americanmalacologists, inc.
PUBLISHERS OF DISTINCTIVE BOOKS ON MOLLUSKS
THE NAUTILUS (Quarterly)
MONOGRAPHS OF MARINE MOLLUSCA
STANDARD CATALOG OF SHELLS
INDEXES TO THE NAUTILUS
{Geographical, vols 1-90; Scientific Names, vols 61-90)
REGISTER OF AMERICAN MALACOLOGISTS
JANUARY 30, 1984
THE
NAUTILUS
ISSN 0028-1344
Vol. 98
No. 1
A quarterly
devoted to
malacology and
the interests of
conchologists
Founded 1889 by Henry A. Pilsbry. Continued 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, MA 02138
Dr. William K. Emerson
Department of Living Invertebrates
The American Museum of Natural History
New York, NY 10024
Dr. M. G. Harasewych
363 Crescendo Way
Silver Spring, MD 20901
Dr. Aurele La Rocque
Department of Geology
The Ohio State University
Columbus, OH 43210
Dr. James H. McLean
Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, CA 90007
Dr. Arthur S. Merrill
c/o Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Donald R. Moore
Division of Marine Geology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 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, IL 60605
Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, OH 43210
Dr. Ruth D. Turner
Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Gilbert L. Voss
Division of Biology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 33149
EDITOR-IN-CHIEF
Dr. R. Tucker Abbott
American Malacologists, Inc.
Box 2255, Melbourne, FL 32902-2255
Mrs. Cecelia W. Abbott
Business and Subscription Manager
P.O. Box 2255
Melbourne, FL 32902-2255
Second Class Postage paid at Melbourne, Florida
and other post offices
The Nautilus (USPS 374-980)
ISSN 0028-1344
A quarterly magazine devoted to malacology.
Copyright *'1983 by American Malacologists. Inc.
OFFICE OF PUBLICATION
American Malacologists, Inc. (United Parcel Address:
2208 South Colonial Drive, Melbourne, FL 32902)
Mail: Box 2255, Melbourne, FL 32902-2255
POSTMASTER: Send address changes to above.
Subscription Price: $13.00 (see inside back cover)
$15.00 (foreign); institutions $18.00
THE
NAUTILUS
Volume 98, number 1 — January 30, 1984
ISSN 0028-1344
CONTENTS
Joseph Rosewater
A Bibliography and List of the Taxa of Mollusca Introduced by
Joseph P. E. Morrison (December 17, 1906 - December 2, 1983) 1
Hans Bertsch and Luis Aguilar Rosas
Range Extensions of Four Species of Nudibranchs Along the
Pacific Coast of Baja California, Mexico 9
Eugene Coan
What is Ervilia califomica Dall? 11
Jane E. Deisler and R. Tucker Abbott
Range Extensions of Some Introduced Land Mollusks in the
Bahama Islands, with First Reports for Four Species 12
John Kraeuter, Laura Adamkewicz, Michael Castagna, Robert Wall, and Richard Karney
Rib Number and Shell Color in Hybridized Subspecies of the
Atlantic Bay Scallop, Argopecten irradians 17
Timothy G. Laman, N. Craig Boss and Harvey D. Blankespoor
Depth Distribution of Seven Species of Gastropods in Doublas Lake, Michigan 20
Freddy Arocha and German Robaina
First Record of Octopus defilippi Verany, 1851 in Venezuelan Coastal Waters 25
Martin Avery Snyder
Fusinus lightboumi (Gastropoda: Fasciolariidae), a New Species from Bermuda 28
Anthony D'Attilio and Barbara W. Myers
A New Western Atlantic Species of Cymatium (Gastropoda: Cymatiidae) 31
M. G. Harasewych and Richard E. Petit
Notes on the Morphology of Olssonella smithii (Gastropoda: Cancellariidae) 37
Louise S. Thompson
Comparison of the Diets of the Tidal Marsh Snail, Melampus bidentatus
and the Amphipod, Orchestia grillus 44
Publications Received ii Recent Deaths ii
Meetings ii News 30
ii THE NAUTILUS
January 30, 1984
Vol. 98(1)
PUBLICATIONS RECEIVED
Mollusca (Section 9), 1983, The Zoological Record, vol. 117,
491 pp. Covers the literature for the year 1980. BIOSIS,
2100 Arch St., Philadelphia, PA 19103-1399.
Inaba, Akihiko. 1982. MoUusran Fauna of the Seto Island
Sea. Japan. 181 pp., 4 pis. Hiro.shima Shell Club, Mukai-
shima Marine Biol. Station, Onomichi P. 0., Hiroshima
Pref., Japan. About $12.50, postage included. A very use-
ful, annotated, modern checklist of 1074 species of mol-
lusks found in the Inland Sea.
Kozloff, Eugene N. 1983. Sen.'ihore Life of th£ Northern
Pacific Coast: An Illustrated Guide to Northern California,
Oregon, Washington and British Columbia. 378 pp, 700
ills., 299 in color. University of Washington Press, Seattle.
Reading for ecologists, but skimpy on moUusks, and omit-
ting author and date from the taxa names. $40.00, hard-
back; $19.9.5, paper.
Seaward, Dennis R. (editor) 1982. Sea Area Atla-s of the
Marine Molluscs of Britain and Ireland. 53 pp., 746 dis-
tributional maps shovdng records for live mollusks both
before and after 1950. Contains annotated checklist of all
species in the area. Nature Conservancy Council, Atting-
ham Park, Shrewsbury, Salop, England SY4 4TW.
Oliveira, de, Maury Pinto, et al. 1981. Catalogo dos Moluscos
da Universidade Federal de Juiz de Fora (Brasil). 520 pp.
Lists, with localities and synonyms, the 903 genera and
2,793 species of mollusks, including 12 holotypes, found in
this University collection.
Kuroda, T. and T. Habe, 1981 (with Preface by Iwao Taki).
A Ca.tal.og7ie of Molluscs of Wakayama Prefecture, the
Province ofKii. Part I, Bivalvia, Scaphopoda and Cepha-
lopoda, 301 pp., 13 pis. Seto Marine Biol. Lab., Special
Pub. Series, vol. 7, no. 1. Excellent annotated checklist
with full synonymies, and useful photos of many species.
Separates available for about $18.00 from Yasuo Koyama,
19 Nishidaikucho, Wakayama City, Japan 640.
Correction for Last Issue
(Vol. 97, no. 4, p. 146: R. Shelley article)
Fig. 1: the bottom clam valve is from Half-
way Pond, Plymouth Co., MA.
Add to the bibliography: Johnson, Richard
I. 1970. The Systematics and Zoogeo-
graphy of the Unionidae (Mollusca: Bival-
via) of the Southern Atlantic Slope Region.
Bull. Mus. Comp. Zool. 140:263-449.
The omissions were not those of the
author.
RECENT DEATHS
Mrs. Betty Jane Allen, longtime amateur
conchologist and shell shop owner in South
Padre Island, Texas, died September 10, 1983,
at the age of 71, after a long illness. She and her
late husband, Larry, contributed much valuable
material to various museums. She was a co-
founder (1959) and first President of the South
Padre Island Shell Club. Also see the Texas Con-
chologist, vol. 20, no. 1, p. 13 (1983).
Joseph P. E. Morrison, former Associate
Curator of Mollusks at the U. S. National Muse-
um, died suddenly, December 2, 1983, at age 74,
at Key West, FL. A biobibliography of our
friend, "Joe", appears in this issue of The
Nautilus.
Alfred J. Ostheimer, III, Philadelphia busi-
nessman, explorer, and amateur malacologist,
died September 1, 1983, at the age of 74, at his
home in Santa Fe, NM. He was a founder of the
Pilsbry Chair of Malacology, and headed numer-
ous expeditions to the South Pacific and West
Indies for the Academy of Natural Sciences of
Philadelphia in the 1960's. He helped finance the
launching of the journal, Indo-Pacific Mollusca
and was the originator of the Natural Science
Foundation (of Philadelphia).
MEETINGS
The American Malacological Union will hold
its 50th Annual Meeting at Norfolk, Virginia, on
July 22-27, 1984. Serious amateurs as well as
professionals are invited to attend. For further
information write Dr. Robert Robertson, Presi-
dent, Dept. Malacology, Academy of Natural
Sciences. Nineteenth and the Parkway, Phila-
delphia, PA 19103. (215-299-1131).
The Conchologists of America's (COA) 12th
Annual Convention will be held at the Don
CeSar Beach Resort at St. Petersburg Beach,
Florida, on June 27 through June 30, 1984. It
will be hosted by the St. Petersburg Shell Club
and welcomes all shell collectors, whether
novice or advanced, as well as shell dealers and
scientists from around the country and the
world. For further information, please contact:
Mr. Donald J. Young, 11975 Third Street East,
Treasure Island, Florida 33706.
Vol. 98(1)
January 30, 1984
THE NAUTILUS
1-9
A BIBLIOGRAPHY AND LIST OF THE TAXA OF MOLLUSCA
INTRODUCED BY JOSEPH P. E. MORRISON
(DECEMBER 17, 1906 -DECEMBER 2, 1983)
Joseph Rosewater
Department of Invertebrate Zoology
National Museum of Natural History
Washington, D.C. 20560
'Ww'
Dr. Joseph P(aul) E(ldred) Morrison was a
recognized expert on freshwater, land and
estuarine mollusks, and longtime associate cura-
tor at the National Museum of Natural History,
Smithsonian Institution.
He was born at South Bend, Indiana, on
December 17, 1906; attended Transylvania Col-
lege (1922-1924); University of Chicago (B.S.-
1926); and University of Wisconsin (1927-1931,
M.S. -1929, Ph.D.-1931). His professional ex-
perience prior to joining the Smithsonian in
1934, included: Zoological Specialist, Illinois
State Museum (summers of 1923 and 1927); stu-
dent assistant in Zoology, Transylvania College
(1923-1924); Zoologist, Mt. Desert Island Biol-
ogical Survey (summers 1927-1928); Zoologist,
Wisconsin State Natural History Survey (sum-
mers 1929-1930); graduate assistant and in-
structor. University of Wisconsin (1927-1931);
Associate Professor, Crane Junior College,
Chicago, Illinois (1931-1933), and Kelley High
School (1933-1934). He joined the staff of the
Division of Mollusks, [then] United States Na-
tional Museum, in 1934, as a Scientific Aid,
became Assistant Curator in 1942, and Asso-
ciate Curator in 1946, in which capacity he re-
mained until his retirement due to ill health in
1975, having served for over 40 years.
Dr. Morrison's accomplishments in science
were many and varied and included contribu-
tions in a number of Natural History disciplines.
He served as an officer in several societies: The
American Malacological Union (Vice President,
1950; President, 1951; Honorary Life Member,
1978); Washington Academy of Sciences (Edi-
tor, 1948-1954); National Capital Shell Club
(Charter Member; President, 1962); Biological
Society of Washington (Vice President,
1961-1963; acting President, 1963-1964);
member: Society of Systematic Zoology; Wash-
ington Biologists Field Club; National Rifle
Association; National Speleological Association;
Sigma Xi; Phi Sigma.
His contributions of specimens to the collec-
tions of the National Museum of Natural
History, and, through exchanges, to the collec-
tions of museums throughout the world, are
almost countless. These specimens resulted
from field work done before his employment at
the Smithsonian, resulting in an enormous per-
sonal collection of North American mollusks,
and from expeditions to: British Guiana (1925);
Gulf of Maine (summers of 1927-1928); Indian
shell mounds, Pickwick Landing Basin, Tennes-
see and Alabama (1937); San Jose Island, Pearl
Islands, Panama (1944); Marshall Islands (1946,
1947); Raroia, Tuamotu Islands (1952); New
Caledonia (1961); Dominica (1965); Mexico
(1966). Through the years of his employment at
the Smithsonian he collected locally, on week-
ends, and during vacation excursions at every
available opportunity, resulting in massive
suites of specimens numbering in the hundreds
of thousands bearing his name as collector.
In connection with his collecting activities he
invented and redesigned a number of special
THE NAUTILUS
January 30, 1984
Vol. 98(1)
aids to capturing natural history specimens.
These include a collapsible funnel fish trap and a
folding mussel bar, the latter having been
patented. In addition, he modified for special
purpose collection activities many different
types of dredges and nets, and various types of
fire arms and ammunition. He was a consultant
to the Smithsonian and the U.S. Fish and Wild-
life Service on collecting weapons. During
World War II he created an experimental 30 cal.
Ml Carbine collecting outfit which was offered
to the armed forces as a survival kit for service
men. He was the only civilian to contribute to
the solution of war survival problems -outside
of major weapons companies.
Dr. Morrison has the distinction of being one
of the few malacologists of our time whose stu-
dies include all three of the major faunal groups
of mollusks, land, freshwater and marine. His
publication list includes well over 100 titles and
his list of taxa numbers 175 names of sub-
species, species, genera, and subfamilies of mol-
lusks named by him and collaborators. His area
of major expertise, the Unionidae, surprisingly,
contains less new taxa than certain other
groups. Nevertheless, he contributed signifi-
cantly to the understanding of their relation-
ships through his work and discussions concern-
ing their nomenclature and higher classification.
His knowledge of the Mollusca is highly re-
spected at home and abroad, and there are few
serious students of Malacology over the last 50
years who have not acknowledged the aid of Dr.
J. P. E. Morrison in their work. Dr. Morrison
died of a heart attack in Key West, Florida,
December 2, 1983, a few days before his 77th
birthday. He is survived by his wife, Dorothy
Louise (Dunn) Morrison, Apt. 703, 3312 North
Side Drive, Key West, FL 33040; and three
children.
There follows a list of the molluscan taxa in-
troduced by J. P. E. Morrison, both alone and
with others. In the latter category the most
significant work was that on the Cyclophorid
mollusks written jointly with Paul Bartsch
(1942b). Following the taxa list is Dr. Morrison's
bibliography arranged chronologically. The
dates of publication of papers are annotated a,
b, c, etc., where there are more than one per
year. These annotated dates are used in the taxa
list so that there is no confusion about which
publication is cited. The following abbreviations
are used in the list of taxa:
AMUB - American Malacological Union Bul-
letin and/or Annual Reports
ANSP - Academy of Natural Sciences of
Philadelphia
BAEB - Bureau of American Ethnology
Bulletin
JWAS - Journal of the Washington Academy
of Sciences
N - The Nautilus
PBSW - Proceedings of the Biological Socie-
ty of Washington
SMC - Smithsonian Miscellaneous Collec-
tions
USNM - National Museum of Natural His-
tory, formerly United States National Museum
USNMB - United States National Museum
Bulletin
Taxa of Mollusca Introduced By
Joseph P. E. Morrison
adamsi Morrison MyfUop^iis 1946, SMC 106(6X3850):46,
pi. 1, figs. 4, 7 (attached by byssus to underside of rocks,
upper end of lagoon, mouth of Musselshell Creek, SE San
Jose Island, Pearl Islands, Panama; Holotype USNM
542183).
agassizi Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:254, pi. 37, figs. 4-6 (Brazil, probably
in Amazon River region [sic]; Holotype USNM 57285).
allantayum Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:230, pi. 32, figs. 4-6 (Peru; Holotype
USNM 524046).
alleei Morrison Aroapyrgiis 1946, SMC 106(6X3850):14,
pi. 2, fig. 4; pi. 3, fig. 3 (from dead leaves, sticks, etc., in a
pool, Allee Stream, Barro Colorado Island, Gatun Lake,
Canal Zone, Panama; Holotype USNM 542142).
amazonen,se Bartsch and Morrison Aperostoma (Apero-
stoma) 1942b, USNMB 181:243, pi. 35, figs. 4-6 (Amazon
River, Brazil; Holot>T)e USNM 356102).
Athearnia Morrison 1971b, N 84(3):110; type species by
original designation ylKcu/osa antkunyi Redfield, 1854.
atratensis Bartsch and Morrison Calacyclotus 1942b,
USNMB 181:179, pi. 23, figs. 10-12 (mountains near
mouth of Atrato River, Colombia; Holotype USNM
206291).
awreum Bartsch and Morrison Aperostoma (NeocyclotiLs)
dysoni 1942b, USNMB 181:209, pi. 28, figs. 13-15 (Pan-
istlahuaca, Oaxaca, Mexico; Holotype USNM 523970).
austratis Morrison Cochtwpina 1946, SMC 106(6X3850):23,
pi. 2, fig. 13; pi. 3, fig. 14 (lowermost reaches of Mussel-
shell Creek, ju.st above lagoon, SE end [San Jose Island,
Pearl Islands, Panama]; Holotype USNM 542165).
aims Bartsch and Morrison Cyrtotuma 1942b. USNMB
181:169, pi. 22, figs. 22-24 (Motzorongo, Vera Cruz,
Mexico; Holotype USNM 128285).
Vol. 98 (1)
January 30, 1984
THE NAUTILUS
hakeri Bartsch and Morrison Addopoma 1942b, USNMB
181:149, pi. 40, fig. 5 (Quebrada, Venezuela; Holotype
ANSP 140916).
balsasense Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:265, pi. 39, figs. 1-3 (Balsas, Peru;
Holotype USNM 524126).
Barbaeycius Bartsch and Morrison 1942b, USNMB 181:175;
type species by original designation Cyclophon/^ iinder-
woodi DaCosta, 1900.
barretti Morrison Odostonua 1965a, PBSW 78:220, fig. 4
(NE Heron Bay, Mississippi; Holotype USNM 635630);
not Odostmnia barreti L. Morlet. 1885, is Hydrohin [sic]
boonae Morrison, 1973.
Mangulata Morrison Quadrula 1942a, BAEB 129:348, 349,
350, 351, 352, 356 (Tuscumbia, Alabama; Holotype USNM
84221).
bicincta Bartsch and Morrison Buckleyia 1942b, USNMB
181:152, pi. 19, figs. 13-15 (Ecuador; Holotype USNM
316063).
boliviense Bartsch and Morrison Aperostoma {Aperostoma)
1942b, USNMB 181:260, pi. 38, figs. 7-9 ("Bolivia"; Holo-
type USNM 307426).
booneae Morrison Hydrobi a 1973a, N 87(1):28; new name for
Odostomia [sic] barretti Morrison, 1965, not 0. barreti
L. Morlet, 1885.
bowdenetms Morrison Poferia 1955d, JWAS 45(5):155
(Miocene fossil beds, Bowden, Jamaica; Holotype USNM
82532a).
Iyrujev.se Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:241, pi. 34, figs. 13-15 (500 feet,
Cerro Bruja, Panama; Holotype USNM 251418).
burringtoni Bartsch and Morrison Aperostoma (Austro-
cyclotus) 1942b, USNMB 181:202, pi. 28, figs. 16-18
(Cariaquita, Venezuela; Holotype ANSP 104625).
Calacyclotus Bartsch and Morrison 1942b, USNMB 181:178;
type species by original designation Amphicyclot us otssoni
Pilsbry, 1926.'
carabobense Bartsch and Morrison Aperostoma (Austro-
cydotus) 1942b, USNMB 181:201, pi. 28, figs. 4-6 (Guare-
males, Venezuela; Holotype USNM 339947).
canmioU Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:233, pi. 32, figs. 19-21 (Costa Rica;
Holotype USNM 25034).
castaneurn Bartsch and Morrison Ape7-ostoma (Aperostoma)
1942b, USNMB 181:252, pi. 36, figs. 7-9 (Venezuela; Holo-
type USNM 524087).
chagresensis Morrison Aroapyrgus 1946, SMC 106(6X3850):
14, pi. 2, fig. 3; pi. 3, fig. 4 (small beds of Chara and other
plants in shallow water near SE side Rio Chagres, near
Gatuncilla, Panama; Holotype USNM 542144).
chagresensis Morrison Lyrodes 1946, SMC 106(6)(3850):16,
pi. 2, fig. 6; pi. 3, fig. 6 (from Chara beds, etc., shallow
water, near margin of Chagres River, near Gatuncilla,
Panama; Holotype USNM 542149).
chesapeakea Morrison Sayella 1939b, N 53(2):44 (Broome's
Island, Maryland; Holotype USNM 530766).
chocolatum Morrison Incidosto7na 1955d, JWAS 45(5):158,
figs. 10-12 (Papallagta, Ecuador; Holotype USNM
543.527).
chrysacme Bartsch and Morrison Aperostoma (Neocyclotus)
1942b, USNMB 181:219, pi. 29, figs. 13-15 (Wani, Nica-
ragua; Holotype USNM 186112).
clarendonensis Morrison Poteria 1955d, JWAS 4.5(5):155;
new name for Ptycocochlis taylori Bartsch, 1942, not P.
(Cydobakeria) welchi tayhri Bartsch, 1942.
darki Morrison Detracia 1951a. JWAS 41(1):18, figs. 2, 6
(Key West, Florida; Holotype USNM 594588).
Cochiiopina Morrison 1946, SMC 106(6)(3850):18; type
species by original designation Cochliopa riograndensis
Pilsbry and Ferriss, 1906.
colabrensis Morrison Subcochliopa 1946, SMC 106(6)(3850):
26; pi. 2, fig. 14; pi. 3, fig. 16 (Rio Colabre, Bayano River
drainage, Panama; Holotype USNM 542169).
colorad/iense Morrison Fluminicola 1940b, N 53(4): 125
(Green River, Wyoming; Holotype USNM 526631).
columna Morrison Retinella (Glyphalinia?) 1937, PBSW
50:57, pi. 4, figs. 8-10 (Olga, Washington; Holotype USNM
362009).
coristrictiis Bartsch and Morrison Tomoeydus 1942b,
USNMB 181:145, pi. 19, fig. 2 (Coban, N Guatemala; Holo-
type USNM 162315).
cookei Bartsch and Morrison Aperostoma (Neocyclotus)
dysoni 1942b, USNMB 181:215, pi. 29, figs. 10-12 (Uaxac-
tun, Peten Province, Guatemala; Holotype USNM
524006).
costaricense Bartsch and Morrison Adelopoma 1942b,
USNMB 181:150, pi. 40, fig. 4 (1550 M, Santa Maria,
Costa Rica; Holotype USNM 516034).
cumingi Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:224, pi. 31, figs. 19-21 (Colombia;
Holotype USNM 307416).
ctirrani Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:261, pi. 38, figs. 1-3 (Rio Gregugy,
Bahia. Brazil; Holotype USNM 322360).
Cydorhittya Morrison 1955d, JWAS 45(5): 154; type species
by original designation Cydotus dentistigmatus Chitty,
1857.
Cydopomops Bartsch and Morrison 1942b, USNMB 181:
219; new name for Cydopoma Troschel, 1847, not Agassiz,
1833; type species by original designation Cydostoma
moricandi Pfeiffer, 1852.
cylindrica Morrison Panamicorbula 1946, SMC 106(6)
(38.50):47, pi. 1, figs. 15, 17 (in drift of Rio Marina man-
grove swamp [San Jose Island, Perlas Islands, Panama];
Holotype USNM 542186).
daltei Morrison Poteria 1955d, JWAS 4.5(5):155; new name
hr Ptychocochlis welchi Bartsch, 1942, not Poteria (Cydo-
bakeria) welchi Bartsch, 1942.
diazensis Morrison Cochliopa 1946, SMC 106(6K3850):27,
pi. 2, fig. 15; pi. 3, fig. 18 (from leaves, roots, etc., E bank
Rio Juan Diaz, just below Las Sabanas Road bridge, E of
Panama City, Panama; Holotype USNM 542170).
diminutum Morrison Incidostoma 1955d, ,JWAS 45(5):159,
figs. 7-9 (Papallagta, Ecuador; Holotype USNM 543530).
dorotheae Morrison Donaj: 1971a, PBSW 83(48):554, pi. 1,
fig. Do (Alligator Point, Franklin County, Florida; Holo-
type USNM 679773).
dugesiana Morrison Durangonella 1945c, N 59(1):21, pi. 3,
fig. 3 (near Andocutira, Michoacan, Mexico; Holotype
USNM 433473).
dunoonense Bartsch and Morrison Aperostoma (Cyclohi-
dalgoa) translucidum 1942b, USNMB 181:273, pi. 30,
figs. 7-9 (British Guiana; Holotype ANSP 140876).
Durangonella Morrison 1945c, N 59(1): 18; type species by
THE NAUTILUS
January 30, 1984
Vol. 98(1)
original designation Durangonella seemani (Frauenfeld)
= Hydrobia seemani Frauenfeld.
dyeri Bartseh and Morrison Aperostoma (Neocyclotun)
dysoni 1942b, USNMB 181:205, pi. 28, figs. 31-33 (La
Ceiba, Honduras; Holotype USNM 215592).
ecuadorense Bartseh and Morrison Aperostoma (Apero-
stoma) 1942b, USNMB 181:248, pi. 36, figs. 4-6 (Quito,
Ecuador; Holotype USNM 316105).
eldredi Morrison Conus (Gastridium) 1955a, JWAS 45(1):
32; new name for Conus geographua rosea Sowerby, 1833,
not C. roseus Fischer, 1807, nor Lamarck 1810; for C.
intermedials Reeve, 1843, not C. intermedins Lamarck,
1810; and for C. mappa Crosse, 1858, not C. mappa
Solander, 1786.
exiguum. Bartseh and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:234, pi. 32, figs. 10-12 (Zhorquin
Valley, Talamanca, Costa Rica; Holotype USNM 190281).
extremis Morrison Cochliopina 1946, SMC 106(6X3850):22,
pi. 2, fig. 11; pi. 3, fig 13 (from small stream with 100- yard
lagoon just E of S tip of San Jose Island, Archipielago de
las Perlas, Panama; Holotype USNM 542163).
Fijidoma Morrison, 1952a, AMUB:8; type species by mono-
typy Fijidojna laddi Morrison, 1952.
Fiiocydtis Bartseh and Morrison 1942b, USNMB 181:157;
type species by original designation Cyclophorua delphinu-
lus Mousson, 1869.
fischeri Bartseh and Morrison Cyrtotoma 1942b, USNMB
181:171, pi. 22, figs. 13-15 (Hacienda Cuatotolapam, Vera-
cruz, Mexico; Holotype USNM 515789).
Jloridana Morrison Retinella (Glypkaloides?) 1937, PBSW
50:56, pi. 4, figs. 11-13 (Pleistocene? near Oeala, Marion
County, Florida; Holotype USNM 421084).
flucki Morrison Diplodon 1943e, N 57(1):14, pi. 5, figs. 5-9
(Orinoco River above Munduapo, Venezuela; Holotype
USNM 521998).
fratemula Morrison Cochliopina 1946, SMC 106(6X3850):
21, pi. 2, fig. 9; pi. 3, fig. 11 (in reaches just above tide-
water of Rio Mata Puerco, San Jose Island, Archipielago
de las Perias, Panama; Holotype USNM 542157).
fultoni Bartseh and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:242, pi. 35, figs. 1-4[31 ("Brazil";
Holotype USNM 307425).
gemm.uln Morrison Dowcw 1971a, PBSW 83(48):565, pi. 2,
fig. G (Praia do Cassino, Rio Grande, Rio Grande do Sul,
Brazil; Holotype ANSP 244125).
glohula Morrison Ohovaria subrotundata 1942a, BAEB
129:348, 349, 350, 351, 352, 360 (Tuscumbia, Alabama;
Holotype USNM 85789).
goldmani Bartseh and Morrison Cyrtotoma 1942b, USNMB
181:174, pi. 22, figs. 7-9 (Mutaltoyuea, Puebla, Mexico;
Holotype USNM 523516).
graminea Morrison Detracia 1946, SMC 106(6X3850):35,
pi. 1, fig. 18 (in and under drift, mangrove swamp side of
sand barrier, near mouth of Rio Marina, Is!a San Jose,
Archipielago de las Perlas, Panama; Holotj-pe USNM
542177).
Guianadesma Morrison 1943d, N 57(2):49; type species by
original designation Guianadesma sinuosum Morrison,
1943.
haughti Bartseh and Morrison Aperostoma (CycLohidalgoa)
belli 1942b. USNMB 181:269, pi. 30, figs. 24-26 (south
part Department of Santander, Colombia; Holotype
USNM 524136).
haughti Morrison Buckleyia 1955d, JWAS 45(5): 150, figs.
26-28 (stream N of Rio Nuqui, Dept. Choco, Colombia;
Holotype USNM 488865).
hedui Bartseh and Morrison Aperostoma (Incidostoma)
1942b, USNMB 181:191, pi. 26, figs. 1-3; new name for
Cyclotus incomptus Reeve, 1863, not Cyclostoma incomp-
tum Sowerby, 1850 (Brazil; Holotype USNM 307480)
[sic].
hinkleyi Bartseh and Morrison Aperostoma (Neocyclotus)
dysoni 1942b, USNMB 181:206, pi. 28, figs. 19-21 (Guate-
mala; Holotype USNM 523968).
hitomi Bartseh and Morrison Aperostoma (Incidostoma)
1942b, USNMB 181:194, pi. 27, figs. 26-28 (Quito, Ecua-
dor; Holotype USNM 316105).
ignotum. Bartseh and Morrison Cyrtotoma 1942b, USNMB
181:171, pi. 22, figs. 16-18 (Mexico; Holotype USNM
.523515).
Incerticydus Morrison 1955d, JWAS 45(5): 156; type species
by original designation Neocydotus (Ptychocochlis) bakeri
Simpson, 1895.
Incidostoma Bartseh and Morrison 1942b, USNMB 181:187;
type species by original designation Aperostoma (Incido-
stoma) malleatum Bartseh and Morrison, 1942.
insula Morrison Cyrenoida 1946. SMC 106(6X3850):45,
pi. 1, figs. 8-11 (from pools in mud of small mangrove
swamp, W side San Jose Island, Perlas Islands, Panama;
Holotype USNM 542182).
intennedvus Morrison Helicodiscus (Hebetodiscus) 1942a,
BAEB 129:374, 375, 376, 378, 379 (10-11 foot sample, at
mound site Lu° 59, Tennessee River flood plain, Lauder-
dale County. Alabama; Holotype USNM 535599).
jacksoni Morrison Incidostoma 1955d. JWAS 45(5):158,
figs. 13-15 (near Mera, Oriente Province, Ecuador; Holo-
type USNM 543524).
joseana Morrison Aroapyrgus 1946, SMC 106(6X3850):15,
pi. 2, fig. 5; pi. 3, fig. 8 (from a northern tributary of the
Rio Mata Puerco estuary, San Jose Island, Archipielago
de las Perlas, Panama; Holotype USNM 542147).
joseana Morrison Cochliopa 1946, SMC 106(6X3850):28,
pi. 2, fig. 18; pi. 3, fig. 19 (Rio Mata Puerco, SW San Jose
Island, Archipielago de las Perlas, Panama; Holotype
USNM 542173).
joseana Morrison Detracia 1946, SMC 106(6X3850):34,
pi. 1, fig. 16 (from under fallen leaves on flood plain of
Rio Marina at upper limits of tidal mangrove swamp at its
mouth, E side San Jose Island, Archipielago de las Perlas,
Panama; Holotype USNM 542175).
joseana Morrison Ferrissia (Laenapex) 1946, SMC 106(6)
(3850):39, pi. 1, figs. 5, 6 (from flood plain pools along
middle reaches of stream opening into NW mangrove
swamp, San Jose Island, Archipielago de las Perlas,
Panama; Holotype USNM 542179).
joseana Morrison Polymesoda 1946, SMC 106(6X3850):44,
pi. 1, figs. 12-14 (in drift of Rio Marina mangrove swamp,
E side San Jose Island, Archipielago de las Perlas. Pana-
ma; Holotype USNM 542181).
juraM Morrison Cochliopina 1946, SMC 106(6X3850):20,
pi. 2, fig. 8; pi. 3, fig. 10 (from rocks in rapids of stream
leading to NW mangrove swamp, San Jose Island, Archi-
pielago de las Perlas, Panama; Holot.vpe USNM 542154).
kobelti Bartseh and Morrison Aperostoma (Incidostoma)
Vol. 98(1)
January 30, 1984
THE NAUTILUS
1942b, USNMB 181:190, pi. 25, figs. 7-9; is Neucydotus
pergrandis var. Kobelt, 1912 (Cundinamarica, between
Bojaca and Tene, Lake of Tedropalo, Colombia; Holotype
Berlin Museum 37582).
kompi Morrison Zetekelta 1946, SMC 106(6X3850); 13, pi. 2,
fig. 2; pi. 3, fig. 2 (Rio Mata Puerco and branches, W side
San Jose Island, Archipielago de las Perlas. Panama;
Holotype USNM 542140).
kugleri Bartsch and Morrison Aperostmna (AuatrocyclotusI
1942b, USNMB 181:201, pi. 28. figs. 1-3 (Riedto, District
Acosta. Falcon, Venezuela; Holotype USNM 515924).
laddi Morrison Fijidonui. 1952a, AMUB: 8 (Lami River,
Viti Levu, Fiji Islands; Holotype USNM 597433); is Ftji-
doma macidata (Mousson, 1865) cf. Morrison. 1954d;
I 384-385.
Lagocydus Bartsch and Morrison 1942b, USNMB 181:154;
type species by original designation Cydophurun crossea-
nus Hidalgo, 1866.
leai Bartsch and Morrison Aperostoma (Aperostoma) 1942b.
USNMB 181:246, pi. 35, figs. 17-19 (Balsas, Peru; Holo-
type USNM 104451).
leai Bartsch and Morrison Calaperostoma 1942b, USNMB
181:165, pi. 21, figs. 17-19; new name for Cydostoma
striata Lea, 1834, not C. striatum Sowerby, 1825, nor
C. striata Quoy and Gaimard. 1832).
limafodeTis Morrison Prubythindla lacustris 1947d. N
61(1):26, 27; new name ior Paludina emarginata Kiister.
1852, not Lymnaeus emarginatus Say.
limellum Bartsch and Morrison Aperosttyma (Austrocydo-
tus) 1942b, USNMB 181:197, pi. 27, figs. 6-8 (100-300 M.
Rio Cesar Valley, Magdelena, Colombia; Holotype USNM
515906).
Liracydotus Bartsch and Morrison 1942b, USNMB 181:274;
type species by original designation Cydostoma psilumi-
tum Pfeiffer, 1851.
louisianae Morrison Vioscalba 1965a. PBSW 78:217. figs.
1, 2 (off Frenier Beach, SW Lake Ponchartrain, Louisiana;
Holotype USNM 635627).
malleatum Bartsch and Morrison Aperostoma (Incidostoma)
1942b, USNMB 181:188, pi. 25, figs. 4-6 (no locality; Holo-
type USNM 317578).
manabense Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:239. pi. 34, figs. 10-12 (between
Quevedo and Calcata, Manabi. Ecuador; Holotype USNM
524066).
mariae Morrison Durangonella 1945c. N 59(1):20, pi. 3,
fig. 2 (shell stratum (marl), 1 M below surface of dry lake
bed, Tlahuac, 20 KM E of Xochimilco, D.F., Mexico; Holo-
type USNM 433399).
marshaUi Morrison Micronaias 1943c, N 57(1):15; new
name for Unio granadensis Lea, 1868, not Conrad, 1855.
jBosi'CTWP Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:254. pi. 37. figs. 1-3 (Cerro Masve.
Guayas Province, Ecuador; Holotype USNM 524048).
Megacydotus Bartsch and Morrison 1942b, USNMB 181:
181; type species by original designation Cydostoma
ponderosum Pfeiffer, 1851.
megaplanus Morrison Amphieydotus 1955d, JWAS 45(5):
160. figs. 29-31 (obtained from a peon at Ocozocoantla.
Chiapas, Mexico; 600-1000 M, forests of El Ocote [sic];
Holotype USNM 618777).
merrilli Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:263, pi. 38, figs. 19-21 (Brazil; Holo-
type USNM ,58310).
Mexcydotus Bartsch and Morrison 1942b, USNMB 181:179;
type species by original designation Cydostoma (Cydo-
phorus) lutescens Pfeiffer, 1851.
nanum Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:262, pi. 38, figs. 13-15 (coastal range,
between sea level - 200 M, between Caracas and Puerto
Cabello. Venezuela; Holotype USNM 336128).
navalis Morrison Cochlwpma 1946, SMC 106(6)(3850):22,
pi. 2. fig. 12; pi. 3, fig. 12 (st'-eam flowing into small bay on
SW San Jose Island, at landing for U.S. Naval lighthouse,
Peari Islands, Panama; Holotype USNM 542160).
nevadense Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:255, pi. 37, figs. 15-17 (8,400 feet,
Sierra Nevada Mountains, Venezuela; Holotype USNM
206494).
nicaraguense Bartsch and Morrison Aperostoma (Neocydo-
tus) dysoni 1942b. USNMB 181:214, pi. 29, figs. 16-18
(Polvon, Nicaragua; Holotype USNM 524005).
nirafe Bartsch and Morrison Aperostoma (Incidostoma)
1942b, USNMB 181:193, pi. 27, figs. 23-25 (13 KM S of
Puerta Santos, Province of Santander del Norte, Colom-
bia; Holotype USNM 380795).
olivaeeum Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:251, pi. 36, figs. 10-12 (Ecuador;
Holotype USNM 524084).
07-bis Morrison Actinonaias carinata 1942a, BAEB 129:348.
349, 350, 351, 352, 361 (Florence, Alabama; Holotype
USNM 84998).
orinocensis Morrison Castalia 1943c, N 57(1): 14, pi. 5, figs.
1-4 (Orinoco River, Maipures, U.S. Columbia; Holotype
USNM 522000).
paezense Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:225, pi. 31, figs. 7-9 (valley of Rio
Paez, Central Cordilleras, Colombia; Holotype USNM
251169).
paezicohum Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:232, pi. 32, figs. 13-15 (2500 M, Rio
Paez Valley, Colombia; Holotype USNM 524047).
pailaerise Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:231, pi. 32, figs. 7-9 (1300 M. Rio
Paila Valley, Colombia; Holotype USNM 251171).
palnwri Bartsch and Morrison Cyrtotoma 1942b, USNMB
181:172, pi. 22, figs. 1-3 (Gomez Farias. Tamaulipas,
Mexico; Holotype USNM 198079).
panarrmisis Morrison Nerititia 1946, SMC 106(6)(3850):5,
pi. 1, fig. 2 (along E bank of Rio Juan Diaz, near Las
Sabanas Road. E. of Panama City, Panama; Holotype
USNM 542133).
parana Morrison Detrafia 1951a, JWAS 41(1):19, fig. 3
(Amazon River, Para'. Brazil; Holotype USNM 594591).
perplexm Morrison Rugicydotus 1955d, JWAS 45(5): 154
(Appleton. St. Elizabeth, Jamaica; Holotype USNM
535988).
peruense Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:245, pi. 35, figs. 10-12 ("Peru"; Holo-
type USNM 103999).
pidiinchense Bartsch and Morrison Aperostoma (Incido-
stoma) 1942b. USNMB 181:191, pi. 26, figs. 10-12 (Quito,
Ecuador; Holotype USNM 316109).
PilshrychUus Morrison, 1952a, AMUB: 7; type species by
6 THE NAUTILUS
January 30, 1984
Vol. 98(1)
monotypy Pachychilus dalli Pilsbry, 1896.
pilsbryi Morrison DurangoneUa 1945c, N 59(1):22, pi. 3,
fig. 4 (Paso del Rio, Colima, Mexico; Holotype USNM
362551).
pilsbryi Morrison Strobilops 1953c, N 67(2):53, pi. 6, figs.
1-3 (Whitby Cave, Bermuda; Holotype USNM 618751).
pittieri Bartsch and Morrison Calaperostoma 1942b,
USNMB 181:164, pi. 21, figs. 7-9 (Panama; Holotype
USNM 523513).
pizarroi Bartsch and Morrison Aperostoma (Incidostoma)
1942b, USNMB 181:193, pi. 26, figs. 7-9 (Maguas, Peru;
Wilkes Exploring Expedition; Holotype USNM 20109).
ponchartrainensis Morrison Mulinia 1965a, PBSW 78:
222, figs. 5-9 ("Middle Ground", E Lake Ponchartrain,
Louisiana; Holotype USNM 635643).
portohellense Bartsch and Morrison Aperostoma (Apero-
stoma) 1942b, USNMB 181:242, pi. 34, figs. 7-9 (Porto
Bello, Panama; Holotype USNM 251434).
Pseudiscus Morrison 1942a, BAEB 129:379; type species by
original designation Helicodiscus (Pseudiscus) punctatel-
lus Morrison, 1942.
Pseudopunctum Morrison 1935, JWAS 25(12):545; type
species by original designation Puyictum (Pseudopunctum)
smithi Morrison, 1935.
pulchellum Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:263, pi. 38, figs. 16-18 (Brazil; Holo-
type USNM 524125).
piinctatellus Morrison Helicodiscus (Pseudiscus) 1942a,
BAEB 129:379 (Kentucky Geological Survey Station 74,
near White's Cave, near Mammoth Cave, Kentucky; Holo-
type USNM 535600).
pygmaeum Bartsch and Morrison Aperostoma (Cyclohidal-
goa) translucidum. 1942b, USNMB 181:272, pi. 30, figs.
19-21 (Caratal, Venezuela; Holotype USNM 24026).
redfieldi Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:261, pi. 38, figs. 10-12 (Brazil; Holo-
type USNM 307399).
reesei Morrison Paravitrea 1937, PBSW 50:58, pi. 4, figs.
5-7 (along state highway #3, about 'A mile from Virginia
boundary, Peters Mountain, Monroe County, West Vir-
ginia; Holotype USNM 423599).
roundyi Morrison Paravitrea 1935, JWAS 25(12):546,
figs. 1-3 (near Dewey, Washington County, Oklahoma;
Holotype USNM 365154).
ruatanense Bartsch and Morrison Aperostoma (Neocyclotus)
dysoni 1942b, USNMB 181:207, pi. 28, figs. 7-9 (Ruatan
Island, Honduras; Holotype USNM 364702).
Rugicyclotus Morrison 1955d, JWAS 45(5);152; type species
by original designation Riigicyclotus perplexus Morrison,
19,55.
salengof-nse Bartsch and Mlorrison Aperostoma (Aperostoma)
1942b, USNMB 181:253, pi. 37, figs. 18-20 (Salengo Is-
land, Ecuador; Holotype USNM 104432).
sailer Bartsch and Morrison Aperostoma (Neocyclotus)
dysoni 1942b. USNMB 181:213, pi. 29, figs. 7-9; new name
for Cyclotus (Aperostomii) dysoni minor von Martens,
1890, not C. corrugatior minor Chitty, 1857.
saludensis Morrison Gastrodonta (Clappiella) 1937, PBSW
50:.58, pi. 4, figs. 1-4 (S side Walnut Mountain, on slope
along Fall Creek, tributary of Saluda River, Saluda Moun-
tains, Greenville County, South Carolina; about 1 mile S
of North-South Carolina boundary, U.S. Route 25 [sic];
Holotype USNM 423597).
sanjosensis Morrison Pomacea cumingii 1946, SMC 106(6)
(3850):6, pi. 1, fig. 1 (3 small streams, W side San Jose
Island, Peari Islands, Panama; Holotype USNM 542136).
schermoi Morrison Cyclochittya 1955d, JWAS 45(5):154
(Miocene fossil beds, Bowden, Jamaica; Holotj-pe ANSP
82532); is C. schumoi Morrison, 1955, q.v.
schumoi Morrison Cyclochittya 1955e, N 69(2):72; emenda-
tion of Cyclochittya schermoi Morrison, 1955.
Semisulcospirinae Morrison, 1952a, AMUB:8, based on
Semisulcospira. Boettger, 1886; is Lavigeriinae Thiele,
1929, Morrison, 1954.
Setaeara Morrison, 1952a, AMUB:8; type species by mono-
typy Thiara cancellata Roding, 1798.
similf Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:227, pi. 31, figs. 13-15 ("Bogota",
(Colombia) [sic]; Holotype USNM 535989).
sinaloa Morrison Strobilops 1953c, N 67(2):54, pi. 6, figs. 4-6
(intercepted by U.S. Dept. of Agriculture at Nogales,
Arizona, on succulent plants from Sinaloa, Mexico; Holo-
type USNM 592719).
sinuosum Morrison Cruiariadesma 1943d, N 57(2):49, pi. 8,
figs. 1-6 (Cuyuni River, opposite Kartabo Point, near its
junction with the Mazaruni River, Essequibo District,
British Guiana: Holotype USNM 536901).
siphonis Bartsch and Morrison Tomocyclus 1942b, USNMB
181:145, pi. 19, fig. 5 (Alta Vera Paz, Guatemala: Holo-
type USNM 162511).
smithi Morrison Punrtum (Pseudopunctum) 1935, JWAS
25(12):545, figs. 4-7 (near Huntsville, Madison County,
Alabama; Holotj-pe USNM 318466a).
stirlinx)i Bartsch and Morrison Aperostoma (Incidostoma)
1942b, USNMB 181:195, pi. 27, figs. 20-22 (Mendez,
Upper Paute River, Ecuador; Holotype USNM 516296).
Subcochliopa Morrison 1946, SMC 106(6)(3850):25; type
species by original designation Subcochliopa trochu^
Morrison, 1946.
sumichrasti Bartsch and Morrison AperostcmM (Neocyclo-
tus) dysoni 1942b, USNMB 181:209, pi. 28, figs. 25-27
(Chontales Forest, Nicaragua: Holot.vpe USNM 523674).
totteni Morrison Hydrohia 1954a, .TWAS 44(1):26; new name
for Turbo minuta Totten, 1834, not T. mimda Brown,
1818, T. minuta Michaud, 1828, norT. mim/to Woodward,
1833.
tridens Morrison Pilsbryna 1935, JWAS 25(12):546, figs.
8-10 (near Strawn, Palo Pinto County, Texas; HolotiiTJe
USNM 3.59722).
trochus Morrison Subcochliopa 1946, SMC 106(6X3850):25,
pi. 2, fig. 17; pi. 3, fig. 20 (Rio Tribique, Sona, Veraguas
Province, Panama; Holotype USNM 542168).
umbilicatum Bartsch and Morrison Aperostoma (Apero-
stoma) 1942b, USNMB 181:224, pi. 31, figs. 1-3 (Bogota,
Colombia; Holotype USNM 307428).
utriaense Bartsch and Morrison Aperostoma (Aperostoma)
1942b, USNMB 181:240. pi. 34, figs. 4-6 (Puerto Utria,
Colombia: Holotype USNM 524068).
valerioi Bartsch and Morrison Aperostoma (Neocyclotus)
dysoni 1942b, USNMB 181:213, pi. 29, figs. 19-21 (1480
M, Cervantes, Costa Rica; Holotype USNM 524003).
venezuelev.se Bartsch and Morrison Apei-ostoma (Apero-
stoma) 1942b, USNMB 181:247, pi. 35, figs. 20-22 (Vene-
zuela; Holotype USNM 307429).
Vol. 98(1)
January 30, 1984
THE NAUTILUS
veracochanum Bartsch and Horrison Aperostoma (Aperosto-
ma) 1942b, USNMB 181:229, pi. 31, figs. 16-18 (Magiias,
Peru; Holotype USNM 524045).
veraguasensis Morrison Zetekelln 1946, SMC 106(6X3850):
12, pi. 2, fig. 1; pi. 3. fig. 1 (Rio Tribique at Sona, Vera-
guas Province, Panama; Holotype USNM 542139).
Vioscalba Morrison, 1965a, PBSW 78:217; type species by
original designation Vioscalba louisianae Morrison,
1965a.
I'irginica Morrison Retinella (Glyphyatus) 1937, PBSW
50:55, pi. 4, figs. 14-16 (W slope Blue Ridge, Clarke Co.,
Virginia, 3 miles W of Trapp, Loudoun Co. [sic]; Holotype
USNM 421081).
watlingsi Morrison Sayelln 1939b, N 53(2):45 (Watling's
Island (San Salvador) Bahamas; Holotype USNM 127488).
weberi. Morrison Odostomia 1965a, PBSW 78:221, fig. 3
(small bay N of Bayou Chene Fleur, N Barataria Bay,
Louisiana; Holotype USNM 635638).
wetmorei Bartsch and Morrison Aperostoma (Neocyclolvti)
1942b, USNMB 181:203, pi. 41, figs. 13-15 (Tierra Nueva,
Sierra Negros, Magdalena, Colombia; Holotype USNM
536033).
wetmorei Morrison Cochlwptna 1946, SMC 106(6X3850):24,
pi. 2, fig. 16; pi. 3, fig. 15 (a little above lowermost rapids
to about V4 mile upstream, through 3 sets of rapids and
pools, Rio Marina, E side San Jose Island, Archipielago de
las Perias, Panama; Holotype USNM 542167).
Zetekella Morrison 1946, SMC 106(6X3850): 11; type species
by original designation Littoridina frenata Pilsbry, 1935;
is Zetekina Morrison 1947b, q.v.
zeUki Morrison CocUiopina 1946, SMC 106(6X3850): 19,
pi. 2, fig. 7; pi. 3, figs. 5, 9 (from leaves and roots along
eastern margin of Rio Juan Diaz, just below bridge of Las
Sabanas Road, E of Panama City, Panama: Holotype
USNM .5421.52).
zeteki Morrison Lyrodes 1946, SMC 106(6X3850):!?, pi. 2,
fig. 10 (Pedro Miguel, Canal Zone, Panama; Holotype
USNM 542151).
zeteki Morrison Poynacea 1946, SMC 106(6X3850):8, pi. 1.
fig. 3 (shallow margin of Chagres River, near Gatuncilla,
Panama; Holotype USNM 542137).
Zetekina Morrison 1947b, N 60(3):102; new name for Zete-
kella Morrison, 1946, not Drake, 1944 (Hemiptera).
Bibliography of
Joseph P. E. Morrison
1928. A contribution to the life-history of the Angler (Loph-
ius piscatorius). Biological Survey of the Mount Desert
Region. Part 2, Fishes: 1-13, pis. 1-2, charts 1-2 (as J. E.
Morrison, with W. Procter, et al.).
1929a. A preliminary list of the MoUusca of Dane County,
Wisconsin. Transactions Wisconsin Academy Sciences
Arts and Letters 24:405-425.
1929b. On the occurrence of Hendersonia in Crawford
County, Wisconsin. The Nautilus 43(2):41-45.
1932a. A report on the Mollusca of the northeastern Wis-
consin Lake District. Transactions Wisconsin Academy
Sciences Arts and Letters 27:359-396, 127 figs.
1932b. Studies on the Life History of Acella haldfinani
("Desh." Binney). Transactions Wisconsin Academy
Sciences Arts and Letters 27:397-413, pis. 11-12, fig.
1933. Acella haldemani ("Desh." Binney). The Nautibis
46(3):107. (Review and quotation of summary of Morrison,
1932b.)
1935. Three new land shells from the Southern United
States. Journal Washington Academy of Sciences
25(12):.545-547, figs.
1937. Five new North American Zonitids. Proceedings
Biological Society of Washington 50:55-60, pi. 4.
1938. Description, habitat, and life history of the inter-
mediate host, Fossana ot.lula. pp. 16-17. In Alicata, J. E.,
Observations on the life history of Faaciola gigantica.
the common liver fluke of cattle in Hawaii, and the inter-
mediate host, Fossana ollula. Hawaii Agricultural Ex-
periment Station, Honolulu, Bulletin 80:1-22.
1939a. Notes on the genera Potamopyrgus and Lyrodes.
The Nautilus 52(3):87-88.
1939b. Two new species ofSayella with notes on the genus.
The Nautilus 53(2):43-45.
1939c. An unusual cave deposit. The Nautilus 53(2):45-47.
1939d. The type locality of Cochliopa rowelli (Tryon). The
Nautilus 5.3(2):67.
1939e. The systematic position of the genus Ekadanta Rao.
The Nautilus 53(2):67-68.
1940a. Another Pleistocene snail is not extinct. The Nauti-
lus 53(4):123.
1940b. A new species of Fiuminicola with notes on "Colo-
rado Desert" shells, and on the genus Clappia. The Nauti-
lus 53{4y.l2i-l27 .
1940c. Notes on the subgenera of Valvata. The Nautilus
53(4):140.
1940d. Haldeman's 1840 Supplement. The Nautilus 54(2):
64-66.
1942a. Prehminary report on mollusks found in the Shell
Mounds of the Pickwick Landing Basin in the Tennessee
River Valley. Bureau of American Ethnology. Bulletin
129:339-392.
1942b. Part .3-The Cyclophorid Mollusks of the Mainland of
America, pp. 142-282. In De La Torre, C, Bartsch. P.
and Morrison, J. P. E. 1942. The Cyclophorid operculate
land mollusks of America. U.S. National Museum Bulletin
181:1-306, 42 pis. (with P. Bartsch).
1943a. Notes on the reproductive morphology of Thais.
The Nautilus 56(3):103-104.
1943b. Oreohelix east of the Mississippi. The Nautilus
56(3): 104.
1943c. Two new Orinoco Unionids, with notes on Unio gra-
nadensis Lea and U. patuius Lea. The Nautilus 57(1):
14-16, pi. 5.
1943d. A new type of fresh water clam from British Guiana.
The Nautilus 57(2):46-52, pi. 8.
1945a. A lost Cyclophorid moUusk. Revista Chilena de
Historia Natural (Ano 1944) 48:95-96 (with Bartsch, P).
1945b. Paraprososthenia gredleri (Neumayr). The Nautilus
58(4):134-135, pi. 6, figs. 6-9 (with Bartsch, P.).
1945c. Durangonella. a new hydrobiine genus from Mexico,
with three new species. The Nautilus 59(l):18-23, pi. 3,
figs. 1-10.
1946. The nonmarine mollusks of San Jose Island, with
notes on those of Pedro Gonzalez Island, Pearl Islands,
Panama. Smithsonian Miscellaneous Collections 106(6):
1-49, 3 pis.
1947a. One hundred six years of Amnicola. The Nautilus
8 THE NAUTILUS
January 30, 1984
Vol. 98(1)
60(3):84-87.
1947b. A new name in Panama Hydrobiinae. The Nautilus
60(3): 102.
1947c. Concerning "Hydrohia" jenkinsi E. A. Smith. The
jVttM<?7ttA'60(3):103-104.
1947d. Notes on the genus ProbythineUa (Hydrobiinae). The
Nautilus 61{\):25-2S.
1947e. Notes on the Phihppine snail, Vivipams burroiighi-
amis Lea. The Nautilus 61(l):29-30.
1947f. The planorbid genus Armigerus. The Nautilus
61(1): 30-31.
1949. The cave snails of eastern North America. News Bul-
letin and Annual report, American Malacological Union
for 1948:13-15.
19.50. Notes on the Florida species of Bursa (A condensa-
tion). News Bulletin and Annual Report, American Mala-
cological Union for 1949:10-13.
1951a. Two new western Atlantic species of pulmonale
mollusks of the genus Detracia and two old ones (Family
Ellobiidae). Journal Washington Academy of Sciences
41(l):17-20, figs. 1-7.
1951b. American Ellobiidae - an annotated list. News Bul-
letin and Annual Report, American Malacological Union
for 1950:8-10.
1951c. How I prepare radulae. News Bulletin and Annual
Report, American Malacological Union for 1950:16-17.
[Title inside front cover.]
1951d. VI. Atoll research in Zoology - Land and Marine.
Coral Atoll Symposia, Pacific Science Board, Jan. -Feb.
1951, Washington and Honolulu. Atoll Research Bulletin
1:16-17.
1951e. The zoogeography of the Cave Snails of Eastern
North America. (Abstract, reprinted) The National Spele-
ological Society News 9(3):3, col. 3.
1951f. Shell Material in Archeology of the Bynum Mounds.
Mississippi. Archaeological Research Series 1, National
Park Service, U.S. Dept. of Interior, p. 50.
1952a. World relations of the Melanians. News Bulletin and
Annual Report, American Malacological Union for 1951:
6-9.
1952b. Correction of the type locality of Pow.acea cumingii
(King) 1834. The Nautilus 65(3): 105- 106.
1952c. The genotype of MicroceramMS. The Nautilus 6b(S):
106-107.
1952d. General Zoology in Field team report on Coral Atoll
Project at Raroia, Tuamotu Archipelago. Zoology. Scienti-
fic Investigations in Micronesia, Pacific Science Board:
12-16 (mimeographed report).
1953a. The Berlese method of collecting small insects and
other animals from leafmold, soil, moss, or other similar
materials. Pacific Science Board. Atoll Research Bulletin
17:73.
1953b. Collecting mollusks on and around atolls. Pacific
Science Board. Atoll Research Bulletin 17:74-77, figs.
1953c. Two new American species oi Strohilops. The Nauti-
lus 67(2):53-55, pi. 6.
1953d, Vim.parus multilineatus (Say) 1829, from Florida.
The Nautilus 67(2):56-58.
1954a. Hydrohia totteni, new name for Turbo minuta
Totten, 1834 (Gastropoda: Hydrobiidae). Journal of the
Washington Academy of Sciences 44(1 ):26.
1954b. Zoogeography, subfamilies and families. Annual
Report, American Malacological Union for 1953:12-14.
1954c. Demonstration of the egg-masses and eggs oi Detra-
cia floridana (Pfeiffer). Annual Report, American Mala-
cological Union for 1953:15-16.
1954d. The relationships of old and new world Melanians.
Proceedings of the U.S. National Ahiseum 103(3325):
357-394, pi. li.
1954e. Animal ecology of Raroia Atoll, Tuamotus. Part 1.
Ecological notes on the Mollusks and other animals of
Raroia. Pacific Science Board, Atoll Research Bulletin
34:1-18.
1954f. Animal Ecology of Raroia Atoll, Tuamotus. Part 2.
Notes on the birds of Raroia. Pacific Science Board, Atoll
Research Bulletin 34:19-26.
1954g. Interrelationships of the organisms on Raroia aside
from man. Pacific Science Board, Atoll Research Bulletin
35:1-61, 9 figs, (with Doty, M.S.)
1955a. Conus eldredi. new name for one of the poison cones.
Journal of the Washington Academy of Sciences 45(1):32.
1955b. Notes on the genera Lanx and Fisherola (Pulmon-
ata). The Nautilus msy.7d-S^. figs. 1-4.
1955c. Some zoogeographic problems among brackish
water mollusks. Annual Report, American Malacological
Union for 19.54:7-10.
1955d. Notes on American Cyclophorid land snails, with
two new names, eight new species, three new genera, and
the family Amphicyclotidae, separated on animal char-
acters. Journal of the Wa.shington Academy of Sciences
45(5): 149-162, figs. 1-15.
1955e. A correction. [Cyclochittya schemioi Morrison to
schunioi] The Nautilus 69(2):72.
1956a. Family relationships of the North .■\merican fresh
water mussels. Annual Reports, American Malacological
Union for 1955, Bulletin 22:16.
1956b. Notes on the spiny freshwater mussels (Canthyria).
Annual Reports, American Malacological Union for 1955,
Bulletin 22:19-20.
1956c. How many Syncei-a species are living in Death Val-
ley? Annual Reports, American Malacological Union for
1955, Bulletin 22:29.
1956d. What is Helix whitneyi Newcomb? Annual Reports,
American Malacological Union for 1955, Bulletin 22:33.
19.58. Ellobiid and other ecology in Florida. The Nautilus
71(4):118-124.
1959a. The primitive history of some salt-marsh snails.
Annual Reports, American Malacological Union for 1958,
Bulletin 25:25-26.
1959b. Brackish water genera of Mactridae. .•\nnual Re-
ports, American Malacological Union for 1958, Bulletin
25:26.
1959c. Americana and Indica Clessin 1879. The Nautilus
72(3): 105.
1961a. Notes on the bivalved "univalves". ,A.nnual Reports,
American Malacological Union for 1960, Bulletin 27:18-20.
1961h. Collecting Meliniopsis in New Caledonia. Annual
Reports, American Malacological Union for 1961, Bulletin
28:13.
1962. Rochefortia - a new record in Tampa Bay. Annual
Reports, American Malacological Uni(m for 1962, Bulletin
29:14-15.
1963a. Cecina from the state of Washington. The Nautilus
76(4):1.50-151.
Vol. 98(1)
January 30, 1984
THE NAUTILUS 9
1963b. Notes on American Siphonana. Annual Reports,
American Malacological Union for 1963, Bulletin 30:7-9.
1964a. Notes on American Melampidae. The Nautilus
77(4):119-121.
1964b. Formation of an epiphragni and true aestivation in
Melampidae. The Nautiluf: 77(4):139-140.
1965a. New brackish water mollusks from Louisiana. Pro-
ceedings of the Biologicnl Society of Washington 78:
217-224.
1965b. On the families of Turridae. Annual Reports, Ameri-
can Malacological Union for 1965, Bulletin 32:1-2.
1965c. Notes on the genera of Hipponicidae. Annual Re-
ports, American Malacological Union for 1965, Bulletin
32:33-34.
1967. Zoogeography of the Family Amblemidae. Annual
Reports, American Malacological Union for 1966, Bulletin
33:43-45.
1968a. Notes on American Hastula. Annual Reports, Amer-
ican Malacological Union for 1967, Bulletin 34:49-50.
1968b. Collecting Mexican freshwater mussels. Annual
Reports, American Malacological Union for 1967, Bulletin
34:50-51.
1968c. Four American Hastula species. The Texas Concho-
logist 4(9):67-70, figs,
1968d. Notes on Hawaiian Lymnaeidae. Malacological
Review l:31-.32.
1969a. Spiroglyphics: A Study in Species Association.
Annual Reports, American Malacological Union for 1968,
Bulletin 35:4.5-46.
1969b. Zoogeography of Hydrobiid Cave Snails. Malacolo-
gia 9(1):278.
1969c. West Atlantic Donaj:. Annual Reports, American
Malacological Union for 1969, Bulletin 36:20.
1969d. The earliest names for North American Naiads.
Annual Reports, American Malacological Union for 1969,
Bulletin 36:22-24.
1970a. 9. Brackish Water Mollusks In American Malacolo-
gical Union Symposium on Rare and Endangered Mol-
lusks. Malacotogia 10(1 ):55.
1970b. East Florida I>o«(ix Seafan 12(7): 1-2.
1971a. Western Atlantic Donax. Proceedings of the Biolo-
gical Society of Washington 83(48):545-568.
1971b. Alhearnia. New Name for a genus of Pleurocerid
Snails. The Nautilus 84(3):110-111.
1971c. Names for the Subfamily Hydrobiinae. Annual Re-
ports, American Malacological Union for 1970, Bulletin
37:7-8.
1972a. Mediterranean Siphonaria: West and East - Old and
New. Argamon, Is7-ael Journal of Malacology 3(l-4):51-62.
1972b. Sympatric species of Elliptio in North Carolina. The
American Malacological Union Bulletin for 1971: 38-39.
1973a. New Name for a Texan Hydrohia. The Nautilus
87(1):28.
1973b. Sympatric species oi Elliptio living in the St. Johns
River, Florida. The American Malacological Bulletin for
1972:14.
1973c. The families of the pearly freshwater mussels. The
American Malacological Union Bulletin for 1972:45-46.
1973d. Zoogeography of the Pleurocerine freshwater snails.
Mahwologta 14(l-2):426.
1975. Maryland and Virginia mussels of Lister. Bulletin of
the American Malacological Union for 1974:36-39.
1976. Relict Mussels from two continents. Bulletin of the
American Malacological Union for 1975:70.
1977. Species of the Genus Uniom^i-^is. Bulletin of the
American Malacological Union for 1976:10-11.
1978. Notes on the Genus Villosa. Bulletin of the American
Malacological Union for 1977:92.
1979a. Further Comments on the Proposed Designation of
a Type Species ior Pleuroc.era Rafinesque, 1818. Z. N. (S.)
83. Bulletin of Zoological Nommclature 36(3):139-146.
(with A. H. Clarke, C. Stein, G. M. Davis and J. Rose-
water).
1979b. Reproduction of the Families Unionidae and Amble-
midae. Bulletin of the American Malacological Union for
1978:.54.
1979c. The specific distinction of Lampsilis anodontoides
Lea and Lampsilis teres Rafinesque. Bulletin of the Amer-
ican Malacological Union for 1978:61.
1980a. Notes on the ecology of East American Donax. Bul-
letin of the American Malacological LInion for 1979:62.
1980b. Recent Corbicula in North America. Bulletin of the
American Malacological Union for 1979:67.
RANGE EXTENSIONS OF FOUR SPECIES OF NUDIBRANCHS
ALONG THE PACIFIC COAST OF BAJA CALIFORNIA, MEXICO
Hans Bertsch' and Luis Aguilar Rosas
Institute de Investigaciones Oceanologicas
Universidad Autonoma de Baja California
Apartado Postal 453
Ensenada, B. C, Mexico
Increased research along the Pacific coast of
Baja California is helping to clarify zoogeo-
'U.S. mailing address: Apt. 83, 4444 West Point Loma
Blvd., San Diego, CA 92107.
graphic patterns in a region of provincial over-
lap where there are numerous species-level af-
finities between adjacent warm temperate and
tropical provinces (Bertsch, 1979). This note on
the distribution of four species of dorid nudi-
10 THE NAUTILUS
FIG. 1. Map of Baja California, indicating the distribution
sites: 1, La Jolla; 2, Ensenada; 3, Cabo San Quintin; 4, Punta
Cone; and 5, El Tomatal.
branchs is part of our ongoing series of publica-
tions on the flora (Aguilar, 1983; Aguilar &
Bertsch, in press), invertebrate fauna (Bertscli,
1983), and comparative opisthobrancii zoogeo-
graphy (Bertsch & Johnson, 1983) of Baja
California. Moreover, this paper complements
several recent notes (Hamann, 1981; Behrens,
1983; and Bertsch & Smith, 1983) on the distri-
bution of opisthobranchs from southern Califor-
nia (USA) and Baja California (Mexico).
Onchidorididae
Acanthodoris rhodoceras Cockerell
in Cockerell & Eliot, 1905
The known range of this species has been
reported from Dillon Beach, northern Califor-
nia, to Punta Mesquite (Halfway House), Baja
California (Farmer & Collier, 1963; Sphon,
1972; McDonald & Nybakken, 1981: 42).
On 16 June 1983 we found one specimen of
Acanthodoris rhodoceras (6 mm in total length)
underneath an intertidal rock on which were
numerous colonies of encrusting bryozoans, on
the south side of Punta Cono (28° 58'). This is a
January 30, 1984 Vol. 98(1)
southward range extension of approximately
440 km.
Triophidae
Triopha catalinae (Cooper, 1863)
Along the eastern Pacific shoreline, the
known range of this triophid is from Coghlan
Island, Alaska, to Isla Todos Santos, Baja
California (Ferreira, 1977:395); it is also known
from Japan.
Our finding of one 4 mm long specimen inter-
tidally at El Tomatal (28°29') 14 June 1983,
extends the range of this species over 470 km to
the south along the Pacific coast of Baja Cali-
fornia.
Triopha maculata MacFarland, 1905
Farmer & Collier (1963) reported this species
from Ensenada, Baja California; later Farmer
(1967) extended its range southward to Cabo
San Quintin. Its northern range limit has
recently been extended to Bamfield, Vancouver
Island, British Columbia, Canada (Millen, 1983).
We found one 18 mm long individual (orange
colored body with white spots) on the north side
of Punta Cono, on 16 June 1983. This represents
a southern range extension of approximately
210 km.
