss. Mn-resunters. 18:232-253.

Clench, W. .J. and R. D. Turner. 19.51. The gemis. Epitonium

in the western Atlantic; part I. Johnsonia 2(30):249-288.

Cuvier, G. [L.C.F.D.] 1808. Memoire sur la Janthine et

sur la Phasianelle de M. Lamarck. Ann. Mus. Hist. Nat.

[Paris] 11:121-135. pi. 11.

Fretter, V. and A. Graham. 1962. British prosobranch

molluscs; their functional anatomy and ecology. London,

Ray Soc, xvi + 755 p.

Graham, .\. 1954. Some observations on the reproductive

tract of lanthina [sic] janthina (L.). Proc. Malacol. Soc.

London 31(l):l-6.

Laursen, D. 1953. The genus lanthina [sic]; a monograph.

Dana- Kept. 38:1-40, pi. 1.

Pruvot-Fol, A. 1925. Contributions a I'etude du genre Jan-

thina Bolten. Comptes Rendus Acad. Sci. [Paris] 181(1):

56-57.

Quoy, [J.R.C.] and [J.P.] Gaimard. 1832. Voyage de . . .

t'Asfrolale . . . Zoologte 2:1-320. Paris, Tastu.

Robertson, R. 1963. Wentletraps (Epitoniidae) feeding on

sea anemones and corals. Proc. Malacol. Soc. London

35:51-63, pi. 5-7.

1981 ("1980"). Epitonium millecostatum and

Coralliophila clathrata: two prosobranch gastropods sym-

biotic with Indo-Pacific Palythoa (Coelenterata: Zoanthi-

dae). Pacific Sci. 34(1):1-17.

CHICOREUS (CHICOMUREX) TURSCHI,

A NEW MURICIDAE FROM NEW GUINEA

Roland Houart

St. Jobsstraat, 8

B-3330 Ezemaal

Belgium

Chicoreus (Chicomurex) turschi n, sp.

(Figs. 1-6)

Description: Shell small for the subgenus,

solid, size variable, from 28 to 40 mm in adult

specimens. Spire moderately high. Color gener-

ally cream with 3 brown bands on varices of the

last whorl; the first one immediately under the

shoulder of the body whorl, the third one on the

lower part of the varices, the second one situ-

ated between these two, generally closer to the

(see opposite page)

FIGS. 1-9. 1 and 2, Chicoreus (Chicomurex) turschi R. Houart sp. nov. Holotype LR.S.N.B. no. 37U. 30 mm. 3. Paratype. R.

Houart collection, 29 mm. 4, Paratype LR.S.N.B. no. 375, 2U.2 mm. 5, Protoconch and first whorls (same specimen as fig. J,). 6,

Protoconch and first whorl. 7, Chicoreus (Chicomurex) venustulus fle/w/*?- & Wilson, 1975. Holotype USNM 70721,1, x2. 8,Pro-

toconch and first vhorU. Paratype U.S.N.M. 7072J,5, xlO. 9, Reproduction of protoconch after figure 8.

Vol. 95(4)

October 29, 1981

THE NAUTILUS IS';

188 THE NAUTILUS

October 29, 1981

Vol. 95(4)

third one. These brown bands sometimes ex-

tended on to the body whorl; coloration some-

times present on the first whorls but almost m-

visible. Brown s})ots most apparent on the su-

ture of the whorls. Completely orange or albmo

examples known.

Aperture bluish white and oval, slightly

angular; anal notch well-delimited; columellar

lip adherent to the shell posteriorly and de-

tached below; 3 or 4 little denticles on the

anterior end and many fine folds on the poste-

rior end with a more apparent denticle, delimit-

ing the anal notch; color white. Outer apertural

lip finely crenulated; interior of the outer lip en-

tirely spirally ridged. Operculum muricine with

an apical nucleus.

Spire consisting of one and one-half nuclear

whorl, glossv and smooth and 6 or 7 postnuclear

whorls. From the first whorl 3 varices and 3 or 4

axial costae, changing on the last whorl to one

very prominent axial node and a smaller second-

ary one. . .

Spiral sculpture of body whorl consisting ot /

or 8 principal ridges; generally not too scabrous

and flanked on each side by 1 or 2 finer and

scabrous cords. A fine spiral cord also situated

between these ridges. These ridges extended on

to the varices, very scabrous especially on the

adapertural side where there are crowded

lamellae. On the varices, spiral ridges producing

short open spines, slightly recurved and most

visible on the body whorl. These spines are

longest on the shoulder and on anterior part of

the last whorl where they are flanged. Siphonal

canal open, moderately long for the subgenus

and slightly recurved on the end; ornamented

with 3 or 4" ridges, producing short open spines,

slightly posteriorly recurved. Holotype 30 mm

in length; 16 mm in width.

Type malenal: Holotype (in the Institut Royal

desSciences Naturelles de Belgique in Brussels)

I. R.S.N. B. no. 374; 3 paratypes I.R.S.N.B. no.

375; 2 paratypes Brit. Mus. (N.H.) 198089; 2

paratypes Amer. Mus. Nat. Hist. 19r,023 &

196024; 2 paratypes United States Nat. Mus.

784589; 2 paratypes Houart collection. All from

the type locality.

Type loralUy: Haiisa bay, Papua New Guinea,

off Durangit, - 45/60 m, with sponges. Para-

types also from Rabaul, Papua New Guinea.

This shell may be compared with Chicmmrex

venustulm Rehder & Wilson. Three important

differences separate them:

1) Ch. turHchi has a much more fusiform shell,

much more slender, and, in most cases, smaller.

2) Ch. vemLstulits has a conical carinate proto-

conch consisting of three and one-half whorls.

Ch. turschi has a convex protoconch, glossy and

smooth, consisting of one and one-half whorl

and never carinate.

3) Ch. venustulus has stronger lirations on the

columellar lip. Ch. turschi always has a smooth

columellar lip, except for the fine posterior folds

and 2 or 3 anteriorly denticles.

The color, if not important, also separates the

two species: rose or orange in Ch. immstulus:

brown and white in Ch. turschi (somewhat as in

Naquetia) although the latter may be rarely

solid orange or albino.

It is a great pleasure to name this shell in

honor of Professor Ben Tursch who so kindly let

me examine all the specimens of this new

species and other members of the family

Muricidae.

ACKNOWLEDGMENTS

I wish to thank, of course, Prof. B. Tursch but

also Dr. Harald A. Rehder of the National

Museum of Natural History, Washington, who

sent me a reprint of his paper concerning Ch.

venustulus and some photographs which are

here illustrated. I am also grateful to Mr. G.

Poppe of Mortsel, Belgium, for some photo-

graphs, and to Dr. Emily Yokes, Tulane Univer-

sity, who revised and commented upon the

manuscript.