Dendrodorididae
Dendrodoris nigromaculata (Cockerell,
in Cockerell & Eliot, 1905)
The known distribution of this rare porostome
is only from its type locality. La Jolla, California
(Behrens, 1980: 58; and McDonald & Nybakken,
1981: 52).
We found 5 specimens of Dendrodoris nigro-
maculata intertidally under rocks on 14 June
1983 at El Tomatal. Total lengths of the living
animals were 8, 9, 15, 25 and 30 mm. The ani-
mals were cream colored; the notum was sprin-
kled with numerous minute black and white
dots, with a row of larger black dots concen-
trated down each side of the dorsum (dividing it
approximately into 3 lengthwise regions); the
6-8 gills were pinkish rose; the notum was
margined with a narrow band of pinkish orange.
This is a southerly range extension of approx-
imately 600 kms, and the first definite report of
this species from elsewhere than its type locali-
ty. (We are aware of the possible synonymy of
Vol. 98 (1)
January 30, 1984
THE NAUTILUS 11
the tropical Panamic Doriopsilla rowena Mar-
cus & Marcus, 1967, with this species).
Acknowledgements
We are grateful to Dr. Enrique Carrillo,
Academic Director of Centro de Investigacion
Cientifica y de Educacion Superior de Ensena-
da, for logistical support; to Roman Lizarraga
Arciniega, Director of the Instituto de Investi-
gaciones Oceanologicas, for expediting our field
work; to the members of the senior author's
graduate course on molluscan ecology (Rodolfo
Moreno, Guadalupe Ochoa, Jose Antonio
Patino, Ernesto Ripa, Ricardo Santes, and
Miguel Angel Tellez); to Gilberto Fuentes G. for
drawing the map; and to M. Pamplona and M.
Kelley.
LITERATURE CITED
Aguilar Rosas, L. 1983. Ocurrencia de algas cafes
(Phaeophyta) en la Bahia Todos Santos, Baja California.
Ciencias Marinas 8(2):25-34.
Aguilar Rosas, L. and H. Bertsch. In press. Algas verdes
(Chlorophyta) de la Bahia Todos Santos, Baja California,
Mexico. Ciencias Mariyias 9(1).
Behrens, D. 1980. PaHfic coast nudibranchs: a guide to the
opisthobranchs of the northeastern Pacific. Sea Challen-
gers, Los Osos, Calif. 112 pp.
1983. Report on the 1982 outer Baja California
expedition. Opisthohranch Newsletter 15(4):18-19.
Bertsch, H. 1979. Tropical faunal affinities of opistho-
branchs from the Panamic province (Eastern Pacific). The
Nautilus 93(2-3):57-61.
1983. Estudios de ecosistemas bentonicos a lo
largo de la costa noroccidental de Baja California, Mexico:
distribucion y presa de varios invertebrados marinos.
Ciencias Marinas 8(2):91-123.
Bertsch, H. and S. Johnson. 1983 Tyoogeografia compara-
tiva de los opistobranquios (Mcilm -a: Gastropoda) con en-
fasis en la cuenca pacifica (Hawan y California): composi-
cion faunal, afinidades provinciales y densidad submareal.
Ciencias Marmiw 8(2): 12.5- 153.
Bertsch, H. and T. Smith. 1983. Range extensions of three
opisthohranch mollusks to the San Diego-La Jolla (Califor-
nia) ecological reserve. Veliger 26(1).
Cockerell, T. D. A. and C. N. E. Eliot. 1905. Notes on a col-
lection of Californian nudibranchs. Joum. Malacol.
12(3):31-53.
Cooper, J. G. 1863. On new or rare MoUusca inhabiting the
coast of California. -No. IL Proc. Calif. Acad. Nat. Sci.
3:56-60.
Farmer, W. M. 1967. Notes on the opisthobranchia of Baja
California, Me.xico, with range extensions- II. Veliger
9(3):340-342.
Farmer, W. M., and C. L. Collier. 1963. Notes on the opis-
thobranchia of Baja California, Mexico, with range exten-
sions. Veliger 6(2):62-63.
Ferreira, A. J. 1977. A review of the genus Triopha
(Mollusca: Nudibranchia). Veliger 19(4):387-402.
Hamann, J. 1981. Range extensions of northeastern Pacific
opisthobranchs. Opisthohranch Newsletter 13(6):21.
MacFarland, F. M. 1905. A preliminary account of the Dori-
didae of Monterey Bay, California. Proc. Biol. Soc. Wash.
18:35-.54.
Marcus, Ev. and Er. Marcus. 1967. American Opistho-
hranch Mollusks. Stud. Trop. Oceanogr. Miami 6:viii-i-
256 pp.
McDonald, G. R. and J. W. Nybakken. 1981. Gui.d.e to the
Nudibranchs of California. American Malacologists, Inc..
Melbourne, Florida. 72 pp.
Millen, S. V. 1983. Range extensions of opisthobranchs in
the northeastern Pacific. Veliger 25(4):383-386.
Sphon, G. G. 1972. An annotated checklist of the nudi-
branchs and their allies from the west coast of North
America. Opisthohranch Newsletter 4{10 + ll):53-79.
WHAT IS ERVILIA CALIFORNICA DALL?
Eugene Coan
Research Associate
Department of Invertebrate Zoology
California Academy of Sciences
San Francisco, "CA 94118
The fact that Ervilia californica Dall, 1916, is
not a member of the eastern Pacific Recent mol-
luscan fauna has not come generally to the
notice of North American workers. According
to Abbott (1974: 493), E. californica occurs from
San Pedro, California, to Baja California and is
"moderately common; just offshore." According
to the recently published catalogue of Bernard
(1983: 41), this species occurs from 25°N to
34°N in the eastern Pacific.
E7n'ilia californica, first introduced as a
nomen nudum in Dall's bivalve checklist (Dall,
12 THE NAUTILUS
January 30, 1984
Vol. 98 (1)
1916a: 40), was validated later that year (Dall,
1916b: 414-415). It was based on a single pair
(USNM 151419), supposedly collected at San
Pedro, California. The catalogue book shows
that it was collected and donated by someone
named Bridwell, who at the same time gave the
USNM some pulmonates from Kansas. The type
specimen was first illustrated by Schenck (1945:
516; pit. 66, figs. 19-20).
Rooij-Schuiling (1972: 60-62; 1973: 236-237)
has shown that the unique type specimen of
Ervilia califomica is indistinguishable from the
western Atlantic E. nitens (Montagu, 1808:
165-166), and she termed the eastern Pacific
locality of the former "dubious" (p. 239). I would
agree with her about the type specimen, which I
have recently studied. Moreover, I have exa-
mined all of the large collections of eastern
Pacific bivalves, and not one has this species
from western North America, the only speci-
mens so labeled being such other genera as
Cumingia. The type was undoubtedly a mis-
labeled Florida specimen.
So, here is a bivalve species that can safely be
removed from our checklists.
LITERATURE CITED
Abbott, R. Tucker. 1974. AnwHcan Seashells. New York
(Van Nostrand Reinhold) 663 pp.; 24 pits.
Bernard, Frank R. 1983. Catalogue of the living Bivalvia of
the eastern Pacific Ocean: Bering Strait to Cape Horn.
Canadian Spec. Publ. Fisheries & Aquatic Sci. ^VMu +
102 pp.; 1 map (15 April 1983).
Dall, William Healey. 1916a. Checklist of the Recent bivalve
moUusks (Pelecypoda) of the northwest coast of American
from the Polar Sea to San Diego, California. Los Angeles
(Southwest Mus.) 44 pp.; 1 port. (28 July 1916)
1916b. Diagnoses of new species of marine
bivalve moUusks from the northwest coast of America in
the collection of the United States National Museum. U.S.
Nation, Mus., Proc. 52 (2183):393-417.
Montagu, George. 1808. Supplement to Testacea Britannica.
With additional plates. London (White) & Exeter
(Woolmer) v + 183 + [5] pp.; pits. 17-30.
Rooij-Schuiling, Louise A. de. 1972. Systematic notes on the
Mesodesmatidae (Mollusca, Bivalvia), and descriptions of a
new species and a new subspecies. Zoologische Mededelin-
gen (Leiden) 46 (5):55-68; 6 figs.
1973. A preliminary report on the systematics
and distribution of the genus Endlia Turton, 1822
(Mesodesmatidae, Bivalvia). Malacologia 14 (1):235-241;
6 figs.; 2 charts.
Schenck, Hubert Gregory. 1945. Geologic application of bio-
metical analysis of molluscan assemblages. Journ. Paleo.
19(5):504-521; pits. 66, 67; 3 text figs.
RANGE EXTENSIONS OF SOME INTRODUCED LAND MOLLUSKS IN
THE BAHAMA ISLANDS, WITH FIRST REPORTS FOR FOUR SPECIES'
Jane E. Deisler
Department of General Biology
University of Arizona
Tucson, AR 85721
and
R. Tucker Abbott
American Malacologists, Inc.
Melbourne, FL 32902
ABSTRACT
Range extensions in the Bahama Islands for 8 species of introduced land snails
are reported. Four additional species are recorded from the Bahama Islands for
the first time. These species probably were introduced by commerce from southern
Florida and Cuba.
During the past 90 years, several surveys have
been published on the land mollusks of the
Bahama Islands (Bendall, 1895; Dall 1905,
1905a; Clapp 1913; Pilsbry 1930; Clench 1933,
1937, 1938, 1938a, 1940, 1942, 1952, 1959, 1961,
1963). These surveys usually were conducted on
'Bureau of Entomology, Gainesville, Contribution No
■)74.
a single island or island-group. However, they
can be used to construct a picture of the ranges
of the taxa found on most of the major islands of
the Bahamas.
There are several prominent adventive taxa
that have appeared on these lists, including 4
large (to 25 mm) and easily distinguishable
species: Orthalicus undatus (Bruguiere),
Vol. 98(1)
January 30, 1984
THE NAUTILUS 13
Zachrysia provisoria (Pfeiffer), Subulina octona
(Bruguiere), and Bulimulus sepulcralis (Poey).
Recent collections (1980, 1981, 1983) in the
Bahama Islands indicate that these species have
extended their ranges since publication of the
latest surveys. The sizes and distinctive ap-
pearances of these taxa make it unlikely that
their presence was overlooked during previous
surveys.
Four other widespread adventive taxa are
present in the Bahama Islands. These are
Lamellaxis gracilis (Hutton), L. micra (Or-
bigny), Opeas puviilum (Pfeiffer), and Hawaiia
minuscula (Binney), all of which have been
reported from these islands in the past. In con-
trast to Zachrysia, Orthalicxis and Bulimulus.
these species are very small (2-10 mm) and could
easily have been overlooked by collectors during
earlier surveys. Thus, it is not possible to deter-
mine whether the ranges of these species have
been extended or simply have become better
understood.
In addition, four other species are reported
from the Bahama Islands for the first time. Two
of these, Praticolella griseola (Pfeiffer) and Dry-
maeus multilineatus (Say), are common in south
Florida, particularly on nursery stock. It is like-
ly that these species were introduced to the
Bahamas on such nursery stock because they ap-
pear to be restricted to landscaped areas. The
Bahamian government does not require inspec-
tion of individual shipments of plants from
Florida (U.S.D.A. 1971), which increases the
likelihood of this mode of introduction.
The third of these taxa, Macroceramus cani-
marensis canimarensis (Pfeiffer), is a native of
eastern Cuba. Its relatively large size (to 20 mm)
indicates that it probably was not overlooked
during previous surveys and therefore was in-
troduced since the work of Clench (1938) on
these islands. The restriction of this species to
the area of Marsh Harbour, Great Abaco Island,
also supports recent introduction, possibly by
commerce.
The fourth species reported for the first time
from the Bahama Islands is Larnellaxis maim-
tianits (Pfeiffer). This small (9-12 mm) species is
distributed widely throughout the tropics and
greenhouses of both hemispheres and so its
presence in the Bahama Islands is not unex-
pected. As with other small achatinids, this
species is easily misidentified. Therefore, it is
difficult to establish when this species might
have been introduced. It also could have been
overlooked by collectors because of its small
size.
The collections on which this study is based
were made on Great and Little Abaco Islands in
1980 by the author, and on North Andros Island
in 1981 by Richard Franz, Florida State
Museum. Additional records were gathered by
an examination of the collections housed at the
Florida State Museum, Gainesville, Florida.
ACHATINIDAE
Subulina octona (Bruguiere)
Bulimus octonus Bruguiere, 1792, Encycl. Meth. 1:32.5.
This species is one of the most widespread of
the adventitious taxa. It is a native of the Carib-
bean and was originally described from Guade-
loupe Island and Santo Domingo. It has been in-
troduced into such remote localities as Ceylon,
Africa, the East Indies, Pennsylvania, and
southern Florida (Pilsbry, 1946). Subulina oc-
tona has been reported in the Bahama Islands
from Nassau, New Providence Island (J. J.
Brown, 1886; W. Bendall, 1895), Arthurs Town,
Cat Island (Clench 1938a), Foxtown, Little
Abaco Island (Clench 1938), and Rock South,
Eleuthera Island (Clench 1952). Collections
made in 1980 and 1981 indicate that this snail is
present at Marsh Harbour, Great Abaco Island,
and at Owenstown, North Andros Island. In ad-
dition, there is an undated lot collected at Mastic
Point, North Andros Island by L. D. Thompson.
S. octona is represented also in the Florida State
Museum collected by 1 lot collected on San
Salvador Island in 1963 by D. R. Paulson.
Specimens Examined. - GREAT ABACO
ISLAND: Marsh Harbour (UF 40225, 40184,
40221). LITTLE ABACO ISLAND: Foxtown
(UF 40185). NEW PROVIDENCE ISLAND:
Nassau (UF 20090, 20092). NORTH ANDROS
ISLAND: Owenstown (UF 35767); Mastic Point
(UF 20091). SAN SALVADOR ISLAND: 3.4
miles south of Cockburn Town (UF 39284).
Lamellaxis gracilis (Hutton)
Bulimus granlis Hutton, 1834, Jour. Asiatic Soe. Bengal
3:93.
This species probably is the most widely distri-
buted land snail, having been carried by man
throughout the tropical regions of the world
(Pilsbry and Bequaert, 1927). It even has
14 THE NAUTILUS
January 30, 1984
Vol. 98(1)
become established in European greenhouses.
In the Bahamas it has been reported at West
End on Grand Bahama Island (Clench 1938),
Arthurs Town and Orange Creek, Cat Island
(Clench 1938a), Bannermantown and Rock
Sound, Eleuthera Island (Clench 1952), 2 miles
east of Matthew Town, Great Inagua Island
(Clench 1959), and Marine Farm Hill, Cripple
Hill, and Church Grove, Crooked Island (Clench
1963). Dall (1905) reported Opeas subula Pfeif-
fer (= gracilis) from Nassau, New Providence
Island, and from Marsh Harbour, Great Abaco
Island. Recent collections indicate that L.
gracilis is also present at Foxtown, Little Abaco
Island, where it was collected for the first time.
Specimens Examined - LITTLE ABACO
ISLAND: Foxtown (UF 40229, 39167). NEW
PROVIDENCE: Nassau (UF 1209).
Lamellaxis micra (Orbigny)
Helix micra Orbigny, 18.3.5. Magazin de Zool. p. 9.
Lamellaxis micra was originally described
from Bolivia but has a wide range throughout
northern South America to Mexico and the
West Indies (Pilsbry 1946). This species also has
been introduced into Florida (Burch 1962). In
the Bahama Islands, Dall (1905) reported L.
micra from Nassau, New Providence Island, as
well as from Mangrove Cay, North Andros, and
Nassau, New Providence, under the name Opeas
octonoides C. B. Adams { = micra). Lam.ellaxis
micra has been reported also from Abraham's
Bay, Mariguana Island (Clench 1937), and
Clarence Town, Long Island (Clench 1940).
Specimens in the Florida State Museum collec-
tion confirm the presence of this species on
North Andros and indicate that L. micra also is
found on San Salvadore Island (1964). It was
collected recently on Little Abaco Island (1980)
as well.
SpeciTnens Examined - LITTLE ABACO IS-
LAND: Foxtown (UF 39184). NORTH AN-
DROS ISLAND: Nicholas Town (UF 7504);
Mastic Point (UF 40331). NEW PROVI-
DENCE: Nassau (UF 40330). SAN SALVA-
DOR ISLAND: 3.4 miles south of Cockburn
Town (UF 39282).
Lamellaxis mauritianus (Pfeiffer)
Bulimus mauritianus Pfeiffer, 1852, Proc. Zool. Soe. Lon-
don 20: l.'SO.
The type locality for this species is Mauritius
(Pilsbry 1906). However, this taxon had been
spread by commerce throughout the tropics to
such a degree at the time it was described that
its original range could not be discerned (Pilsbry
1946). This species has never been reported
from the Bahama Islands before. However, the
small size (9-12 mm) of the shell and the simi-
larity of shape to other adventitious achatinids
make this species easy to overlook. It is reported
here from Nassau, New Providence Island, but
may be much more widely spread in the islands.
Specimens Examined - NEW PROVI-
DENCE: Nassau (UF 40329).
Opeas pumilum (Pfeiffer)
Bulimus pumilus Pfeiffer, 1840, Archiv. f. Natiirgeschichte
1:2.52.
This snail is a native of the New World tropics
and has been introduced widely in greenhouses
in the northern United States and England
(Pilsbry 1946). It is small and has frequently
been misidentified as one of the other achati-
nids. 0. pumilum has been reported from North
Andros Island (Pilsbry 1930) and South Bimini
Island (Clench 1942). It is now present on the
Carter Cays, Powell Cay, and Great Abaco
Island.
Specimens Examined - CARTER CAYS: Lit-
tle Carter Cay (UF 39142, 39149). GREAT
ABACO ISLAND: Marsh Harbour (UF 39206);
Powell Cay (UF 39229, 39214). NORTH AN-
DROS ISLAND: Mastic Point (UF 18602).
Camaenidae
Zachrysia promsoria (Pfeiffer)
Helix immmria Pfeiffer, 1858, Malak. Blatt. 5:39.
This is a large snail (25-30 mm) that is native
to Cuba. It was introduced into southern Florida
prior to 1918 (G. H. Clapp, 1919) where it is
proving to be an agricultural pest on nursery
stock in Dade County. Z. provisoria also has
been introduced into the Virgin Islands, on the
island of St. Croix. This species has been
reported in the Bahama Islands from Nassau,
New Providence Island (J. J. Brown, 1886; Ben-
dall, 1895), and Nield's Place, Little Abaco
Island (Dall 1905). Dall (1905a) reported it from
"Abaco" but gave no further locality data for
these islands. Z. provisoria has been reported
also from Foxtown, Little Abaco Island, and
Great Abaco Island (Clench 1938), and Eleu-
thera Island (Clench 1938, 1952). The continuing
Vol. 98(1)
January 30, 1984
THE NAUTILUS 15
presence of this species on both Great and Little
Abaco Islands was confirmed by collections
made in 1980. It occurs in great numbers in
moist shady areas near human habitation. Z.
provisoria was collected also on Grand Bahama
Island in 1963 by M. L. Paulson and on North
Andros Island in 1981 by R. Franz. Both of
these collections constitute new records for the
species in the Bahama Islands. R. T. Abbott {in
Hit.) informs me that he observed living speci-
mens in Dec. 1983 at Green Turtle Cay, Marsh
Harbour, Hopetown, Abaco Island, and Spanish
Wells, Eleuthera Island, and Nassau, New Pro-
vidence.
Specimens Examined - GRAND BAHAMA
ISLAND: Freeport (Marco City) (UF 39433).
GREAT ABACO ISLAND: Marsh Harbour (UF
39354). LITTLE ABACO ISLAND: Foxtown
(UF 40203, 40208, 40209, 40211); Hawksbill
Cays (UF 40183). NEW PROVIDENCE:
Nassau (UF 1332, 7602, 527, 529, 16600).
NORTH ANDROS ISLAND: Owenstown (UF
35797, 35740).
POLYGYRIDAE
Praticolella griseola (Pfeiffer)
Helix griseola Pfeiffer. 1841, Symbol. Hist. Hel. 1:41.
This species has not been recorded before
from the Bahama Islands. It is a native of Cen-
tral America, with a range extending from Nica-
ragua to Brownsville, Texas. Praticolella grise-
ola has been introduced into Hispaniola, Cuba,
southern Florida, and the Cayman Islands. It
has recently been collected in the Bahama
Islands at Marsh Harbour, Great Abaco Island
(1980). It also has been reported to occur on
North Andros Island (E. P. Keferl, personal
communication).
Specimens Examined - GREAT ABACO
ISLAND: Marsh Harbour (UF 40189, 40222).
BULIMULIDAE
Bulimulus sepulcralis (Poey)
Bulimiis sepulcralis Poey, 1853, Mem. Hist. Nat. Cuba.
1:203.
This snail was described originally from
Havana, Cuba, and was first reported in the
Bahama Islands from Nassau, New Providence
Island (J. J. Brown, 1886 and Bendall, 1895).
Clench (1938, 1952) reported this species from
Settlement Point, Grand Bahama Island, and
from Eleuthera Island, commenting that in each
case it represented an introduction. Recent col-
lections show that B. sepulcralis is found also on
Great Abaco Island, living under rocks in damp
areas. Bendall reported it as "very common on
damp ground."
Specimens Examined - ELEUTHERA IS-
LAND: Spanish Wells (UF 18303), GREAT
ABACO ISLAND: Marsh Harbour (UF 40226,
40219, 40188, 40226), NEW PROVIDENCE
ISLAND: Nassau (UF 36643, 40235); Windsor
Field (UF 40236); unspecified (UF 1185, 16604,
18304).
Drymaeus multilineatus (Say)
Bulimus multilineatus Say, 1825, J. Acad. Nat. Sci. Phila.
5:120.
This species is distributed throughout the
Caribbean, being found in Colombia, Venezuela,
Curacoa, Yucatan, Cuba, and the southern half
of Florida (Pilsbry 1946). It has not been re-
corded before from the Bahama Islands. In
1981, 2 specimens were collected on a hibiscus
bush in Androstown, North Andros Island, by
R. Franz. This species is not known to be an
adventitious taxon but it has been introduced to
the Pacific island of Guam (C. Christensen, per-
sonal communication).
Specimeyis Examined - NORTH ANDROS
ISLAND: Androstown (UF 35738).
Orthalicus undatus (Bruguiere)
Bulimus undatus Bruguiere, 1792. Encycl. Meth. Vers.
1:.320.
This large tree snail, reaching a length of
about 50 mm, has a history of being introduced,
probably from Trinidad, to various parts of the
West Indies, including Jamaica, the Lesser An-
tilles and the Bahamas (Pilsbry, 1899, p. 106). It
occurs near human habitation and may be found
on walls, the sides of houses and in garden trees,
especially during rainy periods. It was first
reported (as zebra Brug.) in the Bahamas from
New Providence Island by W. Bendall in 1895
and later from Andros Island by J. J. White
probably in the 1880's (Pilsbry, 1899, p. 107).
Barbara Mason of Santa Ana, California, found
a live specimen in Spanish Wells, northern
Eleuthera, in December 1983; and at the same
time and place, local residents informed R. T.
Abbott that they had been seeing them common-
16 THE NAUTILUS
January 30, 1984
Vol. 98(1)
ly in their backyards for at least the last 20
years.
Specimens Examined - ELEUTHERA IS-
LAND: Spanish Wells, R. T. Abbott, 1983 (UF
uncataloged).
ZONITIDAE
Hawaiia minuscula (Binney)
Helix minuscula Binney, 1840, Boston J. Nat. Hist. 3:43.5.
Hawaiia minuscula is widely distributed
across the United States and Central America.
It has been carried apparently by commerce to
several Pacific islands, Japan, the West Indies,
and to greenhouses in Great Britain (Pilsbry
1946). This species was reported first in the
Bahama Islands from New Providence (Dall
1905). It is found also on North Andros Island in
the area of Lake Forsyth (Pilsbry 1930) and is
represented in the Florida State Museum collec-
tions by a lot collected in Androstown, North
Andros Island, in 1981. H. minuscula is re-
corded here for the first time from Great Abaco
Island, where it was collected in 1982 by D. M.
Biggar, Jr. The small size of this species (2-5
mm) allows it to be easily overlooked by collec-
tors. It is difficult to ascertain whether or not it
represents a true introduction because of this
possibility of accidental neglect.
Specimens Examined - GREAT ABACO IS-
LAND: Dundastown (UF 39319), Marsh Har-
bour (UF 39351). NORTH ANDROS ISLAND:
Androstown Airport (UF 39297).
UROCOPTIDAE
Macroceramus canimarensis canimarensis
(Pfeiffer)
Bulimiis canimensis Pfeiffer, 1839, Archiv. f. Naturg.
1:351 (typographical error; emended to mnimarensis
Pfeiffer, in Philippi, 1843.
This species is native to central and eastern
Cuba (Pilsbry 1904). It has not been recorded
before from the Bahama Islands. M. c. cani-
m,arensis was collected first on Great Abaco
Island in 1982 by D. M. Biggar, Jr. It appears to
be limited to areas near Marsh Harbour where
other Cuban snails have been introduced.
Specim,ms Examined - GREAT ABACO IS-
LAND: Dundastown (UF 39315); Marsh Har-
bour (UF 39271).
Acknowledgments
This study was supported by travel funds pro-
vided by the Florida State Museum. I would like
to thank David M. Biggar, Jr. for his assistance
in the field, Fred G. Thompson for his comments
on this manuscript, and Kurt Auffenberg for his
insights on Lam.ellaxis and Opeas.
LITERATURE CITED
Bendall, Wilfred. 1895. A list of the land Mollusca of the is-
land of New Providence, Bahamas, with an enumeration
of the species recorded from other islands. Proc. Mai. Soc.
London 1:292-295.
Brown, J. J. 1886. Notes on the Mollusca of the Bahamas,
The Conchologists' Exchange, 1(4):12-13.
Burch, J. B. 1962. How to Know the Eastern Land Snails.
William C. Brown, Dubuque, Iowa. 214 pp.
Clapp, G. H. 1913. Land shells collected on the Bimini Is-
lands, Gun and Cat Cays, Bahamas. The Nautilus 27:
63-64.
1919. Cuban Mollusks Colonized in Florida. The
Nautilus 32(3):104-105.
Clench, W. J. 1933. Notes and descriptions of land mollusks
from the Bahama Islands, based mainly upon collections
obtained during the Utowana expeditions of 1932 and
1933. Proc. New England Zool. Club 13:77-100.
1937. Shells of Mariguana Island, with a review
of the Bahama Helicinidae and descriptions of new Baha-
ma species. Proc. New England Zool. Club 16:57-79.
1938. Land and freshwater mollusks of Grand
Bahama and the Abaco Islands, Bahama Islands. Mem.
Soc. Cub. Hist. Nat. 12(4):303-333.
. 1938a. Origin of the land and freshwater mollusk
fauna of the Bahamas, with a list of the species occurring
on Cat and Little San Salvadore Islands. Bull. Mus. Comp.
Zool. 80(14):481-541.
1940. Land and freshwater mollusks of Long
Island, the Bahama Islands. Mem. Soc. Cub. Hist. Nat.
14(1):.3-17.
1942. Land shells of the Bimini Islands, Bahama
Islands. Proc. New England Zool. Club 19:53-67.
1952. Land and freshwater mollusks of Eleu-
thera Island, Bahama Islands. Rex\ Soc. Malac. de la Torre
8(3):97-116.
1959. Land and freshwater mollusks of Great
and Little Inagua, Bahama Islands. Bull. Mus. Comp.
Zool. 121(2):29-53.
1961. Land and freshwater mollusks of the
Caicos, Turks, and Ragged Islands and islands on the Cay
Sal Bank, Bahamas. Occ. Pap. Moll. Han-ard 2(26):
229-259.
1963. Land and freshwater mollusks of the
Crooked Island group, Bahamas. Bull. Mus. Comp. Zool.
128(8):395-413.
Dall, W. H. 1905. Report on land and freshwater shells col-
lected in the Bahamas in 1904 by Mr. Owen Bryant and
others. Smithsonian Misc. Colls. 47:433-452.
1905a. The land shell fauna of the Bahama Is-
lands, p. 29-42 In Shattuck, G. B. The Bahama Islands.
Geographic Soc. Baltimore.
Pilsbry, H. A. 1899. Bulimulidae Man. Conch. (2) 12:2,58 pp.,
47 pis.
Vol. 98(1)
January 30, 1984
THE NAUTILUS 17
1904. Urocoptidae, Achatinidae. Man. Conch. (2)
16:i-xl, 1-329.
1906. Achatinidae: Stenogyrinae and Coelia.\i-
nae. Man. Conch. (2) 18:i-xii, 1-357.
1930. List of the land and freshwater mollusks
collected on Andros, Bahamas. Proc. Acad. Nat. Sci. Phil-
cdelphia 72:297-302.
1946. Land Mollusca of North America (North of
Mexico). Acad. Nat. Sci. Philadelphia, Monographs No. 3,
vol. 2(1).
Pilsbry, H. A. and J. Bequeart. 1927. Aquatic mollusks of
the Belgian Congo. Bull. American Mus. Nat. Hist. 53(2):
69-609.
United States Department of Agriculture. 1971. Plant
quarantine import requirements of the Bahamas. July 2.
Agricultural Quarantine Inspection Division. 2 pp.
RIB NUMBER AND SHELL COLOR IN HYBRIDIZED SUBSPECIES OF
THE ATLANTIC BAY SCALLOP, ARGOPECTEN IRRADIANS'
John Kraeuter^
Laura Adamkewicz\ Michael Castagna, Robert Wall,
and Richard Karney^
ABSTRACT
Bay scallops, Argopecten irradians (Lamarck), from populations with low rib
number (Texas) and high rib number (Virginia) were bred separately and also
hybridized. The results suggest that rib number is under genetic control and that
the two populations are genetically differentiated. Scallops taken from a popula-
tion polymorphic for shell color (Massachusetts) were bred in groups, each group
containing a single color. The. results suggest that color is also under genetic con-
trol and is not strongly influ£nced by the environment.
The Bay Scallop, Argopecten irradians
(Lamarck), occurs in disjunct populations from
Massachusetts to the Texas gulf coast. Three
subspecies are recognized: Argopecten irra-
dians irradians (Lamarck) from Massachusetts
to New Jersey, Argopecten irradians concen-
tricu^ (Say) from New Jersey to Louisiana, and
Argopecten irradians amplicostatus (Dall) from
Galveston to Laguna Madre along the Texas
coast (Waller, 1969). Clarke (1965) has sug-
gested that the Texas populations should be con-
sidered a separate species distinguished by
fewer ribs per shell and more inflated valves
than other populations. However, the genetic
basis, if any, of these shell characteristics is not
known. Struhsaker (1968) has found a genetic
'Contribution No. 1157 from Virginia Institute of Marine
Science, College of William and Mary, Wachapreaque, VA
23480.
'Crane Aquaculture Center, Baltimore Gas and Electric
Company. P.O. Box 1475, Baltimore, MD 21203.
^Department of Biology, George Mason University. Fairfax,
VA 22030.
••Martha's Vineyard Shellfish Group, Box 1552, Oak Bluffs,
MA 02557.
basis for shell sculpture in the gastropod Lit-
torina picta and Staiger (1957) has demon-
strated that shell thickness is genetically con-
trolled in the gastropod Nucella lapillus
(formerly Purpura lapillus).
The subspecies A. i. irradians is known to be
polymorphic for shell color and pattern. One or
both valves can be orange, brown, yellow or
white and the color can be distributed as solid,
banded or mottled. Shell color has been shown
to be controlled by a single gene in the mussel
Mytilus edulis (Innes and Haley, 1977) as has
the color pattern notata in the clam Mercenaria
mercenaria (Chanley, 1961). However, diet is
also known to influence shell color and banding
in some mollusks (Moore, 1936; Underwood and
Creese, 1976). Genetic and environmental influ-
ences on shell color have not been investigated
in A. irradians.
When shell characteristics are used to distin-
guish populations of mollusks, information on
the genetic control of the trait is very desirable.
We report the results of several experimental
crosses made to investigate the inheritance of
rib number and shell color in A. irradians.
18 THE NAUTILUS
January 30, 1984
Vol. 98(1)
Materials and Methods
All the adult scallops were mated and their
offspring reared at the Virginia Institute of
Marine Science (VIMS) Eastern Shore Labora-
tory using methods described by Castagna
(1975). For the investigation of rib number,
scallops were imported from Laguna Madre,
Texas. These were mated among themselves
(Texas cross) as were animals from a native
Virginia stock (Virginia cross). Individuals from
the two stocks were mated to produce an F,
(hybrid cross). All three matings were made at
the same time and all offspring were the same
age when scored for rib number. During the
growth period, conditions were kept as uniform
as possible.
Scallops for the shell-color matings were ob-
tained from Sengekontacket Pond on Martha's
Vineyard, Massachusetts. The animals were
sorted into three groups based on the colors of
their top and bottom valves: orange top-orange
bottom (o/o, 18 scallops), brown-white (b/w, 21
scallops), and white-white (w/w, 32 scallops).
Each group was mass spawned. When the off-
spring were 1.5 to 2.0 cm long, they were scored
for top and bottom valve color.
Results and Discussion
Table 1 shows the distribution of shell colors
among the offspring of each color group. As ex-
pected in mass crosses of wild-caught individ-
uals, no Mendelian ratios occur. However, the
distribution of colors was completely different in
each of the matings and no single parental
phenotype produced the entire range of colors
among its offspring. All of the white offspring
and none of the orange ones came from the
mating of white-shelled parents. One phenotype
(both valves brown), that was not present in any
of the parents, appeared among the progeny of
TABLE 1. Distribution of shell colors in offspring of mass
matings of single colors. Colors are o = orange, b = brown,
w = white, y = yellow. Top valve is listed first, bottom valve
second.
all three crosses and the phenotype "striped
yellow", also not present in the parents, ap-
peared in the b/w cross.
These results are not compatible with any hy-
pothesis that the environment, particularly the
diet, has a strong influence on shell color. All
three crosses were reared in natural sea water
from a common source. Furthermore, the off-
spring were reared in Virginia where the native
population is not polymorphic for these shell
colors. The results are compatible with the hy-
pothesis that shell color is genetically con-
trolled, possibly by only a few genes. Because
none of the parental phenotypes produced uni-
form progeny none of the three phenotypes
tested can represent a single, homozygous
genotype.
Table 2 presents the data on number of ribs
per top valve in the Texas and Virginia crosses
and their F, hybrid. The Texas and Virginia off-
spring were distinctly different with no overlap
in number of ribs. The maximum number of ribs
for a Texas shell was 18 and the minimum for a
Virginia shell was 19. The mean rib number for
the Texas scallops was 15.96 and for the
Virginia scallops it was 20.39. Clearly the hybrid
cross was intermediate both in range of rib num-
bers, 17 to 21, and in mean rib number, 18.90.
However, the hybrid mean of 18.90 differed
TABLE 2. Distribution of rib number on the top valves of
.4. irradians from experimental crosses.
Number
CROS.S
Vol. 98(1)
January 30, 1984
THE NAUTILUS 19
significantly from the mid-parent value of 18.18
and was closer to the Virginia mean than to the
Texas mean. A one-way analysis of variance
showed a highly significant difference in rib
number among the three crosses (F ratio = 440
with d.f. 2 and 297, error mean square = 1.15,
p<0.0001). These results are exactly what one
expects for a polygenic trait when two geneti-
cally distinct strains, or in this case subspecies,
are crossed (Falconer, 1981).
An examination of size differences among the
three crosses also supports the hypothesis that
differences in rib number are genetically deter-
mined. Figure 1 shows the mean and range of
shell length (lip to hinge) for each of the rib
numbers in each of the crosses. The three
crosses were significantly different in shell
length with the Texas scallops smallest and the
hybrids exactly intermediate (mid-parent =
32.3). A one-way analysis of variance of shell
length among crosses gave an F ratio of 40 with
2 and 169 degrees of freedom, p < 0.001.
However, when each cross was examined separ-
ately, there was no tendency for size to increase
with increasing rib number. The regression
coefficient of size on rib number was not
significantly different from zero in any of the
three crosses. One cannot conclude that the
Texas progeny have low rib numbers merely
because they are small.
Interpretation of the size differences them-
selves is less clear. The intermediate perfor-
24
0£. Yl
LU
CO
^ 20
Zl8
OL 16
M
I • — I
I • (
10 30 50 10 30 50 10 30 50
VIRGINIA HYBRID TEXAS
;o8 6 \-m x:26.o
SHELL LENGTH (mm)
FIG. 1. The range of shell lengths and the mean for each
rib number class in Argopecten irradians. The Virginia,
Hybrid and Texas scallops are the same as those described in
Table 2.
mance of the hybrid cross does suggest that the
differences among the crosses is genetic and ad-
ditive. However, the stocks may have differed in
genes for temperature adaptation rather than in
genes for growth rate. The Texas parents were
native to an area of higher water temperature
than that in which their offspring were raised.
Rearing offspring at a temperature other than
that to which their parents were adapted has
been shown to affect growth rate in clams
(Menzel, 1962).
Conclusions
From this study, shell color appears to be
under genetic control, to be insensitive to the
environment and, therefore, to be a valid char-
acter for distinguishing between individuals and
between populations. Rib number also appears
to be genetically controlled and a good character
for distinguishing individuals and populations.
The data on rib number and shell length show
that rib number is a valid characteristic for
distinguishing two shells regardless of their ab-
solute sizes. The data also suggest that popula-
tions of different geographical origin are
genetically differentiated for rib number. The
Texas scallops maintained their characteristical-
ly lower number of ribs despite being bred and
reared in Virginia.
Acknowledgements
The authors wish to thank Ronald C. Circe for
collecting and shipping the Texas scallops
VIMS. We also thank Allan Sherald and
Stephan Taub for their critical review of this
manuscript.
LITERATURE CITED
Castagna, M. 1975. Culture of the bay scallop, Argopecten
irradians, in Virginia. Mar. Fish. Ren. 37:19-24.
Chanley, P. E. 1961. Inheritance of shell markings and
growth in the hard clam, Venus mercenaria. Proc. Natl.
Shellfish Assoc. 50:163-169.
Clarke, A. H., Jr. 1965. The scallop superspecies Aequi-
pecten irradians (Lamarck). Malarologia 2:161-188.
Falconer, D. S. 1981. Introduction to Quantitative Genetics.
second edition. Longman, Inc., New York.
Innes, D. J. and L. E. Haley. 1977. Inheritance of a shell-
color polymorjihism in the mussel. J. Hered. 68:203-204.
Menzel, R. W. 1962. Seasonal growth of northern and south-
ern quahogs, Mercenaria mercenaria and M. campechien-
sis. and their hybrids in Florida. Proc. Natl. Shellfish
Assoc. 53:111-119.
20 THE NAUTILUS
January 30, 1984
Vol. 98(1)
Moore, H. B. 1936, The biology of Purpura l.apillus. I. Shell
variation in relation to environment. J. Mar. Biol. Ass.
U.K. 21:61-89.
Staiger, H. 1957. Genetical and morphological variation in
Purpura lapillus with respect to local and regional dif-
ferentiation of population groups. Coll. Intern. Biol. Mar.
St. Roscoff. AnneeBiol. 33:251-2.58.
Struhsaker, J, W. 1968, Selection mechanisms associated
with intraspecific shell variation in Littorina picta (Proso-
branchia: Mesogastropoda), £1)0/. 22:459-580.
Underwood, A. J. and R. G. Creese. 1976. Observations on
the biology of the trochid gastropod Austrocochela con-
st ricta (Lamarck) (Prosobranchia). II. The effect of avail-
able food on shell-banding pattern. J. Exp. Mar. Biol.
Ecol. 23:229-240.
Waller, T. R. 1969. The evolution of the Argopecten gibbus
stock (Mollusca: Bivalvia), with emphasis on the Tertiary
and Quaternary species of Eastern North America.
Palemit. Soc. Mem. 3 (J. Paleont. 43(5 supp.)n-l25.
DEPTH DISTRIBUTION OF SEVEN SPECIES OF GASTROPODS
IN DOUGLAS LAKE, MICHIGAN
Timothy G. Laman, N. Craig Boss and Harvey D. Blankespoor
Department of Biology
Hope College
Holland, MI 49423
ABSTRACT
Variations in the depth distribution and size ofoperculate and pulmonate gas-
tropod populations were studied in Douglas Lake, Michigan. The species studied,
in order of decreasing abundance, were: Helisoma campanulata, Campeloma
decisum, Goniobasis livescens, H. anceps, Lymnaea catascopium, Physa Integra,
and P. parkeri. Peak densities occurred at 0.5m for G. livescens, Sm for C.
decisum, 6m for H. campanulata, H. anceps, L. catascopium, and P. Integra, and
9m for P. parkeri. Helisoma campanulata were found at greater depths as water
temperatures rose. Decreases in population size occurred for H. anceps, L.
catascopium, P. Integra, and P. parkeri while an increase occurred for C.
decisum.
Snails represent an important component of
the benthic fauna of most streams and lakes.
However, relatively little information exists
either on the distribution of these aquatic
gastropods at various depths, or their distribu-
tion changes with time. In Michigan, several
earlier investigations involved snails from
Douglas Lake. These studies include: Baker
(1912), Eggleton (1931, 1935), Cheatum (1934),
and Clampitt (1973, 1974). In his most recent
study, Clampitt collected Physa Integra on a
monthly basis to follow its seasonal migratory
cycle. With this exception, studies on the depth
distribution of gastropods in Douglas Lake have
for the most part been based on single collec-
tions at various locations.
Several workers have shown that SCUBA div-
ing can permit direct, quantitative sampling
that is useful in various ecological studies
(Schmid, 1965; Cavancara, 1972; Harman, 1972;
Clampitt, 1973, 1974; Pace et. ai, 1979). This
study was undertaken using SCUBA to assist in
examining the depth distributions and popula-
tion densities of seven freshwater snail species
by making regular collections during an eight-
week period.
Materials and Methods
The depth distribution of gastropods was
studied by making nine collections between
June 20 and August 11, 1982, at a site in
Douglas Lake, Cheboygan County, Michigan.
An area on East Point (see Figure 1) was se-
lected for study because it supported a diversity
of gastropod species through a range of depths.
At this site, a sandy shoal with a very gradual
decline extends to a depth of Im, where a fairly
sharp drop off begins. The steepness of the slope
Vol. 98(1)
January 30, 1984
THE NAUTILUS 21
NORTH
I- I S: ITA 1 L
U of M BIO. STATION
9 . Om
EAST
POINT
FIG. 1. Map of Douglas Lake with close up of
East Point area showing depth contours and
sampling transects (indicated by dots).
gradually decreases to the bottom of a fairly
level basin 12m deep. With increasing depth, the
predominantly sandy bottom gradually becomes
covered by a flocculent organic layer. Sub-
merged macrophytes are most common at
depths of 2-5m, the predominant species being
Potamogeton sp., Elodea canadensis, and Myrio-
phyllum exalhescens. Though sparse over most
of the study area, fairly dense macrophyte
growth is present at the east end of the site.
The use of SCUBA facilitated setting up the
study site and making collections. Sampling
transects along the depth contours of 0.5m, 3m,
6m, and 9m were each marked by ten stakes
placed 3m apart. Depths were determined using
a calibrated float, line, and weight system. The
distances from shore to the centers of the four
transects were 21.5, 29.5, 36, and 46m. Two
sand filled "hula-hoops" each 0.5m^ in area were
sequentially placed on either side of each stake,
resulting in a 1 m- sample per stake, and a total
sample area of lOm^ for each depth. All snails on
or just beneath the substrate within the hoops
were collected manually and placed in pre-
labeled muslin bags. After examination in the
laboratory, all snails were released at the depth
at which they were collected. Temperatures
were measured at each depth for every collec-
tion.
Population densities for each sampling tran-
sect were determined by averaging the values
for the ten sampling sites. Linear regression
analysis was used to determine if statistically
significant trends occurred during the study
period in depth distribution, population size, and
water temperature.
Results
The study area was found to support a number
of species of gastropods, which varied in depth
distribution and population densities. The fol-
lowing gastropods, in order of decreasing over-
all abundance, were the focus of this study:
Helisoma carnpanulata, Campeloma decisum,
Goniobasis livescens, H. anceps, Lynmaea cata-
scopium, Physa iyitegra. and P. parkeri. Other
gastropods collected in the area but occurring in
smaller numbers were: L. stagnalis, P. sayii,
Valvata tricarinata, Amnicola sp., Gyraulus
parviis. and Menetus sp. These species were not
included in this study.
The population densities for all nine collec-
tions are summarized in Table 1. The largest
overall snail population occurred at 6m, fol-
lowed by 9m, 3m, and 0.5m. The single most
abundant snail was Helisoma campanulata
which had an average density of 18.7 snails/m^
at 6m.
The depth distribution of each species, aver-
aged over the nine collections, is shown
graphically in Figure 2. The characteristic
distribution patterns of each species are worth
noting. Physa integra, Lymnaea catascopiuTn,
Helisoma campanulata, and H. anceps popula-
22 THE NAUTILUS
January 30, 1984
Vol. 98(1)
TABLE 1. Population density of each of the seven snail
species by depth, averaged for all nine collections.
tions are largest at 6m and have similar distribu-
tions patterns. The population of P. parkeri in-
creases with depth and is maximal at 9m, while
Campeloma decisum has a pattern with popula-
tion size greatest at 3m. The Goniobasis
livescens population, on the other hand, is
largest in shallow water and decreases with
depth.
Mean depths were calculated for each species
from every collection and were used to deter-
mine if changes in depth distribution occurred
during the eight- week period over which the col-
lections were made. Physa integra and Heli-
soma campanulata both showed a significant
(P<0.05 and 0.01 respectively) increase in mean
depth over the course of the nine collections, in-
dicating that a gradual migration to deeper
water was occurring (Fig. 3). Campeloma
decisum showed no significant trend over the
period as a whole but showed a significant
(P<0.01) increase in depth over the first half of
the period and a significant (P<0.05) decrease
over the second half (Fig. 3). The mean depth for
C. decisum reached its deepest point on July 14.
None of the other four species showed any
significant changes in depth distribution during
the study.
Population sizes were examined to see if
changes occurred for any of the species over the
course of the study. Significant (P<0.01)
decreases occurred for Physa integra, P.
parkeri, Lymnaea catascopium, and Helisoma
anceps. A significant (P<0.01) decrease occur-
red for Campeloma decisum, while no significant
changes occurred for Goniobasis livescens or H.
campanulata.
Analysis of water temperature data showed
that a significant warming trend was present
over the first six weeks of the study at depths of
0.5m, 3m, and 6m (P<0.02, 0.01, and 0.01
respectively). No significant changes in temper-
ature occurred at the 9m depth.
p. parkeri I. catascopium C. Jecisum £. livescens n_. campanulata H. anceps
0.5
3,0
6.0
9.0
/ 50 ', \
Percent of individual population ^scale: J
FIG. 2. Depth distribution of each of the seven snail species averaged over all nine collections.
Vol. 98 (1)
8,0
7.0
January 30, 1984
THE NAUTILUS 23
6.0
5.0 ■
^.o
Q^MEELfitlA DEQSUK
I
7/28
— r-
8/11
b/19
U/J4
-,'14 -/21
TiriE (month aw day)
B/4
FIG. 3. Changes in mean depth of Physa tntcyra, Heiisoma campanulata. and Campeloma decisum during the summer of
1982.
Discussion
The large and diverse populations of snails
naturally present in the study area must be the
result of appropriate substrate and an abun-
dance of food. Harman (1972) has suggested
that gastropod distribution is directly related to
substrate type and has categorized snails as to
preferred substrates. Of five species common
between his study and this one, the preferred
substrate of Lyynnaea catascopium, Campeloma
decisum, Goniobasis livescens, and Heiisoma
anceps was littoral silt and detritus in both
studies. While Harman found Physa integra to
prefer eulittoral silt and detritus, in this study,
where the eulittoral zone had a sandy substrate,
P. integra was most abundant on silt and
detritus in the littoral zone. This could suggest
that substrate type is a more important environ-
mental factor than water depth in determining
the distribution of P. integra in a lake.
Clampitt (1973) sampled pulmonate snails at
four locations in Douglas Lake in July, 1969, and
July, 1970, and reported depth distributions.
One of his sampling sites was located very near
the site of this study, but he found only Physa
integra, Heiisoma campamdata and H. anceps
to be present and found their depth distribution
to vary greatly between the two years he sam-
pled. He found H. campanulata to be most abun-
dant at 5.5m in 1970 and this result is similar to
that obtained in this study, however, no other
similarities were present and considerable
changes in the snail population of the area seem
to have occurred over the twelve years between
the two studies. It appears that populations of
snails in Douglas Lake are not stable over long
periods. They may vary considerably from year
to year, possibly under the influence of such con-
ditions as weather and availability of food.
One example of a short term effect that
weather had on a population was witnessed dur-
ing the study. On July 7, an unusually strong
west wind produced waves which dislodged
Goniobasis livescens from the shoal and an
undertow current carried many of them over the
drop off to deeper water. Very few G. livescens
were collected at the 0.5m contour that week
but the majority observed below the drop off
were ascending the slope. Two weeks after the
storm, the G. livescens population on the shoal
24 THE NAUTILUS
January 30, 1984
Vol. 98(1)
had returned to its original level. It is not sur-
prising that G. livescens is the dominant species
at the 0.5ni level, since pulmonate snails, with
thinner shells and no operculum could probably
not withstand such wave action.
A collection transect was not set deeper than
9m because snail numbers decreased rapidly
below this depth and virtually no snails were
seen below 10m. Temperature in Douglas Lake
is highly stratified in the summer, with the ther-
mocline beginning at about 10m. The rapid drop
in oxygen levels below the thermocline (Bazin
and Saunders, 1971) probably accounts for the
lack of gastropods at such depths.
Three snail species showed significant
changes in depth distribution over the study
period. Physa Integra and Helisoma cam-
panulata both seemed to have moved to deeper
water over the course of the summer. Caution
must be exercised in interpreting these results,
however, since the Physa Integra population
also showed a significantly decline in population
size, which in fact reached zero by the end of
July. The observed trend in depth distribution
could simply be the result of P. integra in
shallow water dying first, possibly due to the
rise in water temperature that was occurring.
This idea is supported by the findings of Brown
(1979), who showed in a laboratory experiment
that though elevated water temperature did not
change the overall life history pattern of P. In-
tegra, it did decrease the average life span.
Since the increase in mean depth shown by H.
campanulata was not accompanied by a popula-
tion size decrease, it is more likely to be showing
an actual migration to deeper water, possibly to
avoid gradually warming water near the sur-
face. Campeloma decisum showed a significant
decrease in mean depth for the first half of the
study followed by a increase in depth. An ex-
planation for this observation is not readily ap-
parent. A lack of similar studies in which snail
populations were sampled on such a regular
basis prevents direct comparison of our results
with others.
The decreases in population sizes oi Physa in-
tegra, P. parkeri, Lymnaea catascopium, and
Helisoma anceps, probably reflect normal mor-
tality that occurs in the reproductive cycle of
these snails. Clampitt (1974) has shown that
adult P. integra die in July after having mated
and laid eggs. Cort, et ai (1940, 1941) have
reported similar life histories for L. catascopium
and P. parkeri. The present study supports the
contention that these species are annuals that
die after reproducing in early summer.
The population of Campeloma decisum.
showed an increase over the course of the study.
It is believed that this is due to the increasing
numbers of offspring produced as the breeding
season progressed. Since C decisum is not an
annual as the pulmonates discussed above, adult
mortality does not seem to be high in the sum-
mer and a population increase was observed to
occur.
Studies of this type in which collections are
made on a regular basis can provide much more
insight into the life histories of gastropods than
single collections from a site. A better under-
standing of gastropod ecology gained in this
way may be of interest not only to ecologists and
malacologists, but also to parasitologists who
study these snails as intermediate hosts for
trematodes.
Acknowledgments
The authors express their thanks to Dr. David
Gates (Director) for providing facilities at the
University of Michigan Biological Station, and
to Dr. Henry van der Schalie and Dr. Eldon
Greij for their assistance in reviewing the manu-
script.
LITERATURE CITED
Baker, H. B. 1912. A few notes on the Mollusca of the
Douglas Lake region. Michigan Academy of Science 14th
Report 209-211.
Bazin. M. and G. W. Saunders. 1971. The hypolimnetic ox-
ygen deficit as an index of eutrophication in Douglas Lake,
Michigan. Michigan Academician 3:91-106.
Brown, K. M. 1979. The adaptive demography of 4 fresh-
water pulmonate snails. Evolution 33:417-4.32.
Cavancara, A, M. 1972. Lake mussel distribution as deter-
mined with SCUBA. Ecology 53:154-157.
Cheatum. E. P. 1934. Limnological investigations on respi-
ration, annual migratory cycle, and other related pheno-
mena in freshwater pulmonate snails. Transactions of the
American Microscopical Society 53:348-407.
Clampitt, P. T. 1973. Substratum as a factor in the distribu-
tion of pulmonate snails in Douglas Lake, Michigan. Mala-
rologia 12:379-399.
1974. Seasonal migratory cycle and related
movements in the freshwater pulmonate snail, Physa in-
tegra. Amei-ican Midland Natwalist 92:275-300.
Vol. 98(1)
January 30, 1984
THE NAUTILUS 25
Cort, W. W., D. B. McMuUen, L. Oliver, and S. Brackett.
1940. Studies on schistosome dermatitis. VII. Seasonal in-
cidence oiCercaria stagnicolae Talbot, 1936, in relation to
the life cycle of its host, Stagnicola emarginata migulata
(Sowerby). American Journal of Hygiene 32 (sect. D):
33-69.
Cort, W. W., L. Oliver, and D. B. McMullen. 1941. Larval
trematode infection in juveniles and adults of Physa
parken Currier. Journal of Parasitology 27:123-141.
Eggleton, F. E. 1931. A limnological study of the profundal
bottom fauna of certain freshwater lakes. Ecological
Monographs 1:231-332.
1935. A comparative study of the benthic fauna
of four northern Michigan lakes. Papers of the Michigayi
Academy ofScieyice, Arts, and Letters 20:609-644.
Harman, W. N. 1972. Benthic substrates: their effect on
freshwater Mollusca. Ecology 53:271-277.
Pace, G. L., E. J. Szuch, and R. W. Dapson. 1979. Depth dis-
tribution of three gastropods in New Mission Bay, Lake
Michigan. The Nautilus 93:31-36.
Schmid, W. D. 196.5. Distribution of aquatic vegetation as
measured by lineintercept with SCUBA. Ecology
46:816-823. '
FIRST RECORD OF OCTOPUS DEFILIPPI VERANY, 1851
IN VENEZUELAN COASTAL WATERS
Freddy Arocha' and German Robaina
Centre de Investigaciones Cientificas
Universidad de Oriente (Nueva Esparta)
Porlamar, Venezuela
ABSTRACT
Octopus defilippi Verany, 1851, is recorded for the first time in the southeastern Caribbean. The
specimens were captured in the coastal waters of Venezuela and are described briefly with an em-
phasis on its color pattern in a. yiatural habitat.
In 1979, a long-armed octopod was collected
in the shallow waters of the eastern side of the
Island of Cubagua, Venezuela. In the summer of
1982, three more long-armed octopods were
captured in the Golfo de Cariaco, Venezuela. All
four specimens showed affinities with Octopus
defilippi Verany, 1851.
The collected material was identified utilizing
the paper published by Voss (1964), the keys by
Roper (1978) and were checked against repre-
sentative materials at Rosenstiel School of
Marine and Atmospheric Science, Miami and
the U.S. National Museum of Natural History,
Washington, DC. The measurements and in-
dices are those defined by Voss (1963).
Octopus defilippi Verany, 1851
(Fig. 1; Table 1)
Octopus defilippi Verany, 1851: 30; Robson, 1929: 135;
Voss, 1964: 554; 1968: 654.
Material examined-l male, ML: 38.3 mm, in
2 m taken by hand using SCUBA, Isla de Cuba-
gua, November 3rd, 1979; 1 male, ML: 85.6 mm,
in 2.5 m taken by hand using SCUBA, Golfo de
Cariaco, June 6th, 1982; 1 male, ML: 66.5 mm,
in 2.5 m taken by hand using SCUBA, Golfo de
Cariaco, June 6th, 1982; 1 male, ML: 49.8 mm,
in 6 m taken by hand using SCUBA, Golfo de
Cariaco, August 8th, 1982.
TABLE 1. Mantle length, number of primary gill lamellae,
indices of bodily proportions, and spermatophore charac-
teristics for Octopus defilippi.
'Mailing address: Apartado de Correo 204, Cumana,
Venezuela 6101
26 THE NAUTILUS
January 30, 1984
Vol. 98(1)
FIG. 1. Octopux dfjilippi. ML ; 85.6 mm. Golfo de Cariaco, Venezuela.
Descripiion- The mantle is small, pyriform
and strongly constricted in the neck region. The
head is wide with very prominent eyes. One long
cirrus over each eye on the two larger speci-
mens, but unnoticeable in the smaller ones. The
funnel organ has the usual W-shape with the
lateral pads shorter than the central ones.
The arms are very long and slender, with very
delicate tips. The asymmetry of the arms is evi-
dent in all specimens. The first five suckers are
in a single row, the remainder are biserial; they
are arranged in an alternating pattern in more
than half of the length of the arms, and in the re-
maining part of the arms they are in a parallel
Vol. 98(1)
January 30, 1984
THE NAUTILUS 27
pattern. The small web extends conspicuously
up the side of all arms. In the larger specimens,
the web on the fourth arm may be as much as 10
mm in its middle portion.
The hectocotylized arm is almost half the size
of the other arms. The ligula is very small and
the calamus very short. The ligula is slender and
tapering with a small slim groove and slightly
inrolled edges.
The gill count per outer demibranch is 11
lamellae in the specimens from the Golfo de
Cariaco and 10 lamellae in the specimen from
Cubagua.
The radula has an A^ seriation in its rachidian
teeth with small ectocones.
The penis is long, slender and tubular with a
small round diverticulum at the base of the
penial aparatus. All four specimens were sexual-
ly mature. The spermatophores are small, with
the sperm mass reduced to one fourth of the
sperm sac.
The overall skin is light-brown, but it shows
dark-brown on the dorsal surface of the mantle
where the pigmentation appears as an irregular
mesh. In nature, the skin looks rugose and re-
mains that way in very well preserved animals.
The ventral surface of the mantle is a plain gray-
ish pink, while the ventral side of the arms is
light yellovdsh cream.
When the animals are observed in their natu-
ral habitat a variety of color patterns appears;
when undisturbed a greenish brown with gray-
ish traces is present; when disturbed the color of
the animal turns to a gray-ash with a black
mesh-like pattern. A light-brown color was
observed on the surface of the body and the
arms. Besides, the arms show a white spot lo-
cated between two thin, dark-brown, transverse
stripes which run along the arms. These white
spots are specially noticeable when the animal is
resting or at shelter after being disturbed. It
was observed that after preserving the animals,
the white spots disappeared leaving only the
transverse stripes.
Type-Musee d'Histoire Naturelle, Nice. Type
locality -Pegii, Italy.
Remarks -One specimen captured in the Golfo
de Cariaco (ML: 49.8 mm) was found over a bot-
tom of sand and broken shells, while the other
three specimens were obtained on Thalassia
and soft bottom.
This species is obtained for the first time in
Venezuelan coastal waters (Fig. 2) and repre-
sents the first record for the southeastern
Caribbean. The first West Atlantic record oc-
curred in Florida, U.S.A. (Voss, 1964), then in
the southwestern Caribbean (Voss, 1968) and
lately in Haiti, Cuba, Costa Rica, and Brazil
:^
AREA DEL MAR CARIBE
65° 40' 20" 64° 40'
FIG. 2. Map showing localities from where specimens of Octopus defilippi were collected.
28 THE NAUTILUS
January 30, 1984
Vol. 98(1)
(Palacio, 1977) and Virgin Islands (Hanlon &
Hixon, 1979).
Drs^rt^M^ron- Mediterranean Sea; Cabo
Verde; vacinity of Dakar; Ghana; Angola; Flori-
da, U.S.A.; Costa Rica; Colombia; Panama; Vir-
gin Islands; Rio de Janeiro, Brazil; Venezuela.
Acknowledgments
We are grateful to Dr. Gilbert L. Voss and
Mrs. Nancy A. Voss for their assistance at
Rosenstiel School of Marine and Atmospheric
Science, Miami, to Dr. C. F. E. Roper and Mr.
Michael Sweeney for their help at the U.S. Na-
tional Museum of Natural History, Washington,
D.C. and to Mrs. Violeta Sanchez and Georgina
Spirutova for reading the manuscript.
LITERATURE CITED
Hanlon, R. T. and R. F. Hixon. 1979. The "Macrotritopus
problem" solved: Octopus defUippi raised from a wild-
caught, pelagic Afaorofritopits. The Bulletin of the Ameri-
can Malacological Union. 1979, page 70.
Palacio, F. J. 1977. A study of coastal cephalopods from
Brazil with a review of Brazilian zoogeography. Ph. D. Dis-
sertation, University of Miami, 310 pp.
Roper, C. F. E. 1978. Cephalopods. in: Fischer, W., ed.,
FAO Species Identification Sheets for fishery purposes.
Western Central Atlantic (fishing area 31), vol. VI.
Voss, G. L. 1963. Cephalopods of the Philippine Island. U.S.
National Museum Bulletin 234, 180 pp.
1964. Octopus defilippi Verany, 1851, an addi-
tion to the cephalopod fauna of the Western Atlantic. Bull.
Mar. Sci. Gulf and Carih. 14(4):554-560.
1968. Octopods from the R/V Pillsbury South-
western Caribbean cruise, 1966, with a description of a
new species. Octopus zonatus. Bull. Mar. Sci. 18(3):
645-659.
FUSINUS LIGHTBOURNI (GASTROPODA: FASCIOLARIIDAE),
A NEW SPECIES FROM BERMUDA
Martin Avery Snyder
745 Newtown Road
Villanova, PA 19085
ABSTRACT
Fusinus lightbourni, n. sp., from 100-200 fms (183-366 m) depths off the south
coast of Bermuda differs from F. frenguellii (Carcelles, 1953) by its sculpture, lip,
and coloration. It grows to about 70 mm while F. frenguellii grows to at least US
mm. The range for F. ceramidus (Dall, 1889) is extended to Bermuda.
For several years Jack R. H. Lightbourn and
Arthur T. Guest have set specially designed mol-
lusk traps in 100-200 fms off the south shore of
Bermuda and obtained dead mollusks borne by
hermit crabs. Notable among the material col-
lected in this manner are specimens of Pero-
trochuji quoyanu.^ (Fisher and Bernardi, 1856)
and Perotrochus adansonianus (Crosse and
Fisher, 1861). During a recent trip to Bermuda
the author was able to examine various Fusirvus
specimens obtained in this matter. One lot
represents a range extension of a known taxon;
another shell represents a new taxon described
herein.
Specimens of the new species are deposited in
the collections of the Delaware Museum of
Natural History (DMNH), Academy of Natural
Sciences of Philadelphia (ANSP), and the
United States National Museum in Washington
(USNM). Additional specimens are in the Jack
Lightbourn collection and the collection of the
author.
Fusinus lightbourni, new species
(Figures 1-3)
Description: Shell moderately large for the
genus, 45 mm-70 mm. Profile somewhat in-
flated, fusiform, with about 10 whorls. Em-
bryonic whorls are smooth, quite pointed, and
waxy white in color (DMNH 154462, 66 mm).
Teleconch bears strong axial ribs which are not
evanescent on the body whorl. Later whorls
bear 13 or 14 such ribs. These ribs present a
slightly angular profile, being crossed by about
Vol. 98 (1)
January 30, 1984
THE NAUTILUS 29
FIGS. 1 and 2, F>mmis lightboumi, n. sp., holotype. 61 mm DMNH 154461.
FIGS. 4 and 5, F. frenguellii (Carcelles, 1953) 71 mm, by fishermen in 30 fms off Rio de Janeiro, Brazil, December 1968;
author's collection.
10 strong spiral lines, the two strongest on the
shoulder giving the angular appearance to the
profile. Between these 10 stronger spiral lines
are finer lines. These in turn are crossed by very
fine axial lines giving the surface of the shell
between the axial ribs and strong lines the tex-
ture of linen. The aperture is ovate, pinched at
the anterior and posterior ends. The parietal
callous is extended forming sharp, thin lamina
on the inner lip along the columellar border of
the aperture. The inner surface of the outer lip
is calloused and strongly denticulate with about
16 lirae. Base and anterior siphonal canal are
straight and slender, being about one half of the
total length of the shell. The shell is white with
pale-brown bands of color just before and just
after the suture. In some specimens the canal is
recurved. The operculum and soft parts are
unknown.
Holotype: Length 61 mm, crabbed specimen
from a fish pot in 100-120 fms taken IV2 miles
due south of Gurnet Rock, south shore of Ber-
muda, summer 1979 (DMNH 154461).
Other Material: 3 paratypes DMNH 154462
(46 mm, 61 mm, 66 mm), 1 paratype ANSP
356701 (60 mm), 3 paratypes USNM 819199 (54
mm, 63 mm, 65 mm), and 3 paratypes in the
author's collection (51 mm, 59 mm, 70.5 mm).
All paratypes from the same locality as the
holotype, but in different collecting hauls and
depths down to 200 fms.
Etymology: The species is named for Jack R.
H. Lightbourn who has done much to extend our
knowledge of the Bermudian molluscan fauna.
30 THE NAUTILUS
January 30, 1984
Vol. 98(1)
lightboumi
IV2 whorl small pointed nucleus
13-14 axial ribs on body whorl
colored bands
10 spiral grooves
heavy calloused toothed lip
slightly angular profile
ribs often prominent on body whorl
frengtieUii
2 whorl large mammillate nucleus
10-18 axial ribs on body whorl
essentially uncolored
7-8 spiral grooves with smaller ones between
thin lirate lip
rounded profile
ribs usually evanescent on body whorl
grows twice as large and has a proportionately
longer canal.
FIGS. 3 and 6. 3, F. lightboumi paratype, 66 nun, U.MNH
154462; protoconch and early whorls. 6, F. frenguellii,
129 mm, by fishermen in 27 fms, sand and mud bottom, off
Rio de Janeiro, Brazil, August 1975, author's collection; pro-
toconch and early whorls.
Discussion: Fusinus lightboumi seems most
closely related to F. frenguellii (Carcelles, 1953)
(Fig. 4-6). The most obvious differences are its
smaller adult size, the pale brown bands of col-
oration, and the details of its body sculpture.
The comparison is facilitated with the aid of a
table.
In the same collecting hauls, we identified a
fair number of Fusinus ceramidus (Dall, 1889)
previously known from Barbados. These are
completely typical specimens of F. ceramidus,
although a bit smaller than usual (28-32 mm).
This represents a significant range extension
for this taxon.
Acknowledgements
Mr. Jack R. H. Lightbourn of Bermuda
donated all of the type material as well as
various other specimens in the Delaware
Museum of Natural History and the author's col-
lection. The author had an enjoyable and helpful
discussion regarding these shells with Russell
Jensen of the Delaware Museum of Natural
History. The photographs were furnished by
Mr. Hal Lewis of Philadelphia, Pa. The author
extends his appreciation to each of these in-
dividuals.
LITERATURE CITED
Carcelles, A. 1953. Nuevas sp. de gastropo des del Uruguay
y Argentina. Com. Zool. Mus. H. Nat Mont. 4(70):16 pp
and 5 pis.
Dall, William Healey. 1889. Reports on the Results of Dredg-
ing under the Supervision of Alexander Agassiz in the Gulf
of Mexico (1877-78) and in the Caribbean Sea (1879-80) by
the U.S. Coast Survey Steamer Blake: No. 20, Report on
the Mollusca, Part 2, Gastropoda and Scaphopoda. Bull.
Mus. Comparative Zool. 18:1-492, pis. 1-40.
NEWS
William J. Clench is recovering from an opera-
tion undergone in Boston in October. He is now
in California with his son who is attending to his
correspondence. Bill would welcome news from
his friends and used postage stamps which he
enjoys collecting. Write c/o Carleton W. Clench,
25431 Classic Drive, Mission Viejo, CA 92691.
Margaret C. Tesky, former Secretary of the
A.M.U., after a serious fall has been hospitalized
in North Carolina, and may be reached through
William Dobo, P.O. Box 424, Wrightsville
Beach, N.C. 28480.
Vol. 98 (1)
January 30, 1984
THE NAUTILUS 31
A NEW WESTERN ATLANTIC SPECIES OF CYMATIUM
(GASTROPODA: CYMATIIDAE)
Anthony D'Attilio and Barbara W. Myers
Department of Marine Invertebrates
San Diego Natural History Museum
San Diego, CA 92112
ABSTRACT
Cymatium raderi, a new species from the east coast of Honduras, Central
Am.erica, and the West Indies, is described and comparison is made with C.
femorale (Linne, 1758) and C. praefemorale (Maury, 1917).
Cymatium femorale (Linne, 1758) was very
briefly described in the 10th edition of the
Systema Naturae, p. 749, and this description
was repeated almost verbatim in the 12th edi-
tion in 1767, p. 1217. To supplement this two-
line description, Linne referred to several
figures in the books of his time. However, three
of the figures he referred to -namely, Rumphius
(1711), t. 26, fig. B; Argenville (1742), t. 13, fig.
B; and Regenfuss (1758), t. 2, fig. 21 -appear to
be referable to Cymatium lotorium (Linne,
1758). Linne corrected this error in his manu-
script notes (Dodge, 1957). Linne's remaining
four references correctly figure C. femorale:
Grew (1681), t. 11 (should be t. 10, figs 7, 8,
wrongly figured as a sinistral specimen);
Buonanni (1681), 3, t. 290. Linne in a manu-
script note designated the figure in Buonanni as
"bene" (Dodge, 1957) (See our fig. 1); Lister, t.
941; and Gualtieri (1742), t. 50, fig. C. Linne
(1767) added to the synonymy Seba (1758), t. 63,
figs. 7, 8 and these two figures are excellent
(See our fig. 2). Figs. 9, 10 on t. 63 of Seba ap-
pear to be juvenile C. femorale. Lotorium lotor
FIG. 1. Cymatium fenwr ale {hinne, 1758), taken
from Buonanni (1681).
FIG. 2. Cymatium femorale (Linne,
1758), taken from Seba (1758).
Montfort, 1810, is a junior synonym of Cyma-
tium femorale Linne, 1758). Although Montfort
referred to Murex lotorium Linne, 1758, Mont-
fort's figure is Cymatium femorale (Linne,
1758).
The type of C. femorale is in the Linnean col-
lection in London and conforms with the de-
scription and with the citations by Linne with
the exceptions, as above stated, of Rumphius,
Argenville and Regenfuss (Dodge, 1957). In his
description Linne states "apertura edentula".
32 THE NAUTILUS
January 30, 1984
Vol. 98(1)
FIG. 3. Cymatium femorale (Linne, 1758),
SDNHM 15664. Photograph by D. Gottleib.
i.e. aperture without denticles. None of the
figures referred to by Linne showed any den-
ticles within the aperture. Figs. 3, 4 illustrate C.
femorale (SDNHM 15664).
Clench and Turner (1957) placed Septa tri-
angularis Perry, 1811, pi. 14, in the synonymy
of Cymatium femorale, but the cited figure in
Perry (1811) from the Southern Ocean appears
to be a composite drawing of C. lotorium Linne,
1758, C. femorale Linne, 1758 and C. perryi
Emerson and Old, 1963. For further discussion
see Emerson and Old (1963).
Cymatium -praefeTnorale (Maury, 1917) was
described from a Tertiary fossil found at Rio
Gurabo, Santo Domingo, West Indies. Figs. 5, 6
illustrate C praefeTnorale (TU 1280).
L. J. Bibbey of San Diego, California, recently
brought to our attention specimens of a Cyma-
tium collected by fishermen in the Caribbean
Sea off the east coast of Honduras, Central
America, which bear a superficial resemblance
to C. femorale. This new species has very ob-
vious dentition within the aperture and in that
respect resembles C. praefeTnorale (Maury,
FIG. 4. Cymatium femorale (Linne, 1758), SDNHM
15664. Photograph by D. Mulhner.
1917). In the monograph by Clench and Turner
(1957) on Cymatiidae, pi. 129, fig. 1, labelled C.
femorale from Great Abaco, Bahama Islands,
the figure appears to be a specimen of the new
species and not C. femorale as described by
Linne. Four lots are in the collection of the
American Museum of Natural History. #182782,
one specimen, (paratype) from Tobago Island,
West Indies, collected by Sol Weiss of New York
City. #205836 from Punta Potuca, Honduras,
trawled from 18 to 27 m, one specimen, sent to
the Museum by Helio Garcia. #107868, one
specimen, from Dry Tortugas, Florida, collected
by shrimpers, 1963. #205350, three specimens,
from off Honduras, by fishermen, obtained from
Jack Rader, via R. T. Abbott.
Differences in the general shape, rounding of
the varices, less rugose sculpture and strong
dentition distinguish this new species from both
C. femorale and C. praefem,orale.
Institutional Abbreviation's: SDNHM (San
Vol. 98(1)
January 30, 1984
THE NAUTILUS 33
FIGS. 5, 6. Cymatium praeferrwrale (Maury, 1917) TU
1280. Photographs by A. Beu.
Diego Natural History Museum); AMNH
(American Museum of Natural History); TU
(Tulane University).
Family: Cymatiidae Iredale, 1913
Genus: Cymatimn Roding, 1798
FIG. 7. Cymatium raderi n. sp., holotype,
SDNHM 81627. Photograph by D. Gottleib.
FIG. 8. Cymatium raderi n. sp., holotype, SDNHM
81627. Photograph by D. Mulliner.
Type Species: Murexfemorale Linne. 1758, by subsequent
designation, Dall 1904, p. 133
Cymatium raderi new species
Figs. 7-12
Description: Length 152 mm by 88 mm wide;
moderately strong with seven convex postnu-
clear whorls; suture distinct except where inter-
rupted by the varices; protoconch eroded; first
postnuclear whorl rounded; weak axial ribs
begin on the second postnuclear whorl (12 per
whorl are apparent up to the first varix which is
on the fourth postnuclear whorl); spiral cords six
on the first postnuclear whorl, increasing in
number for each succeeding whorl; two of the
spiral cords are stronger, one at the shoulder
and one below the shoulder beginning on the
third postnuclear whorl, increasing in strength
on the fourth and fifth whorl and increasing to
five in number on the body whorl; the cord on
the shoulder gives a weakly angulate appear-
34 THE NAUTILUS
January 30, 1984
Vol. 98(1)
ance to the otherwise rounded whorls. One ma-
jor cord and two to three weaker cords are pre-
sent on the canal. The major cords and the re-
maining surface of the body whorl are covered
with spiral threads. The shoulder contains only
minor cords and spiral threads. Aperture elon-
gate, oval, truncate posteriorly; canal open,
tapering and recurved at termination. Inner lip
strongly concave, very thin and adherent above;
below the midpoint of the aperture the inner lip
is slightly erect, with a dull pale-purple stain ex-
tending into the canal. Outer lip with four den-
ticles, one within the truncate portion of the
aperture. The remaining three denticles occur
on the apertural side of the depressions between
the spiral cords on the posterior portion of the
aperture; the most anterior denticle is bifid.
These denticles begin well away from the lip
edge. The outer lip reflects the undulating char-
acter of the spiral sculpture; deep brownish pur-
ple coloring occurs in the depressions between
the spiral cords within the aperture. Inside of
aperture white. Ventral side of the expanded
apertural varix is concave at the peristome and
strongly stained with deep-brown between the
six white spiral cords and extending to the
rounded edge of the varix. These cords are
white only on the ventral surface of the leading
side of the varix. The shell has five rounded
varices, the first on the fourth postnuclear
whorl, the second on the body whorl opposite
the one on the apertural side. The varices ter-
minate posteriorly in a convex sloping plane
from the suture. Axial sculpture consists of
three nodes on the shoulder of the body whorl,
the center node projecting most prominently,
nodes very weakly developed or lacking on the
cords below.
Color: Externally, the color is a warm reddish
ochre, becoming richest on the receding side of
the apertural varix.
Type Material: Holotype, 185 mmx90 mm
(SDNHM 81627); Paratype A, 136 mmx59 mm
(SDMNH 81628); Paratype B, 187 mm x 87mm
(AMNH 182782); L. J. Bibbey collection - Para-
type C, 196 mmx87 mm; Jack Rader collec-
tion - Paratype D, 192 mmx87 mm; Jack Rader
collection - Paratype E, 124 mmx69 mm.
FIGS. 9, U). Cymatium raderi n. sp., paratype C, Bibbey collection. Photographs by D. Gottleib
Vol. 98(1)
January 30, 1984
THE NAUTILUS 35
Type Locality: Collected by fishermen off the
east coast of Honduras, Central America, Carib-
bean Sea. An additional specimen was dis-
covered in the American Museum of Natural
History no. 182782 from Tobago Island, West
Indies.
Etymology: Named for the late Jack Rader,
who first recognized the differences in this new
species.
Discussion: Paratype C, figs. 9, 10 from the
Bibbey collection is a slender, elongate speci-
men, light in weight, with an immature lip.
Paratype D. figs, 11, 12, from the Rader collec-
tion has an extreme development of the central
shoulder node changing into a broad tabulate
projecting shelf. The apertural varix is also
more extensively developed, and the shell is
strong and heavy, with weak, bifid denticles
within the aperture.
Comparison of the new species with Cymati-
umfeniorale shows differences in the shape and
sculpture. Cymatiwm raderi does not have the
more clearly defined trigonal shape of C femo-
rale, and the varices are rounded rather than
pointed at the shoulder. The extension of the
varix in C. femorale rises spinelike into a projec-
tion and slopes concavely to the suture. In com-
parison the varix of the new species is truncate
most posteriorly and slopes convexly and anter-
iorly from the suture. The sculpture of C. raderi
is much less rugose, the spiral cords are broad
and rounded between moderate to weak depres-
sions, and the intervarical areas are without
prominent nodes. The spiral cords of C. femorale
are raised between deep depressions to a
greater degree than in C. raderi; this is especial-
ly emphasized on the varices where the stronger
and heavier cords project into prominent nodes.
These nodes are white, both on the leading edge
and also on the receding edge of the varices. C.
raderi has less prominent nodes that are white
only on the leading edge of the varices. The
shoulders of the whorls in C. femorale are
angulate and they appear tabulate, while in C.
raderi they are very weakly angulate. A promi-
nent feature of C. femorale is the axially
oriented nodes on the spiral cords which in C.
raderi are weak to absent. There are no nodes
or denticles within the aperture of C. femorale,
while the aperture of C. raderi is strongly
dentate.
Comparison of the new species with C. praefe-
FIGS. 11, 12. Cymatium raderi n. sp., paratype D, Rader collection. Photographs by D. Gottleib.
36 THE NAUTILUS
January 30, 1984
Vol. 98(1)
morale shows differences in the following char-
acters: C. praefemorale has stronger cords and
costae than C. raderi. Two to four rows of pro-
minent axially oriented nodes similar to those in
C. femorale appear on the body whorl between
the varices. Within the aperture of C. praefe-
morale there are six strong swollen denticles
(none of these are bifid as in the new species),
beginning at the margin of the outer lip and ex-
tending well into the aperture. All denticles are
of approximate equal size and extend from the
anal trough anteriorly to the siphonal canal.
Cymatium praefemorale also has numerous
plicae that extend along the columella whereas
C. raderi has only one or two plicae on the
anterior portion of the columella. The entire sur-
face of the seven specimens of C. praefemorale
examined have easily visible raised axial striae.
This character is decidedly more weakly devel-
oped in both C. femorale and the new species.
C. praefemorale further differs from the new
species by its much smaller size (ranging from
61 mm to 92 mm), the stronger more numerous
plicae on the columella and the ridged appear-
ance of the surface due to the strong develop-
ment of the growth striae.
In summary, the new species may be most
readily distinguished by the following charac-
ters: the truncate downward-sloping termina-
tion of the varices, the dentate aperture, the
weaker spiral cords and the lack of prominent
intervarical axial nodes present on most speci-
mens of C. femorale and C. praefemorale.
Acknowledgments
Our special thanks to L. J. Bibbey of San
Diego, California, and to Jack Rader of Braden-
ton, Florida, recently deceased, for bringing this
new species to our attention and for donating
specimens to the San Diego Natural History
Museum. Further, we are grateful to Mr. Bibbey
and to Don Pisor of San Diego, California, for
loan of specimens of Cymatium feynorale for
comparison material, and to Dr. Emily Yokes
and Dr. Alan Beu for loan of specimens of C.
praefemorale. We thank Mr. Dan Gottleib of
SDNHM and Mr. David K. Mulliner for the
photography. Dr. Alan Beu has permitted us to
use his photograph of C. praefemorale. Dr.
William K. Emerson, AMNH, kindly reviewed
the manuscript and brought to our attention a
specimen of the new species from Tobago
Island. We also thank him for the suggestion for
comparison with C. praefemorale. We wish to
acknowledge Dr. Hans Bertsch for helpful sug-
gestions on the manuscript. Our thanks also to
Judy Dyer, Librarian at SDNHM, for help in ob-
taining rare and difficult to locate literature.
LITERATURE CITED
Argenville, A. J. D. d'. 1742 L' histoire naturelle..La Litho-
logie et la Conchyliologie... Paris, not seen. The work con-
sulted was the Nouvelle Edition. 1757. La Conchyliologie.
The plate number was 34, Fig. A3.
Buonanni, F. 1681. Riereatione dell' occhio e della mente
neir osservation' delle chiocciole. Rome.
Clench, W. J. and R. D. Turner. 19.57. The Family Cymati-
idae of the Western Atlantic. Johnsonia 3(36): 189-244.
Pis. 110-135.
Dall, W. H. 1904. An historical and systematic review of the
frog shells and tritons. Smithsonian Misc. Coll.
47:114-144.
Dodge, H. 1957. Historical review of the molluscs of Lin-
naeus. Pt. 5. The Genus Murex of the Class Gastropoda.
Bull. Am.. Mus. Nat. Hist. 113(2):77-222.
Emerson, W. K. and W. E. Old, Jr. 1963. A New subgenus
and species of Cymatium (Mollusca, Gastropoda). Am..
Mus. Novitates 2137:1-13, 6 figs.
Grew, N. 1681. Museum Regalis Societatis: or a description
of the natural and artificial rarities belonging to the Royal
Society and preserved at Gresham Colledge, etc. 2 pts.
London.
Gualtieri, N. 1742. Index Testarum Conchyliorum quae ad-
seruvanter in Museo Nicolai Gualtiere. Florence. 110 pis.
Iredale, T. 1913. The generic name to be used for Murex
tritonis Linne. The Nautilus 27(5):55-56.
Lirme, C. von. 1758. Systema Naturae per regna tria
naturae. Editio decima. Vol. 1. 824 pp.
1767. Systema Naturae. Editio duodecima. Vol.
1, pt. 2, pp. 533-1327.
Lister, M. 1685-1692. Historia Conchyliorum. Londini (not
seen).
Maury, C. J. 1917. Santo Domingo Type Sections and Fos-
sils! Pt. 1. Bull of. Am.. Paleo. 5(29):165-251, pis 3-39.
Montfort, D. de. 1810. Conchyliologie Systematique. vol. 2.
676 pp. Paris.
Regenfuss, F. M. 1758. Au^erlesne Schnecken Muscheln und
andre Scha.althiere...Copenh3.gen. (not seen).
Roding, P. F. 1798. Museum Boltenianum.. Hamburg.
199 pp.
Rumphius. G. E. 1705. D'Amboinsche Rariteikamer. Am-
sterdam, (not seen).
Seba, A. 1758. Lonipletissimi Rerum Naturalium Thesauri
Accurata Descriptio et Inconihus Artificiosissimis Ex-
pressio. Vol, 3, 212 pp., 116 pis. Amsterdam.
Vol. 98(1)
January 30, 1984
THE NAUTILUS 37
NOTES ON THE MORPHOLOGY OF OLSSONELLA SMITHII
(GASTROPODA: CANCELLARHDAE)'
M. G. Harasewych and Richard E. Petit
Research Associates
Department of Invertebrate Zoology
National Museum of Natural History
Smithsonian Institution
Washington, D.C. 20560
ABSTRACT
Olssonella smithii (Dall. 1888) is a small cancellariid gastropod that inhabits
sand substrates off the southeastern United States, the Gulf of Mexico, Colombia
and Venezuela. It resembles Cancellaria reticulata (Linne. 1767) in anatomical
organization, but differs in having a less specialized anterior alimentary system
and an unmodified left cephalic tentacle. Shell ultrastructure is similar in these
two species, although 0. smithii hajs a thicker periostracum. Olssonella smithii
also lacks bifurcated columellar folds and has internal varices that differ in
periodicity from those o/C. reticulata. Based on the morphology ofradulae and
jaws we suggest that the subfamilies Cancellariinae and Trigonostominae are
more closely related to each other than either is to Admetinae, in which there is a
trend toward loss of the radula.
The Cancellariacea comprise a highly special-
ized, poorly known and taxonomically enigmatic
group of marine gastropods. Although they
form a morphologically compact natural as-
semblage, their relationships to other proso-
branchs are less than certain. The group has
been included in the Toxoglossa by early
workers (eg. Troschel, 1865; Tryon, 1882;
Fischer, 1883), in the Volutacea (eg. Thiele,
1929; Wenz, 1938-1944; Taylor and Sohl, 1962)
and elevated to ordinal status by Olsson (1970)
who proposed the name Nematoglossa. Golikov
and Starobogatov (1975) reduced the group to a
suborder, but retained the name Nematoglossa.
Most recent workers regard this group as a
superfamily within Neogastropoda (Ponder,
1973; Keen and Coan, 1974; Taylor et al. 1980;
Boss, 1982). Taylor et al. (1980) suggest that
Cancellariacea are derived from the Purpurini-
dae (Middle Triassic-Upper Cretaceous), which
they resemble in shell morphology.
Various higher level classifications based ex-
clusively on shell characters have been proposed
(see Marks, 1949, for a review of the early
'Contribution no. 127, Smithsonian Marine Station, Link
Port, Florida.
work), but phylogenetic relationships have yet
to be investigated.
Anatomical studies have, for the most part,
been limited to radular morphology (eg.
Troschel, 1865; Barnard, 1958; Olsson, 1970;
Oliver, 1982; Schremp and Richmond, 1983;
Schremp, 1983) or to the anterior alimentary
system (Amaudrut, 1898; Graham, 1966). The
gross anatomy of Cancellaria. reticidata (Linne,
1767) has recently been described (Harasewych
and Petit, 1982). "
We recently obtained several preserved speci-
mens of Olssonella smithii (Dall, 1888), a species
taxonomically remote from Cancellaria reticu-
lata, and examined its shell and soft parts in
order to investigate the morphological diversity
within Cancellariacea.
There are few literature citations for Olsso-
nella smithii. This species was originally
described from off Cape Hatteras, North Caro-
lina, a record which probably represents its
most northern range. Specimens were reported
from the northwestern Campeche Bank, Yuca-
tan Peninsula, Mexico (Rice and Kornicker,
1965) and from the coasts of Colombia and
Venezuela [Petuch, 1981, as Agatrix epomis
(Woodring)]. Other Venezuelan specimens ten-
38 THE NAUTILUS
January 30, 1984
Vol. 98(1)
tatively identified as 0. smithii were reported
by Princz (1982).
Several authors have placed Olssonella as a
subgenus of Agatrix. an assignment we do not
accept as we feel that the two genera are
separable and there is no evidence for a sub-
generic relationship.
Materials and Methods
The following specimens were used in this
study:
1 9, trawled in 110-99 meters, E. of Sebastian
Inlet, Florida (27°48'N,79°55'W) on Oculina bed
(Indian River Coastal Zone Museum 65:585).
1 9. dredged in 45.7 meters, about 28 nautical
miles NE of Cape Canaveral, Florida (28°44'N,
80°10'W) R/V Delaware II, Cruise 824, sta. 90.
(Voucher specimen-National Museum of Natural
History, Smithsonian Institution 806986).
1 o" and 2 9, dredged in 80.4-84.1 meters, about
78 nautical miles E of Savannah River Mouth,
Georgia (32°02'N,79°18'W) R/V Delaware II,
Cruise 824, sta. 16.
1 o" and 1 9, dredged in 45.7-47.5 meters, about
24 nautical miles NE of Cape Canaveral, Florida
(28°39'N,80°09'W) R/V Delaware II, Cruise 824,
sta. 91.
Specimens for anatomical and histological
studies were immersed in 10% hydrochloric acid
(HCl) until the shells dissolved. Soft parts were
rinsed in distilled water and returned to 70%
ethanol for dissection. One male and one female
specimen were sectioned at a thickness of 8 ptm
and the sections stained in hematoxylin and
eosin. Dry shells were sectioned with a diamond
saw or fractured in a vise for examination of in-
ternal structure and ultrastructure.
Shell Morphology
External: Shell small (to 15 mm), heavy, elon-
gate-oval, with conical spire and rounded ante-
rior (Fig. 1). Protoconch deviated by 10-15°,
consisting of about 2 dark-brown, inflated
glassy whorls. Transition to teleoconch marked
by abrupt acquisition of spiral sculpture (Fig. 2).
Teleoconch with up to 4% strongly convex
whorls. Suture deeply impressed. Spiral sculp-
ture of 15-19 cords on body whorl and 8 or 9 on
penultimate whorl, with or without one fine
striae between. Collabral sculpture of 8-11
strong, evenly-spaced, prosocline ribs per whorl.
There is a slight increase in number of spiral
cords and a decrease in number of axial ribs
with increase in shell size. Aperture hemi-
elliptical, deflected from coiling axis by 10-15°.
A shallow indentation separates the very abbre-
viated siphonal canal from the outer lip, which
contains 8 or 9 spiral lirae that are thickest
beneath axial ribs. Inner lip with 2 simple col-
umellar folds and a siphonal fold. Anterior half
of inner lip forms a raised inductura beneath
which the pseudoumbilicus appears as a narrow
fissure. Color creamy tan to purplish brown,
lightest on axial ribs, darker between, and
darkest along suture. Some specimens have a
white band across the middle of the body whorl.
Aperture white to purplish brown, columellar
folds and apertural lirae white.
TABLE 1. Olssonella smithii (Dall), measurements of shell
characters (in mm) n= 10.
Intei-nal: Sectioned and fractured shells
reveal that internal surfaces are smooth and
continuous in the early whorls. By the third
post-nuclear whorl, apertural lirae develop and
columellar folds increase in prominence. Aper-
tural lirae span 3 axial ribs then become reduced
or absent for 3 axial ribs before again enlarging
and spanning 3 ribs (periodicity roughly 240°).
Unlike C. reticulata, the location of the apertur-
al lirae is not discernible on the outer surface of
the shell. Columellar folds become pronounced
every 120°, with every other columellar promi-
nence occurring in opposition to the median of
the 3 lirate axial ribs.
Ultrastructure: A thick, yellowish, lamellose
periostracum (Fig. 4) overlies the shell, which
consists of 2 orthogonal layers of crossed-
lamellar aragonite (Fig. 3). The outer layer, in
which the lamellar planes are collabral, varies in
thickness from 400-800 \m\ and comprises the
January 30, 1984
THE NAUTILUS 39
FIGS. 1-6. Shell and radular features of Olssorwlla smitkii (Dall). 1, Apertuial and riKlit .sidr \ i.u;, ni a li mali specimen
dredged in 45.7 meters, about 28 nautical miles NE of Cape Canaveral, Florida. (USNM 806986). 4 x . 2, Protoconch. Scale bar
= 400 ^m. 3, Fracture surface. Plane of fracture parallel to outer lip. Scale bar = 50 /im. 4, Periostracum. Scale bar = 200 /im.
5, Proximal end of radular tooth, detached from radular ribbon. Scale bar = 10 (im. 6, Side view of distal ends of radular teeth.
Scale bar = 3 jim.
40 THE NAUTILUS
January 30, 1984
Vol. 98(1)
axial ribs, spiral cords and internal lirae. The
inner layer, with transversely oriented lamellar
planes, forms a fairly uniform lining (100-150
pm) along the inner surface of the shell.
Soft Parts Morphology
External features: The shell-less animal con-
sists of approximately 3V2 whorls, with the
digestive gland comprising 2 whorls, the kidney
V4 whorl and the mantle cavity extending over %
whorl. Preserved animals were retracted to just
within the final set of apertural lirae. Animals
were light tan in color, with reddish brown spots
that covered the upper and lateral surfaces of
the short, rectangular foot and the symmetrical
tentacles (Fig. 7, t), but stopped just within the
strongly papillose mantle edge (Fig. 7, ma). The
siphon (Fig. 7, s) is short and blunt. The opercu-
os
FIGS. 7-10. Anatomical features of Olssonella smithii (Dall). 7, Male specimen removed from shell, partially uncoiled and
mantle cavity opened mid-dorsally to display contents. 8, Dissection of retracted proboscis, viewed from left side. 9. Diagram-
matic representation of the alimentary system. 10, Diagrammatic representation of the female pallial gonoduct. a, anus; ae,
anterior esophagus; ag, albumen gland; asg, accessory .salivary gland; be, bursa copulatri.x; bg, buccal ganglion; bm, buccal
mass; eg, cap.sule gland; et, ctenidium; hg, hypobranchial gland; ig, ingesting gland; int, intestine; j. jaw; k, kidney; ko,
kidney o[)ening; m, mouth; ma, mantle edge; me, mid-esophagus; nr, nerve ring; od, oviduct; os, osphradiuni; ot, oral tube; pc,
p)ericardium; pe, posterior esophagus; pen, penis, pr, pro.state, r, rectum, rg, anal gland; sto. stomach; t, tentacle; vl. valve of
Leiblein.
Vol. 98(1)
January 30, 1984
THE NAUTILUS 41
lum is lacking.
Mantle cavity: The arrangement of organs
within the mantle cavity is similar to that of
other higher prosobranchs. The osphradium
(Fig. 7, OS) (L/W = 3) consists of 35 leaflets per
side. Immediately adjacent is the ctenidium
(Fig. 7, ct), slightly wider and twice as long as
the osphradium and composed of abjut 115 tri-
angular leaflets. Occupying the roof of the man-
tle cavity is the voluminous, whitish, trans-
versely pleated hypobranchial gland (Fig. 7, hg).
To its right lie the rectum (Fig. 7, r) and genital
ducts. The kidney (Fig. 7, k) lines the rear of the
mantle cavity and opens into it by a single verti-
cal slit (Fig. 7, ko). The pericardium (Fig. 7, pc)
is embedded in the left side of the kidney, with
only a small area bordering the mantle cavity.
Alimentary system: The stout, tubular, pleu-
rombolic proboscis, which can be extended near-
ly the length of the shell, is the same color as the
foot (i.e. tan with reddish brown spots on the
dorsal and lateral surfaces). When the proboscis
is retracted, the large buccal mass (Fig. 8, bm)
extends beyond its posterior limits. A short oral
tube (Fig. 8, ot) leads from the mouth (Fig. 8, m)
to the cuticularized, tube-like jaw (Fig. 8, j), the
expanded posterior portion of which surrounds
the buccal mass. The dorsal surface of the buccal
mass is covered by a broad, medially-grooved
cuticle that supports a radular ribbon consisting
of a single row of 54-56 (n = 4) long ('^'900 ^m),
narrow (~20 jim at base) teeth. Each tooth ap-
pears to consist of a recurved ribbon 30 /jm wide
(Fig. 5), the distal end of which has 3 highly
modified cusps: the 2 lateral, inwardly directed
cusps each have a complex of secondary cusps
(Fig. 6). Two pairs of salivary glands lie behind
the buccal mass. The larger pair (Fig. 8, sg) are
tubular, their ducts entering the buccal mass
anterior to the esophageal opening. A second
longer but narrower pair of glands (Fig. 8, asg)
empty via ducts into the oral tube. The short
anterior esophagus (Fig. 9, ae) runs from the
roof of the buccal cavity to a large, muscular
valve of Leiblein (Figs. 8, 9, vl). Posterior to this
valve lies the mid-esophagus (Fig. 9, me), which
becomes convoluted before passing through the
nerve ring (Fig. 9, nr) and winding posteriorly
along the floor of the cephalic sinus. There is no
gland of Leiblein, but a narrow glandular strip
lines the dorsal surface of a portion of the mid-
esophagus. The straight, narrow posterior eso-
phagus (Fig. 9, pe) begins at the rear of the
cephalic sinus and leads to a simple, U-shaped
stomach (Fig. 9, sto). Longitudinal folds run
through the stomach and into the intestine (Fig.
9, int), which passes through the kidney and
continues along the right side of the mantle cavi-
ty where it expands to form a rectum (Figs, 7, 9,
10, r). A small anal gland (Figs. 7, 9, rg) runs
along the dorsal anterior portion of the rectum
to a point where it detaches from the roof of the
mantle cavity to form the anus (Figs. 7, 9, a). No
identifiable gut contents were found in any of
the specimens examined.
Female reproductive system: The female re-
productive system is similar in most respects to
that of Cancellaria reticulata (Harasewych and
Petit, 1982). The yellowish, ascinous ovary lies
at the posterior-most portion of the visceral
mass. From it a thin- walled oviduct (Fig. 10, od)
runs anteriorly along the columellar side of the
digestive gland, kidney and pericardium before
entering the rear of the mantle cavity. No gono-
pericardial duct was found. The pallial portion of
the oviduct consists of an albumen gland (Fig.
10, ag), a small, tubuliferous ingesting gland
(Fig. 10, ig), a large, ovate capsule gland (Fig.
10, eg) and a triangular bursa copulatrix (Fig.
10, be).
Male reproductive system: The male reproduc-
tive system does not differ markedly from that
of Cancellaria reticulata (Harasewych and
Petit, 1982). The testis lines the columellar side
of the digestive gland and gives rise to a testicu-
lar duct that runs anteriorly along the visceral
mass, becoming convoluted when adjacent to
the kidney, then straightening and entering the
rear of the mantle cavity. Here it expands,
becoming convoluted and glandular (Fig. 7, pr),
then constricts again and leads to the base of a
long, cylindrical penis (Fig. 7, pen). The penis,
ovate in cross-section, contains a coiled penial
duct and has a terminal papilla.
Nervous system: As in Cancellaria reticulata
(Harasewych and Petit, 1982), the nervous sys-
tem is highly concentrated with the cerebral,
pleural, pedal and subesophageal ganglia fused
into a nerve ring (Fig. 9, nr) that encircles the
esophagus and anterior aorta. The buccal gan-
glia are at the rear of the buccal mass, but
neither the proboscis nor the cerebro-buccal
42 THE NAUTILUS
January 30, 1984
Vol. 98(1)
connectives are as long as in C. reticulata.
Discussion
Within the cancellariacean framework, Ols-
sonnella smithii is less specialized than is
Cancellaria reticulata both in shell structure
and in anatomical organization. Table 2 lists ma-
jor anatomical differences between these two
species, with asterisks denoting conditions we
consider to be derived.
The diet of cancellariids remains a mystery, as
no identifiable gut contents could be found in
any species examined. However, the highly
modified chemoreceptive organs and anterior
alimentary system of C. reticulata suggest a
more specialized diet for that species. Olssonella
smithii has a simpler anterior alimentary
system, but the very large hypobranchial gland
suggests the possibility of toxin production
(Halstead, 1965).
Olssonella S7nithii is also less specialized in
shell architecture, lacking the external evidence
of internal varices and bifurcated columellar
folds of C. reticulata. The former species has
apertural lirae every 240° rather than every
120° as found in the latter. Shell ultrastructure
is similar in both species, although 0. smithii
has a thicker, coarser periostracum.
Attempts to investigate morphological diver-
sity within the Cancellariacea have been ham-
pered by a lack of a phylogenetic arrangement
of the approximately 100 nominal supraspecific
taxa within the group. The superfamily has been
divided into the Cancellariidae and the extinct
Paladmetidae (Sohl, 1964; Ponder, 1973). Can-
cellariid genera have, in general, been clustered
around three morphological types that have
been elevated to the subfamilies Cancellariinae,
Trigonostominae and Admetinae (Cossmann,
1899).
Cancellaria reticulata, whose anatomy has
recently been described (Harasewych and Petit,
1982), is the type species of Cancellaria
Lamarck, 1799. Olssonella smithii, the type
species of Olssonella Petit, 1970, may serve as
exemplar of the Trigonostominae. No general
anatomical studies of any species of Admetinae
are known to us, although a brief description of
a living Admete viridula (Fabricius, 1780) is
given by Jeffreys (1876) and repeated by Tryon
(1885). Thiele (1929), Powell (1951) and Oliver
(1982) have published figures or descriptions of
radulae and jaws of members of this subfamily.
The limited data available show that Cancellari-
inae and Trigonostominae are more closely re-
lated to each other than either is to Admetinae.
Representatives of the first two "subfamilies"
have radular teeth in which the outer cusps have
secondary cusps; indeed, the principle radular
differences seem to lie in the patterns of this
secondary dentition. In contrast, the outer
"cusps" of admetine radular teeth are bulbous
TABLE 2. Anatomical differences
condition.
between Olssonella smithii and Cancellaria reticulata. Asterisk denotes derived
Character
Olssonella smithii
Cancellaria reticulata
Left cephalic tentacle
distance between osphradium
and ctenidium
hypobranchial gland
proboscis shape
proboscis
buccal mass
valve of Leiblein
middle esophagus
penis
bursa copulatrix
cerebro-buccal connective
normal
normal
'hypertrophied
tubular, smooth
normal, pleurombolic
large, protrudes posteriorly
when proboscis is retracted
large, normal
•?expanded
cylindrical
triangular
'long
•bilobed
'enlarged
normal
*ventrally flat, papillose
'posterior portion of retracted proboscis
serves as proboscis sheath
'small, contained in anterior portion
of proboscis
'reduced to bulge on esophagus
narrow
•?flat
*?rectangular
"very long
Vol. 98(1)
January 30, 1984
THE NAUTILUS 43
and nearly hemispherical, with the central por-
tion of the tooth lined with longitudinally ar-
ranged barbs (Oliver, 1982: Figs. 3, 5). Within
Admetinae the jaw is shorter (Oliver, 1982: Fig.
4), lacking the posterior lobes present in jaws of
Cancellariinae (Olsson, 1970: Fig. 13) and Trigo-
nostominae (Olsson, 1970: Fig. 24).
Admete magellanica (Strebel, 1905) lacks a
radula but has a tubular jaw (Oliver, 1982:16)
suggesting to us a trend toward loss of radula in
Admetinae with the tubular jaw being used as a
piercing stylet, as in the pyramidellids.
Admittedly, these interpretations are specula-
tive, being based on minimal data. It is hoped
further work will shed more light on some of the
hypotheses proposed.
Acknowledgements
We thank Paula M. Mikkelsen of the Indian
River Coastal Zone Museum, Harbor Branch
Foundation, William G. Lyons of the Depart-
ment of Natural Resources, State of Florida,
and Sanford E. Peek, Jr. of Summerville, South
Carolina, for making available the specimens
used in this study. Much of this work was done
at the Smithsonian Marine Station at Link Port,
Florida, and we thank Dr. Mary Rice for making
these facilities available. Thanks are also due
William D. Lee for help with the histological
preparations. This is contribution number 127 of
the Smithsonian Marine Station at Link Port.
Critical review of the manuscript by Dr.
Richard S. Houbrick and Dr. Joseph Rosewater
of the National Museum of Natural History,
Smithsonian Institution and by Dr. Geerat J.
Vermeij of the Department of Zoology, Univer-
sity of Maryland is gratefully acknowledged.
LITERATURE CITED
Amaudrut, A. 1898. La partie anterieure du tube digestif et
la torsion chez les mollusques gasteropodes. Ann. Sci. nat.
Zoot. (7) 8:1-291.
Barnard, K. H. 1958. Tiie radula of Cancellaria. J. Conchol.
24(7):243-244.
Boss, K. J. 1982. Classification of Mollusca [in] Parker, S.
P. Synopsis and Classification of Living Organisms.
McGraw Hill Book Co., New York. 2:109-1096.
Cossmann, M. 1899. Cancellariidae. Essais de Paleocon-
chologie Comparee 3:1-41, pis. 1-2.
Dall, W. H. 1888. [in] Agassiz, A. Three Cruises of the United
States Coast and Geodetic Survey Steamer Blake, 2(8):
62-75, figs. 282-312.
Fabricius, 0. 1780. Fauna Groerilandica. Hafnia et Lipsiae
452 p.
Fischer, P. 1883. Manuel de conchyliologie et de paleon-
tologie conchyiiologique ou histoire naturelle des mol-
lusques muants et fossils. Paris, F. Savy. 1369 p.
Golikov, A. N. and Y. I. Starobogatov. 1975. Systematics
of Prosobranch Gastropods. Mahwologia 15(l):185-232.
Graham, A. 1966. The fore-gut of some marginellid and
cancellariid prosobranchs. Stud. Trop. Oreonog. Miami
4(1):134-151.
Halstead, B. W. 1965. Poisonous and Venomous Marine
Animals of the World. I - Invertebrates. United States
Government Printing Office, Washington, D.C. 994 p.
Harasewych, M. G. and R. E. Petit. 1982. Notes on the
morphology of Cancellaria reticulata (Ga^^'ori'^da: Can-
cellariidae). The Nautilus 96(3):104-113.
Jeffreys, J. G. 1876. New and peculiar mollusca of tht Euli-
midae and other families of gastropoda, as well as the
Pteropoda, procured in the "Valerous" expedition. Ann.
Mag. nat. Hist. 4(17):317-339.
Keen, A. M. and E. Coan. 1974. Marine Molluscan Genera
of Western. North America: An Illustrated Key. 2nd edi-
tion. Stanford University Press, Stanford. 208 p.
Lamarck, J. B. P. 1799. Prodrome d'une nouvelle classifica-
tion des Coquillages, Comprenant une redaction appro-
priee des caracteres generiques, et I'establissement d'une
grand nombre de genre noveaux. Soc. Hist. Nat. Paris,
Mem. 1:63-85.
Linne, C. von. 1767. Systema Naturae per regno tria
naturae. Editio duodecimo reformata. 1(2):533-1327.
Marks, J. G. 1949. Nomenclatoral units and tropical Ameri-
can Miocene species of the gastropod family Cancellarii-
dae. J. Paleont. 23(5):453-464, pi. 78.
Oliver, P. G. 1982. A new species of Cancellariid gastropod
from Antarctica with a description of the radula. Br.
Antarct. Surv. Bull. 57:15-20.
Olsson, A. A. 1970. The cancellariid radula and its interpre-
tation. Palaeontogr. Amer. 7(43): 19-27.
Petit, R. E. 1970. Notes on Cancellariidae (Mollusca: Gastro-
poda) ■ n. TulaneStud. Geol. Paleont. 8(2):83-88.
Petuch, E. J. 1981. A relict Neogene Caenogastropod fauna
from northern South America. Malacologia 20(2):307-347.
Ponder, W. F. 1973. The origin and evolution of the Neogas-
tropoda. Malacologia 12(2):295-338.
Powell, A. W. B. 1951. Antarctic and subantarctic Mollusca:
Pelecypoda and Gastropoda. Discovery Reports 26:
47-196, pis. 5-10.
Prmcz, D. 1982. New records of living marine gastropoda of
Venezuela. The Veliger 25(2): 174- 175.
Rice, W. H. and L. S. Kornicker. 1965. Mollusks from the
deeper waters of the northwestern Campeche Bank,
Mexico. Pubis. Inst. Mar. Sci. Univ. Texas 10:108-172.
pis. 1-16.
Schremp, L. 1983. Taxonomic problems of "Cancellaria" io
Dall. Western Soc. Makwologists. Ann. Rept. 15:17.
Schremp, L. and R. Richmond. 1983. The Cancellariid radu-
la. Western Soc. Malaeologists. Ann. Rept. 15:16-17.
Sohl, N. F. 1964. Neogastropoda, Opisthobranchia and
Basommatophora from the Ripley, Owl Creek, and Prairie
Bluff Formations. U.S. Geol. Surv. Professional Paper
331-B 344 p., pis. 19-52.
44 THE NAUTILUS
January 30, 1984
Vol. 98(1)
Strebel, H. 1905. Beitrage zur Kenntnis der Mollusken
Fauna der Magalhaen-Provinz. Zoo/. Jh.. Aht. Syst. Jenna
22:575-666, pis. 21-24.
Taylor, D. W. and N. F. Sohl. 1962. An outline of gastropod
classification. Malacologia l(l):7-32.
Taylor, J. D., N. J. Morris and C. N. Taylor. 1980. Food
specialization and the evolution of predatory prosobranch
gastropods. Paleontology 23(2):375-409.
Thiele, J. 1929. Handbuch der systematischeTi. Weichtier-
kunde. Jena, Gustav Fischer, 1929-1935. 1154 p.
Trosehel, F. H. 1856-1893. Das Gebiss der Schnecken zur
Begriindung einer natiirlichen Classification. 2. Berlin.
Tryon, G. W. 1882. Structural and Systematic Conchology:
an introduction to the study of mollv^ca. Philadelphia,
vol. 1, 312 p., 22 pis.
1885. Family Cancellariidae. Manual of Con-
chology 7:65-98, pis. 1-7.
Wenz, W. 1938-1943. Handbuch der Paldozoologie (0. H.
Schindewolf, ed.), Berlin, Band 6, Teil 1 (pt. 2), 1639 p.
[pp. 1355-1371].
COMPARISON OF THE DIETS OF THE TIDAL MARSH SNAIL,
MELAMPUS BIDENTATUS AND THE AMPHIPOD, ORCHESTIA GRILLUS
Louise S. Thompson
Department of Zoology, Connecticut College,
New London, CT 06320, U.S.A.'
ABSTRACT
The diet of the opportunistically-feeding snail, Melampus bidentatus Say is
essentially the same as that of the amphipod, Orchestia grillus (Bosc). These
animals are co-inhabitants in the high marsh regions of the Pataguanset Tidal
Marsh in Niantic, Connecticut. In addition to gut content analyses of both species,
criteria for identifying microscopic samples of the most abundant plant material,
including the animals' main food. Spartina patens, were established. Because of
the abundance of available food items, competition between the two species ap-
pears to be minimal.
In spite of the fact that Melampus bidentatus
appears in large numbers in the tidal marshes
along the east coast of North America, few stud-
ies, either qualitative or quantitative, have been
made on their food preferences or dietary
habits. Although Hausman (1936) reported on
the chief components of the Melampus diet, her
study did not list the number of animals ana-
lyzed nor the methods of data compilation. Thus
only limited conclusions can be drawn from this
previous literature.
The current study consisted of 1) a survey of
the plant material available on the marsh with
compilation of criteria for identifying small
plants and fragments of larger plants under a
microscope to facilitate gut content analysis; 2)
the analyses of the gut and feces contents of
both M. bidentatus and 0. grillus in order to
determine the major seasonal components of
their diets; and 3) a follow-up examination of
winter feeding activity of M. bidentatus.
'Present Address: 401 Factory Square. Mystic, CT 06355.
Study Site and Methods
The initial study was conducted on the tidal
marshes of Watts Island in the Pataguanset
Estuary west of Niantic Bay in Connecticut.
This island, measuring 10 acres, has small areas
of upland vegetation consisting mainly of oaks
and poison ivy. The dominant vegetation, how-
ever, is Spartina patens which occurs in pure
stands or mixed with DistichUs spicata, Juncus
gerardi and Spartina alt.emifl.ora. The estuary
surrounding the island, as well as the ditches
traversing the marsh, are filled with Ruppia
m.aritima and Enteromorpha spp. in the spring
and summer. In the winter large amounts of
loose algae, including Ulva lactu^a, Entero-
morpha spp. and Ascophyllum nodosum, wash
onto the marsh surface along with decaying eel-
grass (Zoster a marina).
The algal mat, densely covering much of the
marsh surface, consists largely of RMzoclonium
riparium, Vaucheria spp. and diatoms, with
lesser quantities of the blue-green algae, Lyng-
bya spp. and Oscillatoria spp. Mixed into the
Vol. 98(1)
January 30, 1984
THE NAUTILUS 45
mat are small animals such as nematodes which
inhabit this layer and large amounts of grass
and animal detritus.
In order to determine changes in the plant
material available to consumer species on Watts
Island, seasonal surveys of the grasses, forbs
and macroalgae were made as well as micro-
scopic analyses of small sections of the algal mat
which had been scraped from the marsh surface.
The plants were collected from various sites on
Watts Island and brought back to the laboratory
for processing.
A series of photomicrographs of cuticular and
epidermal fragments of 16 salt marsh grasses,
forbs and algae, suspected of being possible food
items for M. hidentatus and 0. grillus was
prepared and shows characteristic features
specific to each species.
In preparing grass samples to be photo-
graphed, a handful of grass blades were cut into
2 cm lengths, placed in a Waring blender,
covered with distilled water and processed for
15 seconds. The resulting mixture was then
poured into a petri dish and examined under a
dissecting microscope. Suitable epidermal frag-
ments were removed with a pipette, mounted in
a drop of aerosol and photographed at 100 x
magnification. Macroalgae samples were pro-
cessed in much the same manner. Cuticle repli-
cas were made of the leaf surfaces of forbs by
applying clear nail lacquer to both abaxial and
adaxial sides. After air drying the lacquer
replica was peeled off with forceps, mounted in
aerosol and photographed under low illumina-
tion. Photomicrographs were also made of
microalgae scraped from the algal mat and
sketches were made of the diatoms most com-
monly found on the marsh surface. These photo-
micrographs and sketches were then used for
comparison in identifying fragments taken from
the gut and fecal samples of M. bidentatus and
0. grillus.
Snails and amphipods used for gut content
analyses were collected seasonally from eight
sites across Watts Island, preserved in 70 per-
cent alcohol and transported back to the labora
tory where they were measured and then dis-
sected under a binocular microscope. During the
winter, two groups of inactive snails were col-
lected: one group was preserved immediately
upon removal; the other was used as a control to
determine if the inactive snails were alive. In a
follow-up study two years later, maximum and
minimum air temperatures, peat temperature
and position of Melampus on the marsh were
recorded biweekly from November through
April at Cottrell Marsh. This tidal marsh is
located in Mystic, Connecticut, about 25 km east
of Niantic and has a vegetation pattern similar
to that on Watts Island. Three times during this
follow-up study snails were collected and
preserved for future gut content analyses.
Stomach contents, usually in the form of a
well-compacted amorphous mass, were removed
and placed on a microscope slide in a drop of
distilled water. The mass was broken up with a
fine dissecting needle in order to separate
fragments and then examined under 100 x and
450 X magnification. Food items present were
listed according to species, and the percentage
of the total gut content volume was visually
estimated for each item. A tabulation was then
made of percent frequency of consumption of
each food item by dividing the number of
animals containing a particular item by the total
number of animals examined.
Live animals were also collected seasonally,
rinsed in seawater and placed in a petri dish on
filter paper soaked in seawater. Fecal samples
were collected after 24 hours, mounted in dis-
tilled water and examined under the compound
microscope.
Observations
Diagnostic microscopic features found on the
abaxial and adaxial epidermal surfaces and leaf
margins which were used in the identification of
the tidal marsh grass, rush and forb species fre-
quently found in the gut contents of M. bidenta-
tus and 0. grillus are summarized in Tables 1
and 2. Examples of some of these features are
shown in Fig. 1.
In all seasons plant material, varying from 0.5
mm square fragments to single cells, epidermal
hairs, diatoms, microalgae and cell inclusions
such as chloroplasts, formed the bulk of material
found in the gut and feces of both M. bidentatus
and 0. grillus. Although a large percentage of
the filamentous algae was still fresh and intact,
fresh grass particles or those still containing
large amounts of chlorophyll were never found
in any of the guts. In fact, live animals being
held in the laboratory refused to eat fresh grass
46 THE NAUTILUS
January 30, 1984
Vol. 98(1)
TABLE 1. Microscopic features used in the identification of
grass and rush species.
Species Identifying Features
Spartina altemiflora
Abaxial Epidermis
Long Cells- thin, sinuous walls.
Short Cells -abundant, solitary.
Stomata- numerous, in longitudinal rows.
Adaxial Epidermis
Cells- rectangular with thin, sinuous walls.
Papillae- small; 2-3 rows per cell.
Spartina patens
Abaxial Epidermis
Long Cells- thin, sinuous walls.
Short Cells -abundant, solitary.
Stomata - scattered.
Adaxial Epidermis
Cells -rectangular with thin, sinuous walls.
Papillae -small; single row per cell. \
Distichlis spicata
Abaxial Epidermis
Long Cells- thin, sinuous walls over veins; between
veins, shorter, broader, with coarse sinuations.
Short Cells -abundant.
Stomata -present but infrequent.
Adaxial Epidermis
Numerous pronounced ribs.
Papillae -large, conical; densely cover entire surface.
J uncus gernrdi
Abaxial Epidermis
Long Cells- thin, sinuous walls.
Short Cells -absent.
Stomata- large, abundant.
Adaxial Epidermis
Large, rectangular cells with thin, sinuous walls.
Phragm ites australis
Abaxial Epidermis
Long Cells -thin, coarsely sinuated walls.
Short Cells -solitary between veins; paired over veins.
Prickle Hairs -between veins; hooked, resemble
papillae.
Adaxial Epidermis
Not examined.
particles but readily consumed filter paper. The
percent frequencies of occurrence of particular
food items found in the gut contents of 220 M.
bidentatus and 81 0. grillus during the fall,
winter, spring and summer of 1980 and 1981 are
shown in Figs. 2 and 3.
Animal material, which most frequently in-
cluded jointed insect appendages, occurred in
32% of the Melampus and 17% of the Orchestia.
In some cases intact foraminiferans, mites,
ostracods and nematodes were present.
Of the plant material, S. patens fragments
TABLE 2. Microscopic features used in the identification of
seagrasses, forbs and algae.
Species Identifying Features
Ruppia maritima
Rows of cuboidal cells.
Zostera marina
Cells mostly hexagonal, in rows.
Limonium carolinianum
Elongated cells with nonsinuous walls.
Sunken stomata in longitudinal rows.
Saiicomia europaea
Cells of varying and irregular shapes.
Numerous, dispersed stomata.
Iva frutescens
Cells of varying and irregular shapes
(smaller than Saiicomia).
Dispersed stomata.
Rhizoclonium riparium
Branching filaments.
Uniserate arrangement of cells.
Enteromorpha spp.
Branching filaments.
Multiserate arrangement of cells.
Polysiphonia harveyi (Bail)
Branching filaments.
Four pericentral cells.
Ulva lactuca
Sheets of cells in mosaic-like arrangement.
Lyngbya spp.
Single trichome enclosed in a sheath.
Microcoleus spp.
Many trichomes enclosed in a single sheath.
were present in 51% of the Melamptis examined
and 42% of the Orchestia. S. altemiflora was
present in 27% of the Melampus and 30% of the
Orchestia. Of the other marsh grasses only J.
gerardi was found in more than 10% of the
animals. A small amount, 6% in Orchestia and
3% in Melampus, of eelgrass was found in the
spring samples and in 12% of the fall Melampus
specimens.
Rhizoclonium riparium was the most fre-
quently found alga, occurring in 52% of the
Melampus and 19% of the Orchestia. During the
spring and summer an increased number of both
snails and amphipods showed the presence of
the blue-green algae, Chrococcu^ spp., Lyngbya
spp. and Oscillatoria spp. as well as the yellow-
green, Vaucheria spp. Frequency of diatom con-
sumption was consistently high for Melampus at
69% but averaged only 22% for Orchestia. All
food material was frequently mixed with sand.
In the initial winter study, snails were found
Vol. 98(1)
January 30, 1984
THE NAUTILUS 47
FIG. 1. A) Abaxial epidermis of S. alternijlom showing rectangular long cells, abundant solitary short cells and stomata
(arrow) in longitudinal rows; B) adaxial epidermis of S. altemiflora showing rectangular cells covered with multiple rows
of small papillae; C) leaf surface of Limonium raroliniiinum showing elongated cells and sunken stomata (arrow); D)
abaxial epidermis of 5. patens showing rectangular long cells alternating with short cells and scattered stomata (arrow);
E) adaxial epidermis of S. patens showing rectangular cells covered with single rows of papillae; F) leaf surface oiSalicor-
nia europafa: G) large, conical papillae (arrow) on the adaxial surface of D. spicata: H) abaxial epidermis of D. spicata
showing long cells with coarse sinuations between veins; I) fragment oiRuppia marina: J) abaxial epidermis of J. gerardi
showing large, abundant stomata (arrow); K) abaxial epidermis of Phragmites australis showing coarsely sinuated walls
and hooked-shaped prickle hairs (arrow); L) fragment of Zostera marina.
48 THE NAUTILUS
January 30, 1984
Vol. 98 (1)
)00 —
90 _
80 _
70 —
>. 60 _
c
=> 50 _
«
40
30
20-
10 —
M. bidentotus
IJL
E
'c
FIG. 2. Percent frequency of food items found in the gut contents of 220 Melampus bidentatus.
100 —
90-
80-
70 -
60-
so —
40 -
30 —
20 —
10
N=7
N = 25
N:34
N = 15
Innp
FIG. 3. Percent frequency of food items found in the gut contents of 81 Orchestia grillus.
Vol. 98 (1)
January 30, 1984
THE NAUTILUS 49
buried beneath a layer of frozen peat. Those col-
lected for gut content analysis, as well as the un-
preserved specimens, ranged from 5 mm to 8
mm in shell length. The guts were all found to be
empty. The unpreserved specimens that were
transported back to the laboratory became ac-
tive within 20 minutes after being placed at
room temperature.
In the winter follow-up study, inactive Melavi-
pus with shell lengths greater than 8 mm, re-
mained on the surface of the peat, singly or in
clusters, during periods of mild weather. How-
ever, when maximum air temperature or the
temperature of the peat dropped below 0°C, or
during periods when the marsh surface was
covered with ice and/or snow (as shown in Fig. 4
in mid-January and throughout February and
early March) these large-size snails became par-
tially embedded along Spartina stems. When
the ice and snow disappeared or the tempera-
ture of the air and peat rose, Melampus were
again found on the surface. Snails smaller than
8 mm did not appear on the marsh surface until
April when both air and peat temperatures
began to steadily increase; apparently they were
buried in deeper layers of peat during cold
weather. But even though it appears that
Melampus does move somewhat during the
winter, all specimens dissected for gut content
analysis were found to be empty as in the
previous study. Hence, there is no direct
evidence that Melampiis feeds during the
winter.
Contrary to the apparent inactivity of Melam-
pus, Orchestia, although moving more slowly
than usual, was active under piles of flotsam
during the winter. And while food was present
in the gut of Orchestia during this period, the
quantities were smaller than in other seasons.
Much of the grass removed for examination was
in an advanced state of decomposition, hence, it
could not be identified. Forty percent of the am-
phipods did contain identifiable S. altemiflora
fragments and 39% had consumed Ulva lactuca
which had washed onto the frozen marsh sur-
face and was covering large portions of the up-
30-
28-
26—
24—
22-
20—
18-
16 —
14—
12—
lO—
6-
4—
2—
O-
-2-
-4-
-6-
-8-
-lO-
-12-
-14-
-16"
-18-
T Maximum/Minimum Air Temp.
■ Temp. Peat
[^^^ Snails embedded in peat.
9 V
Nov.
Dec.
// I /// ^//////|
Jan.
Mar.
Apr.
FIG. 4. Maximum and minimum air temperatures, peat temperatures and position of Melampxis bidentatus on high
marsh from November through April, 1982-83.
50 THE NAUTILUS
January 30, 1984
Vol. 98(1)
per regions.
Analysis of fecal contents showed the pres-
ence of grass epidermal cells, diatoms, intact
algal trichomes, as well as empty sheaths, and
undigested animal material. These findings
seem to indicate that much of what is consumed
by Melamptcs and Orchestia is deposited back on
the marsh, although grass and macroalgae are
in somewhat smaller fragments due to mastica-
tion and/or trituration.
While tabulations of percent frequency indi-
cate that both animals are generalists in their
dietary preferences, they do not give an ac-
curate picture of important food sources. For
example, diatoms were consumed by 74% of the
snails but because of the small sizes of these
items, they rarely accounted for more than 5%
of the total food content per gut. Estimations of
percent volume of various food items per gut
(Fig. 5) indicate that grass detritus, especially S.
patens and S. altemiflora, is the major food
component. In both Orchestia and Melampus
these two grasses accounted for more than 60%
of the total gut content per snail. All other food
items, including algae, diatoms and animal
material, contributed to the remaining 40%.
Several plant species such as Phragmites aus-
tralis, Ascophyllum nodosum, Limonium carol-
inianum and Salicomia europaea, although
abundant on the marsh, were not observed in
either gut contents or fecal samples. Fragments
of these species may have been consumed but
were too small to be identified or were too
decomposed or macerated for specific features
to be recognized. Overall, the percent frequency
of unidentifiable material found in the gut
averaged 6% in Melampiis and 9% in Orchestia;
however, it constituted less than 1% of the
overall percent volume.
Figures from this study indicate that approxi-
mately 60% to 65% of the diets of M. bidentatus
and 0. grillus are composed of salt marsh grass
detritus consisting mainly of S. patens and S.
altemiflora. The remaining bulk of the diet is
made up largely of a variety of algal species
which become seasonally available. Animal
material, while frequently ingested, does not
contribute much bulk to the diet because of the
small amounts consumed by each animal.
S. altemiflora
S- patens
0, qerardi
Bhizoclonium
Ulva
Vaucliena
Empty
Other
FIG. 5. A) Percent volume of major food items in Melampus
hiden.tntus calculated per animal; B) percent volume of major
food items in Orchestia yrilius. "Other" category refers to all
items constituting less than .">% of total gut content which in-
cludes unidentifiable material.
Discussion
Although M. bidentatus uses a radula to "lick"
small food particles from the marsh surface and
0. grillus bites off large chunks of solid material
and masticates them with mandibles, both
animals are opportunistic feeders with very
similar diets. Potential nutritional value of a
food item seems to be of little importance since a
large part of what is ingested, such as epidermal
cells from grasses and animal chitin, appears to
be indigestible and ultimately ends up in the
feces. The fact that both species can exist in the
same area and eat the same food substances is
probably due to the large amount of detritus
available on the high marsh. For example,
42,000 tons of plant material are produced an-
nually on 6,277 hectares of Connecticut marsh
land (Niering and Warren, 1974) and only a
small percentage of this production is eaten
while still alive.
It is evident from this study that Melampus
and Orchestia feed primarily on decaying grass
fragments and in particular on S. patents which
is the dominant plant species on Watts Island.
The fact that fresh grass particles were never
Vol. 98(1)
January 30, 1984
THE NAUTILUS 51
found in the ^ts analyzed correlates with a
laboratory study conducted by Valiela et al.
(1979) which showed that when M. bidentatus
and 0. grillus were presented with new S. alter-
niflora detritus as opposed to nine-month-old
dead grass, feeding activity decreased. Their
findings indicate that the animal's feeding is in-
hibited by high concentrations of ferulic and
p-courmaric acids in the fresh material which
decrease as the grass ages. In the present study
Melampus that were offered fresh particles of
various grass species refused to eat the plant
material but did consume the seawater soaked
filter paper lining the petri dishes in which they
were being held. Hausman (1932) stated that
microscopic examination of the stomach con-
tents of actively feeding Melampics showed a
large quantity of epidermal cell fragments of
marsh grasses, but in a 1936 paper she reports
that the proportion of higher plant tissue in the
diet is small.
In this study it has also been shown that al-
though algae were regularly consumed, there
appears to be no set preference for one species
over another; the species consumed most fre-
quently and in the largest quantity was also the
most abundant on the marsh at the time. For ex-
ample, Rhizoclonium riparium had the highest
percent frequency of consumption and percent
volume per Melampus gut in the spring, but it
was replaced by Vaucheria spp. and the fila-
mentous blue-green algae in the summer. Dia-
toms had an overall percent frequency of 69%
with a maximum of 94% in Melamptis in the
spring but the percent volume per gut was never
more than 5%. Hausman (1936) stated a figure
of 75% algae consisting chiefly of diatoms which
more closely correlates with the percent fre-
quency figures from the present study rather
than proportion of material per gut which is
quoted in her paper.
While Melampus is primarily an herbivore, it
is an opportunistic feeder sometimes ingesting
animal material. Although percent frequency of
ingestion of animal material in this study
reached 76% in some instances, the percent
volume of such material rarely accounted for
more than 1% of the total gut content per snail.
Hausman (1936) also reported the presence of
animal components in the gut contents of
Melampus.
Although there is no evidence from gut con-
tent analysis in this study that Melampus feeds
during the winter, Hausman (1948) reported
that on warm winter days the snails emerge
from their cover to feed on nearby mudflats. No
such activity was observed in either of the pre-
sent winter studies. Grandy (1972) reported a
lack of movement of Melampus beginning in
mid-November in a Cape Cod salt marsh. But
evidence from this study indicates that Melam-
pus is not completely dormant. For instance,
large-size snails were usually found to be inac-
tive on the surface of the peat, but they actively
sought cover when the temperature of the air
and/or peat dropped or when the marsh surface
was covered with ice and/or snow. Hausman
(1948) also reported that when air temperatures
averaged about -7°C, snails in a Connecticut
marsh moved under thick tufts of Spartina,
which corresponds to the findings in this study.
The lack of smaller-size Melampus on the
marsh surface during the winter indicates a
possible lack of tolerance of these animals to
cold temperatures. This correlates to findings
by Price (1980) who reported a mortality rate of
85.7% in Melampus measuring less than 5 mm
after 3 days of being exposed to air tempera-
tures of -12°C. This rate decreased to 68.8% in
snails measuring 5 to 7 mm and 26.7% in those
larger than 8 mm, indicating an increased
tolerance to cold with size increase (Price, 1980).
Results from this study indicate that 0. grillus
is also a generalized feeder, indiscriminately in-
gesting whatever is available. For example, dur-
ing the winter when the marsh surface was
covered with ice, 0. grillus readily switched
from eating grass detritus and consumed decay-
ing Ulva lactuca which had accumulated along
the upland border instead. And while there are
no indications that Orchestia attacks live
animals, Smallwood (1905) stated that in con-
finement they will eat one of their own species
that happens to die.
Further quantitative studies need to be made
to determine what components of the diet are
being assimilated and what impact the consump-
tion of large amounts of detritus by inverte-
brates has on the marsh ecosystem. Haines and
Montague (1979), for instance, in tracing carbon
sources through a salt marsh food web in
Georgia, found that the A'^C values in M. biden-
52 THE NAUTILUS
January 30, 1984
Vol. 98(1)
tatus correspond closely to the values for S.
altemiflora. In the present study contents of
the feces in both species were very similar to the
gut contents. This fact indicates that much of
the material consumed by Melamptcs and Or-
chestia is redeposited on the marsh and suggests
that a substantial portion of their nutrition may
be derived from the bacteria growing on the sur-
face of the food particles and not from the
detritus itself. Darnell (1967) and Odum and de
la Cruz (1967) found that large microbial popula-
tions grow on detrital particles and constitute
an energy-rich source for organisms capable of
removing them. Hargrave (1970), in feeding ex-
periments on the amphipod Hyatella azteca,
found an assimilation efficiency of 60% to 82%
with bacteria and diatoms but only 5% to 15%
with blue-green algae. The gut contents of II-
yanassa obsoleta, a snail inhabiting sandflats,
were found to consist largely of sediments,
leading Curtis and Hurd (1981) to conclude that
most of its nutrition is apparently derived from
microflora growing on the sediment. And
Daiber (1982) notes that 0. grillus feeds
primarily on the fungus covering grass detritus,
frequently scraping off and ingesting fragments
of grass from below the fungal layer.
Because of the large numbers of these two in-
vertebrates on the high marsh and the large
amount of detritus that is broken down by them
during mastication and/or trituration and
deposited back on the marsh, they may have a
significant effect on raising the nutritional value
of the detrital particles that are washed into
estuarine waters by tidal action to serve as
direct or indirect food sources for offshore
species. Teal (1962) in a Georgia salt marsh
study, found that only 55% of primary produc-
tivity is assimilated by consumer species with
47% being dissipated by bacteria, 7% by pri-
mary consumers and 0.6% by secondary con-
sumers; the remaining 45% is apparently ex-
ported to estuaries. Odum and de la Cruz (1967)
found that smaller particles of detritus are
richer in protein than large particles; small
pieces have an increased surface-to-volume ratio
for greater bacterial growth which accounts for
the enrichment. On an ash-free basis small
suspended particles were found to contain 24%
protein compared with 10% in living grass and
6% in dead grass (Odum and de la Cruz, 1967).
Certainly much of the food material which
passes through the guts of M. bidentatus and 0.
grillus can be reingested and recycled over and
over again, allowing microbial decomposition
and surface absorption to occur between
passages.
Evidence from this study indicates that both
M. bidentatus and 0. grillus are generalized, op-
portunistic feeders, consuming large quantities
of salt marsh grass production, much of which is
broken into smaller pieces during digestion and
deposited back on the marsh. Further quantita-
tive studies need to be made to determine what
impact these two invertebrates have on the total
marsh ecosystem as well as what components of
their diets are being assimilated.
Acknowledgments
I wish to thank Dr. P. E. Fell for his help and
encouragement during this study and for his
criticisms of this manuscript. I would also like to
thank Dr. R. Ameele for his assistance in the
preparation of epidermal replicas and grass
slides and Mrs. S. Taylor, Dr. F. Trainor and Dr.
M. Villalard-Bohnsack for their helpful
assistance in the identification of algae and
diatoms.
LITERATURE CITED
Curtis, L. A. and L. E. Hurd. 1981. Nutrient procurement
strategy by a deposit-feeding estuarine neogastropod,
Ilyaimssa obsoleta. Est. Coastal and Shelf Sri. 13:211-285.