LITERATURE CITED

Fair, R. H. 1976, The Murex Book. An illustrated catalogue

' uftlw Recent Muncidne (Muricinae. Muricopsinae, Ocene-

I'.rinae) 138 pp, 23 pi,

Radwin, G. E. and D'Attilio, A, 1976. Murex shells of the

World. An Illustrated Guide to the Muricidae, pp. 1-284,

Rehder' H A an<l Wilson, B, R. 197.S, New Species of Ma-

rine Mollusks from Pitcairn Island and the Marquesas.

Smiths. Contr. to Zool. 203:1-16.

Yokes, K, H, 1971, Catalo^fue of the genus Murex Linne

(Mol'lusca: Gastropoda): Muricinae, Ocenebrinae. Bull.

.■\mer. Pat. 61(26S):1-141.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 189

LAMINOPLAX, A NEW GENUS OF CHITONS AND THE TAXONOMIC

POSITION OF HANLEYA DALLI KAAS, 1957

(POLYPLACOPHORA: AFOSSOCHITONIDAE).

Antonio J. Ferreira, M.D.

2060 Clarmar Way

San Jose, California 95128

ABSTRACT

The examination of the holotype o/ Hanleya dalli Kaas. 1957 [new name for

Lepidopleurus carinatus Dall, 1927 (not Leach. 1852)] revealed that this species,

with its elongated body, thick valves, granulo-ve7-7nicular tegmentum, spiculoid

girdle, posterior gills, and well-developed, unslit insertion plates in all valves

belongs in th^ family Afossochitonidae. A new genus, Laminoplax, is proposed to

accommodate the species. Laminoplax dalli is known only from the type material,

off Eastport. Maine.

In 1927 Dall described, but did not illustrate, a

new species of chiton, Lepidopleurus carinatus.

based on material from Eastport, Maine. In

1957 Kaas pointed out that Dall's name had been

preoccupied by Leach (1852), and proposed the

name Hanleya dalli for the taxon. In the course

of a review of the family Lepidopleuridae (Fer-

reira, 1979), I have had the opportunity to ex-

amine the holotype, and only known specimen,

of this taxon. The purpose of this paper is to

redescribe and illustrate this species, reassign it

to a different family and a new genus, and to

discuss the classification of the Lepidopleurina.

The holotype and other comparative material

were made available through the courtesy of Dr.

Joseph Rosewater, National Museum of Natural

History, Washington, D.C. [USNM].

System atic Trea. t men t

POLYPLAC(^PHORA Blainville, 1816

Order Neoloricata Bergenhayn, 1955

Suborder Lepidopleurina Thiele, 1910

Defiyiition: Valves without insertion plates, or

with insertion plates without slits (Van Belle,

1975:135).

Remarks: In the classification of chitons, arti-

culamental features, and, in particular, the

presence or absence of insertion plates and slits

have been considered characters of fundamental

importance (Pilsbry, 1892-1894; Knorre, 1925;

Ashby, 1929; Thiele, 1929; Bergenhayn, 1955;

Smith, 1960; Van Belle, 1975-1978). Thus, the

orders Paleoloricata Bergenhayn, 1955, and

Neoloricata Bergenhayn, 1955, were defined,

respectively, by the absence or presence of

sutural laminae in the articulamentum. The

Lepidopleurina, generally recognized as the

most primitive of Recent chitons [present since

the Ordovician], has been divided, on the basis of

the insertion plates, into four families (Van

Belle, 1975): Lepidopleuridae Pilsbry, 1892 (all

valves devoid of insertion plates), Protochitoni-

dae Ashby, 1925 (insertion plates absent in the

end valves but present, although unslit, in the

intermediate valves), Hanleyidae Bergenhayn,

1955 (unslit insertion plate present in front

valve, but absent, or only vestigial, in posterior

valve; intermediate valves without insertion

plates), and Afossochitonidae Ashby, 1925

(unslit insertion plates present in all valves).

Afossochitonidae Ashby, 1925

Definition: Unslit insertion plates present in

all valves (Van Belle, 1975:147).

Type genus: Afossochiton Ashby, 1925 (Type

species: Afossochiton cvdmorei Ashby, 1925

[fossil, Oligocene], by original designation).

Remarks: Ashby (1925) established the taxon

Afossochitoninae as a subfamily of Acanthochi-

tonidae Pilsbry, 1893 [erroneously attributed to

190 THE NAUTILUS

October 29, 1981

Vol. 95(4)

Hedley, 1916], with a single genus, Afossochiton

Ashby, 1925, and two fossil species, A. cudmorei

Ashby, 1925, and A. rustratiin (Ashby & Tore.

1901), of the Oligocene of Victoria, Australia.

Bergenhayn (1955) considered the taxon Afosso-

chitonina as one of the four suborders in his

Neoloricata, in view of its lepidopleurid con-

figuration, achantochitonid sculpture, and an

articuiamentum represented only by sutural

plates (Bergenhayn, op. cit., pp. 38-40). Smith

(1960) adopted the same interpretation. How-

ever, Bergenhayn's view was incorrect. As Van

Beile (1975) pointed out, Ashby (1925) did

describe insertion plates in the intermediate

valves of the type species, Afossochiton cud-

morei. in addition to the fact that, later, the

description of several other species of Afosa-)-

chiton by Ashby & Cotton (1939) [A. sulci, A.

dendus. A. iscusi. and A. magnicostatus] left no

doubt about the presence of insertion plates in

all valves of the specimens under consideration.

Thus, Van Belle (1975:143) concluded that

"Bergenhayn's [and Smith's] position is unten-

able", and that Afossochitonidae should he

classified in the Lepidopleurina.

The definition of Afossochitonidae contains no

statement concerning the gills, three of the

genera being known only as fossils, and the only

member of Churiplax. C. grayi (Adams &

Angas, 1864), known only from the type speci-

men [and another questionable one reported by

Ashby (1921)], has been cited only a few times in

the literature (Adams & Angas, 1864:194; 1865:

pit. 11, figs. 16, 17; Angas, 1867:222; Pilsbry,

1893:21-22, pit. 6, figs. 9-11, with notes from

Carpenter's unpublished manuscript; Ashby,

1921:136-142, pit. 9; Iredale & Hufl,

1925:99-100, pit. 11, figs. 24-28) with no men-

tion of the gills. It is worth noting that although

Ashby (1921) placed Choriplax in the Acantho-

chitonidae, Pilsbry (1893), Thiele (1910), Smith

(1960), and Van Belle (1975) allocated it to the

Lepidopleurina.

In the Afossochitonidae, Van Belle (op. cit.)

recognized four genera: Glyptochiton Koninck,

1883 [Carboniferous], Afossochiton Ashby, 1925

[Oligocene-Fiiocene], Lirachiton Ashby & Cot-

ton, 1939 [Pliocene], and Choriplax Pilsbry,

1894 [Recent].

Laminoplax Ferreira gen. nov.

Definition: Elongated, carinated chitons, with

thick valves. Obsolete lateral areas. Tegmentum

with granulo-vermicular sculpture. Girdle

covered with spiculoid processes. Gills posterior.

Articuiamentum with slitless insertion plates in

all valves.

Type species: Hanleya dalli Kaas, 1957 [new

name for Lepidopleurus carinatus Dall, 1927

(not Leach, 1852)] by original designation,

herein.

Laminoplax dalli (Kaas, 1957)

(Figs. 1-6)

Synonymy:

Hanleya dalli Kaas, 1957:83

Lepidi>pleurun carinatus Dall. 1927:11 (non Leach, 1847,

male name; non Leach, 18.52).

Type locality: Eastport, Maine [44° 54' N,

67°b0' W]. Holotype: (USNM 225149).

Original description: "Shell rather large . . .

yellowish white, densely covered with minute

pustules which are obscurely arranged concen-

trically to the mucro of the posterior valve,

radially on the anterior valve and longitudinally

on the intermediate valves; back subcarinate,

the angle about 70°; eaves projecting, the inser-

tion plates of the terminal valves not split but

radially rugose, of the intermediate valves en-

tire; girdle narrow, densely pilose, with ex-

tremely fine close minute spinules, with alter-

nating darker and lighter patches; central, jugal

and lateral areas not defined; length in dry,

curved condition about 35, diameter 9; height,

12 mm." (Dall, 1927:11).

Expanded Description: The holotype of

Lepidoplen7~iis carinatus Dall, 1927 (USNM

225149) is accompanied by a museum label

which reads "Eastport / type / 1870 / Maine /

Verrill," with question marks pencilled in by

unknown hand after the words "Eastport" and

"Maine." Specimen preserved dry, tightly

curled; all valves broken, mostly longitudinally,

with loose fragments of valves i, ii, iv, and v.

Uniform cream color. Strongly carinate. Lateral

areas obsoletely defined; tegmentum sculptured

with vermicular, low profile rugosities disposed

longitudinally in central areas, concentrically in

valve i, postmucro area of valve viii, and lateral

areas of intermediate valves (Figure 1). Valves

Vol. 95(4)

October 29, 1981

THE NAUTILUS 191

Fl(j. 1. Holutype y/ Lamir.oplax dalli iKans. i:i:>7). ChiKe-uii

oj valves vi and vii to show tegmental sculpture.

remarkably heavy, up to 800 y^m in thickness on

valve iii. Insertion plates well developed in the

anterior and intermediate valves, but limited to

a ridge in the posterior valve (Figure 2), without

slits or teeth, but with tluted rugosities on the

outer surface (Figure 3). Sutural laminae rela-

tively large, separated by a well defined sinus.

Girdle pilose in appearance, covered uniformly

with juxtaposed spicules (Figure 4), mostly

straight, many broken (Figure 5) measuring up

to 400 piva in length, 30 yun in thickness; under-

surface covered with imbricated, tlat, trans-

parent, lanceolate scales, about 120x15 ]xm in

dimentions (Figure 6). Gills short, posterior.

Radula, still in place, not examined.

Remarks: Laminoplax dalli is known only

from the tj'pe specimen. Although Dall (1927) in-

Uj. 2. Holotype o/' Laminoplax dalli iKaas. 1957). Close-up

I posterior valve to show (arrow) side vie^v of insertion

•lute, here limited to a ridge.

FIG, 3. Holotype o/ Laminciplax dalli /A'rm.s. ;■/.•],-;. Clusi-uji

of fragment of anterior valve to .s/xi/r tegmental sralptun.

and insertion j)late with its Jhited rugosities.

_i 10 mi

FIG. 4. Holotype o/ Laminoplax dalli iKans. iy.',7). Girdle

spicules at junction of ptatet;.

100 M.^

FIG. 5. Holotype of Laminoplax dalli lKaa.s. 19571. Girdle

fragment to show spicules, mostly broken, reduced to stumps

only.

192 THE NAUTILUS

October 29, 1981

Vol. 95(4)

100 ^m

FIG. 6. Holotype o/Laminoplax ilalii iKaas. 1H57I. Scales on

the undprs'urface of the qirdle.

dicated that more specimens of the species were

available to him from Maine and Georges Banks,

none were found. Three lots labelled "Lepido-

pleurus carinatus Dall" in the collections of the

National Museum of Natural History, Washing-

ton, D.C. (USNM 10757; USNM 103477; USNM

34448), examined on a loan arranged through

the kindness of Dr. Joseph Rosewater, proved to

be misidentifications; no specimens so labelled

were found in the Museum of Comparative

Zoology, Harvard University, Cambridge,

Massachussetts (Dr. Kenneth J. Boss, in litf., 22

October 1979). There remains, also, some ques-

tion about the depth at which the single

specimen of Lamlnoplax iialli was collected.

Dall (1927) did not include it in the original

description of the species except for the am-

biguous statement that "others" were found in

12 fathoms [22 m]; the accompanying museum

label gives no indication of depth, either [the

figure "1870" on the original label likely refers to

the date of the collection, not to the depth].

In general shape, tegmental sculpture, girdle

elements, and posterior gills, Ldminiijihix dulU

is undoubtedly in the suborder Lepidopleurina.

Despite assigning it to Lepidopleurus. Dall

(1927:11) regarded the species as "intermediate

between Lcjiidnpleurus and Hanlcya." Ap-

parently based on this statement and Dull's

description, and without examining the ty})e

material, Kaas (1957) assigned dalli to the

genus Hanleya, instead. However, neither Dall's

(1927) nor Kaas' (1957) generic assignment is

correct. Present understanding of these two

genera [Lepidopleut'us having no insertion

plates; Hanleya having insertion plates in the

terminal valves but not in the intermediate

valves] indicates that dal.li, for the presence of

slitless insertion plates in all valves, belongs in

the Afossochitonidae, in a new genus, Lamino-

plax, here proposed.

ACKNOWLEDGMENTS

I wish to express my appreciation to Dr.

Joseph Rosewater, National Museum of Natural

History, Washington, D.C, Dr. Kenneth J.

Boss, Museum of Comparative Zoology, Har-

vard University, Cambridge, Massachusetts,

and Drs. Peter U. Rodda and Barry Roth,

California Academy of Sciences, San Francisco,

California, who generously helped me in several

phases of this work. Credit is also due to Bar-

bara Weitbrecht, California Academy of

Sciences, for assistance with the drawings.

LITERATURE CITED

Adams, Henry and G. F. Angas. 1864. Descriptions of new

genera and species of Chitonidae from the Australian

Seas, in the collection of George French Angas. Proc.