Daiber, F. C. 1982. Animals of the Tidal Marsh. Van Nos-
trand Reinhold Co.. New York and London, 422 pp.
Darnell, R. M. 1967. Organic detritus in relation to the estu-
arine ecosystem, hi G. H. Lauff (ed.), Estuaries. AAAS,
Washington, D.C., p. 376-382.
Grandy, J. W. 1972. Winter distribution oi Melampus biden-
tatus (Say) on a Cape Cod salt marsh. The Nautilus 85:
106-109.
Haines, E. B. and C. L. Montague. 1979. Food sources of
estuarine invertebrates analyzed using "C/"C ratios.
Ecology 60:48-56.
Hargrave, B. T. 1970, Utilization of benthic microflora by
Hyatella azteca (Amphipoda). J. Anim. Ecol. 39:427-437.
Hausman, S. A. 1932. A contribution to the ecology of the
salt marsh snail, Melampus bidentatus (Say). Amer. Nat.
66:541-545.
1936. Food and feeding activities of the salt
marsh snail (Melampus bidentatus). Anat. Rec. 67:127.
1948. Further studies of the salt marsh snail
(Melampus bidentatus or lineatus). Amer. Nat. 82:
137-144.
Niering, W. A. and R. S. Warren. 1974. Tidal marshes of
Connecticut: vegetation, micro-relief and environmental
Vol. 98(1)
January 30, 1984
THE NAUTILUS 53
impacts. Tidal Wetlands of Connecticut. Vegetation and
Associated Animal Populations. DEP, State of Connecti-
cut, 73 pp.
Oduni, E. P. and A. A. de la Cruz. 1967. Particulate organic
detritus in a Georgia salt marsh-estuarine ecosystem. In
G. H. Lauff (ed.), Estuaries. AAAS, Washington, D.C.,
p. 383-388.
Price, C. H. 1980. Water relations and physiological ecology
of the salt marsh snail, Melampuii hidentatus Say. J. exp.
mar. Biol. Ecol. 45:51-67.
Smallwood, M. E. 1905. The salt-marsh amphipod: Orches-
tia palustris. Cold Spring Harbor Mono. 3;3-21.
Teal, J. M. 1962. Energy flow in the salt marsh ecosystem
of Georgia. Ecol. 43:614-624.
Valiela, I., L. Koumjian and T. Swain. 1979. Cinnamic acid
inhibition of detritus feeding. Nature 283:55-57.
Reprints of out-of-print volumes of.
flflUTILU
Vols. 1-40 and Gen. Ind. 1-34. Philadelphia, Pa.,
1886-1926/27.
clothbound $842.00
paperbound $716.00
Kraus Reprint
Millwood, New York 10546
AVAILABLE FROM THE ORIGINAL PUBLISHER
Vols. 73 to date (vol.94 in 1980) per vol. paper $12.00
A 25% discount will be honored if 10 or more vols, are
purchased between vols. 73 and 94. Individual numbers
are not available.
Index to Authors for vols. 1 -75 (with the titles to their
articles) paper $ 8.00
Geographical Index to vols. 1-90 and
Index to Scientific Names to vols. 61-90 in 1 vol. $24.00
Domestic and foreign customers, please direct orders to:
AMERICAN MALACOLOGISTS, INC.
P.O. Box 2255, Melbourne, FL 32901 USA
^
/
LICENSED APPRAISALS
AND
IDENTIFICATION SERVICE
Collections of shells and libraries of shell
books expertly appraised for estate, gift and
tax purposes. Moderate fees, plus travel ex-
penses. Services confidential. Inquire below.
Professional identifications of marine mol-
lusks for biological surveys, environmental
studies and private shell collectors. Fees bas-
ed on hourly basis. Minimum $20.00.
R. Tucker Abbott, Ph.D.
P. 0. Box 2255
Melbourne, Florida 32901
U.S.A.
PHILLIP W. CLOVER
COLLECTOR & DEALER IN
WORLD WIDE SPECIMEN
SEA SHELLS p. O. Box 83
Glen EUen, CA 95442
o
FREE SHELL AND
BOOK LISTS
SPECIALISTS IN RARE
CYPRAEA, CONUS, VOLUTA
MARGINELLA, MITRA, MUREX
54 THE NAUTILUS
January 30, 1984
Vol. 98(1)
THREE CLASSICS A T ALMOST HALF PRICE
1. AMERICAN SEASHELLS, 1972, second
edition. Standard identification manual for
U.S. West and East coast and Canadian
marine mollusks. Lists over 6,300 species,
describes and illustrates 3,000. By R. Tucker
Abbott. We have the last of the main stock,
but instead of the regular price of $60.00,
we offer it (autographed!) for only $38.00,
postage paid. (Florida residents add $1.80
for sales tax).
2. COMPENDIUM OF SEASHELLS by R.
Tucker Abbott and S. Peter Dance. Second
revised printing with 50 corrections. A popu-
lar guide with color plates for each of 4,200
worldwide marine shells. Its large bibliography
is the key to shell literature. Regular price
$50.00. We offer it for only $39.00, plus
$1.50 postage. (Florida residents add $1.95
for sales tax).
3. FLORIDA FOSSILS. Pliocene Mollus-
ca of Southern Florida by Olsson, Har-
bison, Fargo and Pilsbry. 1953. 457 pp. 65
plates, sturdily bound 1979 reprint. We hold
the remaining stock. Formerly $39.00, but
we have reduced it to $19.95, plus $1.05
postage. (Florida residents add $1.00 for
sales tax).
TRULY, THREE GREAT
BARGAINS! Order while the\j
last.
— while thex; last.
60% off!!
SEASHELLS OF WESTERN EUROPE -- Bouchel Brilliant photos
of mollusks 156 pp Regularly $8 95 NOW $4 00
SHELLS ON STAMPS OF THE WORLD - Arakawa. 234 pp . 16
color pis Top source on subject Regularly $15 95 NOW $6,00
GUIDE TO THE NUDIBRANCHS OF CALIFORNIA ■■ 1 12 color
plates of live nudibrancfis 64 pp Reg. $13,50 NOW $6 00
FRESHWATER SNAILS OF AFRICA AND THEIR MEDICAL
IMPORTANCE - Brown Top professional textbook, illus
Reg $55 00 NOW $28 00
(Florida residents please add 5% sfale tax}
Great Sources of New Information on New
Species, New Methods, New Breakthroughs
in Malacology
THE NAUTILUS - A Quarterly Journal devoted to original research
on all phases of malacology America's oldest scientific journal in
zoology -- in its 98th year' The most quoted journal in the field
Keep up-to-date Subscribe now Four numbers for only $13 00
(Foreign. $15 00. InsUlutions. $18 00)
NAUTILUS INDEXES Lists Titles of 90 years of mollusk articles by
states and countries and by land . freshwater or marine categories
Also includes an index of 15,000 scientific names A quick source
of American and foreign information Bound Regularly $24 00.
Now only $12 00
THE WORLDS MOLLUSK LITERATURE - a huge annual listing
of over 3.600 articles gleaned from over 6,000 different journals
Cross-indexed by authors, subjects (500 subjects, such as re-
production, habits, chemistry, anatomy, etc ). geographic categories
(all countries, states, seas and oceans), paleontological strata, and
systematics (from classes and families down to species and sub-
species, including all new ones) Over 450 pages of fine print, or
available on personal computer diskettes A monumental effort
done by 21 full-time indexers This is the Zoological Record;
Mollusca Section Write us for information and prices
Publishers of Distinctive Books on Mollusks.
P. O. Box 2255, Melbourne, FL. 32902-2255
We accept VISA or MASTERCARD orders by mail Please give date
of expiration and your card number Foreign customers may send
international postal money order or check on New York bank or
US. cash by registered mail.
INFORMATION FOR SUBSCRIBERS
The annual subscription rate for The Nautilus
is $13.00 for individuals (foreign $15.00) and
$18.00 for institutions (domestic or foreign).
Subscriptions may begin in January. Send check
or money order made out to "American Mala-
cologists" to the Business Manager, P.O. Box
2255, Melbourne, Florida 32902-2255, U.S.A.
Back issv£s from volume 72 to date are ob-
tainable from the Business Manager. Volumes 1
through 71 (if available) may be obtained in
reprint or original form from Kraus Reprint
Co., Route 100, Millwood, New York 10546.
Advertising rates may be obtained from the
Business Manager or Editor.
CONTRIBUTORS
Manuscripts: Authors are requested to follow
the recommendations of the Style Manuul 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 re-
quired, to facilitate reviews. Tables, numbered
in arable, should be on separate pages, with the
title at the top. Legends to photographs should
be typed on separate sheets. Explanatory terms
and symbols within a drawing should be neatly
printed, or they may be pencilled in on a translu-
cent overlay, so that the printer may set them in
8 pt. type. There is a charge of 50 cents per
word for this extra service. All authors or their
institutions will be charged 50 cents per line of
tabular material and taxonomic keys. The pub-
lishers reserve the right, seldom exercised, to
charge $45 per printed page.
An abstract should accompany each paper.
Reprints are available at cost to authors.
When proof is returned to authors, information
about ordering reprints will be given. They
are obtained from Economy Printing Co., Inc.,
R.D. 3, Box 169, Easton, Maryland 21601-9430.
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 modem facilities and equipment for the
housing and curating of voucher specimens.
Material should be accompanied by the identifi-
cation, locality data and its bibliographic
reference. There is no charge for this perma-
nent curating service, and catalog numbers, if
desired, will be sent to authors prior to publica-
tion.
WANTED - OLD SHELL BOOKS
Will pay good prices for libraries, second- Phone (1-305-725-2260) or write: R. Tucker
hand books and reprints on mollusks, shells Abbott, American Malacologists, Inc., P.O.
and conchology. Back numbers of The Box 2255, Melbourne, FL 32902. Free ap-
Nautilus, vols. 40-71 wanted, $1.50 each. praisals.
americanmalacologists, mc.
PUBLISHERS OF DISTINCTIVE BOOKS ON MOLLUSKS
THE NAUTILUS (Quarterly)
MONOGRAPHS OF MARINE MOLLUSCA
STANDARD CATALOG OF SHELLS
INDEXES TO THE NAUTILUS
{Geographical, vols 1-90; Scientific Names, vols 61-90)
REGISTER OF AMERICAN MALACOLOGISTS
APRIL 27, 1984
THE
NAUTILUS
ISSN 0028-1344
Vol. 98
No. 2
A quarterly
devoted to
malacology and
the interests of
conehologists
Founded 1889 by Henry A. Pilsbry. Continued by H. Burrington Baker.
Editor-in-Chief: R. Tucl<er Abbott
EDITORIAL COMMITTEE
CONSULTING EDITORS
Dr. William K. Emerson
Department of Living Invertebrates
The American Museum of Natural History
New York, NY 10024
Dr. M. G. Harasewych
363 Crescendo Way
Silver Spring, MD 20901
Dr. Aurele La Rocque
Department of Geology
The Ohio State University
Columbus, OH 43210
Dr. James H. McLean
Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, CA 90007
Dr. Arthur S. Merrill
c/o Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Donald R. Moore
Division of Marine Geology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 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, IL 60605
Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, OH 43210
Dr. Ruth D. Turner
Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Gilbert L. Voss
Division of Biology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 33149
EDITOR-IN-CHIEF
Dr. R. Tucker Abbott
American Malacologists, Inc.
Box 2255, Melbourne, FL 32902-2255
Mrs. Cecelia W. Abbott
Business and Subscription Manager
P.O. Box 2255
Melbourne, FL 32902-2255
Second Class Postage paid at Melbourne, Florida
and other post offices
The Nautilus (USPS 374-980)
ISSN 0028-1344
A quarterly magazine devoted to malacoloKj.
Copyright ''1983 by American Malacologists. Inc.
OFFICE OF PUBLICATION
American Malacologists, Inc. (United Parcel Address:
2208 South Colonial Drive, Melbourne, FL 32902)
Mail: Box 2255, Melbourne, FL 32902-2255
POSTMASTER: Send address changes to above.
Subscription Price: $13.00 (see inside back cover)
$15.00 (foreign); institutions $18.00
IV3flffrfHI(« Jtf
UBRAH c ' i THE
n NAUTILUS
♦!AY 111984 1 Volume 98, number 2 - April 27, 1984
ISSN 0028-1344
CONTENTS
A Farewell to Bill Clench 55
William K. Emerson
Conns kiiitoki Habe and Kosuge, 1970: A Validly Proposed Taxon 58
Richard S. Appeldoorn
Sex Ratio in the Soft-Shell Clam, Mya arenaria 61
Dee Saunders Dundee and Roy J. Baerwald
Observations on a Micropredator, Gulella bicolor (Hutton),
(Gastropoda: Pulmonata: Streptaxidae) 63
Raymond W. Neck
Living Terrestrial Gastropods from the Eastern Caprock Escarpment, Texas 68
Garry L. Pharris, James B. Sickel, and Carol C. Chandler
Range Extension of the Freshwater Mussel,
Plectomerus dombeyanus, into the Tennessee River, Kentucky 74
Kenneth J. Boss and Arthur S. Merrill
Architea A. Costa, not an Architectonicid but a Pomatiasid (Gastropoda: Prosobranchia) 77
N. Craig Boss, Timothy G. Laman and Harvey D. Blankespoor
Dispersal Movements of Four Species of Pulmonate
and Operculate Snails in Douglas Lake, Michigan 80
Harald A. Rehder
The Genus Brondelia Bourguignat, 1862, and its
Taxonomic Position (Gastropoda: Siphonariidae) 83
Kerry B. Clark
New Records and Synonymies of Bermuda Opisthobranchs (Gastropoda) 85
Positions Open 84 Review 79
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 55
W'li.i.i \.\i .1. Clench (1897-1984)
A FAREWELL TO BILL CLENCH
In our relatively small field of malacology no
man made a greater personal impact over the
last 60 years than did Bill Clench. He had not
the knowledge of Pilsbry, nor the brilliance of H.
B. Baker, not the cleverness of Bartsch, nor the
precision of Myra Keen, yet he produced dozens
of successful students, set modern standards for
curatorial procedures, gave birth to new
mollusk journals, made over 2,500 collecting
stations, and inspired three generations of
amateurs to contribute their time and energies
to helping our science.
Bill was a gregarious, but lluaightful, ex-
trovert. He Idved people and he loved his
students whom he instructed on a one-to-one
basis. He had a friendly charisma that drew
most people within his spell. Bill was a fatherly
56 THE NAUTILUS
April 27, 1984
Vol. 98(2)
hero to many budding malacologists, hut human
enough to have feet of clay. He often said that if
a student could not go beyond the capabilities of
his teacher, the student was not worth his
weight in salt.
Bill himself had several heros- Charles W.
Johnson, Bryant Walker, Henry Pilsbry and
Matt Dillon of "Gunsmoke." As a young boy, he
roamed the area around Blue Hill, south of
Boston, where he collected insects and moUusks.
The first mollusk he ever collected was a
Tri(xiop^is alholabris (curiously, also the first
species ever collected by C. R. Orcutt, and the
first species ever described by Thomas Say). Bill
took his unidentified treasures into the Boston
Society of Natural History where kindly and pa-
tient Johnson schooled Bill in natural history.
Their association was a long and close one,
and during the last years of Johnson's life. Bill
assisted him in the business managing of The
Naufilu:^. and after Johnson's death, he edited
and sent to the printer Johnson's famous.
Marine Mollusca of the Atlantic Coast from
Labrador to Texas. By a quick coup by Pilsbry,
the business managership of The Nautilus
returned to Philadelphia. Seven years later, Bill
launched a new monographic series and named
it Johnsonia after his bovhood idol.
Bill Clench, at the age of 3.5. on aLiguun hunt with Henry A.
Pilsbry, age 70, at Hammock no. 38, Long Pine Key, Florida
Everglades, on March 13, 1931. For an account of this trip,
see The Nautilus, vol. 4.5, pp. 10-1.5, .July 1931.
Dii, I ni.u,. (ii age 49, in Caniljridge. Mass.. in December
1946. John.ionia was in its second volume. Occasional
Piipera on MoUuslcs had just been launched, and his two
students at the time were Ruth D. Turner and Isabel Far-
fante.
Bill Clench entered Michigan State College in
East Lansing just as America was about to
enter World War L Years later he would regale
his friends and students with boisterous tales of
fraternity life at a mid-West cow college. He
broke his nose showing off to the girls while ice-
skating with his hands in his pockets; earned ex-
tra money by -playing sa.xaphone with his own
college group; and met and married his college
sweetheart, Julia V. Helmick. She was a main
stay in his life and tolerated his consuming pas-
sion for malacology. She was the only person
who repeatedly listened to Bill's famous old
jokes and stories as if each telling was new. Julia
kept the home fires burning during lonely vigils
while Bill was on field trips, and she was a sec-
ond mother to some of Bill's students.
It was during his graduate days in Ann Arbor
that Bill came under the beneficial influence of
another idol of his- Bryant Walker, a well-to-do
lawyer in Detroit who was an accomplished
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 57
malacologist. Walker lit the malacological fires
within Bill and was largely responsible for his
first love, the freshwater mollusks.
As a field director, Clench had few rivals. The
Nautilus abounds with his accounts of early
trips to the rivers of the Southeast and the
Everglades of Florida. Many of his early
students received their baptism of fire on
Clench's expeditions to the Bahamas, Santo
Domingo and Cuba. Nearly every one of his
students spent some time in the field with him.
The collection at Harvard grew tenfold under
his curatorship from 1926 to 1966. He made his
2,500th field station in Florida at the age of 85.
He was an omnivorous collector, but took
greatest delight in collecting Cerion, Liguus,
pleurocerids and unios.
Bill had a great appreciation of the history of
malacology and felt a personal closeness with
the earlier workers. Many of the numbers in his
Occasional Papers on Mollusks were devoted to
the biographies of the malacologists that had
gone down the same science trails. He took
delight in telling his students about the lives and
foibles of his early associates, such as William
Morton Wheeler, Arthur F. Gray, Norman Ler-
mond and Tom Barbour. He often recalled his
visit with the South Carolina malacologist,
William Mazyck, in the 1930's. Elderly Mazyck
had corresponded with other malacologists for
years, but Bill was his first mollusk visitor in 50
years. When Mazyck heard the malacological
terms and names rolling off Clench's tongue, the
tears ran down the old man's cheeks.
If the many students gained much from Bill, it
was certainly true that he, in turn, received a
great deal of support through the years from
those around him. Dick Foster made it possible
to launch Johnsonia and also financed a number
of Bill's projects; "Uncle Joe" Bequaert, a col-
league, supplied him with translations of foreign
languages; Ruth Turner, with her great talents
in dissecting and illustrating, co-authored many
of his better papers; Dave Stansbery and Henry
Russell often went out of their way to furnish
transportation for many of Bill's trips; and Dr.
Merrill Champion proofread and created in-
dexes for his publications.
Bill was a great correspondent. Dui'iiig W'oi'ld
War II he wrote over 2,50U letters to his
students serving in the Armed Forces. It would
be impossible to innumerate the number of
friends to whom he sent postcards and letters
during his lifetime. On field trips, long after
<;ither expedition members had turned in. Bill
could be found sipping on beer and scratching
out postcards in the light of a lantern. At home,
after he had finished a nightime project, he
would sometimes write letters until two in the
morning.
Three tragedies occurred in Bill's later life
that seemed to slow him down. His wife, Julia,
died in 1969 after minor surgery, while she was
in her late sixties. It created a void that was
never filled. A few years later his eldest son,
Harry, the well-known lepidopterist at the
Carnegie Museum in Pittsburgh, died of a heart
attack. He lost a fellow naturalist, as well as a
kindly son. About the age of 82, Bill experienced
a minor stroke. His handwriting and grammar
took a turn for the worse. His memory for cer-
"It's nicirc I'un .-inakiiiK "Ut unios by the tnitful in a place lil<e
Lake Waecaniaw!," was the typical comment macie by Bill
Clench while collectinK. at a^e 7:i, in North Carolina. F'hoto
by Paul Jeniiewein. July 1970.
58 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
tain words failed him. After a thmat operation
in 1983, he was placed in a rest home in Califor-
nia near his son, Carleton.
We must all eross that River Styx someday.
Most malacologists will be destined forever to
an eternity of measuring shells, re-working
their own synonymies, or color-coding their
electrophoresis test tubes, but Rill Clench will be
criss-crossing those sunny Elysian fields collec-
ting new species of unbelievable abundance and
beauty. And at his feet will gather a new and
eager parade of mollusk students.
On a frosty February morning, in 1984, the
boatman came for William James Clench.
Across the River Styx they slowly poled the
boat, and by the time they were halfway across.
Bill had already lost his aged stoop, he was once
more in his youthful collecting duds, and eager
to join his old friends. On top of the far bank six
figures beckoned him on -Charlie Johnson and
Bryant Walker. "Uncle Joe" Beiiuaert, Harry
Clench with buttertly net in hand, Dick Foster
who had leased a whole steam engine train for
the occasion, and finally his wife Julia,
thoughtful as ever with a picnic Itasket and case
of l)eer at hand.
I can report that Bill gave a last farewell
wave, like Matt Dillon riding into the sunset. Bill
drew a huge arrow in the sand pointing up the
bank. It was for his other students due someday
to follow - Harald Rehder, Alan Archer, Henry
Russell, Dick McLean, Tucker Abbott, Dick
Johnson, Ruth Turner, Yoshio Kondo, Isabel
Farfante, Joe Rosewater, Tom Pulley, Arthur
Merrill, J. Lockwood Chamberlin, Joseph
Vagvolgyi, Ed Michelson, Bob Bullock, Ken
Boss, Robert Robertson, Arthur Clarke, Don
McMichael, Sam Fuller, Vida Kenk, and Barry
Wilson.
The train was packed with his old friends.
They had all been waiting a long time, and were
all impatient to set off with Bill for an endless
day of collecting Cerion, Liguus. lo. and foot-
long, spiny unios.
On the following day his son, Carleton, sent
the news from California:
William J. Clench, 1897-1984.
Early in the morning of February 22nd the
world lost a fine person, the scientific co7nm uni-
ty lost an eminent malacologist and I lost my
dad. His passing iras calm and dignified.
R. Tucker Abbott
Melbourne. Florida
CONUS KINTOKI HABE AND KOSUGE, 1970:
A VALIDLY PROPOSED TAXON
William K. Emerson
Department of Invertebrates
American Museum of Natural History
New York, NY l()(i:^4
ABSTRACT
The nomenclatural status of Conus kintoki i/a6e and Kosuge, 1970, is reviewed
and this taxon is determined to have been validly proposed. Conus kintoki
Coomans and Moolenbeek. 1982, is a junior subjectit'e synonym. A specimen of
this cone is illustrated.
A number of authors have commented on the
status of the nominal species Conus kintoki
Habe and Kosuge (1970:9). Most of these
writers have ([uestioned the availability of this
name under the provisions of the International
Code of Zoological Nomenclature (Walls,
1979:350; Tucker, 1980:9, no. I^H; Martin,
1982:4; and Sage, 1982:9). Kosuge (1979:21),
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 59
subsequent to his 1!I7() paper, considered C kin-
toki Hahe and Kosuge a nomen nudum.
Coomans and Mof)lenbeek (1982:136, 137, fig.
4), in the belie!' this taxon was a nomen nudum.
"validated" the name by proposing: "Conus kin-
fnki nov. spec." Tucker (1983:5) subsequently
suggested tliat the name should date from the
earlier citation to "Conus kintoki Habe" made by
Kaicher (1977: no. 1303) on an identification
card. As a result of the conflicting views concer-
ning the availability of the name, Conus kintoki.
a review of the nomenclatural status of this tax-
on was undertaken.
Nomenclatural Status
Conus kintoki was proposed by Habe and
Kosuge in "Pacific Shell News- " (40 pp., April
30, 1970), a popular publication with text in both
Japanese and English and with illustrations of
the species discussed.
In the Table of Contents, under the heading
"New Species" (in English), the description of
the taxon Conus kintoki (in Japanese ideograms)
is cited for page 9. On page 9 is found the latiniz-
ed species name, "Conus kintoki Habe et
Kosuge", heading the brief descriptive text, part
of which is in Japanese and part in English. An
apertural view of the shell of Conus kintoki is
also illustrated on page 9.
The Japanese text on page 9 reads:
"Since the shell is solid and has a thick shell cpider-niis. it
seems to live in shallow water. But it was collected from the
South China Sea at 'Mi) m depth. Aiter the shell epidermis is
removed, we can see a fairly beautiful shell, which is colored
with flesh yellowish pink. I gave the Japanese name (Kintoki
Cone) because the color of the shell reminds me of the
'Sakala's Kintoki' [a mythological Japanese baby warrior
with a yellowish pink complexion]. This species resembles
Viryiamuf: virgo [name in .Ia[>anese ideograms] in ap-
pearance, but the base (anterior part) of this new species is
not stained with dark purple as in I'. (■))•(/() [name in .Japanese
ideograms[. Adilitionally . the color of this shell appears quite
distinct from the others (S. |adao| K. [osuge])".
The text in English on page 9 follows:
"This new cone shell comes from the South China Sea at
about 20(1 m depth. The description of the species will be ap-
peared [sir] in the Venus, .lap. .lour. Malac. Measurement:
102.0 X 49..") mm."
At my re()uest. Dr. Melville kindly iwiewed
the pertinent references to the use of the name,
Conus kintoki. and he has permitted me to quote
his comments on the availability of this name:
"I now c nclude that the name was made
available by Habe & Kosuge, 1970, Pacific Shell
News No. 2, p. 9, for the following reasons:
- the name is published (Art. 11a).
- the name is latinised (Art. 1 lb).
- the (specific) name is a noun in apposition
(Art. llg(i)(2).
- paragraph 2 of the description beginning
"This shell resembles Virgiconus virgo" purports
to differentiate the species and thus satisfies the
provisions of Article 13a(i) for names published
after 1930.
"Since these objective criteria are satisfied,
there is no reason to reject the name as
unavailable. Subjective criticisms of the ade-
(juacy of the description may affect the validity
of the name, or even lead to its being treated as
a nomen dubium, but these considerations do
not affect its availability."
Although for personal reasons, Drs. Habe and
Kosuge did not redescribe this taxon in the
Venus or elsewhere, their original description in
"Pacific Shell News" in my opinion is ipso facto a
valid proposal of a new species. Conus kintoki
Habe and Kosuge, 1970, hence, is an available
name for populations of this cone that are
known from the Philippines and the South China
Sea. This taxon, therefore, should date from
Habe and Kosuge, 1970, and should not l)e at-
tributed to Conus kintoki Coomans and
Moolenbeek, 1982, despite their good intentions
to "validate" the name.
The only condition one might raise to question
the availability of Habe's and Kosuge's nominal
species is that new names proposed "condi-
tionally", after 1960. are not available (Article
15 of "the I.C.Z.N.). In the sense of the Code,
however, the authors of this taxon clearly
recognized it as a new species, which did not re-
quire additional documentation, such as more or
better preserved specimens, or the need for any
additional data. The co-authorship of this taxon
is clearly established by the use of "Conus kin-
toki Habe et Kosuge" (1970:9), regardless of the
fact that Dr. Sadao Kosuge's initals, "(S.K.)",
follow the Japanese text of the species descrip-
tion.
Conus kintoki (here illustrated. Figures, 1-3),
is a member of an Indo-Pacific species complex
including: Comis coelinae Crosse, 1858, C.
60 THE NAUTILUS
April 21, 1984
Vol. 98 (2)
FIGS. 1-3. Conua kintoki Hahe and Kosuge. 1970. Purclias-
ed in Taiwan (probably trawled in the Soutli Cliina Sea), ex.
T. H. and V. B. Munyan coll., AMNH 201877. Fig. 1. x 1;
figs. 2. 3. X y-i.
spiceri Bartsch and Rehder, 1943, and Conus
berdulinus Veillard, 1972. See Walls (1979:347,
350), Coomans and Moolenbeek (1982a: 13fi, 137;
1982b: 19, 20) and Martin (1983:4) for comments
on the taxonomy of this poorly known complex.
Acknowledgments
I am ji:reatly indebted to Mr. Yoshimi Fujioka
of the Mukaishima Marine Biological Station,
Hiroshima University, Hiroshima Pref., for
kindly providing me with an English translation
of the Japanese text. I thank Dr. Henry E.
Coomans of the Zoologisch Museum, Amster-
dam, for his comments on the English transla-
tion, which I transmitted {<> him in November,
1982. 1 am most grateful t<. 1 if. R. V. Melville,
Secretary of the Internal ii ma! Conmiission of
Zoological Nomenclature. Un- critically reading
a draft of the manuscript a!id offering his opi-
nions on the interpretation of certain provisions
of the Code. I also thank my AMNH colleagues:
Ms. Kathleen Marius for word-processing the
manuscript, Mr. Walter E. Sage, III for
technical assistance, and Mr. Jeff A. Teitelbaum
for the ]ihotogra])hy.
LITERATURE CITED
Bartsch. P. and H. A. Rehder. 1943. New cones from the
Hawaiian Islands. Biol. Sor. Washington Proc.
56(18):85-88.
Cooman.s, H. E.. and R. (i. Muolenlieek. Ut82a. Stuilies on
Conidae (Mollusca, Gastropoda). 1. Covks imptif-nxi.-i and
('. kintokh Two new species from deeper water in the
western Pacific. Univ. Amsterdam. Zool. Mun. Hull.
8(1 5): 1.3.3- 1.38. fi figs.
19821). Alphabetical revision of the (sub) species
ill recent Conidae. .5. bafciitiis to hi/s.-^niiis. including Conux
lirettingfuimi noitwn rionim. Bit.-<l<ri(i 4()(l):3-67, figs.
172-292.
Crosse, H. 1858. Ub.servations sLir le genre cone et descrip-
tion de trois especes nouvelles,. . . Ri-r. Mug. Zool.. ser.
2. 10:113-127, pi. 2.
Habe, T. and S. Kosuge. 1970. New species, Conna kitifoki.
Panfir Shdl Neirs. No. 2:9, 1 fig.
Kaicher, S. D. 1977. Card catalogue of world-wide shells.
Pack #12, Conidae, pt. 2, card #1303. (St. Petersburg,
Florida, April, 1977).
Kosuge, S. 1979. Descriptions of new and rare cones from
the western Pacific (Conidae, Gastropoda). Inst. Malar.
Tokyo. Bull. l(2):21-22. pi. 4.
Martin, R. 1982. Conus berdulinus. C. coelinae and "C.
kintoki". Hawaiian Shell News 30(10):4, 3 figs.
Sage, W. 1982. News of new species. Hoicaiinn Shell Neics
30(12):9. 1 fig.
Tucker, ,1. K. 1980. Fifty frequently misused names. Cone
Shell Alert 1(2):7-11. '
1983. Recent cone shell names II, The species
described by Coomans and coworkers. Hiiieaiian Shell
Neivs n{n):r>.
Veillard. M. 1972. New cone from Reunion. Oj'Sea and Shore
3(4):176, 177, illus.
Walls, .1. G. 1979. Cone shells, a synopsis of the living Con-
idae: 1-1021, illus. (Neptune, New Jersey).
Vol. 98(2) April 27, 1984 THE NAUTILUS 61
SEX RATIO IN THE SOFT-SHELL CLAM, MY A ARENARIA
Richard S. Appeldoorn'
Graduate School of Oceanography
University of Rhode Island
Kingston, RI 02881
ABSTRACT
The sex ratio in Mya arenaria, the soft-shell clam., was studied using samples
collected from 25 population,^. The sex ratio was found to be significantly biased in
favor of females (52% F: Jf8% M). The advantages of and mechanism, maintain-
ing, such a bias renfiain enigmatic.
In previous studies on Mya arenaria Shaw
(1965), Pfitzenmeyer (1972), Porter (1974), and
Brousseau (1978b) all reported that the sex ratio
was unbiased. Porter was the only one to give
actual figures: 52% female. To statistically ver-
ify such a small bias in sex ratio on the basis of
one sample would necessitate a sample size of
over 1200 individuals (\\ d.f = \, p=.05). Re-
cently, a survey of 25 soft-shell clam populations
throughout the northeast coast of North
America was made, involving the collection of
over 5,000 individuals (Brown et at., 1977).
Histological sections obtained from this study
were used to investigate the sex ratio in Mya
arenaria.
Methods
Sex proportions were calculated for each
[)opulation by comparing the number of females
to the total number of sexed individuals. All sex
determinations were based on histological ex-
amination of the gonads.
Results
The results are presented in Table 1. From the
table it can be seen that in the majority of popu-
lations females outnumber males. The overall
proportion of females was 52.1% for the entire
sample and 52.3% averaged by area. The null
hypothesis of equal sex ratios among all samples
was tested using a binomial test (Hollander and
Wolfe, 1973). The test showed that the number
of female biased populations (18) was signifi-
cantly greater than the number which were
TABLE 1. Sex ratio of Mya areniirio observed at each site.
N = number of sexed clams.
'FVesent .Address: Department of Marine Sciences. I'nixer
sity of Puerto Rico, Mayaguez, Puerto Rico 00708.
male l)iased (6) so the null hypothesis was re-
jected (T*= 2.45, p=. 0(17).
To test whether the sex ratio varied with age,
populations with similar growth rates (Appel-
doorn, 1983) were pooled and trends in the sex
i-atio with size were examined. Two composite
groups were formed: Wickford-Winnajiaug
Pond and Watchemoket Cove-Portland-Allen
62 THE NAUTILUS
April 27, 1984
98(2)
Harbor-Quunochontaug Pond-1. Table 2 shows
the results. In the former group the proportion
of females increased with size while in the latter
group it decreased with size.
Discussion
Uneciual sex ratios are not uncommon in mol-
lusks, including bivalves, and Fretter and
Oraham (in Wilbur and Yonge. 1964) stateii that
females tentl to outnumber males in giinochoris-
tic species, such as Mi/d. Some examples of per-
cent females found in bivalves are: Cardium
( = Cera>itodennu) edule 60%; Doyiax rittiitus
55%; Tellina(=Maa>niii) hulthica 53%; T.jhnji-
lis 53%); Srrobtcularia p'iprmta 59%; PhoUi><
Candida 55%; ax\A Anodonta cygnea 54% (Pelse-
neer, 1926). Normally in these species the dis-
[larity was not present in the young l.)ut in-
creased with age. It was assumed to result from
a higher mortality rate for the males (Pelseneer,
1926). Brousseau (1978b) reported no change in
the sex ratio ofi1/(y« as a functi(.)n of size, and the
contradictory trends evidenced here, in Table 2,
preclude any meaningful interpretation that
could either support or refute this assumption.
Coe and Turner (1938) observed indications of
bisexuality in the differentiated gonads of young
soft-shell clams. Ropes (1982) theorized that
sexuality in Mya may be under some environ-
mental control which could affect both popula-
tion sex ratio and the incidence of hermaphro-
ditism, and that in stressful environments devia-
tions from the norm should co-occur. In an
analysis of Otto's (1973) data he reported no
significant sex ratio bias existed within the
samples containing hermaphrodites. Re-
examining these data it was found that in 6 of
the 7 samples having a biased sex ratio males
TABLE 2. Variation in the sex ratio of Mya nrcvnriii as a
function of size within pooled groups of samples.
Group = Wickford, Winnapaug Pond
Length Interval (cm) 3-4.9 .S-fi.Vi t>ti.;» 7-8.9
Sample Size 61 110 113 7.5
% Females .50.8 52.7 55.6 57.3
Group = Watchemoket Cove. Portland. Allen Harbor.
Quonochontaug Pond-1
Length Interval (cm) 2-3.9 4-4.9 5-5.9 6-8.9
Sample Size 143 182 118 85
% Females 59.4 57.1 54.2 42.4
predominated. Using the Wilcoxon signed rank
test (Hollander and Wolfe, 1973) this
predominance of male biased samples was found
to be significant (T* = 25.5, p= .039). On the basis
of the data in Table 1 this male bias is
anomalous. That it coincides with a high in-
cidence of hermaphroditism may support Rope's
hypothesis.
The maintenance of biased sex ratios in higher
vertebrates, such as man, is well understood in
terms of genetic theory (Fisher. 1958; Williams,
1966); but in invertebrates, where several genes
and environmental influences may be involved
in sex determination, the origin and mainte-
nance of a biased sex ratio is poorly understood.
Wildish (1976) has developed general theoretical
models which may explain the evolution of sex
ratio biases in terms of r-and A'-selection theory.
However, they are of limited use here as M.
arenaria cannot be strictly classified as either
an r- or /^-strategist (Brousseau, 1978a), and the
underlying mechanisms resulting in biased sex
ratios in Mya remain enigmatic. It is unlikely
that uncontrolled field studies will be able to fur-
ther define the role of the environment. Recent
improvements in laboratory culture of M.
arenaria (Hidu, 1981) may facilitate experimen-
tation through environmental control and
reduced genetic variability.
LITERATURE CITED
Appeldoorn, R. S. 1983. Variation in the gi-owth rate of
Ml/ii (ircnaria and its relationship to the environment as
analyzed through principal components analysis and the cu
parameter of the von Bertalanffy equation. t'.S. Finh.
Bull 81:75-84.
Brousseau. D. J. 1978a. Population dynamics of the snft
shell clam Mya arenaria. Mar. Biol. .50:63-71
1978b. Spawning cycle, fecundity, and recruit-
ment in a population of soft-shell clam. Miia areiunin.
from Cape Ann, Massachusetts. f'..S. F'.--'/ H)ill. 7fi:
15.5-166.
Brown, R. S., R. E. Wolke. S. B. Saila and C. \V. Brown
1977. Prevalence of neopla.sia in 10 New England popula-
tions of the soft-shell clam (.Ui/o urnuma). ,\n)i A' >
Acad. Sri. 288:522-534.
Coe, W. R. and H. J. Turner. .Ir. 1938. Uevelo|,ment of the
gonads and gametes of the soft-shell clam {Mya nri-uana)
Jour. Morph. 62:91-111.
Fisher. R. A. 1958. The Genetical Theory uf Natural .sv/cc
tion. Dover Publications Inc., New York. 291 p.
Fretter, V. and A. Graham. 1964. Reproduction. In: Wilbur.
K. M. and C. M. Yonge (eds.) Physioloyy of Mollusra.
Academic Press, New York. Vol. 1. p. 127-164.
Vol. 98 (2
April 27, 1984
THE NAUTILUS 63
lliilu, II. UtiSl. Mi/ii imnmriii ■ iioiinlilifj-ate infauna. ./. Shi-ll-
fish. Hes. 1:116.
Hollander, M. and IJ. A. Wolfe. IDTIi. Nonparaini-lnr slati.s-
tical methods. John Wiley & Sons, New York. 503 p.
Otto, S. 1973. Hermaphroditism in two species of pelecypod
mollusks. Proc. Natl. Shellfish. Assoc. 63:96-98.
Pelseneer, P. 1926. La proportion relative des sexes chez les
aniniaux et particuliernient chez les mollusques. Mem.
.Acad. r. Bdg. CI. Sci. (8°) 8:1-258.
Pfitzenmeyer, H. T. 1972. Tentative outline for inventory
of molluscs: Mya arenaria (soft shell clam). ('Iirsdpi'dki'
Sri. 13:SI82-S'l84.
Porter, R. C. 1974. Reimxluctive cycle of the soft-shell
clam, Mi/d (irennriii. at Skagit Bay, Washinjjton. U.S.
Fish. Bull. 72:648-656.
Ropes, J. W. 1982. Hermaphroditism, sexuality and sex
ratio in the surf clam, Spisula soiidissima. and the soft-
shell clam, Mya arenaria. The Nautilus 96:141-146.
Shaw, W. N. 1965. Seasonal gonadal cycle of the male .soft-
shell clam, Mya arenaria. in Maryland. U.S. Fish Wildl.
Serr.. Spec. Sci. Rep. Fi.s-/i. 508, 5 p.
Wildish, D. J. 1976. Biased sex ratios in invertebrates. Adv.
In cert. Repro. 1:8-24.
Williams, G. C. 1966. Adaptation and Natural Selection.
Princeton University Press, Princeton, New Jersey. 307 p.
OBSERVATIONS ON A MICROPREDATOR, GULELLA BICOLOR
(HUTTON) (GASTROPODA: PULMONATA: STREPTAXIDAE)
Dee Saunder.s Dundee and Roy J. Baerwald
Department of Biological Sciences
University of New Orleans
New Orleans, LA 70148
ABSTRACT
A micropredotor. Gulella bicolor (Huttnn). is the only member of the St7'epfax-
idae found in the United States. It has been introduced to five known localities.
G. bicolor in the New Orleans area was the subject of observations on food
habits, population structure, and reproductive habits. It is associated only with
mans activities, is a strict carnivore. Three groups of young appear from later
May through mid-September or approximately every other month during the
warm season. Growth rate is approxiynately 2 mm/month. The Inyyje.st snail col-
lected was 7.5 mm in height. Radula, "jaws", and digestive system all bear out the
carnivorous habits of this species.
This report presents findings on the habits
and morphology of the snail, Gulella bicolor
(Hutton) (Gastropoda: Pulmonata: Streptaxi-
dae) in the New Orleans area. These minute
snails (largest observed was 7.5 mm in length)
comprise a portion of the introduced fauna of
the United States and are the only U. S.
members of this large snail family. They have
been found in Charleston, SC; Coconut Grove,
FL; Vicksburg, MS; and Boothville and New
Orleans, LA. They were originally described
from the Seychelles, Indian Ocean. The genus is
one of the largest, containing many species in
southern Africa, the presumed area of origin.
Gulella bicolor occurs (as summarized by van
der Schalie, 1948) also in South America, the
West Indies, on some south Pacific islands, the
Philippines and in the oriental region. Since
these snails are part of our introduced fauna we
must record any findings concerning them for
future reference in case they should ever
become a problem. To that end, we report some
observations on habits and functional mor-
phology.
Materials and Methods
All snails were collected live locally from fif-
teen localities in the New Orleans area. Since
the snails are nowhere abundant, we merely col-
lected for an hour in a given locality and used
those snails as the bases for population struc-
ture studies.
Upon return to the lab, snails were measured
(length X width), whorls counted and then
()4 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
several snails were placed in Bouin's t'oi- shell
decalcification and fixation for sectioning. The
shells were completely decalified by the 3rd day
at which time the entire animal was serial sec-
tioned at 1(1 fj (cross, longitudinal, and sagittal
sections). The animals are so small that entire
serial sections will fit on 3 or 4 slides. Haema-
toxlyin-Eosin stains were used. The remaining
sjiecimens were jireserved in 70% alcohol for us-
ing later for dissections. Cleaned snail shells
were sputter-coated with gold-palladium and ex-
amined in a JEOL 35 C scanning electron micro-
scope at 20 KV.
have never found them away from human activi-
ty areas even though they have been present for
at least thirty years, which would seem to be a
reasonable length of time for them to have dis-
persed to non-human habitats. They are almost
always in shaded areas and are active only when
the humidity is high. They are capable of with-
standing desiccation up to at least 9 months as
evidenced from one of our experiments. The soil
in their habitats in the New Orleans area is often
"cruml)ly"-the t\qje often referred to by natives
as "coffee grounds" soil. It is mostly dried
organic material from pre-existing swamps.
Habitat Type
In the New Orleans area GnlflUi hicolor ap-
l)ears to be "domesticated" in the sense of
English sparrows and house mice in that they
are associated only with man's activities. They
live at the bases of building walls, around grave-
stones, along the edges of river wharves. We
Food
These snails are carnivores and feed on
various soft invertebrates such as earthworms
and on other small molluscs [subulinids (Mead,
1961) and pupillids]. These organisms occur in
the same habitat with G. bicolor in this area. An
experiment was designed to determine if G.
TABLE 1. Preferences of some introduced molluscs for selected habitat food items.
(1 = eaten readily; 2 = eaten reluctantly; 3 = not eaten; * considered a carnivore under nor-
mal circumstances).
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 65
bicolor would eat vegetation.
Individuals were isolated for 2 weeks without
food. Then they were each offered three intact
leaves, stems, roots (Table 1) from each of the
plants in their habitat. Other species of snails
(Dundee, 1970) were also tested simultaneously.
The experiments were run three times. As can
be seen from Table 1, Gulella does not normally
eat vegetation. The one case where it appeared
that there was some radular rasping on Ln^caciti
divericata leaves was possibly a misinterpreta-
tion on our part. The rasp marks were seen only
the one time. Considering the type of radular
teeth, it is not surprising that the snail do not ac-
cept vegetation; it would be very difficult for
them to rasp and scrape vegetation.
Breeding Seasons and Population Structure
Since Gulella bicolor is nowhere abundant, the
population study had to be l:>ased upon those few
snails present in a given area. By sampling the
population regularly we were able to determine
apijroximate breeding periods and population
structure for part of the year (Fig. 1). As seen in
Fig. 1, there were, from April through October,
three crops of young: late May, mid-to-late July,
mid-September. Thus there is a new crop of
young approximately every other month. New
hatches are approximately 1.25 mm in length
(height), 1 mm at the largest width, and have
3.25 whorls. The lip of the shell (Fig. 2) is not
formed until after an individual has exceeded
4.75 mm in length (height) and has about 6.75
whorls. Growth in length, based solely upon the
population growth rather than on individual
growth, appears to be 3 mm per 1.5 months or
approximately 2 mm per month. The largest
snail found was 7.5 mm in length (height). Over-
wintering seems to occur in tlie adult stage
(after the lip is present).
Shell and (ieneral Appearance
The overall morphology of the shell was ex-
amined by scanning electron microscopy. The
shell (Fig. 2), the apertural teeth, (Fig. 2). and
the umbilicus (Fig. 3) are seen without the living-
animal obscuring them. Living s])ecimens often
appear "two-toned" since they have a red-to-
orange anterior and a yellow posterior (apex
area), thus the specific name, "bicolor".
in
o
nn n Q_
n ^ On n n^
H
nnn
n
19 Sept
rl
HR
28 Aug
H
n n nil n
a
II Aug
n
. n nji
14 July
30 June
r^v
29 May
I May
ni]
15 April
cMfOfo^^u^''^ ^D^O^.
Height in mm
FICl. 1. Histograms showing rejiroductive periods o{ Gulella
bicolor ill the New Orleatis area.
Functional Morphology
The radula (Fig. 7t) of this tiny carnivore is in
keeping with those described (Solem, 1974) for
moUuscan carnivores in general. The individual
teeth are long, slender, cutting t.vpes which
have the appearance of gently curving, sharp
blades. The central teeth seem to be vestigial
and the number of rows of teeth varied from 48
to 52 in the specimens examined. Fig. 7 shows a
serial section of tlie entire buccal mass and has
66 THE NAUTILUS
April 27, 1984
Vol. 98(2)
28KU X18
914 1000,8U UNO
P'K'.S. -J. anil 3. 2. Ventral vitnv of shell nl' CnhUa hicolnr
(Huttnn). 3. vSide view of shell ui'Giihlhi /)iri)/ii/- shciwing um-
bilicus.
both radula (t) and "jaws" {,)) showin.t;-. Jaws, as
such, do not exist. However, there are in the
pharynx entrance heavy, chitinous projections
(15 in most G. hicolar) which appear to be ar-
ranjjjed in a circle, which may help in nianuever-
ing the food material.
Aside from the radula-jaw arrangements, the
alimentary canal is relatively simple. A short
esophagus leads from the pharynx to the stom-
ach. The stomach is essentially a bag, lined with
tall, columnar, ciliated epithelium. It, in keeping
with other carnivorous stylommatophorans, is
simple. It has no accessory parts such as a gas-
tric shield, typhlosole, or crystalline style. The
stomach, in sections, shows that extracellular
digestion occurs. Digestive enzymes, probably
secreted by salivary glands and digestive gland
as in other molluscs, are emptied into the diges-
tive system (salivary glands into the esophagus
and digestive gland into the stomach) (Mansour-
Bek, 1948; Hirsch, 1915). The intestine (Figs. 4
& 5,i) seems shoi't in contrast to that of various
other species seen, extending only up into the
.^'^
^A,
V
c /
1 ~
V
■■^'^
i^
f^^.::.
'^.7/'-
»i-
y 4 ^.-, t.:>j^i- - - 5
^■/A<i«K:'^;k
>'i:
\
^ • 1
V'
■*ff*^' -7,
FIGS. 4-7. Gulctlf! hicolor serial sections. 4, is almost mid-
longitudinal. 5, represents a cut 20 microns from Fig. 4
towards the ventral surface. 6, is 20 microns further from
mid-line. 7, is an enlargement of the lower right portion of
Fig. 6. d, digestive gland; c, columellar muscle; a. albumen
gland; v, vas deferens; m, mucus gland; r, rectum; h, heart;
b. buccal mass; k, kidney; i, intestine; t, radula; j, jaws. Fig.
4. .'i, fi bars represent 1 mm. Fig. 7 bar is 0.25 mm.
third whorl below the apex. At that point it
begins a descent and the rectum (Fig. 7r) opens
within the mantle cavity on the right side of the
head.
Mid-longitudinal sections reveal that the top
three and one-half to four whorls are occupied
mostly by the digestive gland (Fig. 4, a). It has
the same basic structure as that described in
many other snails (e.g., Dundee, 1957). Embed-
ded in digestive gland at the level of the third
whorl lielow the apex and lying in close approx-
imation to the columella is the ovotestis (herma-
phroditic gland of some authors). It is usually
white to yellow and resembles a grape cluster.
Each lobule is encased in scjuamous eipthelium
and the entire structure is embedded in connec-
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 67
tive tissue. Oogenesis can be seen around tiie
perimeter; sperm are produced in the interior.
Collecting ducts in the ovotestis are lined by
cuboidal, ciliated epithelium and all ultimately
become one large hermaphroditic duct which
proceeds anteriorly (downward). The duct bifui'-
cates in the lower portion of the 3rd whorl below
the apex. One part becomes the female system
and the other the male. In most snails there is
some type of fertilization chamber present near
this junction but none was found in G. bicolm:
A large, two-part gland occupies the next two
and one-half whorls. The posterior (top) portion
is an albumen gland (Figs. 4, 5, 6a). It is a some-
what convoluted mass with a central, ciliated
cavity. The mass, in section has an "open" ap-
pearance (Fig. 6a). The cells a.-e either filled
with secretions or appear empty (possibly due to
the sectioning). The cell shape is irregular;
nuclei are basal. In the whorl above the body
whorl, the albumen gland joins the mucous (cap-
sule) gland which is also large. This mucous
gland is distinctly different from the albumen
gland histologically. The overall appearance in
section (Fig. 7m) is of a "heavy" gland contain-
ing numerous globules in the epithelial cells. The
cells tend towards cuboidal and have basal
nuclei. Large mucous globules are seen within
the cells and in the lumen.
Ova are presumably fertilized near the bifur-
cation of the male-female ducts, receive albu-
men as they travel through the gland. While
traveling through the mucous gland the fertil-
ized ovum receives its outer coatings so that it is
completed by the time it passes through the
vagina and genital pore, which is located on the
right side of the head of the snail. The female
system also has a bursa copulatrix which is a
stalked sac extending from the vagina. Sperm
found in it seem to be non-oriented. It is believed
(Duncan, 1975) that bursas are organs for the
purpose of digesting excess foreign sperm.
Extending from the hermaphroditic duct
(downward) is the prostate gland. It is composed
of a ciliated columnar epithelivun underlain by a
thin circular muscle layer. It is in the l'oi-ni of
follicles of columnar ghuidular cells and runs
parallel with the albumen-niucous gland of the
female. Often the prostate gland em})ties into
the vas deferens prior to the point at which the
vas passes through the body wall (that secre-
tory duct was not found). The vas deferens (Fig.
5v), after re-entering the hemocoel enters the
verge. A dart sac has been reported in some
streptaxids such as Dicartemon (Berry, 1965),
but it was not seen in G. bicolor.
Discussion
The carnivorous habit is found in only eight
gastropod families and apparently represents
convergent evolution (Solem, 1974). Most likely
it evolved from a form of omnivorous activity
wherein ancestors fed on dead organisms. It
would seem to be only a small step to predation
and/or cannibalism. One usually finds both prey
and predator under the same cover in the field.
As a result of its predatory activities, Gulella
bicolor has been the object of "biological control"
experiments in the past when it was introduced
into Hawaii (Mead, 1961) to control the Giant
African Snail, Achatina. The end result was that
it fed upon subulinids rather thani4t7((;//«o and,
fortunately, did not destroy the endemic snail
fauna.
Since this is an introduced species, and since it
occurs in so few localities, little or no informa-
tion on behavior is available. The fact that these
snails reproduce frequently (every other month
in the New Orleans area in warm weather) indi-
cates that, given ideal conditions, the population
could build up rapidly. If that were to happen, it
is possible that our endemics could be substi-
tuted as food when the prey was decimated.
Gulella as shown here, does form colonies in
given areas whereas anothei- local carnivore,
Euglandina rosea, seems to be solitary. It is dif-
ficult to understand why these predators are so
widely se})arated. Various possibilities come to
mind. Pei'haps the prey is not eveiywhere abun-
dant (we do not yet know how selective these
predators are). Possibly some kind of territorial-
ity involving the coloration is exhibited although
such has not been reported in molluscs. Possibly
this is the "top carnivore" syndrome on a
microscale.
The anatomical aspects included herein verify
that this species is an advanced stylommato-
phoran as evidence by the reduction of access-
ory parts in lioth digestive and reproductive
systems, and those systems lend support to the
fact that this snail is a niicropredator.
68 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
LITKRATURE CITED
Berry. A. lyB."). The j^enital systems (jf twu Strejitaxidae.
Pro,: Malar. Sor. Land. 36:221-228.
Dundee, Dee S. 1957. Aspects of the bioldjjy of Potiiiilioiinit:
lajiidarw (Say) Mine. Pub.. Mux. Zimi. Viiir. Mich. No.
100:1-37.
1970. Intr'oiluced Guif Coast molluscs. Tidniif
Studu'!< inZool. and Bed. 16(3):101-115.
Duncan, C. J. 1975. Reproduction. Ch. 7 in Puhiiiniatcs. (ed.
Vera Fretter and J. Peake). Academic Press. 1 -540.
Harry, Harold W. 196(5. Land snails of I'lithi Atoll, Carolina
Islands: a study of snails accidentally distributed by man.
PanfirSrl. 20(2):212-223.
Hirsch. (;. C. 1915. Die Ki'iiahrunusbioloyie ttei.schfressen-
der (Jastropoden {Mnrc.r. Nalira. Ptfrotrarhac, Pleuro-
hniiichaea. Tritonium). 1. Makroskopischer Bau, Nah-
rungsaufnahme, Verdauung, Sekretion. Zuol. J<ihrh.. .Ahl.
allgcm. Zool. u Plnj^iol. Tifrc 35:357-504.
Mansour-Bek. J. ,1. 1946. Extracellular proteolytic and lipo-
lytic enzymes of some lamellibranchs. Nature 158:378-79.
Mead. Albert R. 1961. The yiarit African snail. A problem
in economic malacology, p. 135. Univ. Chi. press. 1-257.
Solem, Alan. 1974. Patterns of radular tooth structure in
carnivorous land snails, Veliger 17(2):S1-S8.
van der Schalie. Henry. 1948. The land and freshwater mol-
lusks of Puerto Rico. .Mi>^r. Pnl,.. Mii^. /„„/.. Vnir. Mirh.
70:1-1.34.
LIVING TERRESTRIAL GASTROPODS FROM THE
EASTERN CAPROCK ESCARPMENT, TEXAS
Raymond W. Neck
Texas Parks and Wildlife Department
4200 Smith School Road
Austin, TX 78744
ABSTRACT
The terrestrial gastropods of the Eastern Cajn'ock Escarpment of the Texas
Panhandle have been .surveyed. Prei'ioiis studies have largely been composed of
flood debris specim.ens. A total of twelve species, including one slug, were found
alive. The faunal assemblage reflects diverse zoogeographical origins.
Presently, the Eastern Caprock Escarpment
of the southern Texas Panhandle supports a
depauperate terrestrial gastropod fauna. More
is known of the Pleistocene snails of this area
(e.g. Schultz and Cheatum, 1970) than the living
fauna. In order to better interpret certain
samples of Holocene snail faunas (Neck, 1978;
Johnson, et ai. 1982), a survey of the living
snails of several canyon systems of the Eastern
Caprock Escarpment was undertaken.
Previous Studies
As an initial step, the literature on previous
land snail collections in this geographical area
was surveyed. Several references were located,
but most involved collections of drift debris.
Henderson (1909) reported 11 small to minute
species which "were found in drift debris -none
actually alive and crawling about" in a canyon 24
km southeast of Amarillo. Strecker (1910) col-
lected in the canyons of Armstrong County
(southeast of Amarillo). Although he concen-
trated on terrestrial vertel)rates, he reported
four species of land snails which were "dead
shells . . . found among drift material on the
west bank of Salt Fork." Walker (1915) iden-
tified shells collected by E. C. Case over a large
area of the south central U. S., including two
Texas Panhandle localities which yielded six
land species from "samples of drift". Clarke
(1938) reported 11 species of land snails from
"large piles of drift debris" from Palo Duro Can-
yon 8 km northeast of Canyon, Texas.
The above records of drift debris have been
recorded as locality records in subseijuent
literature (e.g., Cheatum and FuUington, 1973).
Wendorf (1961:109) reported that "part" of the
collection recorded by Clarke (1938) was from
drift; in reality only a few of the aquatic forms
were recorded alive. Bequaert and Miller
(1973:9) reported that four of the species which
were recorded by Clarke (1938) and Henderson
(1908) were alive, but no supporting evidence
was provided. A reexamination of the above two
Vol. 98(2)
April
1984
THE NAUTILUS 69
papers revealed that all specimens of terrestrial
gastropods reported therein were obtained from
sti-eam drift debris.
Taylor (1960:26) utilized the species listed by
Clarke (1938) as representative of the modern
fauna because "there are no obvious anomalies
of distribution." Pierce (1975:104-111) reported
several samples of modern drift with some shells
containing dried or charred flesh. Records of
definitely living material known from this area
include those of Vallonia spp. and Rabdotus
dealhatus (Metcalf in Bequaert and Miller,
1973:63; Fullington and Pratt, 1974). Pratt
(1965) reported Stenotrema le.ai in deciduous
woodlands along the Canadian River in Hemp-
hill County. Metcalf (in Franzen, 1971) found
Succinea vaginacontorta living in Sherman Co.,
Texas, on the northern margins of the Texas
Panhandle. Only limited information on suitable
microhabitats has been provided, however.
Methods and Collecting Localities
All snails reported herein were collected alive
(except shell only of Deroceras laeve at locality
E-2 and some Rahdotus dealhatus). Snails were
recovered from selected soil samples which had
been screened through a series of nested soil
sieves (#8, #16, and #30) or collected individually
in random searches of suitable microhabitats.
Collections were made on the following dates:
18-19 February 1976, 4 October 1977, 2 August
1978, 10 May 1979, 29-30 May 1981 and 8-9
March 1983.
Collection sites were located in canyons asso-
ciated with two tributaries of the Red River (let-
ters in locality code are located on Fig. 1). Two
areas were selected in Palo Duro Canyon of the
Prairie Dog Town Fork in Randall County: E-1,
Juniperus scopulorum woodland adjacent to
rural house site on Cedar Way Creek, near
35°2'N, 101°46'W; and E-2, J. scopulorum
woodland associated with lower reaches of
Spring Branch Draw on terrace of Prairie Dog
Town Fork Red River, near 35°2'N, 101°43'W.
A series of collection sites were sampled with-
in and just to the west of Caprock Canyons
State Park (CCSP), Briscoe County, associated
with several tributaries of the Little Red River.
Site A-1 was located below a limestone pouroff
in the North Prong of the Little Red River, near
34°28'N, 101°6'30"W. Site A-2 was located on a
OKLAHOMA
0 32 64 96KM
SCALE
V\i\. 1. Map lit' Texas Panhandle .showing locations of sample
sites. Letters refer to collection localities as li.sted in text.
low Holocene terrace associated with the North
Prong, near 34°27'55"N, 101°5'25". Vegetation
was open scrub dominated by Prosopis glan-
dulosa. Juniperus scopulorum. Opuntia spp.
and Boufeloua hirsuta. Several sites were
sampled along the North Prong of the Little Red
River: B-1, Populus sargentii thicket near
western boundary of CCSP. near 34°27'N,
101°7'W; B-2, open J. scopulorum- J. pinchofii
woodlands on upper terraces, snails collected
from underneath rocks and leaves in juniper
duff, in adjacent Boy Scout camp, near 34°27'N,
101°7'10"; B-3, same general area as B-2 on dif-
ferent date; and B-4, open, scrub-covered flat,
near 34°27'N, 101°6'30"W. Additional sites
were located on Holmes Creek. C-1 is a sandy
point bar with early successional forbs just west
of CCSP western "boundary, near 34°25'30"N,
101°5'30"W. C-2 is scrub slope above Lake Theo
dominated by J. pinchotii. near 34°25'N,
10r4'W. Locality C-3 is located slightly
eastward of C-2 along the margins of Lake
Theo. Site D-1 was a narrow, north facing
header canyon of Mexican Creek next to Texas
Highway 256 near 34°28'15"N. 101°5'30"W.
Substantial soil and Quercus havardii leaf litter
70 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
had accumulated on Triassic Upper Dockum
(.Trujillo) Sandstone.
Discussion of Species Recovered
Vallonia parvula Sterki, 1893, was recovered
from five localities in narrow canyons with ar-
borescent vegetation. Snails were fount! under
rocks, logs and in deep leaf litter. This small
species is found living from Ontario to South
Dakota southward to the Texas Panhandle with
an apparently introduced population in Florida
(Pilsbry, 1948:1028). V. parrula is found in
woodlands that are most often associated with a
river or lake (Baker, 1939:119; Leonard,
19.59:189), although it is adapted to relatively
xeric climatic conditions (Leonard, 1943; Hib-
bard and Taylor, 1960). Fullington and Pratt
(1974:29) reported V. parvula from dee]i leaf lit-
ter oi Fupulus aargentii along Palo Duro Creek.
Vallonia gracilicosta Reinhardt, 1883. is
somewhat less common than V. parrula and is
significantly larger. All three localities with V.
gracilicosta also suppoi'ted populations of V.
parvula. V. gracilicosta has been recorded from
Montana and North Dakota south to New Mex-
ico (Pilsbry, 1948:1029). Published habitat
descriptions encompass prairie groves and
riparian woodlands (Baker, 1929; Woodbury,
1929; Shimek, 1930) where snails are found in
moist humus of protected woodland sites
(Taylor, 1960). Metcalf (in Bequaert and Miller,
1973:63) found V. gracilicosta living in Gray
County approximately 100 kilometers NNE of
Caprock Canyons State Park. Fullington (1979)
found living specimens in Guadalupe Mountains
National Park, Cull.)erson Co., Texas.
Pupoides alhilabris (C. B. Adams, 1841) was
found only in a total of four sample sites but oc-
curred in some of the more exposed sites. This
wideranging species is known from the Dakotas
to Arizona eastward to the Atlantic coastal
areas and southward to Mexico and the Greater
Antilles (Pilsbry, 1948:923). P. albilabris is
found under rocks and downed wood in decidu-
ous woodlands, savannahs and prairies (pers.
observ.).
Gastrocopta procera (Gould, 1840) was found
at five sampling locations encompassing all can-
yons surveyed. G. procera inhabits a large area
of the southern United States from Maryland to
Kansas and Arizona (Pilsbry, 1948:907). G. pro-
cera occurs in many of the same microhabitats
TABLE 1. Occurrencf of living; terrestrial gastropods at various sample sites in Texas Panhandle. See text for
location and description of sample sites. X = presence of species.
Local I'ties
A-1
A-2 B-1 B-2 B-3 B-4 C-1 C-2 C-3 D-1 E-1 E-2 Total
Va1 loni a parvu! a
Val Ionia gracilicosta
Pupoides albil abris
Gastrocopta procera
Gastrocopta pel lucida
Gastrocopta cri stata
Gastrocopta armifera
Succinea cf . a vara
Deroceras 1aeve
Hel icodiscus inermis
Hel icodiscus para1 lelus
Rabdotus dealbatus
# of species (12)
Vol. 98(2)
April 27, 1984
THE NAUTILUS 71
as P. albilabria. but requires slightly more
moisture i.e., tree cover (pers. observ.).
Gnxtroeoptn pellucida honjeacella (Pilsbry,
1890) was found at six localities in the study. G.
p. hordeacella ranges from New Jersey to
Florida to Baja California (Pilsbry, 1948:914).
This small species is often associated with G.
procera but is more drought tolerant and is
often associated with grass roots (Fullington
and Pratt, 1974:17).
Gastrocopta cristata (Pilsbry and Vanatta,
1900) was found in more sites than any other
species recovered in this study. This species oc-
curs from Arizona to central Oklahoma and
Texas (Pilsbry, 1948:913). Habitats are general-
ly calcareous but include both grasslands and
woodlands in both upland and bottomland areas
(Fullington and Pratt, 1974:14).
Gastrocopta armifera (Say, 1821) was found
in only three sample sites. Geographical range
of this species includes an area bounded by
Quebec, Florida, Alberta and New Mexico
(Pilsbry, 1948:875). Leonard (1959:170) states
that G. armifera "occurs in a wide variety of
habitats." A large number of county records in
central, western and north central Texas were
listed by Fullington and Pratt (1974:10-11), but
many of these are probably drift debris shells of
Pleistocene origin. Hubricht (1972) reviewed the
armifera complex and recognized five species;
however, all specimens collected during this
study appear to fall within nominate arnufera.
Recovered living specimens were found under
leaf litter in canyon and floodplain woodlands.
Succinea cf. avara, Say, 1824 {sensu Franzen),
was found only at one locality under old juniper
wood (in contact with soil) which was concen-
trated into small piles during brush-clearing
operations during the late 1950's. Shell color is a
dilute orange-brown while the body was a fea-
tureless grayish-cream. Living mature snails
were most likely to be found underneath trunk
bases than under a simple branch. Smaller in-
dividuals were usually found immediately be-
tween wood and soil whereas larger specimens
were found on semi-exposed portions of wood.
S. avara- is a very troublesome name. Type
specimens are shells with no soft parts, a
necessity for proper identification of members
of the family Succineidae. Franzen (1982) util-
izes S. avara as a name for succineids from a
large geographical area including at least south-
western Kansas. Habitat associations of S.
aiKira (.spw.sm Franzen, 1982) are varied as are
localities reported by Pilsbry (1948: HL 2: 839).
The habitat heterogeneity and "rather wide
variation" in genitalia (Pilsbry, 1948: HL 2: 840)
indicate the likelihood of a number of unrecog-
nized (possibly undescribed) species, especially
in the southern United States. Pending an ex-
tensive anatomical investigation by a future
brave (masochistic?) systematist, the best solu-
tion seems to be to refer to these populations as
Succinea. cf. avara.
Succinea vaginacontorta Lee, 1951, has been
reported from Sherman Co., Texas, on the
northern edge of the Texas Pandhandle (Met-
calf, in Franzen, 1971) and in an urban landfill in
the southern Panhandle (Neck, unpub.). S.
vaginacontorta is found in the High Plains of the
central United States from Texas to North
Dakota (Leonard, 1959; Franzen, 1971). Typical
of xeric sites, S. vaginacontorta appears to be a
regional representation of what many workers
have called Succinea grosvenori Lea, 1864,
(Shimek, 1935; Pilsbry, i948:3(2):821; Hubricht,
1963).