Zoo/. Soc. London, pp. 192-194; 1865. Proc. Zool. Soc.

London, pi. 11, figs. 16-17.

Angas, George French. 1867. A list of species of marine

Mollusca found in Port .Jackson Harbour, New South

Wales, and on tlie adjacent coasts, with notes on their

hahit.s. etc. Pmc. Zool.. Soc. London, pp. 185-233.

Ashby, Edwin. 1921. The rediscovery of Ckoriplax( = Mirro-

plax) (jrnyi Adams and Angas (Order Polyplacophora)

with notes on its true place in natural systems and the

description of a new sub-species. Trans. & Proc. Roy.

Soc. So. Auslriilia 45:1.36-142, pi. 9.

1925. Monograph on Australian fossil Polypla-

cophora (Chitons). Proc. Roy. Soc. Viclorin 37(N.S., 2):

170-205. pis. 18-22.

1929. Taxonomic value of characters in the

Order Polyplacophora. Pror. Mnlaeol. Soc. London

18(4):1,59-16.1.

.•\shby. Edwin and Bernard (\ Cotton. 1939. New fossil

chitons from the Miocene and F^liocene of Victoria. Rec.

So. .Au.-ilralmri A/«.s-. 6(3):209-242. pis. 19-21.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 193

Ashby. Edwin and W. G. Tcirr. 1901. F'ossil Pdlyplacophora

from Eocene beds of Muddy Creek. Moriiin^mi (Schnap-

per Point) and Moorabool, Victoria, with definitions of

nine new species, and notes on others. Trans. Roy. Soc.

So. Australia 25:136-144. pi. 4.

Bergenhayn. J. R. M. 1955. Die fossilen schwedischen lori-

eaten nebst einer vorlaiifigen revision des systems der

ganzen klasse Loricata. Lunds Universitets Arsskrift.

N.F. Avd. 2, vol. 5, no. 8, Kungl. Fysiografiska SalLskapets

Handl. N.F.. 66(8):3-42, 2 tables."

Blainville, H. M., Ducrotay de 1816-1830. Vers et Zoo-

phytes. In: Dictionnaire des sciences naturelles. Ft. 2.

Regiie organise. Paris, (not seen).

Dall, William H. 1927. Diagnoses of Undescribed New-

Species of Mollusks in the Collection of the United States

National Museum. Prop. U.S. Nat. Mus. 70(no. 2668):l-n.

Iredale, Tom and A. F. Basset Hull. 1925. A monograph of

the Australian Loricates (Phylum Mollusca - Order Lori-

cata). Australian Zool.. 4(2):75-lll. pis. 9-12. Reprinted:

1927. Roy. Zool. Soc. New So. Wales, pp. i-xiii, 1-168,

frontis. & pis. 1-21, text figs. 1-4.

Kaas, Piet. 1957. Notes on Loricata. 5. On some preoccupied

names. Basieria 21:83-87.

Kjiorre, Heinrich Von. 1925. Die Schale und die Rucken-

sinnesorgane von Trachydermon iChiton) ciriereus L. und

die ceylonischen Chitimen der Sammlung Plate. (Fauna

et Anatomia ceylonica, IH, Nr. 3) .Jena. Zeitschr. Natur-

viss.. 61 (n. ser., vol. ,54):469-632. pis. 18-35. figs. 1-17.

Koninck, L. G. de. 1883. Faune du Calcaire Carbonifere

de la Belgique. Chitonidae. Ann. jV/«.s-. Roy. Hisf. Nal.

Bely. 8:198-213, pis. 5()-.53.

Leach, William Elford. 1852. Molluscorum Britanniae

Synopsis. A synopsis of the Mollusca of Great Britain

arranged according to their natural affinities and anatomi-

cal structure. L-ondon. 376 pp., 13 pis,

Pilsbry, Henry Augustus. 1892-1894. Polyplacophora. In:

Manual of Conchology (G. W. Tryon, Jr., ed.). 14:i-xxxiv +

1-350, pis. 1-68: 1.5:1-132, pls."l-10.

1894a. Notices of new chitons, HL The Naittilus

7(12):138-139.

Smith, Allyn Goodwin. 1960. Amphineura. In: Treatise on

Invertebrate Paleontology (R. C. Moore, ed.). Part I,

Mollusca 1, pp. 47-76, figs. 31-45.

Thiele, Johannes. 1909-1910. Revision des Systems der

Chitonen. Stuttgart. 132 pp., 10 pis.

1929. Handbuch der systematischen Weichtier-

kunde. Loricata: l(l):l-22, figs. 1-22. Jena.

Van Belle, Richard A. 1975. Sur la classification des Poly-

placophora: H. Classification systematique des Lepido-

pleurina (Neoloricata) avec la description des Helmintho-

chitoninae. nov. subfam. (Lepidopleuridae) et de Meso-

chiton nov. gen. (Helminthochitoninae). Inform. Soc.

Beige Malacol. 4(6): 133- 145, 3 pis.

1978. Sur la classification des Polyplacophora:

Vn. Errata, additions et rectifications. Resume de la

classification. Index alphabetique. Inform. Soc. Beige

Malacol. 6(3):6.5-82.

FRESHWATER SNAILS OF THE SENEGAL

RIVER BASIN, WEST AFRICA^

Emile A. Malek and Jean-Paul Chaine

Department of Tropical Medicine and International

Health Program, Tulane University School of Public Health

and Tropical Medicine, New Orleans, LA 70112

The Senegal River is the second largest river

in West Africa. Its river system is about 1,800

kilometers long and drains an area of about

290,000 square kilometers. The Senegal River is

formed by the union of the Bafing and Bakoye

'This study was carried out for the United States Agency for

International Development, the State Department, and 0.

M. V. S., Dakar, through a contract with Gannett Fleming

Corddry and Carpenter, Harrisburg, Pennsylvania. It is a

part of a study on Assessment of Environmental Effects of

Proposed Developments in the Senegal River Basin. Our

thanks are due to Dr. Max Miller for encouragement.

rivers at the town of Bafoulabe, about 1,060

kilometers u{istreani fmni the Atlantic Ocean.

These two rivers, along with the Faleme River,

supply almost all the flow entering the Senegal

River.

This study on the freshwater snails of the

Senegal River basin was carried out to assess

the situation before two dams are built. One

dam, an antisalt dam about 80 km upstream of

Saint-Louis at the village of Diama, and a high

flow regulatory dam at Manantali in Mali. The

194 THE NAUTILUS

October 29. 1981

Vol. 95(4)

Diama dam wil! create an impoundment of 235

square km and the Manantali dam an impound-

ment with a surface area of 477 square l<m.

Rainfall within the Senegal River basin is

highly seasonal. In the southern part of the

basin, there is a short dry period and the

heaviest rains occuring between May and Oc-

tober. In the central and northern parts of the

basin the rainfall is generally of the short dura-

tion, high intensity type. Rainfall in this area

normally falls between July and September.

Reports on the snail fauna of the Senegal

River have been few and have mainly included

the bulinid and biomphalarid hosts of schistoso-

miasis. A brief reference was made to some of

these hosts by Leger (1923) and by Lefron

(1933). More information was given by Lariviere

et ai. (1963). Deschiens (1951) and Gaud (1955)

lumped the bulinid hosts and referred to them as

groups. Marill (1961), in his snail surveys in

Mauritania, considered the Senegal River as the

main source of spread of the snail hosts into

various types of waterbodies supplied by the

river water. Wright (1956, 1957) included Gam-

bia in his reports, discussed the morphology of

various bulinid snails in Senegambia and gave a

key for their differentiation.

Mandahl-Barth (1958) treated the African

snail hosts of schistosomiasis and included some

West African species. Sellin et al. (1980) in their

studies on the distribution of the snail in-

termediate hosts of schistosomiasis in West

Africa, included Mali only in the Senegal River

basin. They stated that they collected Bulinus

globosus, B. jousseaumei and B. senegalensis in

the Yanfolila region. The freshwater snails of

Africa were treated comprehensively by Brown

(1980). However, it is obvious that only a few

species from the Senegal River basin were dealt

with by Brown, on account of the scarcity of

material from that part of Africa.

Field studies in the Senegal River basin were

conducted by us during three, 1-month visits in

1977-1978 and a 2-week period in January 1979.

Moreover, the junior author carried out an

18-month longitudinal study, the quantitative

results of which will be published elsewhere.

FIG. 1. Senegal River basin encompassing parts of Senegal, Mali and Mauritania.

Vol. 95(4)

October 29, 1981

THE NAUTILUS 195

RESULTS

The following snails were collected during the

surveys. They are arranged by families and the

localities where they were collected are indi-

cated (also see Figure 1).

Family Planorbidae

Bulinus (Bulinus) guernei

(Dautzenberg, 1890)

Senegal: Lac de Guiers northern west tip at

Pach; Lac de Guiers at N'Gnit village; tem-

porary pond near Bokogawe, 48 km west of

Matam; Irrigation canal, Guede Chantier rice

plantation; Irrigation canals at Richard Toll,

sugar-cane plantation; Dakar Bango, cement-

lined canal for Saint Louis water supply; Irriga-

tion canals leading to Kassak Sud; Large ponds

on both sides of the road at Savoigne; Large

pond, 6 km south of dam site at Diama; Lampsar

Marigot at Lampsar and at Makhana; Large

swamp under bridge near Matam.

Mali: Tributary of Bafing river about 63 km

north of dam site at Manantali; Large pond at

Medina, about 30 km southeast of dam site at

Manantali; Senegal River at Moussa Gouya vil-

lage, 25 km southeast of Kayes.

Mauritania: Reservoir at Dionaba dam site in

the Brakna region.

Bulinus (Bulinus) senegalensis Miiller, 1781

Senegal: Pond near abattoir, Matam; pond at

edge of Matam; laterite ponds at Ourossogui air-

field.

Bulinus (Bulinus) forskalii (Ehrenberg, 1831)

Senegal: Irrigation canals, Guede Chantier

rice plantation; Irrigation canals, Richard Toll

sugar-cane plantation; Lac de Guiers at several

sites on east and west sides; Ponds at both sides

of road at Savoigne; Pond about 6 km south of

dam site at Diama; Lampsar Marigot at Lamp-

sar and Makhana; Irrigation canals, Dagana rice

plantation, about 20 km east of Richard Toll.

Mali: Pond at Medina about 30 km southeast

of dam site at Manantali; Tributary of Bafing

river about 63 km north of site at Manantali.

Mauritania: Rice plantation and pond near

Rosso.

Bulinus (Physopsis)

jousseaumei (Dautzenberg, 1890)

Senegal: Lampsar Marigot at Lampsar and

Makhana

Bulinus (Physopsis) globosus (Morelet, 1866)

Mali: Pond at Medina, about 30 km southeast

of dam site at Manantali.

Senegal: Small flood plain between Matam and

Ourossoqui.

Mauritania: Reservoir at Choggar Sud-dam-

site, Brakna region.

Afrogyrus coretus (Blainville, 1826)

Senegal: Lac de Guiers at several sites on both

sides; Swamp at Pahk village; Irrigation canals

at Dagana rice plantation; Lampsar Marigot at

Lampsar.

Gyraulus costulatus (Krauss, 1844)

Mali: Tributary of Bafing river, about 63 km

north of dam site at Manantali; Senegal River at

Moussa Gouya, 25 km southeast of Kayes.

Biomphalaria pfeifferi (Krauss, 1844)

Senegal: Cement-lined canal, Dakar Bango,

Saint Louis water supply; Large swamp on the

side of Lac de Guiers near pumping station,

Dakar water system; Swamp at Pahk village.

Family Lymnaeidae

Lymnaea natalensis Krauss, 1848

Senegal: Cement-lined canal Dakar Bango,

Saint Louis water supply; Lampsar Marigot at

Makhana; Large swamp on the side of Lac de

Guiers, near pumping station, Dakar water

system.

Mali: Large swamp at Medina, about 30 km

southeast of dam site at Manantali.

Family Ancylidae

Ferrissia chudeaui Germain, 1917

Senegal: Lampsar Marigot at Makhana;

Swamp at Pahk village.

Family Thiaridae

Thiara (Melanpides) tuberculata

(Miiller, 1774)

Senegal: Dakar-Bango, Cement lined canal for

196 THE NAUTILUS

October 29, 19S1

Vol. 95(4)

Saint Louis water supply; Lampsar Marigot at

Lampsar; Lac de Guiers at several sites on both

sides; Irrigation canals, Richard Toll sugar-cane

plantation.

Mali: Bafing river at bridge, Mehina.

Cleopatra bulimoides senegalensis

(Morelet, 1860)

Senegal: Large swamp under bridge, near

Matam, Lampsar Marigot at Savoigne; Irriga-

tion canals, Kassak Sud.

Mali: Tributary of Bafing river, about 63 km

north of dam site at Manantali; Bafing river at

dam site at Manantali; Senegal river at Moussa

Gouya village, 25 km southeast of Kayes and in

an irrigation scheme at same village.

Family Viviparidae

Bellamya unicolor (Olivier, 1804)

Senegal: Lac de Guiers at several sites on both

sides; Irrigation canals in sugar-cane plantation,

Richard Toll.

Mali: Bafing river at bridge at Mehina and at

dam site at Manantali.