Deroceras laeve (Miiller, 1774) is a limacid slug
found living at one site (C-3) and represented by
a single internal shell at another site (E-2). Slug
populations referable to D. laeve have been
reported from the Arctic to Central America on
both sides of the Rocky Mountains (Pilsbry,
1948:540-541). The living slugs were found
above the water level of Lake Theo during a low
water period. In comparison to specimens from
central Texas, the slugs were rather slim and
long and of a definite black color. These slugs
are referred to laeve because they do not possess
the greatly thickened shell of aenigm.a. Leonard,
1950, which was widespread in the Great Plains
during the Pleistocene. Shells of the Panhandle
slugs are thinner than shells of central Texas
slugs. However, much variation in shell thick-
ness has been observed among D. laeve popula-
tions (pers. observ.). During the Late Pleisto-
cene the Great Plains apparently supported
varied genetic stocks of D. lacvc east of the
Rocky Mountains. During the Holocene, or even
earlier, a stock with a more gracile shell was
selected preferentially.
Helicodiscijs inermis Baker, 1929, is a minute
72 THE NAUTILUS
April 27, 1984
Vol. 98(2)
s])ecies which was found at mily three collecting-
sites wliich were anion.n' the most protected of
the areas sampled. C)rii:;inally, inermis was
described as a sul)S))ecies of H. sivgleyrnius
(Pilsi)rv, 1890) which has ti;enerally been con-
sidered to ran.u'e from New Jersey to Florida
westward to Iowa and Arizona (Pilsbry, Ui48:
636). However, recent woi'k on the smaller
species of HflicixliscKs by Hubricht (1962, 1965,
1968, 1975) indicates that H. sifiglf^/duus may
be restricted to central Texas, New- Mexico and
Arizona (althoug'h s|.>ecimens from the central
Atlantic coastal region also apjiear to be ti-ue
singleyanu^). A detailed study of populations of
the subgenus Ht'lictodiscxs is needed to separate
genetic and ecophenotypic variation. H. inei'tnis
ranges from New Jersey to P^jorida westward to
Texas and Oklahoma. Chai-acters which place
the Caprock i>opulations in H. i)ier)nis are the
smaller- shell size and relatively tightly coiled
shell (compared to H. siiiglfiidnus). A tyi)ical
shell has a diameter of 2.2 mm with a height of
0.95 mm for a shell with ■i.i^ whorls. This species
is found in a variety of microhaliitats in leaf lit-
ter or under rocks and downed wood.
Helicodiscus parallelus (Say, 1817) was found
only at the more mesic sampling stations. This
species occurs over most of the eastern United
States as far west as the central Great Plains
(Pilsbry, 1948:625), where it is found in relative-
ly mesic deciduous woodlands. In comparison to
shells from eastern Texas, the Pandhandle H.
parallelus are slightly more domed-shaped with
a thinner, less yellowish shell. Apertures are too
narrow to be referred to shimeki Pilsbry, 1890.
Shells of H. parallelus from the Caprock area of
Texas have broad whorls (which narrow the um-
bilicus) and, the aperture is taller than wide.
Raised threads are present but very faint on the
protoconch with transition to the coarser
threads on subsequent whorls being gradual.
Pierce (1975) reported that H. parallelus was
replaced by H. eigenmanni in the early part of
the Altithermal in the High Plains area of
Texas. However, H. parallelus has survived in
the CCSP area where studies of Holocene land
snails (Johnson, et al., 1982) revealed a few H.
parallelus in the upper soil layers but no H.
eigenmanni. The true taxonomic relationship
between these two taxa is still unclear (see
analysis of Oklahoma specimens by Branson,
1963).
Rahilotus dealbatus (Say, 1821) was repre-
sented by one living specimen collected in an
open scrub savannah habitat during a rain-
storm. R. dealbatus occurs from northern Mex-
ico to southern Illinois and east to Mississippi
(FuUington and Pratt, 1974:16). R. dealbatus is
generally found in woodland hal.iitats on stream
terraces, although it is found in prairie areas
east of the range of Rahilotus uKjoreanus (see
Pratt, 1974, for differentiation of these two
forms). The shell of the living snail (height-21.7
mm, diameter- 12.7; 6.0 whorls) is somewhat
thinner and less ridged than a sample of dead
shells found on the surface of a xerie slope above
Holmes Creek. Age of these old shells is
unknown but widespread bulldozing of juniper
and mesquite in the late 1950's probably
devastated the remaining R. dealbatus habitat,
i.e. open woodland. However, the presence of
isolated, single shells found along and down-
slope from the Ogallala scarp woodland in the
western portions of Caprock Canyons State
Park indicates the formei- existence of more
abundant populations at some time during the
past (perhaps prior to the historic period). None
of the shells is sufficiently ridged to be referred
to ragsdalei Pilsbry, 1890.
Discussion
The presently known lanrl snail fauna of the
Eastern Caprock Escarpment of Texas consists
of twelve species of diverse zoogeographical
origins. Three species (Gastrocopta armifera.
Helicodiscus inermis and Helicodiscus
parallelus) are eastern species which are near or
at the western limit of their geographical
ranges. An additional three species {Pupoides
albilabris. Gastrocopta procera and Gastrocopta
pellucida hordeacella) are basically eastern
species but occur farther west than the present
study area; the latter species has a southern
range affinity also. Three species (Vallonia par-
rula. Vallonia gracilicosta and Succinea cf.
avara) have their affinities to the north and
northwest. Single species each have their af-
finities to the southwest {Gastrocopta cristata)
and the south {Rabdotv^ dealbatus). One species
(Deroceras laeve) has a very widespread range in
all directions from the study area.
Certainly, additional living species may l)e
found in the Texas Panhandle, but the number
to be expected is very low. Examination of drift
Vol. 98 (2)
Ai»ril 27, 1984
THE NAUTILUS 73
debris in these same areas revealed no addi-
tional species witii fresli shells.
The current fauna of the study area is a very
depauperate fraction of a richer fauna which ex-
isted along the Eastern Caprock Escarpment up
until about 9000 years B. P. (Schulz and
Cheatum, 1970; Pierce, 1975; Johnson, et (//.,
1982). Twenty-two species are known from the
Caprock Canyons State Park area at 10,000 B.
P. (Johnson, et al. 1982). Additional species
were present in the Panhandle portion of Texas
at that time (Pierce, 1975). With the exception
of J?, dealbatus. S. cf. avara, andZ). laeve, all re-
maining species are minute in size. Species of
small-sized individuals can exist in smaller
microhabitats than can the larger species.
Various VaUo)n<t can survive a series of incle-
ment seasons in small areas witn rock, downed
wood or deep leaf litter. Larger species, e.g. R.
dealhatu.'i. live in a more coarse-grained environ-
ment, i.e. require a larger area of suitable
habitat to survive.
Almost all living snails recovered in this study
were found in wooded areas. More species, in-
cluding the more mesic-adapted species, were
found in relatively heavily wooded areas with
closed canopies and deep leaf litter. Sites with
less wooded cover antl only surficial litter ac-
cumulations supported fewer numbers of
species. D. htci'e was found both along a
lakeshore and in well-drained woodland soil with
deep leaf litter. No pi'aii'ie sites, either native or
reclaimed, were available for sampling during
this study. Should suitable prairie sites become
available, surveys of the snail fauna will be
pursued.
Modern human utilization of the study area
has involved diverse, indirect impacts. Logging
for larger specimens of Rocky Mountain juniper,
Juniperus scopulorum, and hackberry, Celtis oc-
cidentaliN, reduced suitable microhabitats in
canyon slope and stream terrace areas by in-
creasing solar insolation and erosion plus
decreasing accrual rates of leaf litter. Grazing
activity has decreased grass cover and increased
brush cover and soil erosion. Subsequently, ex-
tensive areas were bulldozed to reduce brush
cover. Farming activities definitely disrupted
the prairie conmiunities but the level of .snail
presence in these habitats under natural condi-
tions is still unknown.
Acknowledgments
For comments on a previous version of this
manuscript, I thank R. W. Fullington, A. L.
Metcalf, and R. W. Ralph. Identification of col-
lected succineids was provided by D. S.
P"'ranzen. Figure 1 was drafted by T. D. Samsell
HI.
LITERATURE CITED
Baker, F. C. 1929. Mollusca from Vermillion and Pelican
Lakes. Minnesota, with the description of a new variety of
Hrli.'<oma corpulpnta. The Nautilus i2:95-d7. 131-136.
1939. Fieldbook of Illinois land snails. Illinois
Nat. Hist. Survey Div. Man. 2:1-1.55.
Bequaert, J. C. and W. B. Miller. 1973. The mollusks of the
arid Southwest. V. Arizona Press, Tucson, 271 pp.
Branson, B. A. 1963. The Recent Gastropoda of Oklahoma,
VI. Terrestrial families, Endodontidae and Haplotremati-
dae. Revisions and Retinell.a zikmundi nov. sp. Proc. Okla.
Acad. Sci. 44:2.5-41.
Cheatum, E. P. and R. W. Eullingtou. 1973. The Recent and
Pleistocene members of the Pupillidae and Urocoptidae
(Gastropoda) in Texas. Bull. Dallas Mas. Nat. Hi.^t. 1(2):
Gl pp.
Clarke. \V. T. Jr. 1938. List of molluscs from drift debris of
Paladora Creek, Texas. The Nautilus 52:14-15.
Franzen, D. S. 1971. Anatomy and geographic distribution
of the succineid gastropod, Suecinea vaginaeontorta Lee.
T;/pA'r«(;!7M.s 84:131-142.
1982. Suecinea arani Say from the southern
Great Plains of the United States. The Nautibis 96:82-96.
Fullington, R. \V. 1979. The land and freshwater Mollusca of
the Guadalupe Mountains National Park, Texas. P. 91-111
in Biological investigations in the Guadalupe Mountains
National Park, Texas (H. H. Genoways and R. .1. Baker.
ed.). Nat. Park Seri'ice Proc. and Trans. Ser. 4:1-442.
Fullington, R. W. and W. L. Pratt. Jr. 1974. The Helicinidae,
Carychiidae, Achatinidae. Bradybaenidae. Bulimulidae.
Cionellidae, Haplotrematidae. Helicidae. Orehoelicidae,
Spiraxidae. Streptaxidae, Strobilopsidae, Thysanophori-
dae. Valloniidae (Ga.stroi)oda) in Texas. Bull. Dalht.^i Mus.
Nat. Hist. 1(3): 1-48.
Henderson, J. B. Jr. 1909. List of mollusks from .Amarillo,
Texas. The Nautilus 22:9.
Hibbard, C. C. and D. W. Taylor. 1960. Two Late Pleisto-
cene faunas from southwestern Kansas. Contrih. Mux.
Paleontol. Univ. Michigan 16:1-73.
Hubricht, L. 1962. New species of Helicodiscu)< from the
eastern United States. The Nautilus 7.5:102-107.
1963. Some Succineidae. with a new species. The
Nautilus 76:135-138.
1965. Four new land snails from the south-
eastern United States. The Nautilus 79:4-7.
1968. Four new species of land snails. The
Nautilus 81:63-70.
1972. Gastriicopta arniifera (Say). The Nautilus
85:73-78.
1975. Four new species of land snails from the
eastern United States. The Nautilus 89:1-4.
74 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
Johnson. E., V. T. Holliilay and R. W. Neck. 1982. Lake
Theo: Late Quaternary paleoenvironmental data and new
Plainview date. North Amer. Archaeol. 3:113-137.
Leonard, A. E. 1943. The Mollusca of Meade and Clark
Counties, Kansas. Tnnn^. Kansas Acnd. Sci. 46:226-240.
Neck, R. W. 1978. Molluscan remains and environmental in-
terpretation at the Lake Theo Folsom Site (41BI70), Cap-
rock Canyons State Park, Briscoe County, Texas. Pp.
92-97 in Lake Theo: A stratified, early man bison butch-
ering and camp site, Briscoe County, Te.\as. B. R. Har-
rison and K. L. Killen. Piitihiuidle-Plainf: Hist. Mns. Spec.
Arch. Kept. 1:108 p.
Pierce, H. G. 1975. Diversity of Late Cenozoic gastropods on
the Southern High Pkiins. Ph. D. dis.-ierttition. Texas Tech
Univ., Lubbock, 267 p.
Pilsbry, H. A. 1939-1948. Land Mollusca of North America
(north of Mexico). Acad. Nat. Sci. Philailclphia Mnnoiir.
3:2 vol., 2107 p.
Pratt, W. L., Jr. 196.5. Notes on land snail distnlmtion in
Texas. The Nautilus 78:142-143.
1974. A revision of the mainland species of the
bulimulid land snail genus Rahdotus. Bull. Amer. Malac.
Union 1973:24-25.
Schulz, G. E. and E. P. Cheatum. 1970. Bison occidentnlis
and associated invertebrates from the Late Wisconsin of
Randall County, Texas. J. Paleontology 44:836-850.
Shimek, B. 1930. Pleistocene and Recent niollusks. The
Nantilvs 44:37-41.
1935. The habitats of Iowa succineas. The
Nautilus 49:i'>-li).
Strecker, J. K., Jr. 1910. Notes on the fauna of the canyon
region of northwestern Texas. Bai/lor Bull. 13(4&5):1-31.
Taylor, D. W. 1960. Late Cenozoic molluscan faunas from
the High Plains, U.S. Geol. Surrey Prof. Paper 337:1-94.
Walker, B. 1915. A list of shells collected in Arizona, New
Mexico, Texas and Oklahoma by Dr. E. C. Case. Occ. Pap.
Mus. Zool. U. Michigan 15:11 pp.
Wendorf, F. 1961. Invertebrate collections. P. 105-114, in
Paleoecology of the Llano Estacado. (F. Wendorf, ed.).
Museum of New Mexico Press, Fort Burgwin Research
Center 1:1-144.
Woodbury, A. M. 1929. The snails cif Zic.n Nalional Park.
r/if Mi;////h.-;43:.54-61.
RANGE EXTENSION OF THE FRESHWATER MUSSEL,
PLECTOMERUS DOMBEYANUS, INTO THE
TENNESSEE RIVER, KENTUCKY
Garry L. Pharris, James B. Sickel, and Carol C. Chandler
Biology Department
Murray State University
Murray, KY 42071
ABSTRACT
The naiad moUusk, Plectomerus dombeyanus (Valenciennes. 1827). from the
Mississippi and Gulf of Mexico coastal rivers, is reported for the. first time in the
Tennessee River. Apparently. P. dombeyanus has nether been reported from the
Ohio River System. Of the two live specimens found on Angust 10. 1981. in Ken-
tucky Lake at Tennessee River wile 1^1^.5. one was 5 years old. and the other was a
7 year old gravid female ivith fully developed glochidia indicating successful
reproduction is probably occurring. The i))i porta ncc of naiad surveys in thi^
region is discussed.
The discovery of two, live specimens of Plrc-
tomerus dombeyanus (Valenciennes, 1827) in
Kentucky Lake at Tennessee River mile 44.5
(36°44'12"N, 88°06'0.5"W), Trigg County, Ken-
tucky, on August 10, 1981, extends the known
range of this species into the Tennessee River
System (Pharris et «L, 1982). On that day a col-
lecting team consisting of two SCUBA divers,
Garry L. Pharris and Carol C. Chandler, accom-
panied by James B. Sickel, John M. Bates and
Sally D. Dennis was conducting a survey of the
freshwater mussels in the vicinity of the Han-
cock Biological Station of Murray State Univer-
sity. On one dive covering a 20 m^ area, Pharris
brought u]i the two specimens along with ten
Quadfula quadrula (Rafinesque, 1820), six
Amblema jdicafa (Say, 1817), two Megalonaias
nervosa (Rafinesque, 1820), three Fusconaia
Vol. 98 (2)
April
1984
THE NAUTILUS 75
Jlava (Rafinesque, 1820), three live and five
shells of Obliquaria rejlexa Rafinesque, 1820,
and two live and three shells of Quadrula nodu-
lata (Rafinesque, 1820). Sally Dennis and John
Bates provided the initial identification which
was later confirmed by David H. Stansbery.
The larger of the two specimens of P. dombe-
yanua was a gravid female with fully developed,
unhatched glochidia filling the marsupial water
tubes of all four demibranchs. The smaller speci-
men was not gravid, but its sex was not detei'-
mined. The presence of a gravid female and
another individual of different age is an indica-
tion that successful reproduction is occurring in
Kentucky Lake. Table 1 summarizes the meas-
urements of the two specimens.
The two specimens were located within a few
meters of each other. An area of 10 m^ had been
searched by Pharris using a 1 m^ aluminum
frame quadrat sampler. The other 10 m' had
been searched by Chandler. The habitat was the
crest of a submerged river bank, or levee, adja-
cent and parallel to the old river channel. The
substratum was a firm clay with some gravel
covered by a thin, less than 2 cm, layer of silt
which was easily swept away with water move-
ments created by a diver. The site was 700 m
from the eastern lake shore and at a depth of 6
m. Being adjacent to the river channel, the site
had a detectible, although slight, current
greater than that of ty^Hcal lake haltitats. The
species composition of the associated naiads also
indicated the more riverine character of the
habitat within the river-lake system of Kentucky
Lake.
The previous range of Plectonwrus dondw-
yanus as given by Simpson (lltl4) was the Gulf
T.ABLE 1. Mea.'iurements of two species of FI<:Ho>nfriis
diimbeyiitiiis from Kentucky Lake.
Shell Shell Shell Total Shell
Length Height Width Wet Weight Weight Age
(ima) (mm) (mm) (g) (g) (yrs)
59.8 30.7 16.7
80.1 48.9 29.
21.6
77.9
19.9
64.8
coastal rivers from the Alabama River west to
eastern Texas and north in the Mississippi River
System to northwest Tennessee. Call (1895) re-
ported P. dimdjeynnuH in the St. Francis River
in eastern Arkansas, and Johnson (1980) ex-
cluded it from the Mississippian and Ohioan
Regions above the confluence of the Mississippi
and Ohio Rivers. Ortmann (1926) reported it
from the North Fork Obion River, Union City,
Tennessee, a tributary of the Mississippi River
in western Tennessee. Van der Schalie (1939a)
reported this species from the Tombigbee River
but not from the other tributaries of the
Alabama River System (van der Schalie, 1938),
and Hanley (1981) presented evidence from In-
dian shell mounds that P. dombeynnus has
liecome established in the u[)per Toml)igbee only
within the last 800 years. The headwaters of the
Tombigbee in northeast Mississippi come within
30 km of the Tennessee River, and those of the
Obion River reach to within 15 km of tributaries
of the Tennessee. However, the Obion has been
channelized for much of its length, and it is
unknown whether or not P. dombeyanus sur-
vives there. Extensive surveys of the Tennessee
River naiads by Ortmann (1918, 1924, 1925),
Ellis (in: van der Schalie, 1939b), Scruggs
(19(i0), Isom (1969), Williams (1969), and Yokley
(1972) had failed to reveal the presence of P.
dombeyanus. Apparently, P. dombeyanus has
but recently established a pojiulation in the Ten-
nessee River.
Although the Obion and Tombigbee are the
nearest rivers to the Tennessee, by land, which
historically possessed P. dombeyanus, the near-
est by water which is known to have P. dombe-
yanus is the St. Francis River in Arkansas some
580 km distance, over 500 km of which is the
lower Mississippi River. Iff. ihnnbeyanus does
occur in the tributaries or oxbows of the
Mississippi Rivei- in the vicinity of the Obion, it
is still a distance of 285 km to the Tennessee
Kixer. This i-aises the i)ro\erl>ial question, "How
(lid PlertoDH'fus douibeyanns get into Kentucky
Lake?" Oi)viously, only suggestions may l)e
(ift'ered.
Ortmann (1913) and van der Schalie (1938,
1945) supported the idea of stream confluence,
or capture, as playing the major role in deter-
mining present distributions of North American
tVeshwater mussels. Clearly, there has not been
76 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
a recent connection between tiie Obion or Tom-
bigbee and the Tennessee River, although there
will be one with the Tombigliee in a few years
when the Tennessee-Tombigbee Waterway
opens.
There is no evidence for a gradual population
extension up the Mississippi and Ohio Rivers in-
to the Tennessee, and the main stem of the
Mississippi below its continence with the
Missouri is noted for its depauperate mussel
fauna (van der Schalie and van der Schalie,
1950). It has even been considered a barrier to
some species (Stansbery, 1978). The chance oc-
currence of fish hosts carrying glochidia from
the lower Mississippi tributaries, where P.
dombeyiinuK occurs, up the Mississippi and Ohio
Rivers into the Tennessee over such a great dis-
tance seems unlikely but should not be over-
looked. At least two species of fish which inhabit
Gulf coastal rivers are known to migrate up-
stream into the Tennessee River. The American
eel, Anguilla rostrata. and a striped mullet
(report unconfirmed), Mugil cephalus. have been
collected from Kentucky Lake. However, since
P. dombeyanus females release glochidia during
summer months when water temperatures are
high and larval development is probably rapid,
the likelyhood of a glochidial infection lasting a
sufficient length of time for the fi.sh host to
swim upstream for almost 600 km is remote.
This leaves two other possible origins for P.
dombeyiums in Kentucky Lake: overland trans-
port (or some artificial means by water) and a
remnant population. The idea of a remnant pop-
ulation was suggested by Dr. David Stansbery.
Even with the many surveys of mussels in the
Tennessee River, it is possible that this species
has been overlooked. Since "the species is a
mud-loving one, and delights in sluggishly flow-
ing water" (Call, 1895) and might not have been
present in shoals where the predominant Ten-
nessee River fauna was located, P. dombeyamis
may have been overlooked. With the construc-
tion of Kentucky Dam in 1945, suitable habitat
for P. dombeyanus has been increased greatly
and may have stimulated a population increase.
Clearly, many opportunities exist for overland
or artificial transport. This category should also
include transport by barge or boat over barriers
to natural dispersal such as dams or rivers lack-
ing suitable habitats. Over the past decade, in-
creased commercial harvesting of mussels by
divers has provided a new method for accidental
or intentional transport of mussels from one
drainage basin to another: the diver's bag and
equipment. Juvenile mussels with byssal threads
could become entangled in diving gear on one
day and carried to another river the next.
Larger mussels might be placed in a bag under-
water in one river system and culled from the
catch in another. Without overlooking the com-
plexity of the mussel life cycle and the impor-
tance of suitable habitat and fish hosts for the
establishment of a reproducing population, the
possilMlity of overland transport cannot be ruled
out. This may be more likely today because the
system of 'river-lake' reservoirs of the Ten-
nessee River and the mixing of fish fauna
through intentional fish introductions and other
fishing activities might create a suitable en-
vironment for mussel species not native to the
system.
This discovery of Pleetottwrus donibeyaniis in
Kentucky Lake emphasized the need for contin-
ued monitoring of aquatic systems. It also points
<uit the dynamic nature of aquatic fauna -even
tile naiad mollusks which are more restricted in
their abilities to disperse than perhaps any other
aquatic animal. When the Tennessee and Tom-
bigbee Rivers are connected, extensive faunal
changes can be expected. A record of this
change would be most interesting and useful to
present and future biologists. More intensive
surveys of both river systems should be con-
ducted to determine the existing similarities in
the faunas prior to the opening of the waterway.
The recent discovery of P. dombeyaiuis in the
Tennessee River will avoid mistakenly attribut-
ing its introduction to the Tennessee-Tombigbee
connection.
Acknowledgments
We express our sincere appreciati<.>n to Dr.
David H. Stansbery for information on naiad
distriluition; the Kentucky Department of P'ish
and Wildlife Resources, Fisheries Division, and
the National Marine Fisheries Services whose
funding made the initial survey possible; the
Committee on Institutional Studies and
Research, Murray State University for pro-
viding funds to help establish a museum collec-
tion; and Mrs. Betty Hornsby, Waterfield
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 77
Library of Murray State University for her
diligence in obtaining literature references.
LITERATURE CITED
Call. R. Ellsworth. 189.S. A study of the Unionidae of Arkan-
sas, with incident;!] reference to their distribution in the
Mississippi Valley. Trant!. Acad. Sri. St. Laiin^ 7(1): 1-6.5
+ 21 pis.
Hanley, R. W. 1981. Naiads from the Mobile River System,
past and present. Bull. Amer. Molncol. Uninri. Inc..
1981:31-32.
Isom, Billy G. 1969. The mussel resource of the Tennes.see
River. Malncologin 7:397-42.5.
Johnson, Richard I. 1980. Zoogeography of North American
Unionacea (Mollusca: Bivalvia) north of the maximum
Pleistocene glaciation. Bull. Miin. Comp. Zool.
149(2):77-189.
Ortmann, Arnold E. 1913. The Alleghenian Divide and its in-
fluence upon the freshwater fauna. Pnir. Amcr. Phil. Soc.
52(210):287-390.
1918. The Nayades (freshwater mussels) of the
upper Tennessee drainage. With notes on synonymy and
distribution. Proc. Amer. Phil. Soc. 57:521-626.
1924. The naiad fauna of Duck River Tennessee.
Amer. Midi. Naliii: 9:18-62.
1925. The naiad-fauna of the Tennessee River
System below Walden Gorge. Amer. Midi. Niitiir.
9:321-372.
1926. Unionidae from the Reelfoot Lake region
in west Tennessee. The Nantiliis 39:87-94.
Pharris, G. L., C. C. Chandler, and ,J. B. Sickel. 1982. Range
extension for Plectowcrua dowhcyunun (Bivalvia;
Unionidae) into Kentucky. Abstract: Tnum. Kentucky
.■\c,i,l. Sri. 43:95-96.
Scruggs, G. D., .Ir. 1960. Status of fresh-water mu.ssel stocks
in the Tennessee River. U.S. Fish &■ Wihllife Sen:. Spec.
Sci. Kept. Fis-/!pn>.s' 370:1-41.
Simpson, Charles T. 1914. .4 dtvcripttre ciitiiloii of the
Naiades nr pearlij frenhirater mufixela. Bryant Walker,
Detroit, Mich., xi + 1.540 pp.
Stansbery, David H. 1973. Species and subspecies of naiad
mollusks: definitions and determinations in theory and
practice. Ohio State Univ.. Mus. Zool. Repts. for 1973.
2:1-6.
van der Schalie, Henry. 1938. The Naiades (fresh-water
mussels) of the Cahaba River in northern Alabama. Ocean.
Pap. Mus. Zool. Univ. Mich. 392:1-29.
1939a. Medionidus mcglameriae. a new naiad
from the Tombigbee River, with notes on other naiads of
that drainage. Occa.f. Pap. 2\Iu.<t. Zool., Univ. Mich.
407:1-6 -I- 1 pi.
1939b. Additional notes on the Naiades (fresh-
water mussels) of the lower Tennessee River. .4 m.er. Midi.
Natvr. 22:452-457.
1945. The value of mussel distribution in tracing
stream confluence. Pap. .Mich. Acad. Sci. .Arts and Letters
.30:35,5-373.
van der Schalie. Henry and Annette van der Schalie. 1950.
The mu.s.sels of the Mississippi River. Amer. Midi. Natiir.
44:448-466.
Williams, J. C. 19()9. Mussel fishery investigation Ten-
nessee, Ohio and Green Rivers final report. Kentucky
Dept. Fish & Wildlife Resources. Frankfort. Kentucky,
107 |)p.
Yokley, Paul, .Jr. 1972. Freshwater mussel ecology, Ken-
tucky Lake, Tennessee. Trane.s.sBe Game & Fish Comm..
Proj. No. J,-4i;-R. V + 133 pp.
ARCHITEA A. COSTA, NOT AN ARCHITECTONICID BUT A
POMATIASID (GASTROPODA: PROSOBRANCHIA)
Kenneth J. Boss and Arthur S. Merrill
Museum of Comparative Zoology
Harvard University
Cambridge, MA 02138
Achille Costa (1869) introduced the generic
name Architea with the sole species A. calenu-
lata, A. Costa, as monotype, based on a single
specimen from the Island of Capri in the Gulf of
Naples, giving the following description and
placing the taxon in the gastropod family Solari-
idae (now Architectonicidae):
(Generic): 7V,s7tt turbinata, parum eievata, in-
fra late et profunde umbilicata; apertura. rotun-
data, periostomate continuo, simplici. Opercu-
lum conieiim. pellucidum. spirale. extuii piano,
U'vi, intus spria ad centrum parum prominula.
(Specific): Tr.s/a solida, anfract.ibus. rotun-
da! ix. longitiiditialiter subtililer et crebre sub-
catenulato-costulatis, transversim obsolete
ru()().^is. DinDi. tulll. IS: alt. mill. 9; diam. operc.
mill. f>.
This newly described species and genus was
listed in the reviewing and abstracting periodi-
cals (Gentiluomo, 1870: 54; von Martens, 1870:
78 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
136). Subsequent workers similarly have in-
cluded the genus and species in the family, allot-
ting the name Architea. variously spelled, to
generic or subgeneric rank. Thus, Monterosato
(1875:5 and 36) changed the spelling to Archy-
taea or Arch if aea and noted that the monotyjiic
genus shared features with other gastropod
genera (Mdllerin, Trochxs, and Solariiini).
Kobelt (1887:217) used the spelling Architea
and P^ischer (1885:714), using the spelling Ar-
chytaea assigned it as a questionable subgenus
of Solarium (now Archifertonicd). Thiele
(1929:184), Wenz (1938:666) and Pchelintsev
and Korobkov in Orlov (1960:137) considered
Arrhitea as a subgenus grouping under Toritiia
(now Heliaciis).
In the primary literature on the fauna of the
Mediterranean Sea or its divisions, Architen
catenulata has consistently been included,
generally repeating the description in the
original Latin or in vulgate translations (Kolielt,
1887:217; Carus, 1889-1893:348; Parenzan,
1970:93; Nordsieck, 1968:64). In his monograph
of Torinia (now Heliacus) Bayer (1948:10) con-
sidered A. catenulata as a species without sub-
generic categorization and therefore syno-
nymizing Architea under Torinia (now
Heliacus).
In our own ongoing critical study of the Ar-
chitectonicidae of the Atlantic Ocean including
the Mediterranean Sea, we reexamined the
original figures of Costa which revealed some
rather unusual features inconsistent with archi-
tectonicid characteristics, namely a perfectly
rounded aperture, non adanate to the last
whorl, and similarly tubular, perfectly rounded
earlier whorls and a concentrically multi-spiral
operculum. Such an operculum is not character-
istic of Heliacus to which Architea had been
almost universally assigned though another
representative of the family, phylogenetically
removed from Heliacus, namely Philippia kreh-
si (Morch), has such an operculum. Also, Costa's
figures show a specimen lacking an umbilical
wall which is usually very distinctive in true ar-
chiteconicids.
Further suspicion is also raised by the fact
that the species is known only by a single s{)eci-
men despite the many years of active collecting
and research by the workers of the famed
Zoological Laboratory in Naples.
Some of the charactei's oi Architea are sug-
gestive of a terrestrial prosobranch family. Con-
fusion of an architectonicid with presumed land
snails has a precedent in the naming of Teretru-
potna by Rochebrune (1881:110).
In further reviewing the Italian literature we
came upon a hitherto overlooked footnote ap-
pended to the synopsis of the malacofauna of the
Gulf of Naples" by Bellini (1929:83) which con-
firmed our suspicions; he showed that the
unique holotype of Architea catenulata Costa
housed in the Geological Museum at Naples is a
Madagascarian representative of the terrestrial
prosobranch family Pomatiasidae. He placed it
in Cyclostoma but it is more probably a repre-
sentative of Tropidophora (Boss, 1982:983;
Wenz, 1938:534). We herein quote Bellini's
(1929:83) note in full and append a translation:
"L'unico individuo di questa supposta specie
venne dal COSTA depositato nella collezione del
R. Museo Zoologico di Napoli; ma Yhahitat
(Capri) e la sua determinazione danno luogo a
molti dubbi, essendo la conchiglia rassomiglian-
tissima a quella di alcune Cyclostoma terrestri
del Modagascar. Si puo quinidi pensare che delv
l>a trattarsi di una forma esotica non marina
trovata casualmente nel nostro mare. II fatto di
rinvenire individui morti di specie di altri climi
in localita dove prima mai si erano raccolti, non
e sufficiente per accettarne I'esistenza nelle
fauna locali. Occorre che gli individui sieno stati
osservati alio stato vivente e, per maggior
garenzia, anche piii di una volta."
(English translation) The only specimen of
this postulated species came from those Costa
deposited in the Royal Geological Museum of
Naples; but its habitat (Capri) and its determina-
tion are doubtful, since the shell is extremely
similar to some land Cyclostoma from Mada-
gascar. It is probable that this must be an exotic
land species found by chance in our seas. The
finding of dead specimens, belonging to a
species from other climates, where they have
never been collected before is not sufficient to
ascertain their existence in the local fauna. It is
necessary for the specimens to be observed
while still living and, for greater certainty on
more than one occasion.
This observation of Bellini (1929) is in accord
with, and probably takes its inspiration from,
anothei' much earlier footnote biu'ied in the
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 79
Italian literature, namely Monterosato's (1873:
14) remark which is an addendum to p. 45 of his
earlier Afoime (1872) and which makes the same
suggestion.
Thus, the generic name Architea and its
variant spellings as well as its sole species is
removed from the Architectonicidae and placed
in the pomatiasids where it is probably a syno-
nym of one of the well-known Madagascar
genera.
We thank Mr. Montane Nissotti, Harvard '85,
for correcting and confirming our translation.
LITERATURE CITED
Bayer, C. 1948. Catalogue of the Solariidae in the Rijksmu-
seum van Natuurlijke Historie. 3. Torinin. Zoologische
Verli(indeliiigi'ri. Leiflen, No. 4, 44 pp.
Bellini, R. 1929. I molluschi del golfo di Napoli. Annuario del
IVIuseo Zoologieo della R. Universita di Napoli, (Nouva
Serie), 6(2): 1-87. (no illustrations).
Bess, K. J. 1982. Mollusca, pp. 94.5-1166. in Parker, Sybil
P., ed. Synopsit: and Cla.fsification of Living Organisms.
McGraw-Hill Book Company, New York, 2 vols.
Carus, J. V. 1889-1893. ProdrowMs faunae mediterraneae
sive descriptio animalium maris mediterranei inculamm.
Vol. II (Mollusca). Schweizerliart'sche Verhandung.
Stuttgart.
Costa, A. 1869. Nuovagenere di Molluschi Gasteropodi Pro-
sobranchii. Ann. Mus. Zool. Univ. Napoli, 3(186.5):.52-.')4.
Fischer, P. 188,5. Manuel de Conchyli.ologie el de Paleon-
tologie Conchyliologique ou Histoire Naturelle des Mol-
lusques Vivants et Fossiles. Paris, pp. 712-716.
Gentiluomo, C. 1870. [Review of] Annuario del Museo Zoolo-
gica della R. Universita di Napoli, Vol. 5; per il prof.
Aehille Costa. Bulletlino Malacologica Italia.no. 3:53-54.
Kobelt, W. 1886-1888. Prodromus Fauna.e Molluscorum
Testuceorum maria europaea inhahitantium. Bauer &
Raspe, Niirnberg, 1-550.
von Martens, E. 1870. Mollusca, Zoo/o3!>a//?eco?Y/. 10.5-179.
Monterosato, T. A. di. 1872. Notizie Intorno Atle Conrhiglie
Mediterranee. Palermo, Ufficio Tipografico di Michele
Amenta, 61 pp.
1873. Notizie Intorno Al Solarii Del Mediter-
raneo. Palermo, Ufficio Tipografico di Michele Amenta,
15 pp., 1 pi.
1875. Nuova revista delle Conchiglie Mediter-
ranee. Atti Ace. Palermo Sci. Lett. Arti. 2a, 5. pp. 1-50.
, 1878. Enumerazione e sinonimia delle Conchiglie
Mediterranee . . . Parte prima. Giornale di Seienze Natu-
rali ed Economiche di Palermo 13, 61-115.
Nordsieck, F. 1968. Die europdischen. Meeres-Gehdusesch-
neeken (Prosobranchia). Stuttgart. 273 pp., 1200 figs.
4 colored pis.
Parenzan, P. 1970. Carta d'identitd delle conchiglie del
Mediterra.neo. Vol. 1 Gasteropodi. 283 pp. 53 pi.
Pchelintsev, V. F. and I. A. Korobkov. 1960. Molliuski-
Briukhonogie (Mollusks-Gastropods). In Yu. A. Orlov. ed.
Osnovy Pa.leontologii (Fundamentals of Paleontology-)-
Izdatel'stvo "Nauka" Moskva. Vol. 4, 360 pp.
Rochebrune, A. T. de. 1881. Sur un type nouveau de la
famille des Cyclostomaceae. Bulletin de la Societe Philo-
mathiijue de Paris, Serie 7, 5:108-115.
Thiele, .1. 1929. Handhuch der systematischen Weichtier-
kunde. Tell 1. G. Fi.scher. Jena. p. 1-376.
Wenz, W. 1938-1944. Gastropoda. Teil 1: Allgemeiner Teil
und Prosobranchia. In 0. H. Schindewolf, ed. Handhuch
der Palaozoologie. Borntraeger, Berlin, 6: i-vii, i-xii,
1-1639.
REVIEW
The I'Veshivaf.n' Snail !< of Connect icid hy Eileen
H. Jokinen. 1983. Bull." 109, State Geological
and Natural History Survey of Connecticut, vii
-I- 83 pp., 35 figs. For a copy, send $5.00 to the
Survey, Room 555, Dept. Environmental Pro-
tection, State Office Bldg., Hartford, CT 0610().
This compact guide to the freshwater
gastropods of Connecticut fully covers the 2r)
pulmonate and nine prosobranch species found
in the rivers and ponds of this New England
state. Keys, including both shell and soft-part
anatomy, clear line drawings, and brief, but ade-
quate, descriptions assure easy identification of
these 35 species. The introductory material
covers factors affecting distributions and abun-
dance, instructions on investigating and collec-
ting freshwater mollusks, and how to preserve
and dissect specimens.
The booklet presents distributional maps for
each species and an appendix giving the water
conditions and species [iresent in al)0ut 150
ponds and lakes and the streams running into
three major rivers. A very large and useful
bibliography will allow future students to delve
into the still-existing mysteries of the Connec-
ticut freshwater snails. A re-study of the Physo
(or PJniselht) species, including ones possibly in-
ti'oduced from Europe, may be in order.
This extensive survey puts on record the
physical and biological conditions of the
freshwater bodies of the State, and records the
mollusk inhabitants which are so useful as
ecological indicators.
-R. Turkfr ,\hhnll.
Amcricon MdhtroUuiists. Inc.
80 THE NAUTILUS
April 21, 1984
Vol. 98 (2)
DISPERSAL MOVEMENTS OF FOUR SPECIES OF PULMONATE AND
OPERCULATE SNAILS IN DOUGLAS LAKE, MICHIGAN
N. Craig Boss. Timothv G. Laman and Harvey D. Blankespoor
Biology Department, Hope College
Holland, MI 49423
ABSTRACT
Various species of freshwater operculote and pulmonate snails show marked
differences in rate of dispersion, total distance moved and direction ofmorement.
Field experiments conducted between Jidij and August UiSJ shnu-i-d llial foii/-
eight hours after release, Goniobasis liveseens traveled the greatest distance and
hail the largest percentage of snails that niored a minimum of 1 m. In contrast,
Helisoma anceps dispersed the least with only 5% moving past one meter during
the same time. The longest distance moved by any H. anceps was 1.6 m. Physa In-
tegra and Lymnaea catascopium were similar in the rate of movement, hut dif-
fered in the total distance traveled. Finally, variations in directiiai if movement
were observed among the four species. Both P. integra and L. catascopium moved
up the slope (toward shore): however. G. liveseens preferred to move mvay from
shore to deeper water: H. ance])s appeared to show no directional movement.
Snails represent an important component of
the liiota of most aquatic habitats. As her-
bivores, they graze on many species of algae.
They also serve as prey for several species of
vertebrates. Finally, aquatic gastropods serve
as intermediate hosts for a group of parasitic
flatworms known as digenetic trematodes.
Relatively little is known about the population
fluctuations of either pulmonate or operculate
snails. Even less is known about the rates and
direction of dispersal movements, especially of
operculates. Two workers have indicated that
some species of pulmonates undergo seasonal
migration. Cheatum (1934) reported that snails
go to deeper water during the winter months
and return to shallower water in the spring.
Adults of Physa integra were shown to follow
such a pattern (Clampitt. 1974 and 1975);
however, he also reported in the latter study
that juveniles of the same species demonstrate a
different pattern. They appear to move away
from shore (into deeper water) during the sum-
mer.
Other investigators have found that some
species of pulmonates do not follow seasonal
migratory patterns as outlined by Cheatum
(1934). For example, Lymnaea catascopium
does not go to deeper water during the winter
months (Wall, 1977). Instead, there are random
movements within the population. Clampitt
(1975) also indicated that two species of planor-
bid snails, Helisoma anceps and H. cam-
panulata. showed little if any movements for
weeks or months at a time.
This study was initiated to compare and con-
trast the short-term dispersal movements (rate
and direction) of four species of aquatic snails.
Materials and Methods
Field e.xperiments were conducted on South
Fishtail Bay of Douglas Lake (Cheboygan Co.,
Michigan) from July to August 1982. The
specific area was selected because it was pro-
tected from wave action that results from
strong westerly winds. The substratum, com-
posed of sand with a top layer of organic
material, gradually sloped (approximately 15°)
downward away from shore.
Aquatic snails representing I'our families were
selected for this study: Lymnaea catascopium
(Say) (Lymnaeidae), Physa integra Haldeman
(Physidae), Helismna anceps (Menke) (Plan(.ir-
bidae), and Gonioba.Hs liveseens (Menke)
(Pleuroceridae). All represent pulmonate snails,
except the latter species which is in operculate.
Distances that snails traveled from a point of
release were determined using a ten-meter grid
that was similar in design and location to the
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 81
one used by Clampitt, 1974. However, the grid
was modified by having additional stakes
radiating two meters from the center to
enhance stability and facilitate counting. With
the aid of SCUBA, the middle of the grid was
secured at a depth of 4.5 meters (approximately
32 meters from shore).
For each of the four experiments, a minimum
of 400 snails was collected from Douglas Lake.
Snails representing each species were color-
coded with "Tech-Pen" (Mark-Tex Corporation)
using a small paint brush. This facilitated
locating the snails, especially in turbid water.
In a circle with a radius of approximately 12
cm, snails were placed directly on the substrate
in the middle of the grid. After 10, 24, and 48
hours, the location and number of the released
snails were observed. Dead snails were removed
from the study site after their location had lieen
recorded. Distances that the snails traveled
were grouped as Im, 2m, 3m, 4m, 5m. Data
were recorded under water on a plastic slate. A
pre-calibrated line of 10m was used to measure
the distances of snails outside the 5m radius.
This was also utilized as a "swing line" to mark
off each distance to determine the specific area
of dispersal for each snail. After each count, the
water temperature was recorded.
All work under water was facilitated by using
buoyancy compensators. Observers could then
assume an inverted position approximately 60
cm from the bottom without disturbing the
substratum or the snails.
Results
Data obtained from this study show that snails
do show differences in rate and direction of
movement as well as in total distance moved
after a prescribed time. Of the four species,
Goniobasis livescens moved the greatest
distance (9.5 m) after 48 hours from the point of
release (Fig. 1). I'hysa Integra traveled less than
8 meters during the same time. The remaining
two species of snails, Lymnaea catascophan and
Helisonui unceps dispersed a considerable
shorter distance of 3.6 and 1.6 m, respectively.
Members of all four species moved the greatest
distance during the first ten hours following
release. In fact, little distance was traveled
after the initial 24-hour period.
P'igure 2 illustrates the percentage of snails
OG livescens
o P inlegra
A L. calascopium
▼ H anceps
Time atler Release (hours)
Fit;. 1. Maximum distance traveled by four species of snails,
II), 24. and 48 hours after release.
Time alter Release (hours)
FIG. 2. Percentage of snails that moved at least one meter
1(1. 24. and 48 houi's after release.
that moved one meter or more after 10, 24, and
48 hours. After 10 hours, 83% of G. livescens
had moved at least one meter from the point of
release. At the other extreme, H. ohcc/w had lit-
tle if any movement during the first 24 hours.
After 48 hours, only 5% of the planorbid snails
had dispersed one meter or more. Lymnaea
catascopium and P. integra showed rates of
movement that were intermediate to those of G.
livescens and H. anceps. However, after 48
hours, approximately half of the snails had pass-
ed the one meter mark.
Three species of gastropods showed a disper-
sion in a definite direction. There was a concen-
82 THE NAUTILUS
April 27, 1984
Vol. 98(2)
tration of G. liiHvcen^; down the slope (lower left
quadrant) during each of the observation
periods. Lymnaea cata^copium and P. integra
showed movements in the opposite direction,
compared with G. livescens (up the slope, toward
shore). Consistently, between 24-48 hours, a
greater percentage of snails past one meter
from the release point had moved toward shore.
Because H. ancept< traveled slowly, it was im-
possible to determine significant movements in
any specific direction. After 48 hours, only 3%
had moved past one meter; most were in the up-
per portion of the grid.
The percentage of recovered living snails
after the last observation (48 hours) for Physa
integra and Helisoma nnceps were 72% and
76%, respectively in comparison to Lymnaea
catascopiion and Goniobasis livescem^ which
were 86% and 87%, respectively.
Discussion
The habitat requirements of various species of
operculate and pulmonate snails differ.
Therefore, differences in snail distribution, rate
of movement, direction of dispersion and
distances traveled over time should be expected.
Previous workers (Clampitt, 1973, 1974, 1975
and Wall, 1977) have suggested some factors
that may influence the above parameters. These
factors include substratum preference, gravity,
light intensity, availability of food and direction
of subsurface water currents.
Clampitt (1975) observed that Physa integra
dispersed rapidly while a planorbid, Helisoma
anceps, may move very little for weeks or even
for months at a time. Data from the present
study support his findings and indicate that a
much greater percent of P. integra moved fur-
ther than one meter after 10 hours, than did H.
anceps. However, an operculate snail, Gonio-
basis livescens moved the fastest; Lymnaea
ctitdHcopimn was intermediate in the rate of
movement between the physid and planorbid.
Using the data on subsurface currents in
Douglas Lake, plotted by Gannon and Brubaker
(1969), Clampitt (1974) studied dispersal
movements of P. integra in South Fishtail Bay.
He found that this species of physid had a
tendency to travel against the current. Data ob-
tained during the present study conducted in the
same area of Douglas Lake during the summer
of 1982 do not support his findings. Snails of the
same species moved from the deeper water
toward shore irrespective of the direction nf
water flow. Either P. integra vary their disper-
sal movements independently of current direc-
tion, or other variations in the subcurrent direc-
tion of flow in South Fishtail Bay have occurred
since Gannon and Brubaker i-eported their find-
ings.
Data from our study does confirm the findings
of Clampitt (1974) and Wall (1977) who found
that over a longer period of time, snails will
migrate from deeper water toward the shore
during the summer months. Wall (1977), work-
ing with Lymnaea catascopiion over a three-
year period, found this pulmonate to consistent-
ly move up the slope, toward shore.
Explanation for the rapid dispersal of G.
lirescens remain an enigma. Within a radius of
approximately 10 meters from the release point,
water temperatures did not vary significantly;
however, the type of substratum did. Although
speculative, the rapid dispersal of this oper-
culate gastropod may be a reflection of its ag-
gressiveness to find suitable food sources. Clam-
pitt (1973) analyzed the stomach contents of five
species of snails. He concluded that there was no
evidence that snails show a preference for cer-
tain foods. It must be noted, however, that G.
livescens was not one of the five species he
studied.
It is evident from this study that differences in
the rate and direction of snail movements do oc-
cur among various pulmonate and operculate
snails. Additional field and laboratory studies
are needed to delineate factors that specifically
influence these movements.
Acknowledgments
This study was supported in part by Mr. and
Mrs. Nathan J. Boss. Appreciation is extended
to Dr. David M. Gates for providing facilities at
the University of Michigan Biological Station
for this study.
LITERATURE CITED
clampitt, F. T. 1973. Substratum as a factor in tlie distrilpu-
tion of pulmonate snails in I)iiut;las Lake, Michigan. Mnln-
mlogiii 12(2):379-399.
1974. Sea.'^onal migratory cycle ami I'elateil
movements of the fresh-water pulmonate snail, Pluixa in-
hyni. Ameriam Midhuid Nutnnilint 92(2):275-30().
Vol. 98(2)
April 27, 1984
THE NAUTILUS 83
1975, Hdw fast is a snail's pace? Active and pas-
sive dispersal o{ Physa intcgtii in HdUfjIas Lake, Michigan.
Miilaculoyiral Reriew 8:121.
Gannon, J. E. and D. C. Brubaker. 1969. Sub-surface circu-
lation in south fishtail hay. nouglas Lake, CheboyK^w
(bounty, Michigan. Michiynn Academician 2(2): 19-35.
Wall, R. C. 1977. Seasonal movements of the pond snail,
Lymnaea catascopium in a northern lake. The Xaulilu^
91(2):47-51.
THE GENUS BRONDELIA BOURGUIGNAT, 1862, AND ITS
TAXONOMIC POSITION (GASTROPODA: SIPHONARIIDAE)
Harald A. Rehder
National Museum of Natural History
Smithsonian Institution
Washington, DC 20560
ABSTRACT
The genus Brondelia Bourguignat. 1862, was proposed for two species of
Ancylus from Algeria. One of them. A. drouetianus, had been described by
Bourguignat in 18.5It from a specimen in the Cuming Collection in the British
Museum., supposed to hare been collected in North America. This .•species is here
designated as the type-species q/' Brondelia. A study of the original description
and figure of A. drouetianus, the holotype of which is lost or missing, shows that it
is a member of the genus Williamia (Siphonariidae). An examination of the
original specimens on which Bourguignat based his Brondelia, shows that these
are Williamia gussoni (Costa). Brondelia Bourguignat, 1862 is therefore a
synonym, q/' Williamia Monterosato, 1884. Application is being m.ade to the ICZN
to conserve the generic name Williamia.
In connection with the preparation of an ap-
})lication to the International Commission of
Zoological Nomenclature to conserve the gen-
eric name Williamia. (Pulmonata: Siphonari-
idae), my attention has been called to the name
Brondelia Bourguignat, 1862, by a recent paper
by Bruce A. Marshall (1981), and by John B.
Burch, who discussed this generic name in a
paper given at the American Malacological
Union meetings in Seattle in August 1983.
In order to keep the application to the ICZN
as brief and succinct as possible, yet including
all pertinent facts, and because Dr. Marshall's
paper may not be readily available to readers in
this country, I have felt it advisable to present
this discussion of the systematic position of the
genus Brondelia.
At the outset 1 wish to acknowledge my
thanks to Dr. John B. Burch with whom I have
had numerous talks about this problem, and who
has given me access to his notes, correspond-
ence and borrowed specimens, and is allowing
me to publish this paper. Although Marshall in
his excellent paper on the genus Willianiia in
the Western Pacific (Marshall, 1981:487-488)
has called attention to the fact that Brondelia
may prove to be an earlier name for Williamia,
I take this opportunity to make his conclusions
more widely known and make some additional
observations.
In 1862 Bourguignat proposed the genus
Brondelia (Bourguignat, 1862:13) for two fresh-
water limpets from near what is now Annaba
(formerly Bone), B. drouetiana (Bourguignat,
1854) and B. gibbosa. new species. The first
species he had described previously (Bourguig-
nat, 1854:92) as Ancylus drouetianus from a
specimen in the Cuming Collection in the British
Museum, the Incality being given as North
America. In an earlier paper Bourguignat cited
the species in a catalogue of Ancylidae as com-
ing from "America" (Bourguignat, 1853:177).
Brondelia has been listed as a section and
subgenus oi An.cylw'i by Thiele (1931) and Zilch
84 THE NAUTILUS
April 27, l!t84
Vol. IKS (2)
(1959) respectively. In 1964 Hubendick con-
sidered Brondelia to be a synonym of A)i<'yliis
(Hubendick, 19fi4:21). In a later paper (Huben-
dick, 1970:27) i>resented the results of his ex-
amination of the original material that formed
the basis of Bouj^'ui.Li'nat's lcS(i2 papei'. On the
basis of this examination Hubendick considei'ed
Brondelia, on tlie ))rincipal basis of its distinctly
coiled protoconch, to lie a distinct genus of
unknown taxonomic position, but did comment
that the color pattern found in some shells of
this lot resembled that found in Willinmi<i.
Hubendick calls Bouryuignat specimens "type
material" but this appellation can apply only to
the specimens of B. gibbosd Bourguignat. .4//-
cylua dwuetianut^ Bourguignat, 1854, as has
been pointed out above, is based on a specimen
in the British Museum. In his paper Marshall
follows Hubenilick in calling the material
Hubendick examined "type material". He is cor-
rect, however, in my view, in assigning these
specimens to Willianiid gussDni (Costa, 1829),
although he does so with some reservations.
John B. Burch agrees with this determination
after personally examining these specimens.
Although the type of Ancylus drouetidims
Bourguignat, 1854, cannot be found, the rather
good description and figure of it (Bourguignat,
1854:92, pi. 25, fig.) confirm the fact that this
species is indeed a Willianiia and probal)ly W.
giitfsoni (Costa). The characters given are in my
estimation closer to that east Atlantic species
than to any American species.
Dr. Burch has visited the locality in Algeria
from whence Bourguignat claims his specimens
came, and after a careful search was unable to
find any specimens of the species.
A valid type species has apparently never
been designated for Bninil<l m. Thiele's citation
of/-)'. dfoiH'tiiittuH (Costa) can only be construed
as mention of an example (Thiele, 1931:484),
and Zilch's designation of i?. drductinmis as type
by monotypy (Zilch, 1959:128) is erroneous as
Bnitidclid was based on two species. I therefore
hereby designate Attri/his d rouet intuit
Bourguignat, 1854 (= BraHdclid draucl idnns
Bourguignat 18(i2) as the tyi)e species of
Bnindi'litt Bourguignat, 18(i2. Since A. dntm-
fiinius is ajunior synonym of Willnniiid (///.s-.s-n^/
(Costa, \S29).Br(>iidrli<i Bourguignat, 18H2, is a
senior synonym of Wlllidtiiid Monterosato,
1884. An application has been submitted to the
Intei'iiational Commission on Zoological
Nomenclature requesting that the generic name
Will id III id Monterosato be conserved.
LITERATURE CITED
[-)<iiir.uui'4iiat. .1. R. 1S53. Cataliijjiie iles e.S|)eces du mMirc
Ancylu.s. Jnur. ilr f\i)irh. 4:169-l<ti».
1854. Descriptions d'aiicyles iiduvfaux, tiv la col-
lection de M. Cumin;;, precedee d'une courte notice .'~ni' Ic
^enre Ancylus et d'une catalogue com|)let des especes i|ui
le coniposent. Pror. Zoal. Soc. LidiiIoii 21:7('>-!i;',.
1862. Notices monogTaphi(|Ues sur le.s genres
diiiiilliii'liiti. Piiriilii et Bri'iuhlia. R( i\ Mnii. Zimi. ser. '1.
U:V1--1?,.
Hubendick. (j. 19fi4. Studies on Ancvlidae: Tlie SuligiMUfis.
Mfihi G<>li'hnr(i!< Mils. Zool. Acilrl.. no. l:57:7:i pp.,
textfigs.
1970. Studies on Ancylidae: The Palearctic and
Oriental species and form groups. Aria Rnj. .Soc. .s'r, /, ///
Gotlihurt/cnsis. ZntiUiijirn 5:l-.52, textligs.
Marshall. B. A. 1981. The genus WillimiiKi in the westein
Pacific (Molliisca: SipJKinariidae), .W/r Zrnlmnl Jinir.
ZnnhHjii 8:4X7-492, text figs.
Thiele. .1. 19:^1. llinnllnirh ,lrr Sijslniinl isrhri, W, n-lit iir-
kiiinlr. I't. 2. (;usta\ Fischer. .leiia. |ip. :i77-77S. lextfigs.
Zilch, A. 1959. Eiilhiiiiriini. in Schindeunlf. H„,irll,ii,-I, <l,r
PiiliiiiziiiiUyii. viil. (1. C.astriipnd.a. pi 2, pp. ,S49- 1(;:'.9.
textfigs.
POSITIONS OPEN
Two Zoologist positions at entry level GS- 11/12
($25,366-$30,402) for a malacologist (preferably
in opisthobranchs, bivalves or pulmonates) and a
stony coral specialist. Open to all qualified can-
didates with a Ph.D. or equivalent for re-
search/curatorial functions with emphasis on
Recent collections-oriented systematic and
evolutionary biology. Requires demonstrated
working knowledge of classical contemporary
systematic techniques, hard- and soft-part
anatomy, modern evolutionary theory, and
museum/curatorial and field functions.
Submit by 30 April 1984 Standard Form 171,
resume and statement of long-term research
goals, list or reprints of publications,
transcripts, and names and addresses of
references to Smithsonian Institution, Office of
Personnel Administration, 900 Jefferson Dr..
S.W., Room 1410, Washington, D.C. 20560, At-
tention: MPA-84-200-F. Telephone in(]uiries
may be directed to Dr. Clyde F. E. Roper, (202)
357-2030. The Smithsonian Institution is an
equal opportunity employer.
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 85
NEW RECORDS AND SYNONYMIES OF BERMUDA OPISTHOBRANCHS
(GASTROPODA)'
Kerry B. Clark
Department of Bioloj^ical Sciences
Florida Institute of Technology
Melbourne, FL 32901
ABSTRACT
Twenty species of Bermudinn opisthobrnnchs ore listed and described,
representing significant range extensions, synonymies, or redescriptions of poor-
ly known species with Bermuda type localities. Some biogeographic relationships
are discussed. The Bermudian opisthohranch fauna is heavily dominated by a
Caribbean component. Species with long pelagic development are often found in
low densities, suggesting that thisfaunal component is recruited allochthoyiously.
Species with encapsulated metamorphosis appear to be better adapted to the
island habitat of Bermuda.
Much of the Bermudian opisthohranch fauna
was described in the late nineteenth and early
twentieth centuries, a period in which most tax-
onomic descriptions were unfortunately brief,
and frequently deficient in the diagnostic
characteristics presently used for the separation
of species. Appro.ximately 25 original descrip-
tions are from Bermudian coastal waters
(Heilprin, 1888; Simroth, 1895; Verrill, 1900,
1901; Smallwood, 1910; Russell, 1935). About 20
of these were described by Verrill. Verrill's
descriptions are generally the poorest, usually
omitting any reference to internal anatomy, as
well as lacking detailed descriptions of external
anatomy; his figures were often somewhat
stylized and were reproduced at a scale which
obscures much detail. These deficiencies are
compounded by the apparent loss of most of
Verrill's holotypes (Willan, 1978).
Bermuda lies reasonably close to the Antillean
Archipelago, and is within the influence of the
(uiif Stream, thus should share many species
with the Caribbean fauna. Without dependable
Bermudian descriptions for comparisons, it is
impossible to characterize the Bermuda fauna or
the Caribbean fauna accurately; older species
cannot he compared with new species, and there
may he synonyms among previously described
Bermudian and Caribbean species.
The purpo.se of this study is to redescrihe
'Contribution No. 984 ol' the Bfrmudii Bii)l(igical Station.
some Bermuda Opisthobranchia in order to
clarify the status of these species. Additionally,
some information on habitats and diets of Ber-
muda species is presented, with several new
records for these islands.
Material Examined
Most of the specimens studied were collected
in August 1979 from various sites in eastern
Bermuda. Samples were collected by several
techniques. Most were collected by vigorously
shaking algae, hydroids, etc. underwater, then
collecting the dislodged opisthobranchs with a
suction collector (Clark, 1971). Others were col-
lected by direct visual inspection of potential
substrates. Additional materials were examined
in the museum collection of the Bermuda
Biological Station (BBS), representing a variety
of habitats and seasons; however, the majority
of the material examined was collected in sum-
mer, and probably represents only a portion of
the complete Bermudian opisthobranch fauna.
Materials listed were collected by the author
unless otherwise noted.
List of Species
Subclass Opisthobranchia
Order Cephalaspidea
Runcinidae
1. Rnncina divae (Marcus & Marcus,
1963)
86 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
Order Anaspidea
Notarchidae
2. Stylocheilus longicauda (Quoy &
Gaimard. 1824)
Aplysiidae
3. Aplysia parruln Morch, 1863
Order Ascoglossa
Volvatellidae
4. Vohmtella bermudae Clark, 1982
Oxnoidae
5. Oxynoe antillarxm Morch, 1863
Elysiidae
6. Elysia subornata Verrill, 1901
7. Elysia papulosa Verrill, 1901
8. Elysia tuca Marcus & Marcus, 1967
9. Elysia fl.ava YerrxW. 1901
Boselliidae
10. Bosellia mimetica Trinchese, 1890
Caliphyllidae
11. Cyerce aiitilleyisis Eng\e, 1927
12. Cyerce cristallina {Trinchese. 1881)
Costasiellidae, new family
13. Costasiella ocellifem (Simroth, 1895)
14. Costasiella nonatoi Marcus & Marcus,
1960
Order Pleurobranchacea (Notaspidea)
Pleurobranchidae
15. Berthclla agassizri MacP^uiand, 1909
Order Nudibranchia
Suborder Doridacea
Chromodorididae
16. Chroynodoris bisteUata (Verrill, 1900)
Goniodorididae
17. Okenia zoobotryov (Smallwood, 1910)
Suborder Dendronotacea
Tritoniidae
18. Tritoniopsis J'ryd is Marcus & Marcus,
1970
Suborder Aeolidacea
Favorinidae
19. Farorinus auritulu,s Marcus &
Marcus, 1955
Facelinidae
20. Dondice occidentalis (Engel, 1925)
Descriptions
1. Rimcina divae (Marcus & Marcus, 1963)
New combination
(Fi^s. 1-.",)
FIGS. 1-.5. RiinritKi ilirne. 1. Right lateral view; 2. Dorsal view (e-eye; g-gill; s-shell). 3. (iizzanl [ilate.
4. Rachiilian tooth. 5. Lateral teeth. HGS. 6-9. Stylocheilus longicauda. 6. Kadular teeth
(r-rachidian; m-marginal; 1-lateral). 7. Living animal, from photo. 8. Aplysia pumilit. preserved
animal. 9. Oxynoe antillannn. partially rela.\ed.
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 87
Synonymy:
Ildica divae Marcus & Marcus, 1963 (Pp. 7-9, Figs. 1-7;
Piscadera Bay, Curasao).
Lapinura divae (Marcus & Marcus, I9ty.i) (Marcus &
Marcus. 1970, pp. 19-22, Figs. 20-26).
Localities: East side of Trunk Island, depth 1
m, on Codium (coll. by W. Sterrer); North side
of causeway. Castle Harbor, on Caulerpa
racemosa.
Description: Length, 1-2 mm; body smooth,
elongate elliptical, with lateral groove
separating body into ventral foot and undivided
dorsal mantle. Color reddish brown. Plicate gill
of several indistinct lobes located near midline
of hind end, partially covered by overlapping
end of posterior mantle. Shell, when present,
small, hyaline, located to left of gill and also par-
tially obscured by mantle (Figs. 1, 2). Eyes and
digestive gland faintly visible through mantle of
living animal (Fig. 2). Gizzard with about 10
ridges (Fig. 3); radula 21-23 x 1:1:1; laterals
variably hooked, rachidian tooth with about 18
very delicate denticles on weakly notched cen-
tral cusp (Figs. 4, 5).
Comments: The external shell was absent in
most specimens (about 75%) from Trunk Island,
and present in most from Castle Harbour; its
absence was confirmed by dissection and by
sodium hydroxide treatment of several animals
during radula removal. The median notch of the
rachidian tooth was somewhat less distinct than
described by Marcus and Marcus (1963).
Presence of an exposed larval shell in the
adult animal was used by Marcus & Marcus
(1970) to define the genus La pi num. However,
the variability of this character in Bermudan
populations of this species indicates that this
character cannot be used to establish a separate
genus. This characteristic may be ontogenetical-
ly variable, with loss of the shell occurring
sometime between juvenile and adult phases in
some animals. If one disregards presence of the
larval shell, then major characteristics of this
species (radula 1:1:1, 4 gizzard plates) clearly
place it in Runcina (see Kress, 1977).
Verrill's Runcina inconspicua (1901) differs in
the presence of orange or violet marginal hands
on notum and foot, and the gill was described as
composed of fine filaments, so inmnspirva must
be distinct from divae.
2. Styloche'dus longicauda.
(Quoy & Gaimard, 1824)
(Figs. 6, 7)
Synonymy:
Aplysia longicaudn. Quoy & Gaimard. 1824 (New Guinea).
Locality: eastern Bermuda; collection data for
the single animal in the Bermuda Biological Sta-
tion are missing. Tucker Abbott informs me (in
litt.) that he has collected this species intertidal-
ly on the southshore of Tucker's Town.
However, this species typically occurs in reef
rubble, associated with fine filamentous
rhodophytes.
Description: a color photograph of the
specimen shows typical coloration for this
species, a mottled greyish body with orange-
ringed iridescent blue eyespots scattered over
the dorsal mantle.
3. Aplysia parvula Morch, 1863
(Fig. 8)
Locality not given; collected 10 June 1979, W.
Sterrer.
Description: This species is easily recognized
as a small Aplysia with a narrow foot, and black
parapodial margin, rhinophore tips, and foot
borders; body light brown with small lighter
mottlings. The preserved specimen is 17 mm
long, with the relatively large shell plate (V2 of
body length) lightly calcified and chalky.
4. Volvatella hermudae Clark, 1982
Locality: On Caulerpa racemosa. on vertical
rock faces, 1-3 m.
Description: Strong, channeled shell with
apical "spout"; mantle green, foot white. This
species was believed to be endemic to Bermuda
when described (Clark, 1982a), but also occurs
on mangrove roots in Belize (oum obs.) on
Caulerpa racemosa. Mangrove seems to be the
prime habitat in Belize, with Rhizophora roots
providing a habitat similar to vertical rock walls
in Bermuda. The Bermuda animals are [)robably
a population on the northern fringe of its range.
5. Oxynoe antillarum Morch, 1863
(Fig. 9)
Liicalities: common at Tobacco Bay,
Whalebone Bay, and occasional specimens at
Castle Harbour Causeway; on Caulerpa
racemosa to depths of 3 m, in areas of good cir-
THE NAUTILUS
April 27, 1984
Vol. 98 (2)
dilation, usually occurrin.L;' with VolriitdUi bcr-
mudae (Clark, i982a).
Di'^rripfiim: Body green, to 3 cm, with glossy,
intlated shell covering middle body; shell partial-
ly covered by adherent parapodia; greyish spots
on elongate, greenish tail, with scattered
papillae on parapodia, tail and body. This
species is easily confused with 0. itzuropunctdtn
K. R. Jensen, but Bermuda specimens have
planktotrophic larvae, so are 0. iintillaruni.