Family Potamididae

Tympanotonus fuscatus (Linnaeus, 1758)

This brackfish water species was collected

near Saint Louis, Senegal.

DISCUSSION

Several bulinid species have been described

from material obtained in the Senegal River

basin. BulinuH (Buliriiai) senegalensis is the type

species of the genus Bulinus. It was described

by 0. F. Miiller in 1781 as Bulinus sei-iegalenais

and its type locality is Podor, Senegal. It is a

new name for "Le Bulin" Adanson, 1757.

Bulinus (Bulin u,^) gueniei was described by

Dautzenberg in 1890 as hidora gueniei and its

type locality is Tuabo, near Bakel. Bulinus

(Physopsis) jousseaumei was also described by

Dautzenberg (1890) as Isidora jousseauniei and

its type locality is the Senegal River near

Medine. Bulinus ludovicianus (Mittre, 1841)

was described as Physa ludoviciana. from Saint

Louis, Senegal. It is probably a .synonym of B.

senegalensis.

Two other species, not originally described

from the Senegal River basin, were encountered

in certain habitats, and these are: B. (B.) for-

skalii was described by Ehrenberg (1831) as

Isidora for skalii and its type locality is Damiet-

ta, Egypt; B. (Physopsis) glohosiis was described

by Morelet (1866) as Physa globosa and its type

locality is Dande River, Angola.

The genus Bulinus Miiller is divided into two

subgenera: Bulimis and Physopsis. The mor-

phological features of Physopsis are 1) columella

is truncate. 2) the shell sculpture consists of

spirally arranged rows of small, transverse im-

pressions or nodules. 3) the ventral surface of

the kidney has a distinct renal ridge. In the

subgenus Bulinus the columella is usually

straight, although it is sometimes slightly

twisted and/or retlexed, but it is never truncate.

The shell has pronounced axial sculpture and

sometimes ribs, and there is no renal ridge in

the animal.

The bulinid species which were collected and

studied during this investigation have certain

shell and animal characteristic features. These

features conformed with those enumerated by

Wright (1956) and Mandahl-Barth (1958). It

should be noted, however, from our experience

that young specimens of B. (B.) forskalii. in

which the shouldering of the whorls and the

costae or ribs are not prominent, may be con-

fused with B. (B.) senegalensis. Therefore, ex-

amination of adult mature specimens of both

species is necessary for a correct identification.

Moreover, B. (Ph.) glohosus and B. (Ph.) jous-

seaumei can be easily confused with each other.

This is especially the case when the spire of the

shell oi B. (Ph.) glohosus is low and the trunca-

tion of the columella is not distinct. Further

studies may reveal the synonymy of B. (Ph.)

jousseaumei with B. (Ph.) glohosus, the older

name.

The above bulinid species in the Senegal River

basin are hosts or potential hosts of Schistosoma

hnetnatohiutn. S. boris and Paramphistomum

microhotlirium.

As to distribution and ecology of the bulinid

species, B. (B.) gueniei was the most common

and was generally found throughout the delta

and the lower-middle valley. The only habitat

Vol. 95(4)

October 29, 1981

THE NAUTILUS 197

where B. (B.) guernei was not found is the rain-

fed laterite pools. Habitats which have relatively

long periods of drought showed small popula-

tions. B. (B.) senegalensis was not collected in

the delta or in the Richard Toll area. However,

it was consistently found in laterite pools.

Similar observations were made in the Gambia

by Smithers (1956). In Senegal high densities

were recorded for Matam and Ourossoqui,

where the sites are dry for extended periods

each year, and are rain-fed. Therefore at least

few snails must be able to withstand prolonged

desiccation. B. (Ph.) globosu^s was found in Mali,

Senegal and Mauritania and it seems that it has

preference for ponds and flood plains.

Biomphalaria pfeifferi the intermediate host

of Schistosoma mansoni in West Africa was pre-

sent only in three locations. It seems to have a

preference for swamp conditions, but was also

found in a cement-lined canal in Saint Louis.

Two small planorbids Afrogyrus coretus and

Gyraulus costidatus were collected in swampy

banks of a lake, from irrigation canals and

among vegetation in the Senegal River bank in

Mali, and Lampsar Marigot at Lampsar. The

two species can be differentiated morphological-

ly by the shell and the verge. The whorls of the

shell of G. costulatus are rapidly increasing and

are regularly costulate. Its adult shell measures

1.2x5.5 mm. The shell of A. coretus measures

0.7x3.5 mm, is very flat and the whorls increase

slowly. No animals were available for examina-

tion.

Lymnaea natalensis is the intermediate host

of Fasciola gigantica and the only lymnaeid

species encountered in the Senegal River basin.

Adult shells measure 6x 13 mm.

Two thiarid species, Thiara (Melanoides)

tuberculata and Cleopatra hulimoides and a vivi-

parid, Bellamya unicolor, have a variety of

habitats, such as marigots, rivers, cement-lined

canals, lake, and irrigation canals. Especially

the thiarids occur in large numbers in these

habitats.

The field studies in the Senegal River basin

were conducted on three one-month visits to the

area: September-October 1977; February-March

1978 and August 1978 and one, 2-week visit in

January 1979. The observations made it possible

to determine qualitatively the population

dynamics of the snail fauna throughout the year.

Water in temporary habitats starts receding

about January, and many are dry by the end of

February and early March. The majority of tlie

snails die during this drought period, but a few

are believed to survive by aestivation. This is

rendered possible when the snails become pro-

tected in the shade under vegetation; when they

fall in deep cracks in the mud, or when they

become accidentally buried in the mud. Some of

the temporary habitats are cultivated during the

drought period and this process is believed to

enhance the snails' chance for survival. The

rains in the central and middle parts of the

Senegal River basin begin early in July, and con-

tinue through September. The temporary habi-

tats start filling up, and a gradual build-up of

snail colonies is observable by the middle of

August. Large colonies are detected by October

and they continue as such through December.

The period from about the middle of August

through January corresponds to the transmis-

sion season for human and bovine schisto-

somiasis, fascioliasis and paramphistomiasis.

With regard to permanent habitats, such as ir-

rigation canals and drains, it was found that the

most important determining factor in the fluc-

tuation of snail populations was the silt content

of the water. There is a decrease in the snail

population density following high silt content,

such as during the flood season. Aquatic weeds

also decrease in density during this period.

LITERATURE CITED

Adanson, M. 17.57. Hiatotre naturelle du Sevegal.

Coquilhnge^. Paris.

Brown, D. S. 1980. Freshwater Snails of Africa and their

Medical Importance. Taylor and Francis Ltd., London,

487 pp. [in the Americas, American Malacologists. Inc.|.

Uautzenberg, P. 1890. Mem. Soc. Zoot Fr. 3: 123-135.

Deschiens. R. 1951. Le probleme sanitaire des bilharzio-

ses dans les territoires de I'LInion francaise (fre-

quence, mollusques vecteurs, conditions etiologique).

Bull, Soc. Path. Exot. 44: 631-667.

Ehrenberg, C. G. 1831. Syviholac Physical AiiiiihiIki

Evertehrata. Insectis Exclusis. 1. Mollusca, Berlin.

(laud. .J. 1955. Les bilharzioses en Afrique <iccidentale et en

Afrique centrale. Bull. Wld. Hlth. Org. 13: 209-258.

198 THE NAUTILUS

October 29. 1981

Vol. 95(4)

Lariviere. M.. CJrelillft. S. and Hiicquct. P. liHi.'-!. Con-

siderations et recherches sur repiiiemiologit' dcs hilliar-

zioses au Senegal. 3eme .lournees Medic-ales de Dakar.

Dakar, Senegal.

Lefrou. G. 1933. Presence de Bidinus dyhoiraki au Sene-

gal. La diagnose des Bulinidae Africains. Bull. Soc. Path.

Exot., 26: 1099.

Leger, M. 1923. Les bilharzioses urinaires et intestinales

au .Senegal. Bull. Soc. Path. Exot. 16: 141.

.Mandahl-Barth, C. 19.")8. Intermediate hosts otSchistusDmii.

African Riomphahtrid and Buhniis. Wnrhl Hiiillli Orijui)-

izatitin. Monugraph Scrie.s No. 37.

Marrill, E. G. 1961. Premiere enquete sur I'epidemiologie de

la bilharziose a. Schislosoynn haematobium en Mauritanie.

Bull. Acad. Nation. Med. 145: 436-438.

Morelel. A. 1866. .Jour. Conchyl. (Paris) 8: 189-191

Muller, 0. F. 1781. Naturforscher. Berlin 15: 6

Sellin, B., Siinonkovich, E. and Roux, J. 1980. Etude de la

repartition de mollusques botes intermediaires des .sch-

istosomes en Afrit)ue de TOue.st. Med. Trop. 40:31-39.

Smithers, S. R. 1956. On the ecology' o( Schistosuma vectors

in the Gambia with evidence of their role in transmission.

Trans. Roy. Soc. Trop. Med. Hyg. 50: 354-365.

Wright, C. A. 1956. The anatomy of the six species of the

molluscan genus BuHnus (Planorbidae) from Senegambia.

Proc. Malacol. Soc. (London) 32: 88-104.

1957. Studies on the structure and taxonomy of

Bulinus jousseaumei (Dautzenberg). Bull. Brit. Mus. Nat.

Hist. Zool. 5: 1-28.

TELLINA OAHUANA AND MAUAI IN HAWAII

Tom and Beatrice Burch

Population Surveys

P.O. Box 309

Kailua, Oahu, Hawaii 96734

ABSTRACT

Calculation of the height-length ratio of 1000 valves o/ Tellina oahuana and

Tellina mauai shows that the latter is merely an elongated representative of a

single population and is considered a synonym of the former. This is one of the

most abundant bivalves in the shallow, offshore waters of Hawaii.

We have dredged specimens of Tellina from

the R/V Janthina VII off Oahu, Molokai, Maui

and Hawaii which we had identified as Tellina

oahuana Dall, Bartsch & Rehder, 1938, and

Tellina mauai Dall, Bartsch & Rehder, 1938.

Dr. Alison Kay, 1979, however, placed T. ynauai

in synonomy of T. oahuana. She states that "the

species is known only from beachworn valves, a

valve dredged by the Albatross at a depth of

26 m, and a specimen dredged by the Pele off

Waikiki." As we have numerous specimens, we

felt that a more detailed analysis would be in

order.

The only distinguishing features cited by Dall,

Bartsch & Rehder is that T. oahuana differs

from T. mauai "in being ovate, instead of

elongate-ovate" and that T. mauai is "more

elongate" than T. oahuana. The original descrip-

tions stated that the measurements of the type

of r. oahuana were: height, 4.1 mm and length.

5.7 mm, which gives a ratio of 71.9. In T. mauai

the height was 3.7 mm and the length was 6.2

mm giving a ratio of 59.7. We had specimens of

approximately these dimensions but in order to

ascertain if they were merely parts of a con-

tinuum, we measured 1,000 valves of what we

considered T. oahuana or T. mauai using an

ocular micrometer in a Bausch and Lomb model

5 stereo-microscope. The ratio of height to

length ranged from 60.0 to 86.4 with an average

of 70.7. The distribution of the ratios (Table 1)

was unimodal and hence we have concluded that

all of our specimens belong to the same species,

namely T. oahuana.

We have dredged T. aahuana from 10 to 75

fathoms off Honolulu, Oahu; 25 fathoms off

Kahe Pt., Oahu, 27 fathoms off Kokanakaki,

Molokai; 16-20 fathoms off Lahaina, Maui; and

30 fathoms off Mahukona, Hawaii. The vast ma-

jority of these have been single valves, but living

^ol. 95(4)

October 29, 1981

THE NAUTILUS 199

rABLE 1. Fri'qui'HCij (list ributiiiii uf Ihi- hi'iij)dileiiijl)i rutin

i/'Tt'llina nahuana.

Rali~

Ni'/llhrr nl sprri ilirns

(^O.O-til.y

62.0-63.9

64.0-65.9

66.0-67.9

68.0-69.9

70.0-71.9

72.0-73.9

74.0-75.9

76.0-77.9

78.0-79.9

80.0-81.9

82.0-83.9

84.0-85.9

86.0-87.9

Total

TABLE 2. Drplhs ul ichich Tellina nahuana iir-re ilrfilijiil

triini Jinilhinii \'IL

Dcfilh Snnihi'r nf Xiiinhrr nl' sjhci /inits

lFi}tlu>iiisl Sliittiiiis Lire Ih'iiil

3

34

130

205

342

170

82

21

5

4

2

1

1,00(1

<20

20-29

30-39

40-49

50 +

Total

23

2

4

1

38

specimens have been common. The depth and

ive status of the specimens used in this report

ire shown in Table 2. Twenty-seven of the 38

;tations included in this study were in "Pinna

Beds" (Burch 1980) where T. oahuana is one of

he commonest bivalves.

Although the type specimen of T. mauai is

nore elongate than any of the specimens that

ve have dredged, we concur with Dr. Kay's con-

lusion that it should be considered a synonym

■f T. oahuana. The type of T. mauai was

dredged by Thaanum in 4-8 fathoms near

Lahaina, Mauai, in 1918. This is shallower than

we have dredged with the Janthina VII but we

now plan to dredge at this depth in hopes of

finding such specimens.

The specimens used in this study have been

deposited in the Division of Mollusks, U.S. Na-

tional Museum of Natural History at the Smith-

sonian Institution in Washington, D.C.