6. Eli/siti suhornotd Verrill, 1901
(Fins. 10-14)
Synonymy:
Elysia subornata Verrill. 1901 (Pp. 29-30, PI. 4. P'Ik. 4;
Castle Harbour. Bermuda).
Elysia cauze Marcus & Marcus, 19.57 (Pp. 405-410. Fijis.
35-44; Sao Sebastian Islam). Brazil).
Localities: very abundant at SW end of
causeway. Castle Harbour; common at Tobacco
Bay, Whalebone Bay, Bailey's Bay; on Caulerpa
rncemosa, to 2 m.
Desmption: Specimens within single popula-
tions were often highly variable in coloration,
ranging from yellow green to dusky olive to red-
dish, usually with brownish to black parapodial
margins (pale or absent in some specimens).
Parapodial margin thickened, whitish. Para-
podia usually minutely papillose, sometimes
smooth; heavily ruffled in larger specimens.
Parapodia often bear white spots, with or
without black rings. Rhinophores usually band-
ed with irregular transverse grey or white band,
with distal transverse brownish band. Small
juveniles show the distinctive black "facial
mask" described for Florida specimens (Clark et
III.. 1979). Renopericardium long (ca. Vz total
body length), extending most of distance to tip
to tail, with about 10 vessels extending perpen-
dicularly from each side to the liase of the
thickened parapodial margin, branching more
or less dichotomously, sometimes anastomosing
(Fig. 14). Radular tooth minutely denticulate
(Fig. 9). Body length to ')() mm; one of the
largest Atlantic ascoglossans.
Comments: the range of variation of the
specimens collected here includes all character-
istics of Verrill's (1901) brief description and
figure (except that the marginal line of the
parapodia is rarely orange-brown) and does not
significantly differ from characteristics of E.
ciiuze. The marginal black band is a character
found in several described and undescribed
FIGS. 10-14. Eli/xiii xiih(ini<it(i. 10. Tooth. 11, 12. .luvetiiles. 1.3. Adult, at rest. 14. Adult, fiarapodia
extended to show pericardial comple.x.
Vol. 98 (2)
April
1984
THE NAUTILUS 89
Caribbean and Florida Elysiu. but as Marcus
(1980) notes, the long renopericardium and the
dorsal vessel pattern "are an exceptional feature
of the species." Although Bermuda animals are
more variable in color than Florida populations,
there seems no valid reason to regard them as a
distinct species.
The unusual reddish color of specimens from
Castle Harbour causeway was associated with
relatively eutrophic water and a consequent
growth of reddish epiphytic Cyanophyta on the
Caulerpa.
7. Elysia papillosa Verrill, 1901
(Fifcs. 15-20)
Synonymy:
Elynin p((/i(7?.o.s(! Verrill, 1901 (p. 31, PI. 4, Fig. 3; Hungry
Bay, Bermuda).
Localities: widely distributed: Castle Harbour;
Bailey's Bay; Ferry Reach; Hungry Bay;
Tucker's Town Bay; Harrington Sound; feeding
upon Halimeda spp., Penicillus. and Udotea
Jhibelhrrn. to 4 m depth.
Description: Body pale green with thick white
parapodial margins, white head and parapodia,
brown transverse bands on parapodia,
numerous white papillae on both surfaces of
parapodia, head, and rhinophores; pericardium
brownish; iridescent white blotches are scat-
tered on the upper surface of the parapodia, in-
creasing in size toward the tail. A line of scat-
tered brown granules occurs on the white
parapodial margin, forming a distinct black line
in larger animals (> 1 cm). Foot lighter green
than parapodia. A prominent sperm-filled vesi-
cle lies at about the middle of each side of the up-
per parapodium surface. Pericardial hump
short, with one to three pairs (dependent on
size) of vessels radiating laterally, one pair
posterolaterally (Fig. 19). In some specimens,
especially larger ones, the posterolateral vessels
originate as a single posteriorly directed vessel
which divides part way between the pericardium
and the tail (Fig. 19). Specimens from southern
Castle Harbour, from Udotea, were olive green
and lacked papillae but in other respects were
typical papulosa.
Comments: Non-Bermudan records of E.
papillosa are tied to a descrijition of Florida
animals (Marcus & Marcus, 19(i7). which noted
that Verrill's description lacked critical
characteristics. The present observation
validates the Marcus' conclusion that non-
Bermudan records represent the same species.
E. patina Marcus, 1980 is similar ioE. papillosa
in the presence of "gametolytic vesicles" and
dentition; a more thorough description of patina
FIGS. 15-20. Elyxia papillosa. 15, 16. Dnrsal views of two animal.s, illustrating variability. 17, IS.
Ventral views. 19. Pericardial complex, 20. Teeth.
90 THE NAUTILUS
April 27, 1984
Vol. 98(2)
from living animals would aid separation of the
two species. Dissection of "gametolytic vesicles"
in several living animals of E. papillosa anil
Florida specimens of A', patina showed that they
were filled with highly motile sperm; these
structures appear to function as storage vesicles
for viable sperm, and the term "gametolytic"
should be replaced by "gametic" until function is
defined.
8. Ely,'<ia fitra Marcus & Marcus, 1967
(Fig. 21)
Synonymy:
Elysia crispa (Morch. 1863) Verrill. 1901.
Localities: common in Ferry Reach; Harr-
ington Sound; on Udotea. Halimeda. and
Penicillus: to 3 m, especially in areas of quiet
water.
Description: Body dark green, with irregular
iridescent white patches on parapodial margin
and on head between rhinophores; parapodia
smooth, held tightly rolled against midline of
body, with distinct mid-length notch forming a
ventilatory "chimney". Length to 15 mm.
Comments: This species is easily separable
from all other Caribbean species by the
parapodial notch, coloration, diet, and posture.
Verrill's description noted the distinctive white
patch between the rhinophores, but erroneously
identified the species as Tridachia crispata.
This has led to some confusion that Tridachia
o-ispata occurs in Bermuda; it apparently does
not. This also explains why E. tuca. which is ubi-
quitous throughout the Caril)bean, has n<.>t been
previously reported from Bermuda.
9. Elysia flava Verrill, 1901
(Figs. 22-24)
Syyionymy:
Elusiajtava Verrill. 1901 (P. ;30. PI. 4. Fig. 1)
Locality: A single specimen, collected by W.
Sterrer, Hungry Bay, June 1979, depth 0.1 m.
Description: Body yellow, with irregular dark
green longitudinal band extending along
FIG. 21. Elftaid turn. FIGS. 22-24. Eiysui Jlav<i. 22. Dorsal view, from photo "f Nmiik animal. 23.
Venation of pericardial comple.x. 24. Tooth. FIG. 2r>. Bosetlia mimetica.
Vol. 98 (2)
April 27. 1984
THE NAUTILUS 91
parapodium on each side (color represents
digestive diverticula); parapodial margin white.
Pericardium short, with single posterolateral
vessel on each side, which branches near
pericardium (Fig. 0), forming a long posterad
vessel with a dense cluster of anastomosing
vessels. Teeth small (56-80 /.im) and relatively
uniform in length, with narrow cutting tip,
edenticulate; 31 radular teeth in the single
specimen.
Comments: Thompson's (1977) Jamaican
record of E. jlavn is the first non-Bermudan
record and correctly redescribes this species.
The tooth of E. Jlava is similar to that of E.
papilloma, suggesting that this species may feed
on Udotea, but its diet is so far unknown. At the
time of my visit to Hungry Bay, there were no
visible Siphonales suitable as food for this
species. It is possible that the yellow color of the
parapodia is due to starvation. This species is
quite similar to E. papilloma and E. patina Mar-
cus, and further studies are needed to adequate-
ly define differences between these species.
10. Boadlia mimetica Trinchese, 1890
(Fig. 2.5)
Locality: One specimen, SW end of Ferry
Reach; on Halimeda, d. 2 m.
Description: Body flat, plastic in outline, but
elliptical when at rest, closely conforming with
and adhering to scales of Halimeda: color deep
green with white irregular patches, concen-
trated at margins. Pericardium ovoid, with
about 5 dendritic posterolateral vessels. Tooth
robust, strongly hooked, with strong denticles.
L. 15 mm.
Comments: As Marcus (1982) notes, the genus
Bosellia should be placed in its own family by
virtue of its chromosome number. Also, the
adherent flattened "parapodia" of Bosellia are
distinctly different in morphology and function
from those of Elysia. since they are not rolled
but are used to adhere to the substrate. Actual-
ly, the "parapodia" of boselliids are not true
parapodia, but represent a very broad foot; in
elysiids, the parapodia are lateral extensions of
the dorsolateral body wall and extend well
beyond the foot, which is narrow and well-
defined. In Bosellia the margin of the foot is
directly joined to the dorsal body surface. Also,
the radular teeth oi Bosellia are quite different
from those of elysiids which eat Halimeda. B.
mimetica has a broad distribution, including
Europe and the Mediterranean as well as
throughout the Caribbean. In Florida, this
species is most abundant in areas with heavy
wave action (Jensen & Clark, 1988), and the
broad foot may be adaptive to this high-energy
habitat.
11. Cyerce antillensis Engel, 1927
(Figs. 26-29)
Locality: Ferry reach, uncommon on Peyii-
rillus dumetosus, to 1 m.
Description: Body whitish to yellowish, occa-
sionally deep green, with flat, colorless,
transparent cerata. Body flattened, with broad
foot. Cerata easily detached, adhesive, lacking
digestive diverticula. Rhinophores deeply bifid,
rolled.
12. Cyerce cristallina (Trinchese, 1881)
(Figs. 30-31)
Synonymy:
Lobiaricoia cristallitKi Trinchese, 1881 (F. llti, F"igs. 1-12;
Naples, Italy).
Locality: Hungry Bay, a single specimen coll.
by W. Sterrer, 1 m. depth.
Description: Body translucent, whitish, with
conspicuous white patches on head, rhino-
phores, and transparent cerata, and bright red
patches overlying the white. Radular teeth very
long (300 ^m) and constant in length; about 15
denticles per side. Length 7.5 nmi.
Comments: The bright coloration of this
species easily separates it from C. antillensis. C
cristallina is far less common than C. antillen-
sis, and its diet and development are unknown.
Costasiellidae, New Family
As Clark (1982b) noted, the genus Costasiella
is transitional in characteristics between
Stiligeridae and Caliphyllidae, but differs in
most characteristics from the other transitional
hermaeid genera Hermaen and Aplysiopsis.
Diagnosis: ceratiform Ascoglossa with large
admedian eyes, fusiform non-flattened cerata,
unifid auriculate or digitiform rhinophores
broadly joined to the snout via the anterior
edge; digestive diverticula usually knobby, in
grapelike clusters within cerata; genital aper-
tures polyaulic (rather than diaulic as in Her-
maea or Aplysiopsis). Foot rather narrowly
92 THE NAUTILUS
Af)ril 27, 1984
Vol. 98 (2)
FIGS. 26-29. Cyerce anfillensia. 26. Dorsal view, from phuto. 27. F'eriranlial cumiik'X- 28. Ventral
view (p-penis). 29. Tooth. FIGS. 30-31. Cifen-e cru^tnllnKi. 30. tooth. 31. Ventral view. FIG. :«.
Cofitcuiiella ocellifera. Dorsal view, from photograph. FIGS. 33-36. Co^ta^'nlUi iKiinitnK 33. Dorsal
view. 34. Head. 35. Ventral view. 36. Teeth.
triangular; radular teeth non-denticulate;
esophageal diverticulum absent; visceral loop
with three ganglia. Diet, ArruinrUh-n for
species with known diet; distribution tropical.
13. Costasiella ocellifera Simroth, 1895
new combination
(Fig. 32)
Synonyms:
Doto ocellifera Simroth, 189.5 (Pp. 168-17U. PI. 20, Figs.
6-10: St. George's Harbour, Bermuda)
Stiliger lilinnae Marcus & Marcus, 1969 (Pj). 7-12, Figs.
22-28; Sao Paulo, Brazil)
Costasiella lilianae (Marcus & Marcus), Baba, 1970
Costasiella liliarute (Marcus & Marcus), Thompson, 1977
Localities: Ferry Reach; Bailey's Bay; com-
mon on Avrainvillea to 2 m.
Description: Color whitish, but appearing
deep green, due to dense chloroplasts in
digestive diverticula; cerata and body covered
with scattered large black round chromato-
phores; faint orange rings surround cerata near
distal tip; bluish-green iridescent spots and
small whitish glands scattered on cerata; a
green iridescent spot, surrounded by a yellow
ring, is located between the large eyes and the
pericardium. Rhinophores long, cylindrical,
tapering, with auriculate base; cerata pyriform
(fusiform in relaxed animals), arranged in five to
six diagonal rows on each side, four cerata per
row; cerata separated from the foot by a shallow
furrow. Posterior foot divided by transverse
groove and containing digestive diverticula, ap-
pearing much like a ceras, Radular teeth
uniform in size, about nine teeth in the ascen-
ding arc and 10-12 in the descending; ascus ab-
sent.
Comments: Ferry Reach, from which the pre-
sent material was collected, is an extension of
Simroth's type locality, St. George's Harbor. His
figures, apparently of preserved material, clear-
ly show the grape-like digestive diverticula,
large admedian eyes, and conspicuous
melanophores of the species later described as
Stiliger lilianae. Simroth's Fig. 8 also shows the
distinctive eye structure (heavily pimented cup
enclosing a hyaline lens) as shown by Marcus &
Marcus (1969, Fig. 27) for St. lilianae. Simroth's
figure of the radula (his Fig. 10) appears slightly
different than teeth of Costasiella, as if he failed
to include the laminar edge of the tooth. This
Vol. 98(2)
A()ril 27, 1984
THE NAUTILUS 93
may be the result of uncritical observation, but
the teeth as figured are definitely ascoglossan,
and show the uniform size of C. lilianae.
Simroth also failed to note any transverse
demarcation of the posterior foot, but the re-
maining similarities are so striking that C.
liliatuw is undoubtedly a junior synonym.
Colors of the "eyespot" anterior to the pericar-
dium vary: Florida specimens have a blue spot
with orange ring (personal, observation) and
Jamaican specimens a yellow ring and blue spot
(Thompson, 1977).
14. Costasiella nonatoi Marcus, 1960
(Figs. 33-36)
Synonymy:
Cosfasiplk nonatm Marcus & Marcus, 19(i() (P[). 149-152.
Figs. 26-33; Ubatuba, Middle Brazil).
Placidri nonatoi (Marcus & Marcus, 1960) Marcus & Mar-
cus, 1963.
Locdiity: Uncommon on Ai'rainvillea nigri-
cans in Ferry Reach, occurring together with
Costasiella ocellifera to 2 m.
Description: Body whitish, with much melanic
pigmentation. Cerata black, except tips, with
greenish knobby diverticula visible in some
specimens; scattered white areas toward tips of
cerata. A distinctive whitish mask surrounds the
large black eyes. Rhinophores short, with white
tips, fused to each other anteriorly and to the
snout at their anterior base; snout of head form-
ing two broadly rounded lobes. Cerata clavate,
arranged in 3-4 densely packed rows on each
side. Foot not transversely divided; tail long and
narrow. Length, to 5 mm.
Comrneyita: Individuals burrow into the felty
thallus oi AvrainviUea to feed and deposit egg
masses, and are difficult to collect because this
prevents easily dislodging animals. The small
size of the adults and melanic coloration also
makes them difficult to observe while in the
alga. This habit differs from that of C. ocellifera,
which crawls directly on the surface of the alga,
and may represent a fine partitioning of an
otherwise highly similar niche. The melanic col-
oration and location within the alga makes
retention of syml)iotic chloroplasts in this
species unlikely, though C. ocellifera is one of
the best examples of this fihenomenon (Clark r/
al, 1981).
15. Be rt hella agassizii (MacF&rVdnd, 1909)
(Figs. 37-42)
Synonymy:
PleurobronrliuK nijaxxizit MacFarland, 1909 (Pp. .")9-64,
PI. 11-12, Figs. 43-.57; Riacho Doce, Alagoas, Brazil).
Bouvieriii (tyattsizi (MacFarland. 1909) Odhner. 1926
Locality: Hungry Bay (coll. by S. Gardiner);
(iravelly Bay; under rocks, depth 1 m.
Description: Color white, pink, or orange;
shell internal, flat, nearly rectangular, slightly
longer than half of mantle length, transparent
in living animal, with strong growth lines and
tlat spire. Notum smooth to "orange peel" tex-
ture, overlapping foot; gill rachis non-
tuberculate, with 12-14 plumules on each side of
axis; anus above third or fourth gill leaflet.
Radular teeth thornlike (Fig. 41); Jaw scales
with 7-11 strong denticles.
Comments: This species closely matches the
description of Pleurohranchopsis ourantiaca
Verrill, 1900, except that Verrilfs description
explicitly noted the absence of a shell. As noted
here, the shell is highly transparent and easily
overlooked in live animals, and this might ex-
plain Verrill's establishment of the shell-less
FICiS. 37-42. BerlkeUn agasftizii . 37. Dcrsal view, preserved
animal. 38. Ventral view. 39. Right lateral view. 40. Shell.
41. Teeth. 42. Jaw scales.
94 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
genus Plenrobrnyjchopsis. Willan (1978) reviews
the history of Pleurobranchopsis and Gym-
notoplax, which appear to be based on inac-
curate description and damaged specimens.
However, Verriil's description of P. tiunnitidca
lacks sufficient diagnostic characteristics to
allow synonymy with B. agassizi in the absence
of the holotype; thus, P. aur-antiaca and P. nivea
must remain nomina dubia. Berthella tupala
Marcus, 1957, differs from B. agassizi by
melanic pigmentation of the shell and dif-
ferences in jaw scales.
16. Chrnmofloris bistellatn (Verrill, 1900)
(Fig. 43)
Synonymy:
Doris bistelkitd Verrill. 1900 (P. 548, PL (i6. Fig. 2; Castle
Harbour).
Locality: Coney Island, summer 1976.
Description: Gills 5, simply pinnate (Verrill
notes 7) with alternating leaflets; mantle skirt
high, as in Hypsclodoris: Radular teeth hamate,
non-denticulate, tapering in size from adlaterals
(48 ^xm) to admedian (36 Mm). 30 x 36.0.36.
Notum deep brown, with two white stellate
spots and scattered tiecks of white. The denti-
tion of this species clearly places it in
Chromodoris. The preserved animal is 5 mm
length; Verriil's original specimens were 15-20
mm.
17. Okenia zoobotriioH (Smallwood, 1910)
new combination
(Figs. 44-17)
Synonymy:
Polyrerella zooholryon Smallwodd. lillO (PP. 14:M4.5.
Fig. 10; Agar's Island (?), Bermuda)
Berviudella zoo6ofrj/on (Smallvvodd, I'.MO) (Odhner. HMD
Okenia erelinae Marcus, 19.')7
Citrgofi ereliiiae CMnrcus. UtfiT) (\'<igel & Schultz. 1970)
Locality: Hall's Island, Harrington Sound, on
the bryozoan Zoobotryon pellucida. under rock
ledges 1-5 m.
Description: Radula 1.1.0.1.1 x 18; lateral
50 m wide, with about 11-12 denticles; marginal
20 Mill wide, with distinct notch on distal edge.
Body white with brown spots scattered on
spiculate notum; foot narrow, with slight foot
FIG. 43. Oiromridoris hitstellnta. teeth. FIGS. 44-47. Okfiiui zonhotnioit. 44. Lateral view. 45.
Rhinophore. 46. Papilla. 46. Teeth. FIG. 48. Tritntiin friiihx. 48. Dorsal view. 49. Teeth. FIG. .50.
Fnvori.nuK auritulus. from photo of live animal. FIGS. r)l-.")2. Donilice ocridfiilnlis. teeth. o\. Ver-
tical view. 52. Lateral view.
Vol. 98 (2)
April 27, 1984
THE NAUTILUS 95
corners. Pallial ridge bears several short
papillae; pericardial hump guarded by two
papillae on each side; up to 7 simply pinnate
gills. Rhinophores white, with 5-7 cup-shaped
lamellae (irregular in relaxed animal), blunt
anterior-pointing basal spur. Notal papillae
studded with small tubercles, possibly toxic. L.
to 6 mm.
Comments: This small dorid is highly con-
spicuous on the transparent masses of
Zoobotryon, collected from the type locality of
Polycerella zoobotryon in Harrington Sound
(Smallwood, 1910). The present material agrees
in all respects with Smallwood's type descrip-
tion, but he later described the radula in a secon-
dary description (Smallwood, 1912) with three
lateral teeth. In other respects, the similarity is
so strong that this secondary description must
be regarded as erroneous or possibly variable.
In my material, the laterals stained very poorly
with acid fuchsin and most scattered during
preparation, so this discrepancy may be
understandable, and may explain why this
species has not been properly placed before.
Oketiin evelituie differs only in color of the
rhinophores (purple) and size and number of
rows of radular teeth, which may be due to
variations in diet and size. Specimens from
Sebastian Inlet, FL also feed on Z. pellucidum
and have the same coloring as Bermuda
specimens. Vogel and Schulz (1970) differen-
tiated 0. cupel I a fi'om 0. evelinae solely on the
basis of the number of cupped rhinophoral
lamellae. As their specimens were quite small (2
mm), this may be an unreliable character and
this species is probably synonymous.
18. TritomopHisfrydis Marcus & Marcus, 1970
' (FiRS. 48-49)
Locality: West of Nonsuch Island, Castle Har-
bour, on base of Gorgonid, 8 m. This area con-
tains scattered corals and has a heavy algal
growth. Three specimens, to 0 mm.
Description: Body white to orange; dorsal
papillae 8-12 per side, dendritic, brownish,
resemliling gorgonian polyps. Rhinophoral
sheaths and clubs similarly dendritic. Oral veil
with 2 large and about 8 short digitiform ten-
tacles. Anus midlateral. L to 20 mm.
19. Favor inus aurittilus
Marcus & Marcus, 1955
(Fig. 50)
Locality: Ferry Reach, on Penicillus and
Caulerpa, where it feeds on the eggs of other
opisthobranchs; depth, to 2 m.
Description: The knobbed rhinophores, short,
recurved foot corners, and oral tentacles of the
same length as the rhinophores characterize this
small (5-12 mm) aeolid. Cerata in 3-4 small
groups. Color dull white or beige. Radula
uniseriate, unicuspid, non-denticulate. This
species is easily cultured and can become a
"pest" contaminant of cultures of other slugs.
20. Dondice occidentalis (Engel, 1925)
(Figs. 51-52)
Synonymy:
Caloria occidentalis Engel, 1925 (Pp. 41-44, Figs. 7-15;
Montego Bay, Jamaica.)
Locality: Pt. Shares, Great Sound, July 1979.
Description: This species is easily recognized
by the black jaw epithelium, visible through the
head in living or preserved animals. Radula
uniseriate; tooth with 8 denticles, the first pair
smaller and closely adherent to the central cusp;
jaw denticles were not visible in the single
preserved specimen. Oral tentacles very long,
foot corners short. Cerata in six groups. Color
whitish; iridescent white patches on head, nape,
and sides visible in preserved animal. Length of
preserved animal 9.5 mm.
Comments: This species agrees in some
physical characteristics with Facelina (?) gosl-
ingii Verrill, 1901, but that species has radular
teeth with 10-12 denticles of decreasing size,
black jaws are not mentioned, and there are dif-
ferences in coloration. The differences in denti-
tion alone are enough to separate the two
species.
Di.scussion
Prior to this study, Beniiudian opistho-
branchs appeared to have a large proportion of
endemic species. However, when synonymies
are considered, this proportion falls, and the
predominantly Caribbean characteristics of this
group are evident. The largest endemic compo-
nent is seen among the dorid Nudibranchia, in
which .several of Verrill's species {Doris
oliracea. Lanicllidoris lacfea. Lamellidoris
quadrlmaculata, Chromodoris roseopicta, La-
;t(i
TIIK NAUTILUS
April 127, i;(84
\'<
981
vicllidonx (ui ridpirticfii, Lanull nlans miniatu)
are dissimilar lVi)m known Caribbean species,
The nudibranchs are fairly well-known from
other Caribbean studies (see Mareus, 1980, for a
summary), and it appears that most of these
species are true Bermudian endemics.
Resolution of the status of these species must
unfortunately depend on re-collection, as
generic placement by current standards is quite
dubious. Most of the remaining endemic species
of questionable status were collected in spring,
lience their absence in the present study is not
evidence of non-occurrence. However, increas-
ing human activity in Bermuda, with consequent
alteration of habitat, creates a distinct possibili-
ty that these species may have disappeared, or
will disappear, from Bermuda waters. In such
case, the identity of these species may never be
resolved, and efforts should be made to collect
and redescribe these species at the earliest op-
portunity.
The densest populations of Bermudain
opisthobranchs seem to be those species with
brevipelagic development (e.g. Elysia suhor-
udtii. Elyaid turn, Elyvia papillu^a. Costasielld
oreUifera, Bulla striata. Haminoca antillaruni).
Species with extended pelagic development are,
in contrast, sparse in population though well-
represented in number of species (e.g. Elysin or-
nata. BoselUn mimeticn. Oxynoe antillarinti.
Tritonut frydis). particularly when compared
with mainland Florida populations with similar
food resources. This suggests that species with
pelagic development recruit primarily via
allochthtinously produced larvae originiating on
Bahaman or other Caribbean shores, and that
such Bermudian species are effectively sterile
populations. If this is true, one might predict
that 1) lirevipelagic development will dominate
among Bermudian endemics, and 2) Bermudian
species with l.irevipelagic development will be
genetically more distant from Caribbean con-
specifics than species with longipelagic develop-
ment.
Some interesting taxonomic questions re-
main. Smallwood's Fucelina agari. with tuber-
culate rhinophores, probably belongs mBergkia.
but the description, from a single animal, gives
very few useful characteristics. The primitive
sketch of the animal (Smallwood, 1910) is of lit-
tle use in identification. Several others of Ver-
rill's species (CorypliclUt pallida, KunruKt in-
conspicua. Facelina goslingii) require further
evaluation, as they cannot reliably be placed
even to genus without reexamination.
Additional, previously recorded species of
Bermufla Opisthobranchia are summarized and
illustrated in Jensen and Clark (in press).
Acknowledgments
This research was supported by a Samuel
Riker Fellowship of the Bermuda Biological Sta-
tion. Dr. Wolfgang Sterrer was especially
helpful as a collection partner and did much to
acquaint me with collection sites in Bermuda.
LITERATURE CITED
Clark, K. B. Ut71. Cdnstructimi (if a i-ollectiiig: device for
small aciuatif organisms and a metlmd for rapid weighing
of small invertebrates. Veliger 13:3ti4-3(i7.
1982a. A new VolmtrUn (Mollusea: Ascoglossa)
from Bermuda, with comments on the genus. BnU. Mar.
Sci. 32:112-120.
1982. A new .4/)///.'--/(i/)x/s (Opistholii'anciiia: Hei'-
maeidae) from central Florida, with a brief summary of the
ceratiform families of the order Ascoglossa ( = Sacoglossa).
Bull. Mar. Sci. 32:213-219.
Clark, K. B.. M. Busacca and H. Stirts. 1979. Nutritional
aspects of development of the ascoglossan Ehisia nui-c.
]i|i. 11-14 in: S.E. Stancyk (editor): Rcprfuliiiijiv fcn/o//// nf
marine inrertehrates. University of South Carolina Press.
Clark. K. B.. K. R. Jensen, H. M. Stirts and C. D. Fermin.
1981. Chloroplast symbiosis in a non-elysiid mollusc.
Ca.-<ta.^iella lilianae (Marcus) (Hermaeidae: Ascoglossa
( = Sacoglossa)): effects of temperature, light intensity, and
starvation on carbon fixation rate. Biol. Bull. ltJ0:43-.54.
Engel, H. 1925. Westindische Opisthobranchiate Mollusken
I. Bijdr. Dierk. 24:33-80.
Heilprin, A. 1888. Contributions to the natural history of the
Bermuda Islands. Pror. Acad. Nat. Sci. Philiidclpliia:
302-328.
.lensen, K. R. and K. B. Clark, 1983. Ann(jtated checklist of
Florida ascoglossan Opisthobranchia. The Naiitihit:
97:1-13.
Jensen, R. and K. B. Clark, (in press), (lastmpoda. ///
Marine flora and fauna of Bermuda (VV. Sterrer. ed).
Wiley, N.Y.
Kress, A. 1977. Riincina ferruginea n. sp. (Cephalaspidea;
Opisthobranchia: Gastropoda), a new runcinid from Cireat
Britain. J. Mar. biol. Assoc. U. K. 57:201-211.
MacFarland, F. M. 1909. The opisthobranchiate Moll ii.-<ca of
tlie Branner-Agas.':iz expedition to Brazil. Stanfonl I'niv.,
California. 104 pp.. 19 pi.
Marcus, Ev. 1980. Review of western Atlantic P^lysiidae
(Opisthobranchia: Ascoglosssa) with a description of a new
Elysia species. Bull. Mar. Sci. 30:.54-79.
Vol. 98 (2)
April 127, 1984
THE NAL'TILrS
!)/
1982. Systcmatics of Iht' gt'iiera of the unler
Ascoglossa (Gastropoda). ./. moll. Stud.. Svppl. 10:l-:-!l.
Marcus. E. and Ev. Marcu.s. 1957. On Opisthobranchia from
Brazil (2). J. Linn. S»c. London. Zool. 43:39()-4SG.
Marcus, Ev. and E. Marcus. Opistliohranclis from American
.'\tlantic warm waters. Bull. .Mm: Sri. 10:129-203.
Marcus, E. and Ev. Marcus. 19R3. Opisthobranchs from the
Lesser .\ntilles. Sliid. Fainui Curiii;<ui .3.3:1-129.
1967. Tropical American Opisthobranchs.
Studies in Tropical Oceanography 6:1-2.56.
1969. Euthyneure Meeresschnecken Brasiliens
(2). Beitriigc zur Neotropischeri Fauna 6:1-1.5.
1970. Opisthobranchs from Curasao and fauiiis-
tically related regions. Stud. Fauna Curapio 33:1-29.
Odhner, N. H. 1941. New polycerid nudibranchiate Mollusca
and remarks on this family. Mcddcl. ddtchnrg.s. Mu.s. Zool.
Ai'd. 91:1-20.
Quoy, J. R. C. and .1. P. Oaimard. 1832. Description des
Mollusques. pp. 410-516 in Freycinet, L. Voyage autour
du m.onde execute xur les corvettes de S. M. I'Uranie el la
Physicicnne pendant les annees 1R17-1820. Paris.
Russell, H. D. 1935. Some nudibranchs of Bermuda with a
description of a new species. The Nautilus 49:59-61.
Sinu'oth, 11. 1895. Opisthobranchia t;ymnol)ranchia. in Die
Gastropoden der Plankton Expedition 2. V. d. 1-20G.
Smallwood, W. M. 1910. Notes on the hydroids and nudi-
branchs of Bermuda. Proc. Zool. Soc. London: 137-145.
1912. Pol/icrrella zoohotryou. Proc. Amer. Acad.
Arts Sci. 47:609-629.
Thompson, T. E. 1977. .Jamaican opisthobranch molluscs I.
.J. Molluscan Stud. 43:98-140.
Trinchese, S. 1881. Breve descrizione del nuovo genere
Lobiancoia. R. Accad. Sci. Fis. Mat. Napoli 20:116.
Verrill, A. E. 1900. Nudibranchs and neked tectibranchs of
the Bermudas. Trans. Conn. Acad. Arts. Sci. 10:545-561.
1901. Additions to the fauna of the Bermudas
from the Yale e.xpedition of 1901 with notes on other
species. Trnn.s. Conn. AcaiL Arts. Sci. 11:15-62.
\'ogel, R. M. and L. P. Schultz. 1970. Cargoa cupella. new-
genus and new species of nudibranch from Chesapeake
Bay and the generic status of Okenia Menke, Idalia
Leuckart and Idalia Orsted. Veliger 12:388-393.
Willan, R. ('. 1978. An evaluation of the notaspidean genera
Pleurobranchopsis Verrill and Gymnotoplax Pilsbry (Op-
isthobranchia: Pleurobranchinae). J. Conchology
29:3.37-344.
.Reprints of out-of-print volumes of.
nnuTiLus
Vols. 1-40 and Gen. Ind. 1-34. Philadelphia, Pa.,
1886-1926/27.
clothbound $842.00
paperbound $716.00
Kraus Reprint
Millwood, New York 10546
AVAILABLE FROM THE ORIGINAL PUBLISHER
Vols. 73 to date (vol. 94 m 1980) per vol. paper S 12.00
A 25% discount will be honored if 10 or more vols, are
purchased between vols. 7 3 and 94. Individual numbers
are not available.
Index to Authors for vols. 1 -75 (with the titles to their
articles) paper $ 8.00
Geographical Index to vols. 1 90 and
Index to Scientific Names to vols. 61 -90 in 1 vol, $24.00
Domestic and foreign customers, please direct orders to:
AMERICAN MALACOLOGISTS, INC.
P O. Box 2255, Melbourne, FL 32901 USA
^
/
LICENSED APPRAISALS
AND
IDENTIFICATION SERVICE
Collections of shells and libraries of shell
books expertly appraised for estate, gift and
tax purposes. Moderate fees, plus travel ex-
j)enses. Services confidential. Inquire below.
Professional identifications of marine mol-
lusks for biological surveys, environmental
studies and private shell collectors. Fees bas-
ed on hourly basis. Minimum $20.00.
R. Tucker Abbott, Ph.D.
P. 0. Box 2255
Melbourne. Florida 32901
U.S.A.
98 THE NAUTILUS
April 27, 1984
Vol. 98 (2)
THREE CLASSICS AT ALMOST HALF PRICE
1. AMERICAN SEASHELLS. 1972. second
edition. Standard identification manual for
U.S. West and East coast and Canadian
marine mollusks. Lists over 6,300 species,
describes and illustrates 3,000. By R. Tucker
Abbott. We have the last of the main stock,
but instead of the regular price of $60.00,
we offer it (autographed!) for only $38.00,
postage paid. (Florida residents add $1.80
for sales tax).
2. COMPENDIUM OF SEASHELLS by R
Tucker Abbott and S. Peter Dance. Second
revised printing with 50 con-ections. A popu-
lar guide with color plates for each of 4,200
worldwide marine shells. Its large bibliography
is the key to shell literature. Regular price
$50.00. We offer it for only $39.00, plus
$1.50 postage. (Florida residents add $1.95
for sales tax).
3. FLORIDA FOSSILS. Pliocene Mollus-
ca of Southern Florida by Olsson, Har
bison, Fargo and Pilsbry. 1953. 457 pp. 65
plates, sturdily bound 1979 reprint. We hold
the remaining stock. Formerly $39.00, but
we have reduced it to $19.95, plus $1 .05
postage. (Florida residents add $1.00 for
sales tax),
TRULY, THREE GREAT
BARGAINS! Order while they
last.
60% off!!
— while the\; last.
SEASHELLS OF WESTERN EUROPE - Bouchel Brilliant photos
of mollusks 156 pp Regularly S8 95 NOW M 00
SHELLS ON STAMPS OF THE WORLD -- Arakawa. 234 pp . 16
color pis Top source on subject Regularly $15 95 NOW $6,00
GUIDE TO THE NUDIBRANCHS OF CALIFORNIA -112 color
plates of live nud.branchs 64 pp Reg $13 50 NOW $6 00
FRESHWATER SNAILS OF AFRICA AND THEIR MEDICAL
IMPORTANCE ■- Brown Top professional textbook, illus
Reg $55 00 NOW $28 00
IFh"do residents please add 5% stole lax)
Great Sources of New Information on New
Species, New Methods, New Breakthroughs
in Malacology
THE NAUTILUS -- A Quarterly Journal devoted to original research
on all phases of malacology America's oldest scientific journal in
zoology -- in its 98th year' The most quoted journal in the field
Keep up-to-date Subscribe now Four numbers for only $13 00
(Foreign, $15 00. Institutions. $18 00}.
NAUTILUS INDEXES Lists Titles of 90 years of mollusk articles by
slates and countries and by land, freshwater or marine categories
Also includes an index of 15.000 scientific names A quick source
of American and foreign information Bound Regularly $24 00
Now only $12 00
THE WORLDS MOLLUSK LITERATURE - a huge annual listing
of over 3.600 articles gleaned from over 6.000 different journals
Cross-indexed by authors, subjects (500 subjects, such as re-
producCon. habits, chemistry, anatomy, etc ). geographic categories
(all countries, stales, seas and oceans) . paleonlological strata, and
systematics (from classes and families down to species and sub-
species, including all new ones) Over 450 pages of fine print, or
available on personal computer diskettes A monumental effort
done by 21 full-time indexcrs This is the Zoological Record:
MoUusca Section Write us for information and prices
/^[i:!i[^D©/^K] [M]/^y^(g@[L®(iOg¥g, m©.
Publishers of Distinctive Books on Mollusks.
P. O. Box 2255. Melbourne. FL. 32902-2255
We accept VISA or MASTERCARD orders by mail Please give date
of expiration and your card number Foreign customers may send
international postal money order or check on New York bank or
US cash by registered mail.
INFORMATION FOR SUBSCRIBERS
The annual subscription rate for The Nautilus
is $13.00 for individuals (foreign $15.00) and
$18.00 for institutions (domestic or foreign).
Subscriptions may begin in January. Send checi<
or money order made out to "American Mala-
cologists" to the Business Manager, P.O. Box
2255, Melbourne, Florida 32902-2255, U.S.A.
Back issv£s from volume 72 to date are ob-
tainable from the Business Manager. Volumes 1
through 71 (if available) may be obtained in
reprint or original form from Kraus Reprint
Co., Route 100, Millwood, New York 10546.
Advertising rates may be obtained from the
Business Manager or Editor.
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 re-
quired, to facilitate reviews. Tables, numbered
in arable, should be on separate pages, with the
title at the top. Legends to photographs should
be typed on separate sheets. Explanatory terms
and symbols within a drawing should be neatly
printed, or they may be pencilled in on a translu-
cent overlay, so that the printer may set them in
8 pt. type. There is a charge of 50 cents per
word for this extra service. All authors or their
institutions will be charged 50 cents per line of
tabular material and taxonomic keys. The pub-
lishers reserve the right, seldom exercised, to
charge $45 per printed page.
An abstract should accompany each paper.
Reprints are available at cost to authors.
When proof is returned to authors, information
about ordering reprints will be given. They
are obtained from Economy Printing Co., Inc.,
R.D. 3, Box 169, Easton, Maryland 21601-9430.
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 identifi-
cation, locality data and its bibliographic
reference. There is no charge for this perma-
nent curating service, and catalog numbers, if
desired, will be sent to authors prior to publica-
tion.
WANTED - OLD SHELL BOOKS
Will pay good prices for libraries, second- Phone (1-305-725-2260) or write: R. Tucker
hand books and reprints on mollusks, shells Abbott, American Malacologists, Inc., P.O.
and conchology. Back numbers of The Box 2255, Melbourne, FL 32902. Free ap-
Nautilus, vols. 40-71 wanted, $1.50 each. praisals.
americanmalacologists, mc.
PUBLISHERS OF DISTINCTIVE BOOKS ON MOLLUSKS
THE NAUTILUS (Quarterly)
MONOGRAPHS OF MARINE MOLLUSCA
STANDARD CATALOG OF SHELLS
INDEXES TO THE NAUTILUS
{Geographical, vols 1-90; Scientific Names, vols 61-90)
REGISTER OF AMERICAN MALACOLOGISTS
JULY 27, 1984
THE
NAUTILUS
ISSN 0028-1344
Vol. 98
No. 3
A quarterly
devoted to
malacology and
the interests of
conchologists
Founded 1889 by Henry A. Pilsbry. Continued by H. Burrington Baker.
Editor-in-Chief: R. Tucker Abbott
EDITORIAL COMMITTEE
CONSULTING EDITORS
Dr. William K. Emerson
Department of Living Invertebrates
The American Museum of Natural History
New York, NY 10024
Dr. M. G. Harasewych
363 Crescendo Way
Silver Spring, MD 20901
Dr. Aurele La Rocque
Department of Geology
The Ohio State University
Columbus, OH 43210
Dr. James H. McLean
Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, CA 90007
Dr. Arthur S. Merrill
c/o Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Donald R. Moore
Division of Marine Geology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 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, IL 60605
Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, OH 43210
Dr. Ruth D. Turner
Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Gilbert L. Voss
Division of Biology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 33149
EDITOR-IN-CHIEF
Dr. R. Tucker Abbott
American Malacologists, Inc.
Box 2255, Melbourne, FL 32902-2255
Mrs. Cecelia W. Abbott
Business and Subscription Manager
P.O. Box 2255
Melbourne, FL 32902-2255
Second Class Postage paid at Melbourne, Florida
and other post offices
The Nautilus (USPS 374-980)
ISSN 0028-1344
A quarterly magazine devoted to malacolo^*.
Copyright*1983 by American Malacolojrists. Inc.
OFFICE OF PUBLICATION
American Malacologists, Inc. (United Parcel Address:
2208 South Colonial Drive, Melbourne, FL 32902)
Mail: Box 2255, Melbourne, FL 32902-2255
POSTMASTER: Send address changes to above.
Subscription Price: $13.00 (see inside back cover)
$15.00 (foreign); institutions $18.00
THE
NAUTILUS
Volume 98, number 3 - July 27, 1984
ISSN 0028-1344
CONTENTS
M. G. Harasewych and Russell H. Jensen
Natica guesti, a New Naticid Gastropod from the Western Atlantic 99
Fred E. Wells
Population Characteristics of the Periwinkle, Nodilittorina unifasciata,
on a Vertical Rock Cliff in Western Australia 102
Andrew C. Miller, Liz Rhodes, and Richard Tippit
Changes in the Naiad Fauna of the Cumberland River Below
Lake Cumberland in Central Kentucky 107
Robert J. DiStefano
Freshwater Mussels (Bivalvia: Unionidae) of Horse Lick Creek,
Rockcastle River, Kentucky 110
Randal L. Walker
Effects of Density and Sampling Time on the Growth of the Hard Clam,
Mercenaria mercenaria, Planted in Predator-Free Cages in Coastal Georgia 114
Raymond W. Neck
Occurrence of the Striped Ram's Horn Snail, Marisa comuarietis,
in Central Texas ( Ampullariidae) 119
James H. McLean
Agathodonta nortoni. New Species: Living Member of a Lower
Cretaceous Trochid Genus 121
David Nicol
Critique on Stenzel's Book on the Ostracea 123
David Nicol and Douglas S. Jones
Bellaxinaea, a New Subgenus of Glycymeridids (Pelecypoda)
From the Western Hemisphere 126
Reprints of out-of-print volumes of
flfiUTILUS
Vols. 1-40 and Gen. Ind. 1-34. Philadelphia, Pa.,
1886-1926/27.
clothbound $842.00
paperbound S716.00
Kraus Reprint
Millwood, New York 10546
AVAILABLE FROM THE ORIGINAL PUBLISHER
Vols. 73 to date (vol. 94 in 1980) per vol. paper $12.00
A 25% discount will be honored if 10 or more vols, are
purchased between vols. 73 and 94. Individual numbers
are not available.
Index to Authors for vols. 1 -75 (with the titles to their
articles! paper $ 8.00
Geographical Index to vols. 1-90 and
Index to Scientific Names to vols. 61-90 in 1 vol. $24 00
Domestic and foreign customers, please direct orders to:
\
AMERICAN MALACOLOGISTS, INC.
P.O. Box 2255, Melbourne, FL 32901 USA
J
LICENSED APPRAISALS
AND
IDENTIFICATION SERVICE
Collections of shells and libraries of shell
books expertly appraised for estate, gift and
tax purposes. Moderate fees, plus travel ex-
penses. Services confidential. Inquire below.
Professional identifications of marine mol-
lusks for biological surveys, environmental
studies and private shell collectors. Fees bas-
ed on hourly basis. Minimum $20.00.
R. Tucker Abbott, Ph.D.
P. 0. Box 2255
Melbourne, Florida 32901
U.S.A.
Collectible Shells
of Southeastern U.S., Bahamas
& Caribbean by R Tucker Abbott. Ph D
A Take it to the Beach' Field Guide
WATERPROOF - TEARPROOF
105 beautiful color photos of living animals and
their shells 64 pages of color 300 species il-
lustrated How to clean shells. Where to find
them Includes fossils, pond and tree snails, as
well as sealife.
Collectible Shells stresses conservation, but
also has helpful hints about collecting and
cleaning shells. The book introduces the tourist
and beginner to famous Florida fossils and the
unique world of tree and pond mollusks
Printed on a washable, tearproof plastic 'paper
Drop It in the ocean, use it in the rain, or let your
wet shells drip all over it. Keep it on your boat or
take It to the shore A popular new seller retailing
for $8 95 Postage and state tax are included as a
big savings
American Malacologists, Inc.
Publishers of Distinctive Books on Mollusks
P.O. Box 2255, Melbourne, FL 32902-2255
We accept VISA ot MASTERCARD otafs By maM Piearie give dale ol e.
piraiion and your card numbef Foreign cusiofners may send mtefna
Iional postal Ttoney order or r fierjk on New York tiank or U S rafh h,
regrsiereo rnail
MEETING
The Western Society of Malacologists
will hold its 17th Annual Meeting on the
campus of the University of California,
Santa Cruz, California, on August 16-19,
1984. All persons interested in mollusks,
whether they be amateur shell collectors or
professionally trained malacologists, are
invited to attend. For further information,
please contact Dr. George L. Kennedy,
U.S. Geological Survey, 345 Middlefield
Road, Menlo Park, CA 94025. (415-323-
8111, ext. 2634).
PHILLIP W. CLOVER ,:g>
COLLECTOR & DEALER IN WORLDWIDE
SPECIfVIEN SEA SHELLS
CURRENT AND OUT OF PRINT SHELL BOOKS
FREE PRICE LISTS UPON REQUEST
P O Box 83. Glen Ellen. CA 95442
Vol. 98 (3)
July '^n, 1984
THE NAUTILUS 99
NATICA GUESTI, A NEW NATICID GASTROPOD
FROM THE WESTERN ATLANTIC
M. G. Harasewych
Research Associate
Department of Invertebrate Zoology
National Museum of Natural History
Smithsonian Institution, Washington, D.C.
For more than a decade the deep-water trap-
ping operations of the Lightbourn-Guest North
Star Expeditions, conducted off the south shore
of Bermuda, have brought up numerous hermit-
crab-borne molluscan shells. Many of these
specimens represented considerable range ex-
tensions (Finlay, 1978; Finlay and Vink, 1982;
Snyder 1984) and several new species (Harase-
wych and Jensen, 1979; Snyder, 1984; Okutani
and Goto, 1983). Included in this material were
numerous examples of a new species of naticid
that is described herein.
Examination of the molluscan collections at
the Museum of Comparative Zoology, Harvard
University, and at the National Museum of
Natural History, Smithsonian Institution,
revealed that this species is widely distributed,
occurring in Bermuda, along the southeastern
coast of the United States as well as throughout
the Gulf of Mexico and the Caribbean Sea.
Institutional abbreviations: AMNH, American
Museum of Natural History, New York; DMNH,
Delaware Museum of Natural History; MCZ,
Museum of Comparative Zoology, Harvard Uni-
versity; USNM, National Museum of Natural
History, Smithsonian Institution.
Family Naticidae Gray, 1840
Genus Natica Scopoli, 1777
Natica (Natica) guesti new species
(Figs. 1-11)
Description- SheW of moderate size (to 33
mm), globose, thin but strong; spire angle 111°-
136°; protoconch (Fig. 10) of 2V4 whorls,
smooth, glossy, straw-colored; transition to tele-
oconch abrupt, marked by beginning of regular
incised furrows; teleoconch with up to 3V3
smooth, rounded whorls; suture adpressed; axial
sculpture of fine growth lines and incised fur-
rows that become pronounced to form fine ribs
along suture; umbilicus narrow, deep; funicle
small, situated at midpoint of columella; parietal
Russell H. Jensen
and Department of Mollusks
Delaware Museum of Natural History
Greenville, DE 19807
callus reduced, extending along apical Vs of col-
umella; aperture large, subcircular; interior
glossy, translucent; shell color milky beige, with
lighter band below suture; other markings,
when present, comprised of spiral bands of
brown dots or flammules, one midway between
suture and periphery, one just below periphery,
and rarely a third one midway between periph-
ery and base; periostracum very thin, straw-
colored; operculum (Fig. 6) calcareous, pauci-
spiral; nuclear callus raised; a deep, wide, flat-
bottomed groove and 2 raised ribs border
periphery; outer surface of operculum pure
white; inner surface straw-colored; radular rib-
bon (Fig. 11) (one examined) taenioglossate,
short (0.22 shell height), consisting of 81 rows of
teeth; rachidian trapezoidal, with broad attach-
ment area and 2 blunt basal processes; cutting
edge tricuspid, central longer than flanking
cusps; lateral tooth with complex, hourglass-
shaped attachment area, anterior portion giving
rise to broad, rounded cutting edge with one
large cusp flanked by reduced cusps; inner mar-
ginal tooth broad, curved, bicuspid, outer cusp
broader, blunter; outer marginal tooth simple,
scythe- shaped.
Type materia/. -Holotype: USNM 765087, in
201 m, about 40 miles NW of St. Martin, Lee-
ward Islands (18°13'N, 63°19'W) R/V Oregon
sta. 5914. Paratypes: USNM 765077, in 384 m,
about 50 miles SW of St. Croix, Virgin Islands
(18°14'N, 64°20'W) R/V Oregon sta. 2646 (1
specimen); USNM 765079, in 404 m, about 20
miles NNW of Mayaguez, Puerto Rico (18°32'N,
67°09'W) R/V Oregon sta. 2659 (1 specimen);
USNM 765080, in 210-201 m, about 70 miles
SSE of Pascagoula, Mississippi (29°15'N,
88°05'W) R/V Oregon sta. 2826 (1 specimen);
USNM 765081, in 320-347 m, about 20 miles
NNW of Riohacha, Colombia (11°50'N,
73°05'W) R/V Oregon sta. 4911 (2 specimens);
100 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
FIGS. 1-9. Naticd guest i new species. 1-5, Holotype, USNM 765087, trawled in 201 meters, about 40 miles NW of St.
Martin, Leeward Islands (18°13'N, 6.3°19'W) R/V Oregon sta. 5914, 1.5x (Figs. 1-3 whitened with ammonium chloride to
enhance sculptural details). 6, Operculum of holotype, 2.0 x . 7. Parat.vpe, dredged in 174 meters, off St. James, Barbados.
C. J. Finlay collection, 1.75x. 8, Paratype, DMNH 164500, in trap" set in 347 meters, 21/2 miles off Castle Roads, Ber-
muda, Lightboui-n-Guest Northstar Expeditions, 1.5 x. 9, Paratvpe, USNM 76.5082, trawled in 274 meters, about 40
miles E of El Portete, Guajira Peninsula, Oilombia (12°17'N, 72°03'W) R/V Oregon sta. 4921, l.Ox.
USNM 765082, in 274 m, about 40 miles E of El
Portete, Colombia (12°17'N, 72°03'W) R/V
Oregon sta. 4921 (2 specimens); USNM 765084,
in 320 m, oiT Bridgetown, Barbados (13°00'N,
59°33'W) R/V Orepon sta. 5018 (3 specimens);
USNM 765085, in 205 m, off Puerto Obaldia,
Panama (8°5rN, 77°25'W) R/V Oregon sta.
5734 (1 specimen); USNM 765086, in 296 m,
about 20 miles NW of St. Martin, Leeward
Islands (18°irN, 63°15'W) R/V Oregon sta.
5913 (1 specimen); USNM 765088, in 165 m, W
of St. Lucia, Windward Islands (13°41'N,
60°53'W) R/V Oregon sta. 5955 (1 specimen);
DMNH 96986, in traps set in 402 m, 2V2 miles
off Castle Roads, south shore Bermuda, Light-
bourn-Guest Northstar Expeditions (1 speci-
men); DMNH 164500 and AMNH 213734, in
traps set in 347 m, 2% miles off Castle Roads,
south shore, Bermuda, Lightbourn-Guest A^ori/i-
star Expeditions (7 specimens); MCZ 294668, in
146-183 m, % mile off Castle Rock, Bermuda,
Bermuda Biological Station #7 (2 specimens);
MCZ 294667, in 421 m, off Puerto Tanamo,
Cuba (20°45'N, 75°20'W) Atlantis sta. 3375 (1
specimen); C. J. Finlay collection, dredged in
174 m, off St. James, Barbados (1 specimen); J.
R. H. Lightbourn collection, in traps set in
340-400 m, 2V2 miles off Castle Roads, south
shore, Bermuda, Lightbourn-Ciuest Northstar
Expeditions (14 specimens); A. T. Guest collec-
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 101
FKi. 10. Natica guesti new species, protoconch, scale bar
500 /jm.
FIG. 11. Half row of radular riliboii taken from the holot_vpe,
scale bar = 100 /jm.
tion, in traps set in 340-400 m, 2V2 miles off Cas-
tle Roads, south shore, Bermuda, Llghtbourn-
Guest Northstar Expeditions (12 specimens).
Type locality -In 201 meters, about 40 miles
NW of St. Martin, Leeward Islands (18°13'N,
63°19'W) R/V Oregon sta. 5914.
Remarks -This new species may be distin-
guished from other western Atlantic naticids by
its moderate size, globose shape, small funicle,
deep umbilicus and distinctive operculum.
Natica guesti most closely resembles the Medi-
terranean species A^. dUlwynii Payraudeau,
1826, from which it differs in being larger, and
having a greater spire angle, a less pronounced
funicle, fine axial ribs adjacent to the suture,
and lacking the 3 or 4 white spiral bands. Oper-
cula of these two species are similar, but the
marginal groove is proportionally much broader
in N. gv£sti.
N proxima C. B. Adams, 1850, from Jamaica
(non Wood, 1848) has a higher spire and propor-
tionately larger funicle. Dall (1889, p. 292)
synonymized p'roxima with maroccana Dillwyn,
1817.
Although introductions of European species
into Bermuda waters have been documented
(Abbott and Jensen, 1968), the wide geographic
and deep bathymetric ranges of A'', guesti argue
convincingly against it being a recently intro-
duced species.
It was through the intensive investigations of
TABLE 1. Shell measurements of Natica guesti
(linear measurements in mm) n = 10.
the mollusks of Bermuda by Arthur T. Guest, of
Cardinal Hill, Bermuda, that this species came
to light, so we take great pleasure in naming
this taxon in his honor. The popular, English
name for this species may be Guest's Moonsnail.
LITERATURE CITED
Abbott, R. T. and Jensen. R. H. 1968. Portuguese marine
mollusks in Bermuda. The Nautilus 81(3):86-89.
Finlay, 1978. Review of the Genus Bursa in the western
Atlantic. The Nautilus 92(4):147-150.
Finlay, C. J. and Vink, D. L. N. 1982. New records of Cyma-
tiidae (Gastropoda) in the western Atlantic. The Nautilus
96(4):132-134.
Harasewynch, M. G. and Jensen, R. H. 1979. Review of the
subgenus Pterynotus (Gastropoda: Muricidae) in the west-
ern Atlantic. Nemouria 22:1-16.
Okutani, T. and Goto, Y. 1983. A new subspecies of Adan-
son's slit shell from Bermuda. Venus 42(4):30.5-311.
Snyder, M. A. 1984. Fusinus lighthourni (Gastropoda:
Fasciolariidae), a new species from Bermuda. The Nauti-
lus 98(l):28-30.
102 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
POPULATION CHARACTERISTICS OF THE PERIWINKLE,
NODILITTORINA UNIFASCIATA. ON A VERTICAL
ROCK CLIFF IN WESTERN AUSTRALIA
Fred E. Wells
Western Australian Museum
Perth, 6000, Australia '
ABSTRACT
Population characteristics of the periwinkle snail, Nodilittorina unifasciata,
were monitored on a vertical rock cliff at Wntermans Bay, Western Australia,
from Novemeber 1980 to November 1981. During the year the population suffered
a massive density decline, from Jf26/m^ to os low as 29/m^. Two primary causes of
the mortality are hypothesized: post-reproductive mortality of adults in summer
and the failure of recruitment in 1981. Density recovered to 62% of its original
level by November 1982. Small, medium and large individuals were evenly spread
over the vertical area occupied by N. unifasciata; there was no segregation by size.
Presence of crevices in the rocks was more important to N. unifasciata than the
open space of the cliff. The snail has a lifespan in this area in which recruits reach
reproductive maturity in two years. There is substantial post-reproductive mor-
tality but a portion of the population survives for a third year. Thus, there is an
overlap of the reproductive population from one year to the n^xt, preventing
genetic isolation between year groups.
Littorinid snails are common on shallow sub-
tidal and intertidal shores in most regions of the
world (Rosewater, 1970). The animals often oc-
cur in high densities (thousands per square
meter) and are presumably important in energy
flow in the environment in which they live. Lit-
torines are surface raspers, scraping micro-
scopic algae from the rock face or plant surfaces
(Robertson and Mann, 1982) and converting it
into animal tissue available to the higher levels
of the trophic system. Despite their apparent
importance there are few studies of the level of
somatic production by littorinids. Borkowski
(1974) examined the productivity of six species
in southern Florida and a number of papers have
shown population densities and growth of vari-
ous species (e.g. Bingham, 1972; Borkowski,
1974; Hughes, 1980; Robertson and Mann,
1982).
The dominant littorinid of southern Australia
is Nodilittorina unifasciata (Gray, 1839)' which
extends from southern Queensland to North
'This species has generally been placed in the genus Lit-
torina but recent work on the anatomy of Caribbean littori-
nids by Bandel and Kadotsky (1982) suggests that it should
be transferred to Nodilittorina.
West Cape, Western Australia (Underwood,
1974). Few data are available on the population
characteristics of this species in any area of its
range. Underwood (1974) included N. unifas-
ciata in a study of the reproductive periodicity
of 10 common intertidal species in eastern
Australia. Black et al (1979) recorded densities
of 0 to about 40/m^ at Rottnest Island, W. A.
Branch and Branch (1981) investigated the
species in detail in the Sydney area with a view
to confirming the presence of intraspecific com-
petition in A^. unifasciata and its level. The pre-
sent paper is intended to provide preliminary in-
formation on variations in such population char-
acteristics as density, size-frequency, shore
height, and biomass at a site in the Perth area of
Western Australia.
Materials and Methods
A sampling station was established just south
of the fishery reserve at Waterman's Bay,
Perth, Western Australia (31°50'S; 115°42'E).
The sample area is a small limestone peninsula
with a platform extending seaward at a tidal
level of 0.4 m. Landward of the platform is a
vertical cliff approximately three meters high.
Vol. 98(3)
July 27, 1984
THE NAUTILUS 103
Tides are a mixture of semidiurnal and diurnal
with a maximum range of 0.3 to 1.3 m; levels are
generally higher in winter than summer. They
can be altered substantially by atmospheric con-
ditions (Hodgkin and DiLollo, 1958). The Water-
man's Bay site is exposed to wave action from
the open sea, though this is dampened some-
what by a subtidal reef several kilometers off-
shore. Wave action is greater in winter than
summer.
Samples were made on the cliff at approxi-
mately monthly intervals from November 1980
to November 1981, except for April; a follow-up
sample was made in November 1982. On each
occasion four transects were sampled. The
transects, which were 20 cm wide and divided
into quadrats 15 cm high, extended up the cliff
from the platform surface to the maximum
height of the A^. unifasciata population. To
determine size-frequency and shore height
characteristics all individuals of N. unifasciata
in each quadrat were counted, measured to the
nearest 0.1 mm in shell length with calipers, and
returned to the area. For the dry weight bio-
mass determination 50 individuals covering the
entire size range of N. unifasciata were
measured to the nearest 0.1 mm, decalcified in
7% hydrochloric acid, washed in freshwater,
dried to constant weight at 60°C, and weighed
to the nearest 1 mg on a Sartorius microbalance.
The lengths and weights were converted to
logarithms and a linear regression calculated.
The resulting equation relating shell length to
dry tissue weight was then used with the size-
frequency and density data to estimate monthly
biomass.
Results
The highest densities were recorded at the
beginning of the study (Fig. la), with 426/m^ in
November 1980. Density remained high until
January 1982 then declined sharply to 122/m^ in
February. There was some recovery of the popu-
lation in May as new recruits entered but densi-
ty was still only 199/m\ half of the initial value.
Density declined steadily after May and ranged
from 29 to 32/m^ during the period of September
to November 1981. When density was checked
in November 1982 it had recovered to 263/m^
still only 62% of the initial value.
L. unifasciata inhabited the shoreline from
CNI
E
\
>- 250
a
N D J F M A M J J
1980 I 1981
A S 0 N
UJ
N D J
1980 I
M A M J J
1981
A S 0 N
0 N
FIG. 1. Population characteristics oi Nodilittorina unifas-
ciata on a vertical rock cliff at Watermans Bay, Western
Australia from November 1980 to November 1981. la. Den-
sity, lb. Shore height. Ic. Dry weight, shellfree biomass.
Vertical bars are standard deviations.
the top of an algal zone 40 cm above the plat-
form to a maximum height of 240 cm above the
platform. Figure lb shows the changes in mean
height of the population over the year sampled.
The mean height was 75 cm above the platform
in November 1980 and moved up steadily to 118
cm in February. As new recruits entered the
population in May and June the mean shore
height dipped temporarily to 83 cm but in-
creased steadily during the winter to 147 cm by
October. There was no clear seasonal variation
in the shore height occupied by the population,
but during the winter a filamentous green algae
grew on the lower part of the cliff. Areas of
algal growth were avoided by N. unifasciata.
Newly metamorphosed individuals seemed to
settle initially over the entire vertical range of
104 THE NAUTILUS July 27, 1984
50t Under 3mm "^.O.
Vol. 98(3)
LU
cc
HEIGHT (cm)
FIG. 2. Shore heights occupied by three size
classes of all individuals of A^. unifasciata collected
at Waternians Bay, Western Australia, from
Noveniber 1980 to November 1981,
N. unifasciata with somewhat larger numbers
settling lower on the shore. However the verti-
cal distribution of the recruits soon matched
that of the population as a whole. Figure 2 com-
pares the vertical distribution of all N. uni-
fasciata in three size classes collected during the
study: less than 3.0 mm (mean height 88.7 ±
32.8 cm); 3.0 to 6.0 mm (mean height 90.3 ± 48.6
mm); and greater than 6.0 mm in shell length
(mean height 93.1 ± 47.1 cm). There was no
statistically significant difference between the
mean heights of the three groups (t-test, 0.05
level).
Figure 3 plots the relationship between shell
length and dry tissue weight on a log/log basis.
The equation is a straight line of Y = -4.61 +
o, -1.0-^
E
LU
3:
O
-2.0-
-ao-
■4.a
..;••
• * •
0.4 ~"a6 S to 12 14
LOG, LENGTH(mm)
10
FIG. 3. Log/log graph of shell length versus shellfree, dry
weight oi Nodilittorina unifasciata collected at Watermans
Bay, Western Australia. Y"= -4.61+ 2.68 x (H = 0.93).
2.68 X (r^ = .93). The biomass each month is
shown in figure Ic, and closely parallels density
(Fig. la). Biomass was highest (4.2 g/m^) in the
sample of November 1980 and remained high
until January 1981. In February biomass de-
clined sharply to 0.7 g/m^ It increased slightly
to 1.0 g/m^ in June due to the influx of recruits
into the population but then declined to a mini-
mum of 0.3 g/m^ in October. The mean biomass
during the year examined was 1.4 g/m^ This
was concentrated in the first half of the period,
with a mean biomass of 2.3 g/m^ from November
to May and only 0.5 g/m^ in June to November.
Figure 4 shows the size-frequency curves for
each month examined. Recruits to the popula-
tion were first seen at a length of 1.2 mm. In-
dividuals smaller than 2 mm were present in all
months except August and September. The
peak number of small individuals was recorded
in May and June. Changes in the size-frequency
curves from May to November can be used to
estimate growth of the juveniles. Their mean
size was 3.0 mm in May, 3.7 mm in August and
4.6 mm in November. The curve for November
1981 is distinctly bimodal, indicating that there
are at least two, and possibly three, year classes
in the population. In contrast to the November
1981 graph the plot for November 1980 is uni-
modal with large numbers of small individuals
spread over the range of 2 to 8 mm. This does
not necessarily contradict the suggestion that
A^. unifasciata lives two years but does suggest
Vol. 98 (3)
30-|Nov 80
July 27. 1984
THE NAUTILUS 105
cc
LlJ
a.
0 2 ^ 6 8 10 12 K 0 2 4 6 8 10 12 14
LENGTH (mm)
FIG. 4. Size-frequency gi-aphs of Nodilittorina unifasciata
collected at Watermans Bay, Western Australia, from
November 1980 to November"l981.
that 1979 was a better year for recruitment and
subsequent growth than 1980.
When sampling began in November 1980 the
study site was at the southern end of a small
peninsula. Beginning the following April fall
storms washed sand away from the southern
end of the peninsula, exposing an underlying
rock platform. A'^. unifasciata began to migrate
southward onto the expanding platform. The
migrating individuals were 8 mm or longer, and
were not simply small juveniles which had set-
tled on the platform. The population of A'', uni-
fasciata on the platform was surveyed in August
1981 when the platform reached its greatest
width of 50 m. For the survey transects ropes
were laid up the shore every 5 m on the platform
and all N. unifasciata 30 cm each side of the
rope counted. A similar series of transects was
made on the vertical cliffs of the peninsula. An
estimated 5500 snails had migrated onto the
platform, 3.1% of the total on the cliff of 171 000
and 7.8% of the population longer than 8 mm.
As summer approached the returning sand
covered the platform adjacent to the peninsula
first then covered up the platform further south.
This killed all, or nearly all of the A'^. unifasciata
which had migrated onto the platform.
Discussion
During the brief period of this study, the A^.
unifasciata population declined in density by
93%. The resurvey one year after the study
showed that the population had recovered to
62% of its initial level. The most dramatic mor-
tality occurred in January-February. While the
source(s) of this mortality are not obvious
several possibilities can be discussed. Predation
by other animals is one possible source. N.
unifasciata lives high on the shore where the
population is never covered by water, elimi-
nating the possibility of predation during high
tide by fish. The predatory whelk Thais orbita
(Gmelin, 1791) is present on the lower part of
the cliffs in small numbers. The species is a
heavy predator of limpets (Black, 1978) but oc-
curs too low on the shore to be a major predator
of N. unifasciata. Sea birds, particularly oyster
catchers, have been observed on the platform
feeding on molluscs, but never on the cliff. In ad-
dition dead shells washed up on the beach
showed no signs of predation. This suggests the
possibility of animal predation can be discounted
as a major source of the mortality. A similar
conclusion was reached by Branch and Branch
(1981). Human predation could have occurred
but was never observed during the study period.