LITERATURE CITED

Burch, B. L. 1980. Action of the Fcn-.shell Beds. Hdivaiimi

Shell News. 28(7): 1.

Dall, W. H.. Bartsch, P. & Rehder, H. A. 1938. A Manual of

the Recent and Fossil Marine Pelecypod Mollusks of the

Hawaiian Islands. B. P. Bishop Mus. Bull. 153.

Kay, E. A. 1979. Hawaiian Marine Shells. B. BMop Mu-

seum Special Piihl. 64.

FIGS. 1-4. 1, Tellina oahuana, lype specimen. USNM no. 333059. Height/length ratuj = 71.8. Burch

photo Al7J,-5. 2, Tellina mauai, type specimen. USNM no. 33731,7. Height/length ratio = 59.7. Burch

photo Al7Jf-8. 3, Tellina oahuana, Burch Station 77080. 22-26 fathoms offWaikiki. Oahu. (interior)

HeightJlength ratio = 69.8. Burch photo N2i9-12. 4, Tellina oahuana, Burch station 77080. (interior

of speeimen shoum in Fig. 3). Burch photo N2I,9-1J,.

200 THE NAUTILUS

October 29, 1981

Vol. 95(4)

Freshwater Snails of AtYica and their Medical Importance

bv David S. Brown

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For the first time:

A comprehensive account of freshwater snails

in Africa and neighbouring islands.

An exhaustive guide to species

of medical and veterinary importance.

An invaluable reference work for malacologists,

epidemiologists, parasitologists, freshwater

biologists and biogeographers.

Published by TAYLOR & FRANCIS LTD, LONDON.

Distributed in the Americas by AMERICAN MALACOLOGISTS, INC. FLORIDA.

The knowledge resulting from intensive study in recent years is

brought together lor the first time in this book. Dr. Brown presents

a systematic synopsis of nearly 400 species, most of them

illustrated, together with chapters on host/parasite relations, snail

control, ecology, distribution and biogeography, accompanied by

many maps, photographs of shells and drawings.

Dr. David S. Brown is a senior scientist on the staff of the Medical

Research Council of Great Bntatn and has been based for 20 years

at the Bntish Museum (Natural History) working with a team on

research into host/parasite relations. Dunng long penods of field-

work in Afnca. he has studied the entire gastropod fauna of fresh

and brackish waters over large areas of the continent.

450 pp. 230 ^ 152mm i" x 6")

0 850b6 145 5 Cloth

153 Figs.

GUIDE TO THE NUDIBRANCHS OF CALIFORNIA

INCLUDING MOST SPECIES FOUND FROM ALASKA TO OREGON

Bn G\k> K. McDonald ano

'/ (lih-il l>\ K I tH kfr

Destined to be the "bihle" lor tidcpool .ind stuh.i hiDJiii^ists, the

CukIv In IIh- iVudi/jf.UK /)s III ( ,i/i/iif;)M will f(|UiilK st'r\r those

resejrchers Irom Al.isk.i ,ind P,n ilii ( .in.id.i to ( )rfKon I he cvIitisivc

inlorm.ilion on the s|)f( lali/cd toods ,m<l hahit.its ot eai h s|)i'( ics uill

<iid not only in idt'nlilK ,ition hut ,ilso in (•( oloi;ii .il an.ilvt's

Unique among similar guides this hook h.i-, the advantage ol e\

tensive keys, authoritative intorm.ition .ind con\enn'nt ph\ logenetu

organization. This liook will he welcomed In m.irine hiologists

anidtt'iir naturalists, marine aquarium enthusiasts ,vni students ol

oceanogrd()hv.

Years in the making, this compait account gives the scientitic

essentials to all the known nudihranc hs snails oi C alitornia mc luding

the higher c lassit^ation and descriptions ot e.u h genus with their

lype-species. With top qu.ility in ()h()togr,i|ihv .ind undersi.inil.ihU-

concise morphologic ,\l descriptions identilic .ilions oi species , in-

made much e.isier.

american malacologists

/ 'I M.ISHLKS OF /)/S77,V( Tl I'B BoOfcS (l\ Ml ILI. I SKS

■ 2255

Mf - TA 32901

. .- .•■^\'», 4

lAMES VV. N>BAKKEN

■\d()i)//i

I I -' c olor plates (i4 p<ige'

Soltc over SI i "id

• BIOLOGY

• KE\ TO SPECIES

• GENERIC DESCRIPTIONS

• SPECIES DESCRIPTIONS

• 112 COLOR PLATES OE LIMNG ANIMAL:

• COLLECTING TECHNIQUES

• PHOTOGRAPHING TECHNIQUES

• \NATOMN

• BIBHOGRAPHN

m\

■n^^

SECOND, REVISED AND IMPROVED PRINTING - July 15, 1981

INFORMATION FOR SUBSCRIBERS

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Back issu£s from volume 72 to date are ob-

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through 71 (if available) may be obtained in

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Advertising rates may be obtained from the

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CONTRIBUTORS

Manuscripts: Authors are requested to follow

the recommendations of the Style Manual for

Biological Journals, which may be purchased

from the American Institute of Biological Sci-

ences, 1401 Wilson Boulevard, Arlington, Va.

22209. Manuscripts should be typewritten and

doublespaced; original and one copy are

required, to facilitate reviews. Tables, numbered

in arable, should be on separate pages, with the

title at the top. Legends to photographs should

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Easton, Maryland 21601.

MOLLUSK VOUCHER SPECIMENS

It is becoming increasingly important for

future research purposes that an identified sam-

pling of species mentioned in publications be

deposited in a permanent, accessible museum

specializing in mollusks. This is particularly

true of mollusks used in physiological, medical,

parasitological, ecological, and experimental

projects.

Several museums of natural history have ex-

tensive modern facilities and equipment for the

housing and curating of voucher specimens.

Material should be accompanied by the identifica-

tion, locality data and its bibliographic reference.

There is no charge for this permanent curating

service, and catalog numbers, if desired, will be

sent to authors prior to publication.

WANTED -OLD SHELL BOOKS

Will pay g.x,d prices for libraries second- 305-725-2260) or write: R. Tucker Abbott,

hand books and repnnts on mollusks shells An.erican Malmoloqhts, Inc.. P. 0. Box 2255

and conchology. Back numbers of The Nauti- Melbourne, FL 32901. Free appraisals.

Ins, vols. 40-71 wanted, $1.50 each. Phone (1-

americanmalacologists, inc.

PUBLISHERS OF DISTINCTIVE BOOKS ON MOLLUSKS

THE NAUTILLTS (Qmrterly)

MONOGRAPHS OF MARINE MOLLUSCA

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REGISTER OF AMERICAN MALACOLOGISTS

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