Hodgkin (1959) showed that during the summer
coastal platforms could remain dry throughout
the day, or . even for several days, when at-
mospheric high pressure systems caused con-
tinuous easterly winds. The easterlies come off
the hot desert areas of central Australia, often
raising temperatures to 40°C or more. These
periods of high temperatures and continuous ex-
posure are times of catastrophic mortalities on
the platforms. This could have caused the sum-
mer mortality in A^. unifasciata. However, the
mortality was concentrated amongst the largest
individuals of the population suggesting that
post-reproductive mortality was the primary
cause. The size-frequency graphs changed
markedly between January and February. In-
106 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
dividuals 9 mm or more in shell length were 68%
of the population in January but only 33% in
February; the large individuals accounted for
81% of the decline which occurred between the
January and February samples.
Density increased in May and June as recruits
entered the population but declined steadily in
subsequent months as many of the young indi-
viduals died. Recruitment during 1981 was
largely a failure, the causes of which are not
known. Recruitment was better in 1982 as evi-
denced by the return of the population to a den-
sity of about 62% of its original level. Thus there
are substantial year to year variations in the
population density of A^. unifasciata, which can
be as high as at least one order of magnitude.
I originally expected recruits to be at the low-
est shore levels then move up vertically as they
grew. Such a pattern has been found in other
gastropods (Edwards, 1969) including littorinids
(Robertson and Mann, 1982). Branch and
Branch (1981) found the lowest mean size was in
the middle of the range of A^. unifasciata. There
was an initial tendency for small individuals to
be at low shore levels, but this concentration
was rapidly dissipated and was not statistically
significant. The more important small scale
determinant of distribution within the main por-
tion of the vertical area inhabited by N.
unifasciata was the presence of crevices in the
rocks. A^. unifasciata were concentrated in the
crevices during the summer and were inactive.
They were scattered about the entire rock face
during winter and were actively moving about.
During winter temperatures were lower and the
rock face was constantly wetted by wave action.
The number and type of crevices as areas of
refuge for N. unifasciata during the summer
might be a factor setting an upper limit on the
population as was shown for Littorina rudis and
L. neglecta by Raffaelli (1978). Branch and
Branch (1981) demonstrated intraspecific com-
petition in A^. unifasciata. This occurred at den-
sities several times greater than those recorded
at Watermans, and intraspecific competition
was probably not important in this study.
Because of the decline in the population over
the year no attempt was made to estimate soma-
tic production. The six species of littorinids ex-
amined by Borkowski (1974) had production to
biomass ratios ranging from 1.3 to 4.7. The
mean biomass of A'^. unifasciata at Waterman's
Bay was 1.4 g/m^ If the P:B ratios of Borkowski
are used, a dry tissue production of 1.8 to 6.1
g/mVyear can be estimated for A^. unifasciata
during 1980-81. This figure must be regarded as
preliminary as it would vary considerably de-
pending on the population level. Borkowski
(1974) demonstrated that spawn production is a
significant component of secondary productivity
in littorinids and may substantially exceed
somatic production. This aspect of production
was not investigated for N. unifasciata.
The data presented here suggest that A^. uni-
fasciata has a lifespan of at least two years. Re-
cruits entering the population, predominantly in
May, reached 4.6 mm by November. If growth
continued at the same rate the animals would be
adults during their second summer of life and
would spawn then. Despite the substantial post
reproductive mortality found in summer at least
some individuals survived to their third year.
This lifespan is within the range of other lit-
torinids demonstrated by Borkowski (1974) and
Robertson and Mann (1982). The continuance of
a portion of the reproductive population into
another year is important as it prevents the
development of two reproductively isolated year
groups alternately spawning in the same area.
Acknowledgments
I thank Dr. D. S. Hancock of the Western
Australian Department of Fisheries and Wild-
life for access to the fishery reserve.
LITERATURE CITED
Bandel, K. and D. Kadolsky. 1982. Western Atlantic species
of Nodililtorrna (Gastropoda: Prosobranchia): Compara-
tive morphology and its functional, ecological, phylogene-
tic and taxonomic implications. Veliger 25:1-42.
Bingham, V. O. 1972. .Shell growth in the gastropod Litto-
rina irrorata. The Nautilus 85:\'X-\4\.
Black, R. 1978. Tactics of whelks preying on limpets. Marine
Biol. 46:157-162.
Black, R., K. Fisher, A. Hill and P. McShane. 1979. Physical
and biological conditions on a steep intertidal gradient at
Rottnest Island, Western Australia. Ainit. Jour. Ecol.
4:67-74.
Borkowski, T. V. 1974. (!rowth, mortality and productivity
of south Floridian Littorinidae (Gastropoda: Proso-
branchia). Bull. Mar. Sci. 24:408-438.
Branch, G. M. and M. L. Branch. 1981. Experimental analy-
sis of intraspecific competition in an intertidal gastropod,
Littorina unifasriata. Auiit. Jour. Mar. Freshwater Kes.
32:573-.589.
Edwards, D. C. 1969. Zonation by size as an adaptation for
intertidal life in Olivella biplicat.a. Amer. Zool. 9:399-417.
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 107
Hodgkin, E. P. 1959. Catastrophic destruction of the littoral
fauna and flora near Freniantle, January 1959. West.
Autit. Naturalist 7:6-11.
Hodgkin, E. P. and V. DiLollo. 1958. Tides of southwestern
Australia. Jour. Roy. Soc. Wes:t. Aust. 41:42-51.
Hughes, R. N. 1980. Population dynamics, growth and
reproductive rates of Littorina nigrolineata Gray from a
moderately sheltered locality in North Wales. Jo7ir. Exp.
Mar. Biol.Eml. 44:211-228.
Raeffaeli, P. G. 1978. Factors affecting the population struc-
ture oi Littorina neglecta. Jour. Moll. Studies 44:223-230.
Robertson, A. I. and K. H. Mann. 1982. Population dynamics
and life history adaptations of Littorina neglecta Bean in
an eelgrass meadow (Zostera marina L.) in Nova Scotia.
Jour. Exp. Mar. Biol. Ecol. 63:151-171.
Rosewater, J. 1980. The family Littorinidae in the Indo-
Pacific. Part 1. The subfamily Littorininae. Indo-Pacific
Moll. 2:417-.533.
Underwood, A. J. 1974. The reproductive cycles and geo-
graphic distribution of some common eastern Australian
prosobranchs. Aust. Jour. Mar. Freshwater Res. 25:
63-68.
CHANGES IN THE NAIAD FAUNA OF THE CUMBERLAND RIVER
BELOW LAKE CUMBERLAND IN CENTRAL KENTUCKY
Andrew C. Miller,
Environmental Laboratory,
US Army Engineer Waterways
Experiment Station,
Vicksburg. MS 39180
Liz Rhodes, and Richard Tippit
Water Quality Section,
US Army Engineer District,
Nashville, TN 37202
ABSTRACT
A survey for live mussels was conducted below Wolf Creek Dam, miles U60.8 to
393.2, on the Cumberland River, Kentucky, on 21-23 October 1982. The purpose of
the study was to determine ifnfiussel recruitment had taken place following com-
pletion of the dam in 1952. The only live bivalves found were the Asian clam-, Cor-
bicula, and two unionid moUusks, Cumberlandia monodonata and Cyclonaias
tuberculata. Physical and chemical factors which include very cold (less than 20°
throughout the year), nutrient-poor release waters from Lake Cumberland plus
turbulent flow andfiux;tuating water levels contribute to conditiort.s unsuitable for
maintenance of reproducing populations of naiad mollu^ks in this portion of the
river.
Wolf Creek Dam, at mile 460.9 on the
Cumberland River in south-central Kentucky
(Fig. 1), was fully completed in August 1952 and
resulted in the creation of Lake Cumberland, a
50, 250- acre (at maximum pool) body of water.
Wolf Creek Dam releases water into the Cum-
berland River which is free- flowing for about 50
miles until just past the town of Burkesville,
Kentucky, where it becomes influenced by Cor-
dell Hull Reservoir located near Carthage, Ten-
nessee. At the dam is a power station capable of
generating 270,000 kw with six generators.
Water is taken from Lake Cumberland by way
of six conduits; the inlets are located below the
thermocline in the lake. As a result, the station
operates with cold, hypolimnetic waters during
all times of the year. Typically the power plant
functions only during periods of peak energy
demand, from about 7 a.m. until 12 p.m. during
each 24-hour period. During this routine shut-
down period, virtually no water passes from the
lake into the river, and water levels immediately
below the dam decline by 5 feet or more by 7 a.m.
On 20 October 1982 at 12 midnight, the Wolf
Creek Power Station was closed for mainte-
nance; electricity generation was suspended for
a total of 150 hours and resumed on 26 October
at 6 a.m. During this time water levels below the
dam declined by approximately 6 ft. and water
depth and velocity were reduced in the river
past Burkesville. The brief low-water period in
this section of the Cumberland River provided
an excellent opportunity to search for fresh-
water mussels, and document the effects of dam
108 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
FIG. 1. Sites Sampled for Mussels on the Cumberland River, Russell, Cumberland, and Monroe
Counties, Kentucky, on 21-23 October, at river miles shown.
closure on the native naiad fauna.
The unionid fauna of this area was docu-
mented by Wilson and Clark (1914) and col-
lected most recently by Neel and Allen (1964) in
1948-49 just prior to dam closure. In 1961
Stansbery (1969) collected naiad mollusks at
Cumberland Falls, and compared the results of
his work with the two sets of previous workers.
A general discussion of the effects of storage
release reservoirs can be found in Pfitzer (1954)
who collected snails (no mussels), aquatic in-
sects, Gammarus. and fish in the tailwaters of
rivers in the Tennessee Valley.
Methods
A total of seven sites below the dam on the
Cumberland River were surveyed for mussels on
21-23 October 1982. Sampling equipment used
during the survey included modified garden
rakes, a handheld basket dredge, a 2-ft wooden
brail bar equipped with handmade hooks, and
viewing buckets. Intensive searching was con-
ducted at areas where it was judged that mu.s-
sels would most likely occur; i.e. below tributary
streams, in mud and gravel/sand substrate, and
around and under medium to large-sized rocks.
Results and Discussion
Two live mussels were collected on the
Cumberland River in the study area, the Spec-
tacle Case (Cum.berlandia inonodonta) and the
Purple Pimpleback {Cyclonaias tuberculata),
which were found at miles 409.5 and 403.4, re-
spectively. These mussels were lying on, not
buried in, the substrate in water that was 50 cm
deep or less. The umbones on C. tuberculata
were deeply eroded, and the periostracum on C.
7nonodonta were heavily worn, indicating the
erosive action of turbulent water in the river.
These specimens were found some distance
downriver of the dam; i.e., 60.3 and 57.4 river
miles, respectively.
The Asian Clam {Corbicula Jluminea) was the
only other live bivalve collected during the
survey. This species became progressively more
common as one proceeded downriver of the
dam; for example, below the mouth of Sulfur
Creek (river mile 393.2) a dozen or more in-
dividuals were obtained. Although fairly com-
mon here, numbers at this site were much fewer
than 1.0/m^ All Corbicula collected were very
small (i.e., less than 3.0 cm long, with average
weight about 4.0 grams), and the umbones were
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 109
deeply eroded.
Because the release water from the dam is
hypolimnetic, water temperatures in the sum-
mer do not exceed 20°C (Fig. 2). Evidently, the
low water temperatures inhibit mussel recruit-
ment in this portion of the river. In a study of
the Pigtoe Mussel {Pleurobema cordatum) in
Alabama, for example Yokley (1972) found that
embryo development did not occur until water
temperatures had achieved 23° C. On the other
hand, mussel recruitment can occur in cool
waters. Zale and Neves (1982) studied four
lampsiline species in Big Moccasin Creek, a
third-order tributary of the Holston River in
southwestern Virginia. Spawning times and
temperatures ranged from July to late August
and from 16.4°C to 25.8°C, respectively;
however, Medionidu^ conradicu^ glochidia were
collected with drift nets during winter months
when temperatures were above 5°C and
juvenile recruitment for the species occurred
throughout the year (Zale 1980).
Neel and Allen (1964) during their survey in
1948-49 identified 39 species from the Cumber-
land River below Wolf Creek Dam. Three
species {Elliptio dilatatus, Ptychobranchus
fasciolaris, and Lampsilis ovata) were con-
sidered abundant. Cyclonaias tuberculata and
Cumberlandia monodonta were both judged to
be rare; live specimens of the latter species were
not found in this stretch of the river. C.
monodonta was taken only from sheltered areas
near large rocks. This species avoids the stress
of turbulent water and is usually taken from
firm mud, protective cracks between boulders,
or beds of vegetation (Stansbery 1966).
Conclusion
Turbulent water, fluctuating water levels, and
temperatures which remained below 20°C
throughout the year are not conducive to mussel
recruitment below Wolf Creek Dam. Although
previous workers found a diverse assemblage of
species, this survey yielded only two live
unionids. When the dam was completed, unionid
recruitment essentially ceased and existing
mussels were gradually lost because of adverse
conditions, predation, or natural mortality. The
two live mussels collected in October 1982
evidently had survived since dam closure. The
Corbicula taken in several locations were un-
doubtedly the product of natural recruitment.
Acknowledgments
The authors appreciate the support and infor-
mation provided by Mr. H. T. Sansing, Chief,
Water Quality Section, US Army Engineer Dis-
trict, Nashville. Funds to conduct this work
were provided by the Nashville District Office.
OCT
FIG. 2. Water Temperatures at Burkesville in Russell County, Kentucky, river mile 422.8,
from 1 October 1980 to 30 September 1981 (from US Geological Survey 1982). Each point
is the mean of from 8 to 11 values.
no THE NAUTILUS
July 27, 1984
Vol. 98(3)
LITERATURE CITED
Neel, J. K., and Allen, W. R. 1964. The Mussel Fauna of the
Upper Cumberland Basin Before its Impoundment, Mahi-
cologia 1:427-459.
Pfitzer, D. W. 1954. Investigations of Waters Below Storage
Release Reservoirs, Nineteenth North American Wildlife
Conference, pp. 271-282.
Stansbery, D. H. 1966. Observations on the Habitat Distri-
bution of the Naiad Cumberlandia monodonta (Say, 1829),
Bull. Amer. Mai. Union for 1966: 29-30.
1969. Changes in the Naiad Fauna of the Cum-
berland River at Cumberland Falls in Eastern Kentucky.
Bull. Anwr. Mai. Union for 1969. pp. 16-17.
US Geological Survey. 1982. Surface Water Records for
Kentucky, Water Year 1981. Frankfort, Ky.
Wilson, C. B., and Clark, H. W. 1914. The Mussels of the
('umberland River and Its Tributaries, Report US Com-
mission of Fisheries for 1972 and Special Papers, pp. 1-63
(.separately issued as Bureau of Fisheries Document No.
781).
Yokley, P., Jr. 1972. Life Historj' ol Pleurohema cordatum
(Rafinesque 1820) (Bivalvia: Unionacea), Malacologia
11:351-364.
Zale, A. V. 1980. The Life Histories of Four Freshwater
Lampsiline Mussels (MoUusca: IJnionidae) in Big Moccasin
Creek, Russell County, Virginia, MS Thesis, Virginia
Polytechnic Institute and State University, Blacksburg,
256 pp.
Zale, A. v., and R. J. Neves. 1982. Reproductive Biologj' of
P'our Freshwater Mussel Species (Mollusca: Unionidae) in
Virginia, Freshwater Invert. Biol. 1:17-28.
FRESHWATER MUSSELS (BIVALVIA: UNIONIDAE) OF
HORSE LICK CREEK, ROCKCASTLE RIVER, KENTUCKY
Robert J. DiStefano
Virginia Cooperative Fishery Research Unit
Virginia Polytechnic Institute and State University
Blacksburg, VA 24061
ABSTRACT
A survey of the mussel fauna of Horse Lick Creek, a 26.2-km tributary of the
Rockcastle River, was conducted from the fall of 1982 through the summer of 1983.
Twenty-two species of mussels and Corbicula fluminea were recorded, including
the federally endangered Villosa trabalis and state-endangered Pegias fabula. The
stream appears to be one of the last refuges for several Cumberlandian species in
Kentucky.
Horse Lick Creek originates in northeastern
Jackson County, Kentucky, approximately 300
meters east of the Rockcastle-Jackson County
line, and ilows southward 26.2 km (16.3 miles) to
join the Rockcastle River near the boundaries of
Jackson, Laurel and Rockcastle Counties (Fig.
1). The creek is a low-gradient, fourth order
stream, characterized by extensive, deep pools
with intermittent, shallow riffles (Carter and
Jones, 1969). Water chemistry is affected by
limestone deposits, interspersed with shale,
siltstone and sandstone bedrock (Barker et aL,
1979, 1980).
Human impacts such as agriculture, logging
and mining are limited within the Horse Lick
Creek drainage basin, which is 65% forested and
almost totally contained in the Daniel Boone
National Forest. Although roughly 10% of the
Clover Bottom watershed (the largest tributary
to Horse Lick Creek) is disturbed by strip min-
ing (Harker et al, 1980), Horse Lick Creek is
considered one of the highest quality streams in
the upper Cumberland River drainage.
Several mussel surveys have been conducted
on the Rockcastle River at Livingston, Ken-
tucky, downstream of Horse Lick Creek
(Williamson, 1905; Wilson and Clark, 1914;
Blankenship and Crockett, 1972). Blankenship
(1971) reported Pegias fabula (Lea) at two sites
in the lower 3.1 km of the creek, and Harker et
al. (1980) collected 12 mussel species from
Horse Lick Creek during their survey of the up-
per Cumberland River basin. This study was in-
itiated in the fall of 1982 to develop a list of
mussel species in Horse Lick Creek.
Methods and Materials
Shells were handpicked from the stream bot-
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 111
torn using a waterscope; some voucher speci-
mens were taken. The stream banks provided a
paucity of shells. Many sections of the creek
were visited, and collecting stations chosen. The
entire creek below the KY 1955 bridge (Fig. 1)
was floated and/or walked to locate existing
mussel beds. Designated stations were sampled
for a period of 2.5 to 5.5 man-hours. At each sta-
tion, qualitative observations were made on
habitat and mussel abundance.
Scientific names follow those of D. H.
Stansbery of the Ohio State Museum of Zoology,
where voucher specimens have been deposited.
Some specimens have also been retained in the
author's collection.
Collecting Stations
Mussels were collected at eight stations on
Horse Lick Creek and one site (Station 2) on
Clover Bottom (Fig. 1).
Station 1 -The 6.4 km of stream from the KY
1955 bridge downstream to Clover Bottom were
float-surveyed by two individuals.
Station 2 -This site is on Clover Bottom,
about 400 m upstream from its mouth. The sta-
tion is 200 m in length, 6 to 10 m wide, and
varies in depth from 10 to 60 cm.
Station 3 - Located 200 m below the mouth of
Clover Bottom at Horse Lick Creek Mile
(HLCM) 9.4 (15.1 km). The site is 100 m long,
and shallow (30-45 cm). Stream width is approx-
imately 10 m.
Station 4 -This 75 to 80 m section is 12 to 15
m wide, and of variable depth. It is situated at
HCLM 5.5 (8.9 km), about 400 m above the
mouth of Raccoon Creek. The upper riffle in-
cluded a samll center shoal with Justicia sp.
Station 5 -Located approximately 650 m
below the mouth of Raccoon Creek, and 100 m
downstream from a concrete low-water bridge.
Stream width ranges from 10 to 15 m.
Station 6 -Situated at a ford, HLCM 2.0 (3.2
km), extending 100 m upstream of the ford. The
creek here is approximately 12 m wide, deeper
at the upper end, and bordered by several small
beds of Justicia sp.
Station 7-3.0 to 3.1 km above the mouth
(HLCM 1.9), this station is a long (100 m),
shallow (10-30 cm) riffle stretch. Width varies
from 5 to 15 m as the stream winds around and
through several shoals and fallen trees.
FIG. 1. Collecting stations along Horse Lick Creek. Locali-
ties are identified in te.xt.
Station 8 -Located about 0.5 km upstream
from the mouth (HLCM 0.3). This site is 80 m in
length, and changes in habitat composition,
noticeably, from a shallow upper riffle to a
deeper run, with an exposed sandbar along the
mid-section. Stream width varies from 5 to
10 m.
Station 9 -Located 0.2 km above the conflu-
ence of Horse Lick Creek and the Rockcastle
River. The stream width is a fairly constant
10 m.
Results and Discussion
A total of 22 species of naiades and the Asian
clam, Corbicula Jluminea, were collected in
Horse Lick Creek (Table 1). Of the 22 species, 18
were collected live. Villosa taeniata punctata
was the most common mussel species in this
stream. Medionidus conradicus, although not as
112 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
Table 1. Checklist of mussel species found at stations along Horse Lick Creek,
1982 - 1983.
Mussel Species
Actinonaias lipamentina carinata (Barnes, 1823)
Act inonaias pectorosa (Conrad, 183^)
Alasmidonta marginata Say, 1818
Alasmidonta yiridis (Rafinesque, 1820) >
Amblema plicata pi i_c_a t_a (Say, 1817)
Elliptic crassidens crassidens (Lamarck, 1819)
Elliptio dilatata (Raf inesque, 1820)
Lampsilis f asciola Rafinesque, 1820 *
Lampsilis ventricosa (Barnes, 1823)
Lasmlgona costata (Rafinesque, 1820)
Ligumia recta (Lamarck, 1819)
Medionidus conradicus (Lea, 1836) >
Pegiag fabula (Lea, 1838)
Pleurobema oviforme (Conrad, 1834)
Pleurobema sintoxia (Rafinesque, 1820)
Ptychobranchus fasciolaris (Rafinesque, 1820)
Ptychobranchus sub ten turn (Say, 1825)
Strophitus undulatus undulatus (Say, 1817)
Toxolasma lividus lividus (Rafinesque, 1831)
Vlllcsa iris (Lea, 1829)
Villosa taenlata punctata (Lea, 1865) 3
Villosa trabalis (Conrad. 183A)
Corbicula f luminea (Muller)
Station No.
123456789
Total
15 14 14 15
12
* Shells only
X Live specimens
abundant, was found at every station. Other
naiades that were relatively common included
Alasmidonta viridis (especially in upstream sec-
tions), Elliptio dilatata, Ptychobranchus fascio-
laris, and Lampsilis ventricosa. Many freshly
dead valves of Lam,psilis faJiciola were collected
but no live individuals were found. Fallo (pers.
comm.), however, reported a live specimen at
Station 6 following completion of this survey.
The following species were uncommon in Horse
Lick Creek: Actinonaias ligamentina carinata,
Alasmidonta marginata, Amhlema plicata, El-
liptio crassidens, Pleurobema sintoxia, Ptycho-
branchus subtentum and Strophitus undulatus.
Villosa trabalis, a federally endangered spe-
cies (U.S. Fish and Wildhfe Service, 1982), has
been reported extirpated from most of the Cum-
berland River drainage in Kentucky (Clarke,
1983). This species was found live at stations 4
(7 specimens) and 6 (3 specimens), and freshly
dead specimens were collected at station 8. Live
mussels were located in sandy habitat im-
mediately above or on the edge of riffles, where
the current was slower.
Six live specimens of Pegias fabula. desig-
nated as endangered in Kentucky by the Ken-
tucky Academy of Science (Branson et al.,
1981), were observed at stations 3, 5 and 6.
Freshly dead valves of this species were also col-
lected at stations 4, 6, 7 and 9. Blankenship
(1971) found several live individuals at a site
near station 7 on Horse Lick Creek, while
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 113
Marker et al. (1980) reported a live specimen ap-
proximately 100 m upstream from station 5. Lit-
tle is known about the habitat preferences of
Pegias fabula. Blankenship (1971) and Starnes
and Bogan (1982) reported individuals laying on
or imbedded in the substrate. In this study,
specimens were found laying on the substrate,
buried in the gravel and sand substrates of pools
and riffles, and beneath large rocks (20-50 cm
diameter).
The occurrence of Pleurobema oviforme, Pty-
chobranchios subtentum. and Toxolasma lividus
in Horse Lick Creek is also noteworthy. The
first two species are listed as threatened in Ken-
tucky, and the latter is of special concern (Bran-
son et a/., 1981).
Alasmidonta viridis appeared to prefer sandy
substrate in slower currents. Ptychobranchus
fasciolaris was usually collected in the slack-
water immediately above a riffle. Medionidus
conradicus seemed to favor fast riffles, but also
occurred in high densities under large rocks
(20-50 cm diameter).
This survey indicates that Horse Lick Creek
contains a diverse and healthy assemblage of
mussels, especially for a stream of its size. The
scarcity of live individuals near the mouth (sta-
tion 9) might be attributed to sampling difficulty
due to depth, or to the presence of a red
precipitate along the banks, possibly iron ocher
from a local coal mine.
Horse Lick Creek appears to be one of the few
remaining refuges for several Cumberlandian
species of mussels in Kentucky, including
Villosa trabalis and Pegias fabula. Adverse im-
pacts to the watershed by human intervention
appear minimal at this time. The author urges
that steps be taken to insure the future integrity
of this stream in order to preserve the few re-
maining endangered species.
Acknowledgments
The author wishes to thank Robert S. Butler,
Glen J. Fallo, Yvonne Thompson, Mark J. Vogel
and Elizabeth J. Ziegler for field assistance.
Richard J. Neves, Louis A. Helfrich, and Ronald
R. Cicerello reviewed the manuscript, and
Arthur H. Clarke provided verification of the
identifications. Eastern Kentucky University,
Department of Biological Sciences provided sup-
plies and facilities. Guenter A. Schuster pro-
vided field assistance, review of manuscript, and
invaluable guidance.
LITERATURE CITED
Blankenship. S. 1971. Notes on Alanmidonta fahulri (Lea) in
Kentuci<y (Unionidae). The Nautilm 85(2):60-61.
Blankenship, S. and D. P. Crockett. 1972. Changes in the
freshwater mussel fauna of the Rockcastle River at Liv-
ingston, Kentucky. Trans. Kentucky Acad. Sci. 33:37-39.
Branson, B. A., D. F. Harker, .Jr., J. M. Baskin. M. E.
Medley, D. L. Batch, M. L. Warren, Jr.. W. H. Davis, W.
C. Houtcooper, B. Monroe, Jr., L. R. Phillippe and P.
Cupp. 1981. Endangered, threatened, and rare animals
and plants of Kentucky. Trans. Kentucky Acad. Sci.
42(3-4):77-89.
Carter, J. P. and A. R. Jones. 1969. Inventory and classifica-
tion of streams in the Upper Cumberland River Drainage.
Kentucky Dept. Fish and Wildlife Res., Fish. Div.. Frank-
fort, Ky." Fish. Bull. No. .52. 70 pp.
Clarke, A. H. 1983. The distribution and relative abundance
of Lithasia pinguis (Lea). Pleurobema plenum (Lea),
Villosa traba.lis (Conrad), and Epioblasma sampsoni
(Lea). Amer. Malac. Bull. 1:27-30.
Harker, D, F., Jr., S. M. Call, M. L. Warren, Jr., K. E. Cam-
burn and P. Wigley. 1979. Aquatic biota and water quality
survey of the Appalachian Province, eastern Kentucky.
Kentucky Nat. Pi-es. Comm. Tech. Rep.. Frankfort, Ky.
11.52 pp.
Harker, D. F., Jr., M. L. Warren, Jr., K. E. Camburn, S. M.
Call, G. J. Fallo and P. Wigley. 1980. Aquatic biota and
water quality survey of the LIpper Cumberland River
Basin. Kentucky Nat. Pres. Comm. Tech. Rep., Frankfort,
Ky. 679 pp.
Starnes, L. B. and A. E. Bogan. 1982. Unionid mollusca (bi-
valvia) from Little South Fork Cumberland River, with
ecological and nomenclatural notes. Brimleyana
8:101-119.
U. S. Fish and Wildlife Service. 1982. Endangered and
threatened wildlife and plants. Federal Register. U. S.
Dept. of the Interior, 50 CFR 17.11 and 17. 12. 13 pp.
Williamson, E. B. 190.5. Odonata, Astacidae, and Unionidae
collected along the Rockcastle River at Livingston, Ken-
tucky. The Ohio Naturalist. 5(6):309-312.
Wilson, D. B. and H. W. Clark. 1914. The mussels of the
Cumberland River and its tributaries. Bur. of Fish. Doc.
781:1-63.
114 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
EFFECTS OF DENSITY AND SAMPLING TIME ON THE GROWTH
OF THE HARD CLAM, MERCENARIA MERCENARIA,
PLANTED IN PREDATOR-FREE CAGES IN COASTAL GEORGIA
Randal L. Walker
Skidaway Institute of Oceanography
P. 0. Box 13687
Savannah, GA 31416-0687
ABSTRACT
Hard clams, Mercenaria mercenaria (Linne), were planted in predator-free
cages on an intertidal sandflat at Cabbage Island at densities of 509. 1009, 2018
and 3027/m^. Replicate plots per density were sampled monthly and seasonally,
with clams at all four densities sampled seasonally growing significantly greater
(analysis of variance °^ = 0.05) in shell length than those sampled monthly and
within the same time period. The seasonally sampled cage was lost after 6 months.
Clams planted at the lowest density and sampled monthly reached commercial
size (iJf mm) in 16 months with 52% of the clams being legal size. After 19 months,
83% of the clams at 509 m^ had obtained legal size as compared to 57, 13 and 3%
for the clams grown at 1009, 2018 and 3027lm^. Overall clam survival increased
from, 77% after the first month to > 99% three months later, and remained greater
than 99% throughout the remainder of the experiment. Survival of clams less than
18 mm in shell length is dependent upon the monthly removal of newly meta-
morphosed crabs from within cages.
The hard clam, Mercenaria mercenaria
(Linne), represents a new and potentially impor-
tant fishery for the State of Georgia. Clamming
is presently a winter activity in Georgia per-
formed by crabbers during their slack season.
Thus it is viewed primarily as a potential supple-
ment to the blue crab, Callinectes sapidus
(Rathbun), fishery in Georgia.
The coastal waters of Georgia contain approx-
imately 450,000 acres of salt marsh much of
which is pollution-free and maintains sizable
shellfish populations. As more northern waters
are closed to shellfishing, due to pollution (Na-
tional Marine Fisheries Service, 1977), the
potential opportunity for utilizing the coastal
waters of Georgia for culturing shellfish in-
creases.
Previous hard clam density studies (Manzi et
a/., 1980; Eldridge et ai, 1979; Godwin, 1968)
utilized larger-size seed clams (11 to 26 mm)
planted at densities up to 3040/m^ and only
Eldridge et al. (1979) maintained initial densities
(290, 869, and 1159/m^). The purpose of this
study is to determine the feasibility of planting
smaller-size and less expensive seed clams (6
mm) at high densities in predator-free cages in
the coastal waters of Georgia.
Methods
Two cages (1 x 1 x 0.5 m) constructed of
3-mm-mesh vexar plastic attached to a frame of
13-mm steel reinforcement rods were divided in-
to nine compartments (0.1 1/m^). Cages were
buried to a depth of 0.25 m in May 1982 on an in-
tertidal sand flat at Cabbage Island, Georgia
(Fig. 1). In June 1982, 6-mm seed clams supplied
by Aquaculture Research Corporation, Dennis,
Massachusetts, were planted at the following
replicate density per cage: 56, 111, 222 and 333
per 0.1 1/m^ or the equivalent to 509, 1009, 2018
and 3027/m\ respectively. The center compart-
ment of each cage was seeded with approxi-
mately 500 clams used as replacements for dead
clams. A third cage was stocked with 2,000
clams to be used as replacements.
Cage I was sampled monthly while Cage II
was sampled seasonally. In Cage I, clams, crabs
and sediment to a depth of 10 cm were sieved
through a 5-mm mesh screen. Clams were
counted, a subsample (N = 70) measured for shell
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 115
FIG. 1. Map of Wassaw Sound showing experimental study
sites.
length (longest possible measurement, i.e.,
anterio-posterior), additional clams added if
needed and returned to their respective com-
partments. Crabs were identified to species,
measured for carapace width and discarded.
Cage II was sampled as above, but seasonally;
however, the top cm of sediment was sieved
monthly to remove newly set crabs (blue crabs,
Callinectes sapidus Rathbun, and/or mud crabs,
Panopeus herbsti Milne-Edwards). Cage I was
sampled seasonally beginning January 1983,
since monthly clam survival had obtained and
remained at approximately 100% for several
months.
Results
Clam growth and survival in Cage II were
high until the cage washed out during a severe
storm in January 1983. Clams grew from a
mean shell length of 6.1 to 28.3 mm in 6 months
(Table 1) or at a rate of 3.7 mm per month.
Growth rates are given in Figure 2. No differ-
ences in final size or in percent survival between
densities (ANOVA « = 0.05) occurred. Clam
survival increased with time and growth from
75 to 87% (Table 1).
In Cage I (sampled monthly) clams grew from
a mean shell length of 6.1 to 49.7 mm in 18
months (Table 2); however, differences in
growth between all densities (ANOVA « = 0.05)
occurred in September 1983, 14 months after
planting. By September 1983, 52, 31, 4 and 0%
of the clams planted at 509, 1009, 2018 and
3027/m\ respectively had reached the legal size
TABLE 1. Growth in mm and percent survival of hard clams planted at densities of 509,
1009, 2018, and 3027/m' and sampled seasonally on an intertidal sandflat at Cabbage
Island, Georgia.
116 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
Growth of Mercenaria mercenaria
seasonal
2018 m ■=
3027 m"2
60-
"g 50
« 40-1
Ol
I 30
"S 20-
10-
l)i
= 6 09x'
= 0 9999
2) y .6 0<lx'"° ,r2, 0 9983
3J y=6.13x°",r2=09997
4)y =6,12x"",r2=09998
monthly
5) y =5 40x°" ,r2=0.9794
6) y-5.75x°'°,r2 =0.9850
7) y =5,97x°^'' r2.0.9814
8)y =6.09x°^' , r2=0.9753
M J J A S 6 N b J F M A M J J A S 6 l>J 6
1982 I 1983
FIG. 2. Growth curves of hard clams planted at different
densities and sampled monthly and seasonally. Y = shell
length in mm and x = time in months.
limit of 44.4 mm shell length proposed for
Georgia (Walker, 1984). By December 1983, 83,
57, 13 and 3% of the clams planted at 509, 1009,
2018, and 3027/m^ respectively, had obtained
this size. Overall clam survival increased from
77% in July to > 99% after 4 months (Table 3).
Overall clam survival was > yy% throughout the
remainder of the experiment.
Differences in shell length for equivalent den-
sities between monthly and seasonal cages
(ANOVA oc = 0.05) occurred. In September
1982, clams sampled seasonally had grown ap-
proximately 29% greater in shell length (3.7
mm/m') than those of equivalent densities but
sampled monthly (2.8 mm/m'). By December
1982, the difference in shell length between
cages sampled monthly and seasonally was 20%
and significant (ANOVA « = 0.05)
Discussion
Optimum seeding density for the hard clam
has yet to be determined. Eldridge et al. (1979)
planted seed clams (13 mm) and maintained den-
sities of 290, 869 and 1159/m^ in cages in the
coastal waters of South Carolina. Clams at the
lower density reached commercial size (44 to 45
mm) in 19 months after planting with clams at
the highest density taking an additional 12
months to obtain this size. In other experiments,
hard clams (11 mm) were planted at densities of
380, 760, 1520 and 3040/m' in protected cages in
South Carolina (Manzi et al.. 1980). Clams grew
from 11 mm (according to methods) or 13.9 mm
(according to Table 1) to 39 to 40 mm in shell
length in 13 months. No differences in final size
TABLE 2. Growth in mm of hard
3027/m^ and sampled monthly on an
clams planted at densities of 509, 1009, 2018. and
intertidal sandflat at Cabbage Island, Georgia.
Vol. 98(3)
July 27, 1984
THE NAUTILUS 117
TABLE 3. Average percent survival per clam density per month for hard clams planted in
protective cages on an intertidal sandflat at Cabbage Island, Georgia.
Density
Overal )
509m-2 1009ni-2 ?018m-2 3027m-2 Survival
between densities occurred; however, survival
ranged from 9 to 19% and densities at the end of
the experiment were approximately equal. In
Georgia, clams (13 to 26 mm) were planted in
cages and unprotected plots at densities of 108,
269, 538 and 807/m^ (Godwin, 1968). No dif-
ference in final size (ANOVA « = 0.05) occur-
red, but mortality ranged from 0 to 60% in
cages and 48 to 100% in unprotected plots.
Eldridge et al. (1979) recommends seeding plots
with 12 to 15 mm-size seed clams at 300/m^
Menzel (1971a, b) recommends 250 to 538/m^ as
a suitable seeding density. In this experiment,
seed clams at 509/m^ reached an average size of
44 mm in 16 months as compared to 19 months
for a larger size seed clam in South Carolina
(Eldridge et al, 1979). Clams at 1009/m' in this
study were approaching 44 mm after 16 months
and reached it after 19 months, indicating an op-
timum seeding density of 500 to 750/m^ for
Georgia.
In this experiment, 6-mm seed clams were
tested as compared to > 11-mm size used by
Manzi et al. (1980), Eldridge et al. (1979), and
Godwin (1968). Clam survival in this study using
6-mm seed clams was higher than that for >
11-mm in the other experiments because cages
were checked monthly to remove newly set
crabs (Fig. 3). When the replacement seed clam
cage was checked in October, 1982, there were
no clams but one 75-mm blue crab. Cages seeded
earlier at the same site with 10-mm clams and
checked seasonally had 14 to 31% survival after
a year (Walker, 1984) because blue crabs and/or
mud crabs settled in the cages and were allowed
to obtain a size capable of preying upon the
clams. Thus, if the top cm of sediment is sieved
to remove crabs at least monthly until clams
reach approximately 18 mm, then high clam sur-
vival is possible and clam mariculture at high
densities is feasible.
The difference in growth as a function of sam-
pling time is important in terms of clam growth
and survival. The difference in growth between
clams sampled monthly and those sampled sea-
sonally may be due to stress. Before planting,
clams had been stressed due to handling and
shipping procedures. Once planted, clams in
Cage I were stressed monthly by being redug
and handled; whereas, those in Cage II received
this treatment only seasonally. Clams in these
cages appear to be relatively free of predation
from blue and mud crabs once they reach a shell
length of 18 mm (Table 3). Clams sampled sea-
sonally obtained this size a month earlier than
those sampled monthly. Crabs which enter the
cages in this experiment were removed monthly
and were not allowed to reach sufficient size to
118 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
10-
9-
8-
*» 7-
o
»- 6
O
h.
<j 5-
E
3
2 .
3-
1-
^Blue Crabs
I I Mud Crabs
ili
LJ
I
Aug
Sep Oct
1982
Nov
Dec
1983
FIG. 3. Number and species of crabs removed from experimental clam cages locateci on an
intertidal sandflat at Cabbage Island. The number in parenthesis is the average carapace
width per crab species.
prey upon larger size clams (i.e., for P. herbsti
35 mm (Whetstone and Eversole, 1977) and for
C. sapidus 40 mm (Arnold, 1983)). Since pre-
venting crab entry is not possible, high clam sur-
vival is dependent upon removal of crabs and
clams growing to a predation-free size.
Planting time may also prove to be an impor-
tant factor in clam growth, and survival. In the
southeastern United States clams grow year
around with best growth occurring in fall and
spring (Eldridge et ai, 1976, 1979; Menzel,
1963). Mercenaria mercenaria seed clams ob-
tained from a Connecticut hatchery and grown
in coastal Florida grew well in spring and fall
with slow growth in winter and least growth in
summer; however, with natural sets of Mer-
cenaria campechiensis seed clams growth was
best in spring and fall, rapid in summer and
slowest in winter (Menzel, 1963). Mercenaria
mercenaria seed clams from a North Carolina
hatchery and planted in coastal South Carolina
grew best in spring and fall, with least growth in
winter (Eldridge et ai, 1979). In Georgia,
Mercenaria mercenaria seed clams from a
Virginia hatchery and those spawned from a
natural Georgia stock grew best in spring and
fall with good growth in summer and least
growth in winter (Walker, 1984 and unpublished
data). Thus, by planting in early spring in
Georgia, clams may be allowed to pass through
three seasons of good growth before reaching
the winter growth period. Furthermore, by
planting in early spring or late winter, clams
may grow to a sufficient size to prevent their
predation by newly metamorphosed crabs which
enter the cages. Blue crab spawning occurs
from early May through October in Chesapeake
Bay (Van Engle, 1958), from March to Septem-
ber in Georgia (Palmer, 1974) and from Febru-
ary to October in Florida (Tagatz, 1968). Peak
spawning for blue crabs occurs from June to
October. Mud crabs spawn from late spring
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 119
through summer in South Carolina with highest
numbers of newly metamorphosed crabs occur-
ring in July and August (Dame and Vernburg,
1982) and from February to October in Florida
with peak spawning in June to October (Tagatz,
1968). Thus, by planting seed clams in late
winter or early spring, clams may grow to suffi-
cient size to prevent predation by newly meta-
morphosed crabs in Georgia before the peak
spawning season of crabs are reached.
Acknowledgments
The author wishes to thank Drs. E. Chin, J.
Harding and K. Tenore for reviewing the manu-
script. Special thanks are given to Ms. A.
Boyette and S. Mcintosh for the graphics and to
L. Land for typing the manuscript. The work
was supported by the Georgia Sea Grant Pro-
gram, under grant number USDL-RF/8310-21-
RRlOO-102.
LITERATURE CITED
Arnold, W. S. 1983. The effects of prey, predator size and
sediment composition in the rate of predation of the blue
crab (Callinectes sapidus Rathbun) on the hard clam (Mer-
cenaria mercenarin Linne). Masters Thesis. Department
of Zoology, University of Georgia, Athens. Georgia. 47 pp.
Dame, R. F. and F. J. Vernburg. 1982. Energetics of a popu-
lation of mud crab, Pnnopeus herbstii (Milne-Edwards) in
the North Inlet Estuary, South Carolina. Jour. Exp. Mar.
Biol. Ecol. 63:183-193'.
Eldridge, P. J., W. Waltz, R. C. Gracy and H. H. Hunt. 1976.
Growth and mortality rates of hatcherv seed clams, Mer-
cenaria tnercenana. in protected trays in waters of South
Carolina. Proc. Natl Shellfish. Assoc. 66:13-20.
Eldridge, P. J., A. B. Eversole, and J. M. Whetstone. 1979.
Comparative survival and growth rates of hard clams,
Mercenaria mej-cenaria. planted in trays subtidally and in-
tertidally at varving densities in a South Carolina estuarv.
Proc. Natl. Sheilfi,sh. Assoc. 69:30-39.
Godwin, W. F. 1968. The growth and survival of planted
clams. Mercenaria ■mercenaria. on the Georgia coast. Mar.
Fish. Division. Georgia Game and Fish Comm.. Contrih.
Series No. 9. 16 pp.
Manzi, J. J.. V. G. Burrell, Jr. and W. Z. Carson. 1980. A
mariculture demonstration project for an alternative hard
clam fisherj" in South Carolina: Preliminary results. Pro-
ceed. World Mariculture Soc. 11:79-89.
Menzel, R. W. 1963. Seasonal growth of the northern qua-
hog, Mercenaria mercenaria and the southern quahog, M.
campechinesis. in Alligator Harbor, Florida. Proc. Natl.
Shellfish. Assoc. 52:37-46.
1971a. Quahog clam.s and their possible maricul-
ture. Proc. Seco7id Ann. Workshop. World Mariculture
Soc. :23-36.
1971b. The mariculture potential of clam farm-
ing. Amer. Fish Farmer 2:8-14.
National Marine Fishery Service. 1977. The nwlluscan shell-
fish indMStries atid water quality: Problems and Oppor-
tunities. U.S. Dept. of Commerce. NOAA, Natl. Mar. Fish.
Ser., Off. Fish. Devel., Supt, Docs., Washington, D.C. v +
46 pp.
Palmer, B. A. 1974. Studies on the blue crab {Callinectes
sapidus) in Georgia. Georgia Dept. of Natl. Resources.
Brunswick, Georgia. Contribution Series No, 29, 59 pp.
Tagatz, M. D. 1968. Biology of the blue crab, Calliiiectes
sapidus Rathbun, in the St. .Johns River, Florida. Fish.
Bull. 67:17-33.
Van Engle, W. A. 1958. The blue crab and its fishery in
Chesapeake Bay. Part I: Reproduction, Early Develop-
ment, Growth and Migration. Comm. Fish. Revieiv 20:
6-17.
Walker, R. L. 1984. Population dynamics of the hard clam,
Mercenaria mercenaria (Linne) and its relation to the
Georgia hard clam fishery. Masters Thesis. Department of
Applied Biology, Georgia Institute of Technology, Atlanta,
Georgia. 121 pp.
Whetstone, J. M. and A. G. Eversole. 1981. Effects of size
and temperature on mud crab, Panopeus herbsti. preda-
tion on hard clams, Mercenaria merceyiaria. Estuaries
4:153-156.
OCCURRENCE OF THE STRIPED RAM'S HORN SNAIL,
MARISA CORNUARIETIS, IN CENTRAL TEXAS (AMPULLARIIDAE)
Raymond W. Neck
Texas Parks and Wildlife Department
4200 Smith School Road
Austin, TX 78744
Marisa comuarietis (Linnaeus, 1758) is a
large planorboid-shaped, prosobranch snail be-
longing to the apple snail family, Ampullariidae.
Native to an area of tropical America from
Panama to the Guianas and Trinidad (Baker,
1930; Pain, 1950), this species has subsequently
become established in Puerto Rico, Cuba and
Florida (Harry and Cumbie, 1956; Penalver,
1950; Hunt, 1958).
In June 1983, a population of Af. comuarietis
120 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
was discovered in the San Marcos River in a
municipal park in San Marcos, Hays Co., Texas.
A sample of ten adults and two juveniles was
collected in a short period of time. Within the
park, a portion of the banks of the river consist
of concrete walls which support a noticeable
growth of algae. Water temperature and chem-
istry are relatively constant, because the locality
is only 550 to 850 river-meters below San Mar-
cos Springs. Water temperature of San Marcos
Springs varies from 21.7°C to 23.3°C. Dissolved
chemical levels are fairly constant, e.g. clacium,
81 to 90 mg/1; magnesium, 15 to 21 mg/1; bicar-
bonate, 250 to 334 mg/1; pH, 6.6 to 7.8; dis-
solved solids, 310 to 349 mg/1 (Guyton &
Associates, 1979).
The population sample included adult and ju-
venile snails with variation in number of bands
as well as darkness of bands and background
color. Most likely source of the population is a
disgruntled aquarist who discovered that M. cor-
nuarietis eats essentially all aquatic vegetation.
Unwanted and released animals often become
environmentally destructive. (Courtenay and
Robins, 1973). '
Degree of environmental impact of M. cor-
nuarietis upon the aquatic communities of cen-
tral and southern Texas in the future will be
determined by degree of tolerance to low winter
temperatures and poor summer water quality in
habitats other than spring-fed streams. Pain
(1950) reported a "preference for small clear
woodland streams and pools." Robins (1971)
reported that M. cvmuarietis withdraw into
shells and aggregate on the bottom at water
temperatures of 19°C and below. Five hours ex-
posure to 8°C is fatal, but this species can sur-
vive 24 hours at 11°C. On the upper end of the
range of thermal range, M. comuarietis feed
normally at 35.5°C with the "upper limit" of the
short-term heat tolerance being 39°C (Robins,
1971).
Substantial environmental impact is possible
according to previous studies on Marisa
(Robins, 1971). Environmental impact could be
greatest upon the restricted Central Texas
Spring Snail, Elirnia (Elimia) comalensis
(Pilsbry, 1890), which occurs in this portion of
the San Marcos River. At the present time these
two aquatic snails occur micro-sympatrically on
the algae-covered concrete walls. However, at
this point no data exist concerning population
trends of either species. Also present on the
banks of the San Marcos River is Texas wild
rice, Zizania texana Hitchcock, a species cur-
rently listed as Endangered by the U.S. Fish
and Wildlife Service. Likelihood of feeding by
M. comuarietis upon roots of Z. texana is
unknown at this time.
Ongoing studies are concentrating on biono-
mics and potential expansion of Marisa cor-
nuarietis in Texas waters.
I thank Brian D. Frisbie for bringing this
population to my attention.
LITERATURE CITED
Baker, H. B. 1930. The Mollusca collected by the University
of Michigan-Williamson Expedition in Venezuela. Occ.
Papers Mus. Zool. U. Michigan 210:1-94.
Courtenay, W. R. Jr. and C. R. Robins. 1973. Exotic aquatic
organisms in Florida with emphasis on fishes: A review
and recommendations. Trans. Amer. Fish. Soc. 102:1-12.
Guyton, W. F. and Associates. 1979. Geohydrology of Com-
al, San Marcos, and Hueco Springs. Texas Dept. Water Re-
sources Report 234:1-85.
Harry, H. W. and B. G. Cumbie. 1956. Stream gradient as a
criterion of lotic habitats suitable for Australorbis glabra-
tus in Puerto Rico. Am. J. Tropical Medicine and Hygiene
5:921-928.
Hunt, B. P. 1958. Introduction of Mama into Florida. The
Nautilus 72:53-55.
Pain, T. 1950. Pomacea (Ampullariidae) of British Guiana.
Proc. Malacol. Soc. London 28:63-74.
Penalver, L. M. 1950. Infeccion experimental de moluscos
fluviales Cubanos con Schistosoma mansoni. Arch.
Venezol. Patol. Trap, y Parasitol. Med. 2:297-308.
Robins, C. H. 1971. Ecology of the introduced snail, Marisa
comuarietis (Ampullariidae) in Dade County, Florida. The
Biologi.'it 53:U6-152.
Vol. 98(3)
July 27, 1984
THE NAUTILUS 121
AGATHODONTA NORTONI. NEW SPECIES: LIVING MEMBER OF A
LOWER CRETACEOUS TROCHID GENUS
James H. McLean
Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, CA 90007
ABSTRACT
Agathodonta nortoni, new species, from archibenthal (300 meter) depths in the
Philippines, repr-esents a living record of a genus presum.ed extinct since the
Lower Cretaceous. It is assigned to the tribe Chilodontini, subfamily Margariti-
nae, in agreement with an earlier placem,ent of other living genera in this group.
In a preliminary report on classification of the
trochid subfamily Margaritinae (McLean, 1982),
I assigned such Recent genera as Euchelus
Philippi, 1847, Danilia Brusina, 1865, and Tur-
cica A. Adams, 1854, to the tribe Chilodontini of
the subfamily Margaritinae, a group previously
regarded as limited to the Mesozoic, Middle
Triassic through Upper Cretaceous. My alloca-
tion of these genera was based on a similarity of
sculpture, aperture shape, and apertural denti-
tion among the fossil and living genera.
Here I describe a new Recent species of the
chilodontine genus Agathodonta Cossmann,
1918, which until now had been known only in
the European Neocomian and Albian Stages of
the Lower Cretaceous, 110 to 135 million years
in age. This living link to such Mesozoic genera
as Pseudoclanculus Cossmann, 1918, Chilodon-
toidea Huddleston, 1896, Wilsoniconcha Wenz,
1939, Chilodonta Etallon, 1862, and the Recent
genera mentioned above is a further indication
that the Recent genera are related to the fossil
genera of the Chilodontini.
Shell characters of the chilodontine genera
are: clathrate sculpture, some expression of
apertural dentition, and an oblique aperture
with the entire apertural rim in the same plane,
enabling a close fit against the substrate. Living
genera have epipodial and radular features in
common, essentially as described by Beu and
Climo (1974) for their new species Danilia in-
sperata. Based on shell and radular characters,
Mirachelus Woodring, 1928, is also a member of
the group.
This and my earlier note (McLean, 1982), are
preliminary to a full revision of higher classifica-
tion in the Trochacea (in collaboration with C. S.
Hickman), in which epipodial and radular char-
acters of chilodontine genera will be illustrated.
Genus Agathodonta Cossmann, 1918
Agathodonta Cossmann, 1918: 200; Wenz, 1938: 296 [as
"Agnathodonta"]; Cox, in Knight et ai, 1960: 249. Type
species (original designation): Trochus dentigerus
Orbigny, 1843. Lower Cretaceous (Neocomian).
Agathodonta dentigera (Orbigny, 1843)
Trochus dentigerus Orbigny, 1843: 185, pi. 77, figs. 9-12.
Agathodonta dentigera, Cossmann, 1918: 200, pi. 7, figs.
8-11; Wenz, 1938: 298, fig. 653; Cox, in Knight et. al.
1960: 249, fig. 160, 2.
"High turbiniform, anomphalous, with strong-
ly convex whorls and base; ornament granose
spiral cords; columellar lip with two strong, ob-
tuse teeth." Cox, in Knight et al. (1960).
In addition to the type species, Cossmann
(1918) referred two other species to Agatho-
donta: Trochus guyotianus and T. tollotianus.
both of Pictet et Roux, 1849, from the Albian
Stage of the Lower Cretaceous.
Agathodonta is characterized by two pro-
nounced columellar plications, a trait shared
with the Jurassic Wilsoniconcha Wenz, 1939,
which differs in having a pupiform shape, and
the Recent Turcica, which has a much larger
shell with flat-sided whorls. Turcica was as-
signed by Keen, in Knight et al. (1960), to the
Monodontinae, but is related to Euchelus and
Danilia on the basis of radular, and epipodial
characters.
The genus Danilia, recently reviewed by Beu
& Climo (1974), differs irom Agathodonta in hav-
ing an exterior thickening of the final lip, and in
122 THE NAUTILUS
July 27, 1984
Vol. 98(3)
having a single columellar plication. According
to these authors, Danilia has a fossil record
dating from the Lower Cretaceous (Albian),
nearly as old as Agathodonta. Six living species
of Danilia were reported to occur offshore in
archibenthal depths similar to those in which
our new species of Agathodonta is found.
The only living trochacean genus with a
longer fossil record than that of Agathodonta is
Angaria Roding, 1798, which dates from the
Upper Jurassic (Cox in Knight et ai, 1960).
Rather few living trochacean genera originated
as early as in the Mesozoic. Aside from Angaria.
Agathodonta, and Danilia. only 13 additional
living trochacean genera were reported by
Keen, in Knight et al. (1960), in the Mesozoic, all
in the Upper Cretaceous. .
Agathodonta nortoni, new species
Figures 1-3
Description of holotype -^heW small; height
10.6 mm, maximum diameter 7.8 mm. Perio-
stracum thin, in lamellar ridges; color uniformly
buff with scattered, irregular brown markings.
Protoconch eroded, teleoconch whorls .572;
whorls rounded, suture deeply impressed,
slightly descending on last whorl; aperture
markedly oblique; umbilicus absent. Spiral
sculpture of strong cords and equal interspaces:
3 on 2nd whorl, 4 on third whorl, 6 on 4th and
penultimate whorl, seventh cord emerging at
aperture; base with 3 additional cords. Axial
sculpture of oblique ribs weaker than spiral
cords, producing strong projecting nodes at in-
tersections. Aperture circular, nacreous within;
columellar wall with two strong projecting
folds, uppermost the larger, with notch and ad-
jacent denticle below the two main plications;
columellar shield forming a slightly raised
peritreme, nearly concealing spiral sculpture
over which it lies; columellar shield with 6 low
tubercles. Lip thickened by apertural ridge
within, with 9 lirae corresponding to interspaces
of exterior spiral cords; apertural ridge with
single, small pustules between lirae. Chitinous
operculum present.
Type locality -296-320 m on sand bottom, off
Baltazar Island, Marinduque Province, Philip-
pine islands (approximately 13°14'N; 121°49'E)
(coordinates of island, U.S. Board on Geo-
graphic Names Gazeteer).
Holotype -hos Angeles County Museum of
Natural History (LACM), cat no. 2031, collected
by James E. Norton, 17 October 1966. The
single specimen was collected alive; the oper-
culum was in place but efforts to extract the
operculum and body after soaking in trisodium
phosphate solution were unsuccessful.
Discussion -Agathodonta nortoni is smaller
than the Cretaceous A. dentigera, for which
Orbigny gave a height of 18 mm. It further dif-
fers from A. dentigera in having the interior of
FIGS. 1-3. Agathodonta nortoni new species, holoty))e; shell length 10. (i mm. 1, Apertural view; the uppermost columel-
lar plication does not show in this view; 2, Oblique dorsal view; 3, View perpendicular to the plane of the aperture, show-
ing the two columellar plications, a notch anil bordering node belcjw the lowermost plication, the apertural ridge and
strong lirae.
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 123
the outer lip thickened and prominently lirate,
rather than thin and smooth.
Although I prefer not to base new species on
single specimens, this species can be confused
with no other. I therefore make an exception to
call attention to the record of this genus in the
Recent fauna.
The name commemorates the late James E.
Norton, whose collecting in the Philippines dur-
ing the 1960s has greatly enhanced the research
potential of the LACM mollusk collection.
(Note Added In Proof)
In a recently published paper, Guidastri et al.
(1984) transferred Putzeysia Sulliotti, 1889,
from the Cailiostomatinae to the Margaritinae,
noting that the Mediterranean species P. wiseri
(Calcara, 1842) has many features of such
genera as Danilia Brusina, 1865, and Miy'ache-
lus Woodring, 1928, except for lacking the col-
umellar tooth of these genera. Putzeysia is
evidently another member of the tribe Chilo-
dontini, one lacking apertural dentition, as does
Euchelus Philippi, 1847.
Acknowledgments
I am particularly grateful to Tina Norton
(Mrs. James E. Norton) for the gift of the Nor-
ton Collection to the LACM in 1981. I also thank
Alan G. Beu, Eugene Coan, Myra Keen, and
Patrick I. LaFollette for reading the manuscript
and offering helpful suggestions.
LITERATURE CITED
Beu, A. G. c& F. M. Climo. 1974. Mollusca from a Recent cor-
al community in Palliser Bay, Cook Strait. New Zealand
Journal of Marine and Freshwater Research 8:307-332.
Cossmann, M. 1918. Essais de Paleuronchologie comparee.
Paris, vol. 11, 388 pp., 128 text figs., 11 pis.
Guidastri, R., G. Melone & M. Taviani. 1984. Systematic
position of "Trochus" wiseri Calcara (Prosobranchia:
Trochidae). Arch. Moll.. 143:125-136.
Knight. J. B., L. R. Cox. A. M. Keen, R. L. Batten, E.
Yochelson, & R. Robertson, 1960, Systematic descriptions
(Archaeogastropoda). in R. C. Moore, Ed., Treatise on
Invertebrate Paleontology. Part I. Mollusca 1: 169-310,
Geological Society of America and University of Kansas
Press.
McLean. J. H. 1982. Importance of gill structure in trucha-
cean classification. The Western Society of Malacologists,
Annual Report 14:11.
Orbigny, A. d'. 1842-1843. Paleontologie Frangaise, Ter-
rains Cretares. Paris, 456 pp.; Atlas, pis. 149-236.
Wenz, W. 1938. Gastropoda. Handhuch der Pala£ozoologie.
vol. 6. Teil 1: Allgemeiner Teil und Prosobranchia. Berlin,
1639 pp.
CRITIQUE ON STENZEL'S BOOK ON THE OSTRACEA
David Nicol
Box 14376, University Station
Gainesville, Florida 32604
ABSTRACT
Stenzel assumed that the Ostracea are diphyletic and that the Gryphaeidae and
the Ostreidae arose independently from two similar but different ancestral
groups. Although the fossil record of the Ostracea is excellent, the stratigraphic
evidence tends to refute Stenzel's assumption. It is more likely that the
Gryphaeidae appeared first and that the Ostreidae arose later from a gryphaeid
ancestor. The Ostracea are a distinctive group and appear to be monophyletic.
Stenzel (1971) subdivided the superfamily
Ostracea into two families, five subfamilies,
three tribes, and more than 50 genera and sub-
genera. This includes both fossil and living taxa,
and the fossil record of the Ostracea is excellent
because the shell is commonly thick and com-
posed of resistant calcite. Furthermore, the
Ostracea live in shallow seas where the fossil
record is best. Stenzel did not analyze his exten-
sive data of these groups stratigraphically. If
one looks at the geologic ranges of the families,
subfamilies, and tribes, one will see a significant
fact (Fig. 1). All of the taxa above the generic
level appeared no later than the middle Cretace-
124 THE NAUTILUS
July 27, 1984
Vol. 98(3)
FIG. 1. Geologic ranges of families, subfamilies, and tribes of the Ostracea. Dotted lines indicate doubtful
distribution.
ous, about 100 million years ago and no more
than 95 million years after the Ostracea appear
in the fossil record. In other words, no new
families, subfamilies, or tribes of the Ostracea
have appeared in the last 100 million years. This
pattern of evolution of a major taxon is a typical
one in that the primary differentiation appears
early in its history. The more primitive family
(Gryphaeidae) appeared without doubt in the
late Triassic Carnian Stage, but the Lophinae of
the family Ostreidae doubtfully appeared as
early as the Gryphaeidae and may not have
arisen before the middle Jurassic.
In Table 1 the geologic ranges of the genera
and subgenera of the Gryphaeidae and Ostrei-
dae have been recorded. The Gryphaeidae are
the more diverse from the Triassic through the
Paleocene, with the greatest dominance of the
Gryphaeidae over the Ostreidae in the Jurassic.
It seems evident from the data that the Cretace-
ous was the time of greatest diversity of the
Ostracea. All but one of the subfamilies lived
during that period; and the warm, shallow,
widespread seas were conducive to speciation
during the Cretaceous. The Exogyrini became
TABLE 1. Geologic range of genera and subgenera of the
Gryphaeidae and Ostreidae. Genera and subgenera are con-
sidered of equal rank in this compilation.
extinct at the end of the Cretaceous, and possi-
bly 12 genera and subgenera failed to survive
the Cretaceous Period. The Ostreidae and
Gryphaeidae were equally affected by this major
period of extinction. The Gryphaeidae are repre-
sented by few genera and subgenera after the
Cretaceous, but the Ostreidae did increase in
diversity during the Eocene. The tribes Grypho-
Vol. 98 (3)
July 27, 1984
THE NAUTILUS 125
streini and Flemingostreini became extinct at
the end of the Miocene and four genera and sub-
genera disappeared at the Miocene-Pliocene
boundary. Three of the four genera and sub-
genera that became extinct in the Miocene have
been allocated to the Gryphaeidae. This ac-
celerated extinction took place at the time that
the seas became cooler and the onset of a major
period of glaciation in the polar regions. As I
pointed out (Nicol, 1978), even the Ostreidae,
which can live in colder water than other shell-
cemented pelecypods, do not live in areas where
the sea water is less than 10° C during the
warmest month of the year, and no shell-
cemented pelecypods live in the polar regions
nor the deep sea today. The Gryphaeidae have
only two living genera and few living species,
whereas the Ostreidae are represented by six
genera and about 50 living species.
Stenzel (1971) came to the conclusion that the
Ostracea are diphyletic. He thought that the
oysters arose from two different but similar
ancestral stocks. The Gryphaeidae first ap-
peared in the northern circumpolar region, and
the Lophinae of the Ostreidae arose in the
Mesogean and Pacific realms. In other words,
these two basic oyster stocks originated in two
different marine provinces in the late Triassic.
On the basis of shell morphology and compara-
tive anatomy of the soft parts, the Gryphaeidae
and Ostreidae have several consistently distinc-
tive differences, as Stenzel noted, and the
Gryphaeidae have the more primitive morpho-
logical characters. The appearance of the
Gryphaeidae during the late Triassic is without
question, but Stenzel claims that the Ostreidae
appeared at approximately the same time. How-
ever, when one looks at Stenzel's basic data,
there seems to be some doubt as to the first ap-
pearance of the genus Lopha of the Ostreidae.
On page N1056 Stenzel has this to say: "Recog-
nition of Lopha found in the Triassic deposits is
difficult. Externally the lophas are quite similar
to some species of E mint lost reon, Atreta. Placu-
nopsis, and Pseudomonotis. The former are
attached by their left and the latter by their
right valves. The distinction cannot be made
unless location of the adductor muscle insertion
is clearly visible. However, most specimens
found in Triassic deposits have tightly closed
valves." The figures of Triassic Lopha. p. N1055,
appear inconclusive because only three badly
fragmented valves of the interior view are
figured. Furthermore, Stenzel does not assign
any of the Triassic lophas to his subgenera -
Lopha. s. s. (Miocene to Recent), Abruptolopha
(Cretaceous), or Actinostreon (Jurassic,
Cretaceous). One wonders if Lopha is nothing
but a form genus because the Paleocene,
Eocene, and Oligocene, as well as the Triassic,
are not mentioned in the geologic ranges of the
subgenera of Lopha. The genus Lopha may not
have appeared before the middle Jurassic. The
fact that the Gryphaeidae are more diverse as to
genera and subgenera in the Triassic, Jurassic,
and Cretaceous also leads me to believe that the
Gryphaeidae appeared some time before the
Ostreidae.
Stenzel assumed that because the Gryphaei-
dae and the Ostreidae have several distinct basic
differences and that these two families appeared
at essentially the same time in two different
marine provinces, they must have arisen from
two different but similar stocks, and, thus, the
Ostracea are diphyletic. He also assumed that
the Gryphaeidae and Ostreidae arose slowly
over a period of millions of years from their
ancestral stocks, but there is no evidence of this
slow evolution in the fossil record. However, the
pattern of diversity as seen in the fossil record is
very different from Stenzel's assumption on the
evolution of the Ostracea. As I have pointed out
(Nicol, 1972), the basic differentiation of the
animal phyla occurred in the late Precambrian,
Cambrian, and Ordovician, and this explains
why, in part, there are more animal phyla living
in the seas than in fresh water or on land. Even
a large number of classes of animals can be
traced back to the Ordovician or earlier in the
fossil record. It seems to be a rule that the pri-
mary differences within the higher taxa (phyla,
classes, orders, families) occur at the outset of
the history of the group, and the evolution of the
Ostracea fits into this general pattern.
I prefer to think that the Ostracea are mono-
phyletic. It seems to me that it is every bit as
logical to believe that such a distinctive group as
the Ostracea arose once and within a relatively
short time span (no more than one or two million
years) from a single ancestral species, as to con-
sider that this distinctive group arose from two
different but similar ancestral species. The basic
126 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
data given by Stenzel are questionable in sup-
port of his thesis, despite the fact that the fossil
record of the oysters is excellent. It appears that
the Gryphaeidae are the sole ancestral stock of
the Ostracea, and the Ostreidae arose from the
Gryphaeidae no earlier than middle Jurassic
time.
LITERATURE CITED
Nicol, D. 1972. Species, class, and phylum diversity of
animals. Quart. Jour. Florida Acad. Sci. 34:191-194.
1978. Shell-cemented pelecypods. Florida Sci.
41:39-41.
Stenzel, H. B. 1971. Treatise on Invertebrate Paleontology.
Part N, Vol. 3, Mollusca 6, Bivalvia. Univ. Kansas Press.
Lawrence, p. N953-N1224, figs. J1-J153.
BELLAXINAEA, A NEW SUBGENUS OF GLYCYMERIDIDS
(PELECYPODA) FROM THE WESTERN HEMISPHERE
David Nicol
Box 14376, University Station
Gainesville, FL 32604
and
Douglas S. Jones
Department of Geology
University of Florida
Gainesville, FL 32611
ABSTRACT
The new pelecypod suhgemts Bellaxinaea is proposed for a distinctive group of
splii-ribhed glycymeridids which can he allocated to the genus Tucetona. Bellaxi-
naea IS confined to the tropical western hemisphere, and its geologic range is from
late Eocene to Recent.
Woodring (1973, p. 521) recognized a distinc-
tive stock of tropical American glycymeridids
which he referred to as the group of Glycymeris
arctata. Woodring noted that the species of this
group generally increased in size from the
Eocene to the late Miocene. He also discussed
the relationships of several Oligocene and Mio-
cene species.
As Nicol (1956) pointed out, most fossil and
living species of glycymeridids can be separated
into two major groups based on the type of
radial ribs. The more ancient group is typified
by Glycymeris, sem^u stricto. This group has
shown little change in the type of ribs since the
inception of the Glycymerididae during the early
Cretaceous. The radial ribs of this group are
relatively flat with superimposed radial striae.
Living specimens commonly have a luxuriant
growth of hairlike periostracum. This group is
found living in both tropical and temperate seas,
but is not found where the yearly average tem-
perature is less than 5° C. The second group is
typified by the genus Tucetona, and the radial
ribs are raised and are either simple or divided.
Superimposed radial striae are never present,
and there is little or no periostracum on living
specimens. This group does not appear before
the Eocene and is almost exclusively confined to
tropical seas. Woodring's group of Glycymeris
arctata is clearly related to Tucetona on the
basis of the radial ribs.
Family Glycymerididae Newton, 1922
Genus Tucetona Iredale, 1931
Subgenus Bellaxinaea new subgenus
Type species-/lj-(>/<i^a intercostata Gabb, 1860
Description- SmaW to medium-sized glycy-
meridids; valve outline circular to subtrigonal,
symmetrical;, ratio of convexity to height of both
valves commonly less than 0.55; beaks small,
orthogyrate; ligament amphidetic, small; hinge
plate strong, with high arch; teeth small and
numerous, from 20 to 35 in number, central
teeth under ligament present in mature speci-
mens; radial ribs raised and numerous, on um-
bonal region or in immature specimens simple,
later dividing one or more times and with secon-
dary radial ribs sometimes forming in the in-
terspaces between the primary ribs; crenula-
tions on Interior ventral margin medium-sized
to large, about 15 to 20 in number, ends some-
times truncated and bifid, central portion of
Vol. 98 (3)
July 21, 1984
THE NAUTILUS 127
crenulations may or may not be depressed.
Geologic range-'Late Eocene to Recent.
Geographic ranc/e- Tropical western hemis-
phere; Florida, Georgia, Mississippi, California,
Trinidad, Brasil, Venezuela, Colombia, Panama,
Costa Rica, Mexico.
The earliest species of Bellaxinaea commonly
have the greatest number of radial ribs, as, for
example, Axinaea inter costMa. In other words,
these oldest species tend to have more splitting
of the primary ribs and also more secondary
radial ribs developed between the primary radial
ribs. There are, however, some exceptions to
this general rule. Bellaxinaea has its greatest
diversity of species during the Oligocene and
Miocene.
One species that probably does not belong to
Bellaxinaea is Axinaea bellasculpta Conrad,
1860. The description is short and vague, and
the species was never figured. The locality is
simply stated as Mississippi. Unfortunately, Dall
(1898, p. 607) synonymized Axinaea bellasculpta
and Axinaea intercostata with Pectunculus
arctatus Conrad, 1848. What probably led Dall
to synonymize Axinaea bellasculpta with the
other two species is Conrad's statement in his
description of Axinaea bellasculpta, "radii in the
middle of the disk trilineate." We borrowed the
one specimen from the Academy of Natural
Sciences of Philadelphia labeled Axinaea bella-
sculpta and Glycymeris bellasculpta (catalog no.
16399). Neither of the two labels in the box is in
Conrad's handwriting, according to Ms. Elana
Benamy, and it has not been ascertained that
this specimen is Conrad's type. However, the
ventral margin is densely crenulate, which fits
Conrad's description. One label has "Axinaea
bellasculpta Conr. =ham:ula Morton," and the
label also has "Cretaceous and Mississippi" on it.
The collector is stated as Spillman. The speci-
men appears to be a Cretaceous species, and the
ribbing is much like that of Glycymeris, sejisu
stricto, although the outer surface of the shell is
somewhat worn. One can, at present, regard
Axinaea bellasculpta Conrad as a species in-
quirenda, but not synonymous with A. arctata
Conrad.
Species allocated to Bellaxinaea - Some of
these species are synonyms, as Keen (1971) and
Woodring (1973) have noted, and with detailed
study there are likely to be no more than ten
valid species.
1. intercostata Gabb, 1860. This species oc-
curs in the Rotularia vemoni zone (Nicol and
Jones, 1982) which is approximately equivalent
to Pun s (1957) Asterocyclina-Spirulaea vemoni
faunizone. This is the uppermost zone of the
Crystal River Formation (Eocene) in peninsular
Florida, and three specimens from this zone are
figured herein (Figs. 1-3). This species also oc-
curs in the Red Bluff and Mint Spring Forma-
FIGS. 1-3. Tueetona (Bellaxinaea) intercostata (Gabb, 1860).
1. Exterior view, left valve, height l.S.S mm. length 16.3
mm, hypotype cat. No. 570.5. 2. Interior view, right valve,
height 16.6 mm, length 17.1 mm, hypotype cat. No. 5706. 3.
E.xterior view, right valve, height 20.4 mm, length 21.0 mm,
hypotype cat. No. 5707. The three specimens are siliceous
pseudomorphs and are housed in the invertebrate paleon-
tology collection at the Florida State Museum. Locality -
Gainesville West Quadrangle in a shallow quarry 0.5 mi.
south of the intersection of State Road 26 and 1-7.5, west of
Gainesville, Alachua County, Florida, SWA, Sec. 4, T. IDS,
R. 19E.
128 THE NAUTILUS
July 27, 1984
Vol. 98 (3)
tions (lower Vicksburg Group) lower Oligocene
in Mississippi. For a more detailed discussion of
the stratigraphy of the upper part of the Crystal
River Formation in peninsular Florida, see
Nicol, et ai, 1976.
2. arctata Conrad, 1848. Mint Spring and
Byram Formations in Mississippi and Rosefield
Formation in Louisiana, lower Oligocene (mid-
dle and upper Vicksburg Group). See Dockery,
1982, for the differences between arctata and
intercostata.
3. bicolor Reeve, 1843, Mexico to Ecuador
(Pacific), Recent. A synonym of ■multicostatu
Sowerby, according to Keen, 1971.
4. canalis var. colombiensis Weisbord, 1929.
Colombia, Miocene.
5. canalis democracia.na F. & H. Hodson,
1927. Venezuela, Miocene.
6. chemnitzii Dall, 1909. Mexico to Ecuador
(Pacific), Recent. A synonym of multicostata
Sowerby, according to Keen, 1971.
7. cookei Dall, 1916. Flint River Formation,
Georgia. Uppermost Eocene to lower Oligocene.
Also see Dockery, 1982.
8. crashleyi Maury, 1925. Brasil, late
Miocene.
9. larnyi Dall, 1915. Florida, late Oligocene or
early Miocene.
10. lamyi tampae Mansfield, 1937. Florida,
late Oligocene or early Miocene.
11. Uoyd-smithi Pilsbry and Brown, 1917.
Colombia, Miocene.
12. lloydsmithi striatidentata Nicol, 1945 =
lloydsmithi multicostata Weisbord, 1929, not
multicostata Sowerby, 1833. Colombia,
Miocene.
13. minor Orbigny, 1846. Mexico to Ecuador
(Pacific), Recent. A synonym of multicostata
Sowerby, according to Keen, 1971.
14. multicostata Sowerby, 1833. Mexico to
Ecuador (Pacific), Recent.
15. schencki Nicol, 1947. Panama, Miocene.
16. secticostata Nicol, 1945. Costa Rica,
Miocene.
17. trilobicosta Pilsbry and Brown, 1917. Col-
ombia, Miocene.
18. usiacurii Anderson, 1929. Colombia, late
Miocene.
19. whaleyi Nicol, 1947. California, late
Oligocene or early Miocene.
Acknowledgments
We are indebted to Dr. George M. Davis and
Ms. Elana Benamy for the loan of a cataloged
specimen labeled Axinaea bellasculpta Conrad
from the invertebrate paleontology collection at
the Academy of Natural Sciences of Phila-
delphia.
LITERATURE CITED
Conrad, T. A. 1848. Observations on the Eocene P'ormation.
and descriptions of one hundred and five new fossils of
that Period, from the vicinity of Vicksburg, Mississippi,
with an appendix. Proc. Acad. Nat. Sci. Philadelphia,
18J,7. 3:280-299.
1860. VIII. -Descriptions of new species of Creta-
ceous and Eocene fossils of Mississippi and Alabama.
Jour. Acad. Nat. Sci. Philadelphia, 2nd. ser. 6:275-298.
Dall, W. H. 1898. Tertiary fauna of Florida. Trans. Wagner
Free Inst. Sci. Vol. Ill, Part IV, p. 571-947.
1916. A contribution to the invertebrate fauna of
the Oligocene beds of Flint River, Georgia. Proc. U. S.
Nat. Mus. (No. 2162) 51:487-524.
Dockery, D. T., III. 1982. Lower Oligocene Bivalvia of the
Vicksburg Group in Mississippi. Mjsss.s.si'ppi Bureau Geol.
Bull. 123: 261 pp.
Gabb, W. M. 1860. Descriptions of new species of American
Tertiary and Cretaceous fossils. Jour. Acad. Nat. Sci.
Philadelphia. 2nd. ser. 4:375-406.
Keen, A. M. 197\. Sea Shells of Trupiad West America, 2nd.
ed. Stanford Univ. Press, Stanford, California. 1064 pp.
Nicol, D. 1956. Distributionof living glycymerids with a new
species from Bermuda. The Nautilua 70:48-.53.
Nicol, D., and D. S. Jones. 1982. Rutularia vernoni. an anne-
lid worm tube from the Eocene of peninsular Florida.
Florida Scientist 45:139-142.
Nicol, D., G. D. Shaak, and J. W. Hoganson. 1976. The Crys-
tal River Formation (Eocene) at Martin, Marion County,
Florida, Tulane Studies Geol. & Palexmt. 12:137-144.
Puri, H. S. 1957. Stratigraphy and zonation of the Ocala
(iroup. Florida Geol. Survey. Geol. Bull. 38 248 pp.
Woodring, W. P. 1973. Geology and paleontology' of Canal
Zone and adjoining parts of Panama: Descriptions of Ter-
tiary niollusks (additions to gastropods, scaphopods, pele-
cypods: Nuculidae to Malleidae). U. S. Geol. Survey Prof.
Paper 306-E. p. 453-539,
INFORMATION FOR SUBSCRIBERS
The annual subscription rate for The Nautilus
is $13.00 for individuals (foreign $15.00) and
$18.00 for institutions (domestic or foreign).
Subscriptions may begin in January. Send check
or money order made out to "American Mala-
cologists" to the Business Manager, P.O. Box
2255, Melbourne, Florida 32902-2255, U.S.A.
Back issues from volume 72 to date are ob-
tainable from the Business Manager. Volumes 1
through 71 (if available) may be obtained in
reprint or original form from Kraus Reprint
Co., Route 100, Millwood, New York 10546.
Advertising rates may be obtained from the
Business Manager or Editor.
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 re-
quired, to facilitate reviews. Tables, numbered
in arable, should be on separate pages, with the
title at the top. Legends to photographs should
be typed on separate sheets. Explanatory terms
and symbols within a drawing should be neatly
printed, or they may be pencilled in on a translu-
cent overlay, so that the printer may set them in
8 pt. type. There is a charge of 50 cents per
word for this extra service. All authors or their
institutions will be charged 50 cents per line of
tabular material and taxonomic keys. The pub-
lishers reserve the right, seldom exercised, to
charge $45 per printed page.
An abstract should accompany each paper.
Reprijits are available at cost to authors.
When proof is returned to authors, information
about ordering reprints will be given. They
are obtained from Economy Printing Co., Inc.,
R.D. 3, Box 169, Easton, Maryland 21601-9430.
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 identifi-
cation, locality data and its bibliographic
reference. There is no charge for this perma-
nent curating service, and catalog numbers, if
desired, will be sent to authors prior to publica-
tion.
WANTED - OLD SHELL BOOKS
Will pay good prices for libraries, second- Phone (1-305-725-2260) or write: R. Tucker
hand books and reprints on mollusks, shells Abbott, American Malacologists, Inc., P.O.
and conchology. Back numbers of The Box 2255, Melbourne, FL 32902. Free ap-
Nautilus, vols. 40-71 wanted, $1.50 each. praisals.
americanmalacologists, inc.
PUBLISHERS OF DISTINCTIVE BOOKS ON MOLLUSKS
THE NAUTILUS (Quarterly)
MONOGRAPHS OF MARINE MOLLUSCA
STANDARD CATALOG OF SHELLS
INDEXES TO THE NAUTILUS
{Geographical, vols 1-90; Scientific Names, vols 61-90)
REGISTER OF AMERICAN MALACOLOGISTS
OCTOBER 31, 1984
THE
NAUTILUS
ISSN 0028-1344
Vol. 98
No. 4
A quarterly
devoted to
malacology and
the interests of
conchologists
Founded 1889 by Henry A. Pilsbry. Continued by H. Burrington Baker.
Editor-in-Chief: R. Tucker Abbott
EDITORIAL COMMITTEE
CONSULTING EDITORS
Dr. William K. Emerson
Department of Living Invertebrates
The American Museum of Natural History
New York, NY 10024
Dr. M. G. Harasewych
363 Crescendo Way
Silver Spring, MD 20901
Dr. Aurele La Rocque
Department of Geology
The Ohio State University
Columbus, OH 43210
Dr. James H. McLean
Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, CA 90007
Dr. Arthur S. Merrill
c/o Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Donald R. Moore
Division of Marine Geology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 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, IL 60605
Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, OH 43210
Dr. Ruth D. Turner
Department of Mollusks
Museum of Comparative Zoology
Cambridge, MA 02138
Dr. Gilbert L. Voss
Division of Biology
School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, FL 33149
EDITOR-IN-CHIEF
Dr. R. Tucker Abbott
American Malacologists, Inc.
Box 2255, Melbourne, FL 32902-2255
Mrs. Cecelia W. Abbott
Business and Subscription Manager
P.O. Box 2255
Melbourne, FL 32902-2255
Second Class Postage paid at Melbourne, Florida
and other post offices
The Nautilus (USPS 374-980)
ISSN 0028-1344
A quarterly magazine devoted to malacology.
Copyright®1984 by American Malacologists. Inc.
OFFICE OF PUBLICATION
American Malacologists, Inc. (United Parcel Address:
2208 South Colonial Drive, Melbourne, FL 32902)
Mail: Box 2255, Melbourne, FL 32902-2255
POSTMASTER: Send address change to above.
Subscription Price: $15.00 (see inside back cover)
$18.00 (foreign); institutions $20.00
THE
NAUTILUS
Volume 98, number 4 - October 31, 1984
ISSN 0028-1344
CONTENTS
Robert G. Hudson and Billy G. Isom
Rearing Juveniles of the Freshwater Mussels (Unionidae) in a Laboratory Setting 129
Artie L. Metcalf and Donald A. Distler
Gastropods Collected from Eastern Oklahoma by Dwight Isely in 1911 135
James E. Joy and Kenneth J. Welch
Chuetoyastfr linniaei (Oligochaeta: Naididae) in the Aquatic Snail,
Helisoma trivolvis, from Charles Fork Lake, West Virginia 138
Charles M. Cooper
The Freshwater Bivalves of Lake Chicot, an Oxbow of the Mississippi in Arkansas 142
Artie L. Metcalf
A New Humboldtiana (Pulmonata: Helminthoglyptidae)
from Extreme Eastern Chihuahua, Mexico 145
Michael A. Zeto and John E. Schmidt
Freshwater Mussells (Bivalvia: Unionidae) of Monroe County, West Virginia 147
Joseph Rosewater
Bermuda Marine MoUusk Type Specimens Transferred to the Smithsonian 151
James J. Hall
Production of Immature Corhicula flnminea (Bivalvia: Corbiculidae),
in Lake Norman, North Carolina 153
Edward C. Wilson and George L. Kennedy
The Boring Clam, Penitellu cunradi. (Bivalvia: Pholadidae) in Nephrite
from Monterey County, California 159
Ralph W. Taylor
The Midwestern Naiad Uniomertcs tetralasmus in West Virginia 162
David Nicol
Constraints to Adaptive Radiation in Deposit-Feeding Pelecypods 165
News 164 Obituary 166
.Reprints of out-of-print volumes of_
nnuTiLus
Vols. 1-40 and Gen. Ind. 1-34. Philadelphia, Pa.,
1886-1926/27.
clothbound $842.00
paperbound $716.00
Kraus Reprint
Millwood, New York 10546
^
AVAILABLE FROM THE ORIGINAL PUBLISHER
Vols. 73 to date (vol. 94 in 1980) per vol. paper $12.00
A 25°o discount will be honored if 10 or more vols, are
purchased between vols. 73 and 94. Individual numbers
are not available.
Index to Authors for vols. 1 -75 (with the titles to their
articles) paper $ 8.00
Geographical Index to vols. 1-90 and
Index to Scientific Names to vols. 61-90 in 1 vol. $24.00
Domestic and foreign customers, please direct orders to:
AMERICAN MALACOLOGISTS, INC,
P.O. Box 2255, Melbourne, FL 32902 USA
/
LICENSED APPRAISALS
AND
IDENTIFICATION SERVICE
Collections of shells and libraries of shell
lx)oks expertly appraised for estate, gift and
tax purposes. Moderate fees, plus travel ex-
penses. Services confidential. Inquire below.
Professional identifications of marine mol-
lusks for biological surveys, environmental
studies and private shell collectors. Fees bas-
ed on hourly basis. Minimum $20.00.
R. Tucker Abbott. Ph.D.
P. 0. Box 22.5.5
Melbourne, Florida .32902
U.S.A.
Collectible Shells
of Southeastern U.S., Bahamas
& Caribbean by R Tucker Abbott. Ph D
A Take It to the Beach' Field Guide
WATERPROOF - TEARPROOF
105 beautiful color photos of living animals and
their shells 64 pages of color 300 species il-
lustrated How to clean stiells. Where to find
them Includes fossils, pond and tree snails, as
well as seaiife
Collectible Shells stresses conservation, but
also has helpful hints about collecting and
cleaning shells. The book introduces the tourist
and beginner to famous Florida fossils and the
unique world of tree and pond mollusks
Printed on a washable, tearproof plastic 'paper
Drop It in the ocean, use it in the ram, or let your
wet shells drip all over it Keep it on your boat or
take It to the shore A popular new seller retailing
for $8 95 Postage and state tax are included as a
big savings
American Malacologists, Inc.
Publishers of Distinctive Books on Mollusks
P.O. Box 2255, Melbourne, FL 32902-2255
We accept VISA o' MASTERCARD orders by ma'i Please give dale ol f
pffatioit arid you' card number Fceign custorriers may send miprn,,
t'Ofiai poslai money order or check on New York bank or U S cash b^
ror.pMe'ed mail
Sea^kell Tjreadurei (Booni
SHELL
SEAOF
505 EAST PASADENA, PHOENIX
ARIZONA 85012 U.S.A.
(602) 274-3615
»
SEASHELL TREASURES BOOKS
WORLD WIDE RETAIL and WHOLESALE
Over 450 shell books and journals in stock
Orders shipped within 72 hours of receipt
All prices include postal charges
SEND for FREE LIST NOW!
PHILLIP W. CLOVER r:;^>
COLLECTOR & DEALER IN WORLDWIDE *
SPECIMEN SEA SHELLS
CURRENT AND OUT OF PRINT SHELL BOOKS
FREE PRICE LISTS UPON REQUEST
P O Box 83, Glen Ellen. CA 95442
Vol. 98 (4)
October 3 L 1984
THE NAUTILUS 129
REARING JUVENILES OF THE FRESHWATER MUSSELS
(UNIONIDAE) IN A LABORATORY SETTING
Robert G. Hudson
Associate Professor of Biology
Department of Biology
Presbyterian College
Clinton, South Carolina 29325
and Billy G. Isom
Division of Air and Water Resources
Office of Natural Resources
and Economic Development
Tennessee Valley Authority
2 E and D Building
Muscle Shoals, Alabama 35660
ABSTRACT
This is the first report indicating success in rearing juvenile mussels in the
laboratory. Juvenile mussels transformed by in vitro methods (Isom and Hudson
1982) and those obtained from fish were reared successfully during the summer of
198J, and continuing.
Basically, the mariculture procedures of Castagna and Kraeuter (1981) were
modified for rearing the juveniles. Results of a matrix of experiments utilizing
difj'erent water sources, plankton blooms, and sediments led to the successful rear-
ing of juveniles.
Isom and Hudson (1982) first reported success
in the transformation of glochidia of freshwater
mussels (Unionidae) in vitro. Following this suc-
cess, numerous attempts to rear the trans-
formed juveniles in laboratory and field settings
proved unsuccessful. Similar results have been
reported from Europe, Australia (Young and
Williams 1983; Walker 1981), and the United
States (personal communication); that is, the
juveniles obtained from fish live only a few days
to two or three weeks, and then die.
Howard (1922) reported rearing oV'Lampsilis
luteola" in floating crates placed in a river
setting, but no experiments were conducted,
nor were food or environmental parameters
revealed.
Late in the summer of 1983, we attempted to
adapt the procedures of Castagna and Kraeuter
(1981), used for growing the marine hard clam,
Mercenaria, to growing freshwater juvenile
Unionidae and were successful. The information
reported in this paper largely resulted from our
1984 research which was catalyzed by personal
assistance from Castagna and resulted in suc-
cessful rearing of Anodonta imbecilis and
Dysnomia triquetra.
Materials and Methods
Initiation of Cultu re
Mature glochidia from the species Anodonta.
imbecilis^ were removed from culture medium,
rinsed in distilled water, and placed into either
large colorless Nalgene® containers (10 cm x
20 cm X 13 cm deep) filled with ca. 1,500 ml of
lakewater or into beakers (250 ml) containing
ca. 200 ml lakewater, both of which had plank-
ton as food. Dysnomia triquetra were also
placed in lakewater from the same source fol-
lowing encystment on a fish host. The 1,500 ml
containers were seeded with 200-1,000 juveniles,
while the 200 ml volumes had 50-250 juveniles.
These containers were placed in two incubators
having temperatures of 23°C and 30°C.
Maintenance of Cultures and
Testing of Growth Variables
Water was changed daily, or twice daily, with
Tennessee River water. Change was accom-
plished by pouring the contents of each con-
tainer through a screen (Fig. 1) which had a
mesh small enough to catch the juveniles. The
'See Clarke and Berg (1959) for comments on the correct
spelling of A. imbeciHs (Say 1829).
130 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
^
'v- V
r
Fl(!. 1. Cuti'hinjj juveniles in 202 ^ni screen while changing
water in gmwth containers.
mesh opening was usually 34 i^m (Nitex®) for
small juveniles. Later, as they grew, progres-
sively larger-sized screens were used (75, 100,
and 202 ^m).
Prior to changing the water in the juvenile
containers, the river water had been allowed to
produce an algal bloom for one to four days.
This was accomplished by pouring fresh river
water through a 5 i^m polypropylene sack filter
(to allow smaller sized plankton to pass) into
large 20 gallon (ca. 76 L) colorless Nalgene con-
tainers (Fig. 2). This water, containing a diver-
sity of small plankton genera (Table 1) was held
outdoors (it should be held in a greenhouse for
winter blooms) in a semi-shaded area. Full sun-
light kept the water at 3 or 4° C higher than the
normal high temperature of 30°C reached in
semi-shade and produced a lower algal bloom
density having more ciliates. Algal blooms of
100,000-700,000 cells/ml were maintained.
When plankton yields were low (cloudy days),
plankton supplements were added from concen-
trated plankton prepared with a continuous flow
centrifuge. This concentrate often included the
diatoms and other algae scraped from the walls
of the holding container.
(irowth comparisons were also made using tri-
algal cultures having three genera of green
algae (SelennMrum, Telra'Odon. and Chlordla).
Some Iri-algal food was supplemented with Jim
Dandy® catfish chow (32 percent protein). Also,
addition of silt, fertilization, and fre<]uency of
change of cultured water were compared with
growth rates and survivability of the juveniles.
Silt was collected and added to some groups of
culture water by passing pond or lake substrate
FIG. 2. Filtering water with .5 nm sack filter tn make small
plankton culture.
TABLE 1. Representative Plankton Found in Cultured
River Water.
GoniHtn
Anabaena (and/or AnabaenopsU)
Achnanthes
Navimla
Oticillatoria (and/or Lyngbya)
Bodo
Fragilnria
Kuiiiirhiii
Stnilor
X'tirticeUa
Srenedesmus
Trac.helomonas
Crurigenia
Phacus
Stephanodiscus (and/or
Cyclotella)
Chlorococcales
through a 25 t^m polypropylene sack filter. Addi-
tion of silt involved three comparisons: (1) river
water with no additional silt (contained ca. 125
mg natural silt/L); (2) addition of silt suspension
sufficient to cloud the water (contained at least
700 mg silt/L); and (3) addition of silt sufficient
to produce a layer (ca. 1 cm) on the container
floor.
Fertilization of some algal cultures was ac-
complished by the addition of 2 g of 13-13-13
(N-P-K) fertilizer to five gallons (ca. 19 L) of
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 131
river water. This is slightly less than the amount
used to fertilize farm ponds.
Three water change frequencies were com-
pared in the experiment: once daily, twice daily,
and continuous flow. Continuous flow designs
included flowing water into the top of a con-
tainer which held the mussels, with side screens
to allow water to escape; flowing water over
rock substrate in a series of descending steps
(Fig. 3); and flowing water up through a screen
that the mussels were resting upon (Fig. 4). The
last design would only work if the mussel holder
was placed into an aquarium that was higher
than the overflow of the holder. This overflow
tube would drain water from a lower level than
the aquarium top and, therefore, force water to
pass up through the screen from under the
holder. Flow rates for all of these containers
were from a slow drip to 1.5 L/min.
Results and Discussion
Juvenile mussels of Anodonta imbecilis are
the oldest that we have transformed and raised,
as of this writing, in our laboratory. These
juveniles measured over 5.1 mm in length after
74 days in river water. The original length of
juveniles when they were introduced into lake-
water was 0.28 mm (n = 20, S^ = 0.002). This
represents over 18 x increase in length and an
increase in estimated side surface of over llOx .
The juveniles have also increased in internal
complexity. Their gills, initially three pairs of
lobes, now are comprised of at least 23 finger-
like lobe pairs. Siphons and a well-developed
pelecypod foot are evident. The massive diges-
tive organ, initially not visible, has spread
FIG. .3. I)fSceii(lint,^-sU'iJ hoMcr fur juvi'iiili' mussrls.
FIG. 4. Mussell holder designed fur water ascending up
through screen on which mussels rest.
throughout the visceral cavity and upper foot.
The adductor muscles are large and easily seen,
as is the dark intestine (Fig. 5).
A. imbecilis has proven to be a good labo-
ratory animal, especially since it requires fish
host for transformation, and glochidia are avail-
able most of the year (Hudson et al. 1984, in
manuscript).
Plankton Feeding
Feeding by changing the water daily with tri-
algal culture water in 1983, even with addition
of catfish chow suspension, would allow the
juveniles to live and add on some shell growth
for two to three weeks. During the second week,
slowing of mussel activity and mortality was
observed. This loss would continue until all
juveniles were dead, usually about the third
week. Castagna (personal consultation) indi-
cated that this gradual slowing of acitivity and
death over a period of a couple of weeks was in-
dicative of starvation.
132 THE NAUTILUS
October 31, 1984
Vol. 98(4)
FIG. 5. Anodonta rmtirnli
ing internal development.
■ lay-old, 3 mm juvenile show-
The use of naturally occuring plankton cul-
tured for one to five days in fresh river water
resulted in sustained life and growth of juveniles
for the duration of the experiment in 1984; how-
ever, mortality often exceeded 90 percent
within five to six weeks when silt was not added.
Effect of Silt
The above-mentioned mortality in juveniles
was shown to be substantially decreased in cul-
tures where silt was added. One experiment
withyl. imbecilis, involving over 500 juveniles in
each of two containers, had only 10.2 percent
survival at an age of 30 days in the container
with no silt, while 89.1 percent survived in the
container with silt additions. Another compari-
son involving 16 beakers containing ca. 50-250
juveniles each, eight receiving additional silt
and eight without additional silt, resulted in
significantly different survivability percentages
with those in silt having 91.9 percent survival
(S,; = 2.1) and those without silt having 68.9 per-
cent survival (S^ = 9.2). The no-silt replicates in
beakers may have had higher survival rates than
the larger containers because the latter were
replaced daily, whereas the juveniles in each
beaker were screened and rinsed, but returned
to the same beaker. This allowed natural silt to
accumulate to some degree in the bottom of the
beaker, even in beakers not receiving additional
silt.
Mussel growth was also enhanced by silt addi-
tions. Although there appears to be considerable
individual variation in growth rates, compari-
sons of 30-day-old randomly measured juvenile
A. imbecilis revealed that those having addi-
tional silt had significantly greater growth than
those without (Table 2). Another comparison in-
volving the same treatments and species for
28-day-old juveniles showed similar results
(Table 3).
Addition of greater amounts of silt, producing
a layer (ca. 1 cm) which covered A. imbecilis
juveniles in three beakers, yielded no significant
increase in growth over the cloudy silt suspen-
sions. The extremely heavy silt layer was not
detrimental to survival or growth.
The fact that A. imbecilis survives and grows
better with silt additives may be related to its
ability to live naturally in pond and silty lake
habitats. For comparison, approximately 100
Dysnomia triqitetra juveniles, a t^'pical "head-
water" species, were obtained following trans-
formation on fish and placed into one of two con-
tainers. Both containers were treated the same
with the exception that silt suspension was
added to one of them. After 18 days in the two
treatments, the juveniles in the extra silt were
significantly larger than those without addi-
tional silt and also had 85 percent survival, as
opposed to 77 percent without extra silt (Table
4). This would imply that the need for silt is com-
mon to both lotic- and lentic-water species.
The mechanism of silt enhancement on the
survival and growth of juveniles has not been
clearly determined. It is possible that the silt
TABLE 2. Size (mm) of 30-day-old juveniles, .4. iriilx'rilis,
with and without silt suspension.
TABLE 3. Size (mm) of 28-day-nld juveniles, A. imbecilis
with and without silt suspension.
Vol. 98(4)
October 31, 1984
THE NAUTILUS 133
TABLE 4. Size (mm) o{ Dii-'oioiiiiii trtquiira juveniles held
in culture for 18 days, with and without silt.
merely adds another food source in the form of
associated organic particulate matter. Urban
and Langdon (1984) reviewed the work of others
and also treated the effect of artificial silt
(kaolinite) on oysters {Crassostrea virginica)
growth. In all cases a significant increase in
growth was obtained when kaolinite was added.
This phenomenon was attributed to one or more
of three possibilities: (1) increased filtration
rates; (2) adsorption of soluble organic food
material onto the kaolinite, which was later
easier to assimilate by the oysters; and (3) use of
kaolinite to grind food in the alimentary canal,
which should result in better absorption efficien-
cy within the oyster.
The Effect of Temperature
Temperatures of 23 °C and 30 °C were com-
pared mAnodonta imhecilis: however, compari-
sons of two samples of 23 individuals each, one
at each of the above temperatures, indicated no
significant difference in the growth of the
mussels at an age of 30 days. No silt was added
to either treatment. Another comparison involv-
ing the same temperatures, but with silt added
to both temperature treatments, revealed a
barely significant growth increase in the 30°C
group (Table 5). This increase, compared to the
above lack of difference without silt additions,
may be the result of silt providing the additional
needed energy for growth in the higher tem-
peratures.
TABLE 5. Size (mm) oi Anodonta imherilis juvenWes held in
culture for 1.5 days at 23°C and 30°C, both with additional
silt.
Water Changing Variables
Frequency of water change was compared,
with three containers changed twice daily as op-
posed to the standard practice where water was
changed once daily. Growth rates and surviv-
ability were not significantly different in young
16-day-old juveniles. It seems reasonable, as the
juveniles increase in size, food may become
limiting; therefore, more frequent water
changes would allow better growth.
The various flowing systems all failed to main-
tain living juveniles for more than a couple of
weeks, with the exception of the one where the
water was forced up through the .screen which
held the juveniles (Fig. 4). Most of our speci-
mens were washed out during early back flush-
ing of the screen and only two living and one
dead juveniles remained. The two living ones
were 0.43 and 0.47 mm long at 14 days old,
which falls within the expected range. The suc-
cess of this design is thought to be due to the
fact that a large volume of water (usually > 1
L/min) passes directly past the juveniles. This
large flow, coming in contact with the mussels,
apparently provides enough total plankton for
growth. The other designs, which usually had a
lower flow of water coming into a more stag-
nant or harder to reach area, apparently did not
provide the food volume necessary to sustain the
juveniles.
While we have had no problems with disease,
bleach treatments were tried in an effort to con-
trol bacteria and other organisms which may be
attached to the juvenile shells. Treatment at
recommended levels for marine bivalves
(Castagna and Kraeuter 1981), 0.5 ml bleacli/
1,000 ml water in three beakers containing 10
juveniles each for one hour, resulted in survival
of only 14 to 57 percent. Six other beakers, hav-
ing the same age juveniles not treated with
bleach, had 90 to 100 percent survival. Growth
of the bleached individuals was not significantly
different from non-bleached individuals. It ap-
pears that the juveniles are quite capable of
coexistance with these extraneous organisms,
and that bleach treatments are generally un-
necessary and harmful.
Other Species
Most of the above work has resulted from data
collected using A. imhecilis. Attempts were
134 THE NAUTILUS
October 31, 1984
Vol. 98(4)
made to rear other species, La7tipsiiis ouata,
Fusconaia ebena, Ligumia recta, Pleurobema
cordatum. and Carunculina moestn (Figs. 6 and
7), in 1983, but their juveniles lived only a couple
of weeks. In 1984 Dysnoinia triquetra (Fig. 8),
as already mentioned, are still thriving after 42
days in juvenile culture and show good growth
and survivability (see section on silt).
Growth Rate
Overall growth of A. vmbecilis was measured
for the largest individuals in our oldest experi-
200 >jm
FIO. 6. Lampsilis ovata 10-day-oid juvenile (shell length:
.66 mm).
FIG. 8. Dysriomia triquetra 19-day-old juvenile (shell
Length: 68.2.5 ^m).
100 pm
I i
FIG. 9. Growth of largest individual Anodtmla imbecilis.
200 pm
I 1
FIG. 7. Carunailinn moenta six day-old-juveiiile (.shrl
length: .54 mm).
ments. As seen in Fig. 9, the growth appeared
fairly slow initially (0.16 mm/week during the
first two weeks) and picked up substantially to
0.95 mm/week during the eighth week. The in-
crease in size and complexity is easily seen when
comparing a 1 day old juvenile (Fig. 10) with a
57 day old juvenile (Fig. 5). This tremendous in-
crease in growth places a heavy demand by juve-
niles on the plankton food source, and is prob-
ably related to the death of juveniles during
their third week in the 1983 culture attempts.
We think these experiments demonstrate that
this problem has been solved. Many cultures
(between 2-4 mm) are now ready for field trans-
plantation.
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 135
FIG. 10. Anodoiita (m/)('r)7).<,- nne-day-old juvenile.
Application and Future Needs
Many more variables and species need investi-
gation. This first breakthrough in the laboratory
raising of juvenile freshwater mussels repre-
sents a significant step toward mussel conserva-
tion. Endangered species can now have their
glochidia removed and transformed in the labor-
atory without injury to the parent mussel (Isom
and Hudson 1982) and the juveniles can be
grown to a size that will enhance their ability to
survive when released into tlieir natural habitat.
This development may also have significance in
future projects for the artificial farming of pear-
ly mussels from which beads are made for cul-
tured marine pearls.
LITERATURE CITED
Castagna, M. and J. N. Kraeuter. 1981. Manual for Growing
the Hard Clam Mercenaria, Sjiecial Report No. 249. Vir-
ginia Institute of Marine Science. 110 pages.
Clarke, A. H., Jr. and C. 0. Berg. 19.59. The Freshwater
Mussels of Central New York. Memoir 367, Cornell Uni-
versity, p. 41.
Howard, A. D. 1922. Experiments in the Culture of Fresh-
Water Mussels. Bull, of the U.S. Buremi of Fi^heriefi
38:89 pages.
Hudson, R. G., L. M. Koch and B. G. Isom. 1984. Obligate
Parasitism and Summer Breeding in Avodonia imhecilis
(Say 1829). In Prcs.s.
Isom, B. G. and R. G. Hudson. 1982. In Vitro Culture of
Parasitic Freshwater Mussell Glochidia. The Niiutilun
96(4):147-1.51.
Urban, E. R., Jr. and C. J. Langdon. 1984. Reduction in
Costs of Diets for the American Oyster, Crasnostrea vir-
ginica (Gmelin), by the Use of Non-Algal Supplements.
Aqiiariiltiire (Elsevier Sci. Pub. B.V.) 38:277-291.
Walker, K. F. 1981. Ecology of Freshwater Mussels in the
River Murray. Tech. Paper No. 63. Australian Water
Resources Council. 119 pages.
Young, M. and J. Williams. 1983. The Status and Conserva-
tion of the Freshwater Pearl Mussel Margaritifera mar-
gciritifera Linn, in Great Britain. Biological Conservation
(England) 25:3.5-.52.
GASTROPODS COLLECTED FROM EASTERN OKLAHOMA
BY DWIGHT ISELY IN 1911
Artie L. Metcalf
Department of Biological Sciences
University of Texas at El Paso
El Paso, Texas 79968
and
Donald A. Distler
Department of Biological Sciences
Wichita State University
Wichita, Kansas 67208
ABSTRACT
A collection of aquatic and terrestrial gastropods made by Dwight Isely in
eastern Oklahoma in 1911 is reported. The collection comprises 32 lots, involving
18 species and 8 localities. Habitats at some localities have been greatly altered in
the past 74 years.
Shepard (1982) reported the rediscovery of
specimens of unionacean mussels collected by
Frederick B. Isely during his survey of the
mussel fauna of eastern Oklahoma in the years
1910 to 1912. F. B. Isely noted (1924:45) that
during the field season of 1911 he was assisted
136 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
by "Dwight Isely of Fairmount College." Dwight
and Frederick were brothers. Fairmount Col-
lege was a progenitor of the present Wichita
State University, Wichita, Kansas. Several
members of the Isely family were involved with
Fairmount College early in this century. Distler
discovered some lots of gastropods collected by
Dwight Isely in collections long stored at
Wichita State University. These have subse-
quently been incorporated (Nos. 6157-6193) into
the invertebrate collections of the University of
Texas at El Paso.
The specimens were contained in small
envelopes with locality of collection indicated on
the outside and, in some cases, repeated on a
slip of paper within the envelope along with an
indication of Dwight Isely as the collector. Both
aquatic and terrestrial snails were included.
Comparison of the localities indicated on the
labels shows them to correspond to localities
reported by F. B. Isely (1924) in his survey of
mussels. It seems, then, that Dwight Isely was
collecting gastropods at these localities while in-
volved in the survey of mussels in the summer of
1911. Eight localities are represented in his col-
lection. These are listed below indicating (1) the
corresponding station number of F. B. Isely
(1924), (2) date of collection (all in 1911), (3)
county in which collection was made, (4) locality
data supplied on the lots of gastropods, and (5)
additional remarks.
27. August 26. Noble Co. "Black Bear Creek,
Black Bear." Black Bear is on the St. Louis-San
Francisco Railroad in the center of Sec. 32, T.
22 N, R. 1 E, ca. 0.65 km S of Black Bear Creek.
28. July 20. Tulsa Co. "Slough, Tulsa." F. B.
Isely (1924:63) describes this locality as "A small
nameless slough that entered the Arkansas
from the south above Tulsa . . . ." "Arkansas"
refers to the Arkansas River.
30. July 27. Cherokee Co. "Fourteenmile
Creek, McBride." Fourteenmile (or Spring)
Creek enters Grand River from the east. At pre-
sent, the lower part of the creek is impounded
and forms a major arm in the southeastern part
of Fort Gibson Reservoir. F. B. Isely (1924:64)
noted that his party ascended the creek some
2V4 miles (3.6 km) from its confluence with
Grand River. This would place them in the area
now covered by the reservoir, probably near
NEV4, Sec. 1, f. 16 N, R. 19 E.
34. August 8. Mayes Co. "Pryor Creek,
Pryor." F. B. Isel/s locality was west of Pryor,
probably near the intersection of Sees. 11, 12,
13, and 14, T. 21 N, R. 18 E.
36. August 9. Craig Co. "Big Cabin Creek,
Vinita." Big Cabin Creek heads in northern
Craig Co. and flows south. F. B. Isely collected
on it at a locality west of Vinita, probably in Sec.
17, 20, or 21, T. 25 N, R. 20 E.
37. August 11. Cherokee Co. "Illinois R.,
Tahlequah." The Illinois River flows past the
east side of Tahlequah.
38. Aquatic and terrestrial species collected
on August 2 and 4, respectively. Wagoner Co.
Aquatic species: "Marsh near Verdigris River,
Wagoner;" terrestrial species: "Near Verdigris
River, Wagoner." F. B. Isely's station was west
of Wagoner on the Verdigris River at "Mingo
Ferry." This area has been greatly modified in
recent decades by channelization of the Verdi-
gris River and with abandonment of much of the
previous channel.
41. August 21. Rogers Co., Catoosa area.
Two labels by Dwight Isely read: (1) "Near
Verdigris River, Catoosa" and (2) "Near Spunky
Creek, Catoosa." All specimens are land snails.
F. B. Isely (1924:71, 72) noted that collections
were made on the Verdigris River, below a ford,
east of Catoosa and in lowermost Bird Creek,
north of Catoosa. Spunky Creek flows past
Catoosa, on the east, northeastward to its con-
fluence with the Verdigris River and near the
confluence, also, of Bird Creek with the Verdi-
gris. At the present time this general area has
been much modified by channelization of the
Verdigris River, the installation of facilities at
the Port of Catoosa, encroaching urbanization,
freeways, etc.
In Table 1 identifications and numbers of
shells of gastropods in the Dwight Isely collec-
tion are given, utilizing numbers of the collec-
tion stations of F. B. Isely discussed above. All
lots contain at least some shells that appear to
have been living or recently defunct at time of
collection except for bleached shells (only) of
Polygyra leporina and Triodopsis divesta from
Locality 41.
The Dwight Isely collection contains several
new county records for Oklahoma and docu-
ments presence of some species in areas that
subsequently have been variously modified in
Vol. 98(4)
October 31, 1984
THE NAUTILUS 137
TABLE 1. Freshwater and terrestrial gastropods collected by Dwight Isely in Oklahoma in liUl.
Number of specimens for each species is indicated for corresponding locality numbers of F. B. Isely
(1924).
Speci es
Locality Numbers of F.B. Isely
27
30 34 36 37
38 41
Cartipel oma d e c i s u m (Say)
Ci nci nna ti a c i nc i nna ti ens i s
(Anthony)
El i m i a potosi ens i s (Lea)
Physel la gyrina (Say)
He! 1 soma anceps (Menke)
Planorbel la tri vol vi s (Say)
Pupoides a 1 b i 1 a b r i s (Adams)
Gas trocopta armi f era (Say)
Succineid, sp. indet.
Angui spi ra a1 terna ta (Say)
Glyphyal i nia indentata (Say)
Polygyra 1 epori na (Gould)
Polygyra dorfeuilliana Lea
Stenotrema 1 eai a 1 i c i a e
(Pil sbryT
Mesodon cl ausus (Say)
Mesodon thyroi dus (Say)
Mesodon 1 n f 1 e c t u s (Say)
Triodopsi s di vesta (Gould)
25
1 38
1
2
8
3
1
1 1
3
2 2
regard to habitats. This is especially true of
Localities 30, 38, and 41, with Locality 30 now
being within a large reservoir instead of along a
small creek.
We are grateful to Mr. K. B. Isely, Wichita,
Kansas, for information concerning the Isely
family. Dwight Isely later became an entomolo-
gist, associated with the University of Arkansas
and the state agricultural experiment station in
Arkansas.
LITERATURE CITED
Isely, F. B. 1924. The fresh-water mussel fauna of eastern
Oklahoma. Proc. Oklahoma Acad. Sci. 4:43-118.
Shepard, W. D. 1982. Rediscovery of a portion of the Isely
unionid collections. The Nautibis 96:8.
138 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
CHAETOGASTER LIMNAEI (OLIGOCHAETA: NAIDIDAE)
IN THE AQUATIC SNAIL, HELISOMA TRIVOLVIS,
FROM CHARLES FORK LAKE, WEST VIRGINIA
James E. Joy and Kenneth J. Welch
Department of Biological Sciences
Marshall University
Huntington, West Virginia 25701
ABSTRACT
The oligochaete worm, Chaetogaster limnaei, was recovered from 3Jt2 of 366
freshwater planorbid snails, Helisoma trivolvis, examined from February thru
May 1981. and February thru November 1983. Monthly prevalence rates generally
exceeded 80%. while mean intensity levels were < 18 C. limnaei individuals. Infec-
tions were somewhat higher in smaller snails for every month sampled, although
differences were statistically significant (P<.05) only for March and April '81.
and July '83. Temperatures of> 26° C or < 15° C supressed mean intensity levels
ofC. limnaei.
Despite the occurrence of large numbers of
freshwater oligochaetes in many parts of the
United States, few detailed studies at the
generic or specific level have been published on
this group, comprised mainly of free-living
species (cf. Maciorowski et ai, 1977). Thus it is
not surprising that symbiotic oligochaete
species have received little attention.
The objectives of this paper are to: determine
monthly prevalence and mean intensity of C.
limnaei infections in a restricted population of
Planorbidae snails, Helisoma trivolvis (Say);
determine if any correlation exists between host
size and intensity of infection; and evaluate the
effect of tem()erature upon a specific C. limnaei
population.
Materials and Methods
A total of 366 Helisoma trivolvis individuals,
75 snails in 1981 (February thru May) and 291 in
1983 (February thru November), were collected
from Charles Fork Lake, West Virginia (MG
70169125, USGS Topographic Map, Spencer
Quadrangle, Photorevised 1976) and examined
for Chaetogaster limnaei.
Snails collected each month in 1981 were
placed in a common container with = 4.0 liters of
lake water, then carried to the lab. However,
throughout 1983 each snail was j)laced in a sepa-
rate vial with = 100 ml of lake water (to preclude
migration of naidids from one snail to another),
then transported to the lab. Snails were kept
segregated in a Freas Model 816 low tempera-
ture incubator at temperatures approximating
the water temperature on date of collection.
Within six to 36 hours of capture, all snails were
measured for shell diameter with vernier cali-
pers to the nearest 0.1 mm, dissected, then exa-
mined for C. limnaei individuals with the aid of a
stereomicroscope. Chaetogaster limnaei in-
dividuals were examined while alive in water
mounts, and identified by using the key of
Hiltunen and Klemm (1980). Additional speci-
mens were killed by freezing, fixed in 10% buf-
fered formalin, stained with diluted Semichon's
acid carmine (in 70% ethanol), dehydrated in an
ethanol series, and cleared in methyl salicylate
before mounting in Kleermount®. Voucher
specimens were deposited in the USNM under
Collection Numbers 081913, 081914, and
081915.
The ecological terms of prevalence and mean
intensity follow the definitions of Margolis et al.
(1982). "
Results
Chaetoga.'fter limnaei was recovered from 342
of 366 (93.4%) Helisoma trivolvis individuals ex-
amined. Monthly prevalence rates were high,
falling below 80% only once. Monthly mean in-
tensities were highest at temperatures of 16° C
Vol. 98(4)
October 31, 1984
THE NAUTILUS 139
to 26° C with ranges of worms deviating con-
siderably from the mean (Fig. 1).
There was a low negative correlation between
host shell diameter and number of C. limnaei in-
dividuals present for each month sampled, al-
though significant (P<.05) levels of correlation
were noted only for the months of March and
April '81, and July '83 (Fig. 2).
Discussion
The present study demonstrated that tem-
perature played an important role in the biology
of a C. limnaei population. Notable increases in
mean intensity levels were evident from April to
May in both '81 and '83 when temperatures were
rising from 14° C to 17° C; and again in October
and November '83 when temperatures were fall-
ing through the 18° C to 14° C range (Fig. 1).
Gruffydd (1965) also demonstrated that the
most dramatic increase in mean intensity levels
of C. limnaei limnaei in Lymnaea pereger occur-
red from April (mean = 15) to May (mean = 40)
when temperatures were increasing from 10° C
to 17° C. And Streit (1974) recorded a sharp in-
crease in the mean number of C limnaei during
the Spring when temperatures were rising from
= 6° C to 13° C, reaching a maximum of 7.0
worms per host in May.
One would expect low temperatures to depress
mean intensity levels, but until now there was
no evidence that high temperatures {> 26° C)
could supress mean intensity levels as well (Fig.
1). This is understandable, because previous in-
vestigators rarely collected snails at ^ 26° C.
Still, the role of temperature must be examined
cautiously because another important variable -
host size -may influence both prevalence and
numbers of C. limnaei individuals in gastropods.
For example, Buse (1971) noted a positive corre-
lation between size of snail {Lymnaea stagyialis)
and number of C. limnaei vaghini individuals.
And Streit (1974), working with C. limnaei in
the river limpet, Ancylus fiuviatilus, reported
correlations of r = 0.934 for host length versus
prevalence, and r = 0.880 for host length versus
number of Chaetogaster.
In a more extensive study Gruffydd (1965)
stated that, ". . . in general, larger snails harbor
more Chaetogaster than smaller snails." While
that may have been true for his overall sample,
the size frequency distribution of L. pereger
samples for April and May were virtually identi-
lOOn
80
0^
ui 60"
<
>
iij
o.
40
20
rSO,
<
O
>
a
z
•30 5
0
c
£
UI
CO
no I
Z
1981
FIG. 1. Monthly prevalence rates (closed circles) and mean intensity levels (open circles) of Chaetoga.tter lim-
nnei in Helisovia trivolvis. Numbers above closed circles = sample size; vertical bars = one standard deviation;
vertical lines = range; closed triangles = temperature.
140 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
Fig. 2
20
10'
20 APR
20i
r = -.338
10'
• • •• •••••
r:-.049
20
10
Ul
20n
10
40i
10 MAY
r = -.29»
40
Z 20-
3
Z
18 JUN
'f = 18.68 +(.
r=-.125
19 X)
20120 JUL
10
20t 14 AUG
r = -.4a4
*- •
r = -.300
• •• • ♦»—
*• •
16 SEP
20
DIAMETER
(m m)
FIG. 2. Scatter diagram depicting relationship between host length and number of C. limnaei individuals. Each dot represents
a single infected snail. F^ach slash mark along X-axis indicates non-infected snail, '.significantly different from zero at P<.05.
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 141
FIG. 3. Ventral view of the oligochaete
worm, Chaetogaster limnaei. M =
mouth; C = chaetae bundle; P =
pharynx; E = esophagus; S = stomach;
I = intestine.
cal. Since Gruffydd reported that temperature
and mean number of C. I. limnaei individuals
were increasing for those months, temperature,
rather than host size, was the more important
variable in determining mean number of Chaeto-
gaster individuals in the host population. Joy
and McBride (1983) noted that prevalence rates
and mean intensity levels of C. limnaei in the
operculate river snail, Oxytrema canaliculata,
paralleled the temperature curve over an eight
month period (April thru November '82). Since
they confined their investigation to a single
height class (18 to 23 mm), host size had little or
no bearing on C. limnaei infections. Those in-
vestigators did not observe a supression of mean
FIG. 4. Chaetae bundle of the oHgoehaete worm,
C. limnaei. (Length of chaeta approximately
100 m).
intensity levels because of high temperatures,
but then their maximum recorded temperature
was 26° C (for August '82).
In the present study prevalence was high
regardless of host size or temperature, and con-
trary to the findings of Gruffydd, Buse, and
Streit, there was a consistent negative correla-
tion between host size and number of C. liynnaei
present (Fig. 2).
The data suggests that host size is a factor -
secondary to temperature -in determining
mean intensity levels of C. limnaei infections.
Still, there is an obvious need for laboratory in-
vestigations monitoring C. limnaei population
dynamics in selected host size classes at dif-
ferent temperature regimes.
Acknowledgments
We are indebted to Mr. Gary Bender for his
assistance in collecting snails. Thanks are also
extended to Dr. Jarl Hiltunen, U. S. Fish and
Wildlife Service; and Dr. Carol Stein, the Ohio
State University Musuem of Zoology, for con-
142 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
firming our identifications of Chaetogaster
Limnaei and Helisoma trivolvis, respectively.
LITERATURE CITED
Buse, A. 1971. Population dynamics oi Chaetogaster limnaei
raghini Gruffydd (Oligochaeta) in a field population of
Lymnaea stagnalis L. Oikos 22:50-55,
Gruffydd. L. D. 1965. The population biology of Chaeto-
gaater limntwi vaghini (Oligochaeta) Jour. Anim. Ecol.
34:B67-(i9().
Hiltunen, J. K. and U. .1. Klenim. 1980.^ Guifk to theNaidi-
dae (Annelida: Cliiellata: Oligochaeta) of North America.
U. S. EPA Tech. Kept. No. EPA-600/4-80-031, 48 pp.
Joy, J. E. and S. McBride. 1983. Chaetogaster limnaei
(Annelida: Naididae) in a()uatic snails, Oxytreriia canali-
culata, from Mud River, Cabell Co., W. Va. W. Va. Acad.
Sci. meeting 14-16 Apr., Glenville, W. Va.
Maciorowski, A. F., E. F. Benfield and A. C. Hendricks.
1977. Species composition, distribution, and abundance of
oligochaetes in the Kanawha River, West Virginia. Hydro-
hiotogia 54:81-91.
Margoiis. L.. G. W. Esch. J. C. Holmes. A. M. Kuris and
G. A. Schad. 1982. The use of ecological terms in para-
sitology (Report of an ad hoc committee of the American
Society of Parasitologists). Jour. ParcLsitol. 68:131-133.
Streit, B. 1974. Populationsdynamik von Chaetogaster
limnaei limnaei in einer population von Ancylus jluviati-
lis. Arch. Hydrobiol. (SuppL). 47:106-118.
THE FRESHWATER BIVALVES OF LAKE CHICOT,
AN OXBOW OF THE MISSISSIPPI IN ARKANSAS'
Charles M. Cooper
Sedimentation Laboratory
U.S. Department of Agriculture
Oxford, Mississippi 38655
ABSTRACT
The 17 bivalve Molliisca of Lake Chicot, Arkansas, were examined from 1977
through 1981 to assess species composition and to compare the Lake Chicot fauna
with that of other area lakes. Three other large delta oxbow lakes examined during
the same period had 6 or fewer species and fewer individuals of each species. Sedi-
ment deposition was 1 to i cm. annually in all the lakes, but flow-through
drainage, percolation from a subsurface sand layer and shor-eline wave action
kept the sandy littoral zone of Lake Chicot cleared of detrimental deposited
sediments. Although numerous environmental factors may have been limiting,
fine sediment accumulation in the littoral zone or extreme water level fluctuations
were obvious detriments to mollu^k habitation in the other lakes. Predominant
species in Lake Chicot included Anodonta grandis. Amblema plicata, Lampsilis
teres, Plectomerus dombeyana, Potamilus purpuratus, and Quadrula pustulosa.
Sixteen of the 1 7 species found lived in the sandy littoral zone.
Information on freshwater moUusks inhabit-
ing large oxbow lakes bordering the lower
Mississippi River is very limited. Bivalve fauna
from Lake Chicot, Arkansas, were collected
from 1977 through 1981 as part of an ecological
study on the effects of sedimentation on lake
systems.
' Contribution of the Sedimentation Laboratory.
Agricultural Research Service. U.S. Department "f
Agriculture, Oxford, MS 38655.
Several researchers have collected mollusks
from Arkansas waters but most collections have
been limited to river systems. Meek and Clark
(1914) made extensive collections on the Buffalo
River. Wheeler (1914) found 19 species of
bivalves in the Cache River, part of which lies in
the delta region of northeastern Arkansas.
Vanatta (1909) found numerous mollusks in col-
lections from the piedmont and delta reaches of
the Ouachita River in south central Arkansas
and Louisiana, and Branson (1966) found a
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 143
OUACHITA RIVER BASIN
LAKE CHICOT
CHICOT COUNTY, ARKANSAS
SCALE KILOMETERS
FIG. 1. Morphometric map of Lake Chicot, an oxliow of the
Mississippi River in Arl<ansas.
single species in a strip-pit west of Monroe,
Louisiana. The purposes of this study were to in-
vestigate mollusk habitation in Lake Chicot, a
unique two-part river oxbow lake, and to add
distribution data to regional mollusk records.
Study Area
Lake Chicot, a 19.3 km^ oxbow of the
Mississippi River located in southeastern
Arkansas, originally had a small drainage area
(> 200 km^) and excellent water quality. A series
of events involving channelization, basin
enlargement by a major flood in 1927, and con-
struction of the Mississippi River levee enlarged
the drainage entering the southern portion of
the lake (Fig. 1) via Connerly Bayou to 932 km^
by the 1930's. Increased inflow from the en-
larged watershed formed a sand spit which par-
tially isolated the northern part of the lake after
the 1927 flood. In the 1930's a permanent levee
was constructed on the sand spit, dividing the
lake into two sections.
Lake Chicot is a typical large river Itend with a
deep thalweg on the outside of the bend (Fig. 2).
A subsurface sand layer creates a sandy littoral
zone which drops rapidly into the river bed on
the outside of the bend while the littoral zone on
the inside of the bend gradually slopes into
deeper water.
I collected in littoral and profundal zones at
sites C4, C6, C7, Connerly Bayou (inlet) and
Ditch Bayou (outlet). I also collected in littoral
zones of three river oxbows (Lake Washington,
Lake Ferguson, and Lake Bolivar) on the east-
ern side of the Mississippi River within 100 km
of Lake Chicot. Lake Ferguson is directly con-
nected to the Mississippi River and exhibits
large water level fluctuations; the other two
lakes are isolated from riverine flow.
I collected in shallow reaches by hand sam-
pling, shallow diving, and dragging the bottom
substrate with a rake or D-frame dip net.
LEGEND
^ BACKSWAMP DEPOSITS [
:fe BAR DEPOSITS [,
CLAtS AND
SILTY CLAYS
SILTS AND
SILTY SANDS
SAND 8 GRAVELS
36
_i
5 30
r SILTY CLAYS 52
5fl NATURAL LEVEE DEPOSITS [3,^,*ND^„ £ 24
18
z
O 12
>
UJ 6
_i
UJ
FIG. 2. Cros.s-section of Lal<e Chirot, Arkansas, at Station C'-7 (Mollified after Saueier, lltllT ).
144 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
Deeper water (4 to 9 m) was sampled by Ekman
and Peterson grabs. Representatives of all
species of clams were verified by David Stans-
berry of Ohio State University. Vouclier speci-
mens are on files at the Mississippi Museum of
Natural Sciences, Jackson, MS.
Results and Discussions
Representatives of 17 species of Mollusca
were collected from Lake Chicot during the
study (Table 1). Predominant species included
Anodonta grandis, Amblema plicata, Lampsilis
teres, Plectomerus dombeyana, Potamilus pur-
puratus, and Quadrula pustulosa.
Fingernail clams, Musculium sp., were occa-
sionally encountered in profundal regions. Un-
fortunately all shells were either juvenile or too
severly eroded for species identification. All
other mollusks were collected from littoral
zones, mainly from large clam beds on sandy
substrate. Deposited sediments, a problem to
clam existence in most delta lakes, did not
adversely affect clam populations in Lake
Chicot. Percolation from a subsurface sand
layer (Fig. 2) and shoreline wave action kept the
sandy littoral zone cleared of the 1 to 4 cm/year
of detrimental sediments that were normally
deposited in other parts of the lake. The isolated
north basin of the lake had fewer observed mol-
lusk beds than the main basin but no statistical
comparison could be made because of the quali-
tative nature of sampling procedures.
Three other large delta oxbow lakes examined
had six or fewer species (Table 2) and fewer in-
TABLE 1. Taxonomic- list of Mollusca identified from Lake
Chicot, Arkansas from 1977-1981.
Amhlnnii jilicdtn jicrpUcatii ((Conrad, 1841)
Anodonta yriUKlix grdiidit; Say, 1829
Anoilontii (jrinidis rorpulcnta Cooper, 1834
Corhirulo Jluminca (Muller, 1774)
Fusconaia Jlavti Jlava (Kafiiiestiue, 1 820)
Lampxiiis ovata vmtricoxa (Barnes. 1823)
LiimpsiUs radiala hydinna (Lea, 1838)
Lniniisilis ulriimini'ii flaihoniensix (Lea, 1838)
Liimpsiliii teren (inodonUiidt'x (Lea, 1831)
Lcptodfa hievixnimn (Lea, 1829)
PU'clornerux dombeyamt (Valenciennes, 1827)
PoUimiiua purimridus (Lamarck. 1819)
Quadndo apiculnta nspern (Lea, 1S31)
Quiidndii puntulosa (Lea, 1831)
Quadrula rumphiana (Lea, 1852)
Villosa Lienoxa (Conrad, 1834)
Muxculium sp.
TABLE 2. Ta.xonomic list of Mollusca identified from three
Mississippi oxbow lakes, 1977-1981.
LAKE BOLIVAR (Bolivar Co., MS)
Aniidoiiln iiniiidiH cotyulenta Cooper, 1834
Anod/inla. yrandis yrandis Say, 1829
Anodontn xuhorbiculafa Say, 1831
LAKE EERGL'SUN (WashinKlon Co,, MS)
Anodonta grandis grandis Say, 1829
Anodonta sulmrbindnta Say, 1831
Corhirulii Jhiminca (Muller, 1774)
Lrpfodca fragilis (Rafinesque, 1820)
Quadrula apindata aspera (Lea, 1831)
To.i-dlosnio parriis (Barnes, 1823)
LAKE WASHINGTON (Wash. Co., MS)
Aninloiiin grandis grandis Say, 1829
Ligumia suhrost)-ata (Say, 1831)
Quadrula apiculata (Say, 1829)
Tiixnlaama parvus (Barnes, 1823)
dividuals of each species. Lakes Bolivar and
Washington had similar sediment problems but
exhibited two major differences from Lake
Chicot: (1) they were not part of flow-through
systems but had only limited inflow and outflow
and (2) neither lake exhibited a stable sandy lit-
toral zone because of periodic sedimentation.
Specific explanations for fewer species in these
two oxbow lakes could include disruptions in
glochidia-host relations as exhil)ited by Yokley
(1972) or a disruption of gill processes by set-
tling sediment particles (Ellis, 1936). Although
pesticide or heavy metal contamination for in-
tensive agriculture is a possibility. Price and
Knight (1977) found that heavy metals were not
excessively bioaccumulated in mollusks in Lake
Washington. Lake Ferguson had large expanses
of sandy shoreline but since it was connected
directly to the Mississippi River, water levels
fluctuated several meters annually. Although
the three lakes on the eastern side of the
Mississippi River supported fewer species of
mollusks, they were inhabited by four species
not found in Lake Chicot: Anodonta suborbicu-
lata, Leptoden jVagilis. Ligumia subrostrata,
and Toxolasma parrus.
Summary
Optimal habitat conditions allowed abundant
growth of 17 species of clams in Lake Chicot,
AR where basin morphometry produced a nat-
ural maintenance of sandy littoral zones. Three
other oxbow lakes on the eastern sides of the
Vol. 98(4)
October 31, 1984
THE NAUTILUS 145
Mississippi River liad less suitable littoral condi-
tions and supported six or fewer species because
of water level fluctuations, lack of flow, and/or
sediment accuniulati<.in. They were, however, in-
habited by four species not found in Lake
Chicot.
Acknowledgments
This paper is a contribution of the USDA Sedi-
mentation Laboratory, Agricultural Research
Service. Research on Lake Chicot was done in
cooperation with the U.S. Army Corps of Engi-
neers, Vicksliurg District. The author wishes to
thank Scott Knight for field assistance and Paul
Hartfield, Invertebrate Curator, Mississippi
Museum of Natural Sciences and Dr. David
Stansberry, Ohio State University for species
verification. Dr. J. R. McHenry was the USDA
principal investigator over the entire Lake
Chicot project.
LITERATURE CITED
Bran.son, B. A. 19ti(i. Uni()ni<l rei'ords fnmi Kansas. Arkan-
sas and Louisiana. Sterkiana 23:7-8.
Meel<, S. E. and Clark, H. W. 1914. The Mussels of the Big
Buffalo Fork of the White River, Arkansas. Washington,
D.C., U.S. Dept. of the Interior. Biirriiii of Fiahcrieft,
Docunwnt No. 759. 20 p.
Price, R. E. and L. A. Knight, Jr. 1977. Mercury, Cadiuni,
Lead, and Arsenic in sediments, plankton and clams from
Lake Washington and Sardis Reservoir, Mississippi. Jour.
Pest. Mori. 11:182-189.
Saucier, R. T. 1967. Geological Investigation of the Boeuf-
Tensas Basin, Lower Mississippi Valley. US Army Water-
ways Experiment Station, Corps of Engineers. Technical
Rpt. No. 3-757.
Vanatta, E. G. 1909. Unioiiidae from southeastern Arkansas
and N. E. Louisiana. The Nautilus 2.3:102-104.
Wlieeler, H. E. 1914. The Unionefauna of Cache River, with
Description of a new Fuseomiin from Arkansas. The
Nautilus 28:73-78.
A NEW HUMBOLDTIANA (PULMONATA: HELMINTHOGLYPTIDAE)
FROM EXTREME EASTERN CHIHUAHUA, MEXICO
Artie L. Metcalf
Department of Biological Sciences
University of Texas at El Paso
El Paso, Texas 79968
ABSTRACT
A new species of pulmonale land snail, described from shells, is assigned proi'i-
sionally to the helminthoglyptid genus Humboldtiana. The shells are unusual for
the genus in being relatively small, depressed, smooth and glossy. Types were col-
lected in the Sierra Santa Eulalia. Chihuahua, Mexico.
The species described herein was collected on
23 March 1982 by Mr. Waily Lippincott (U.S.
Department of Agriculture, Lake Worth, FL),
who kindly sent them to me in June 1982. The
lot consisted of four specimens, one of which
contained a desiccated body. At first glance, the
general configuration of the shells suggested a
member of the genus Sonorella. However,
despite the atypical shell morphology, other
features seem to indicate that the species
belongs to the genus Humboldtiana.
Humboldtiana eulaliae, new species
(Figs. 1-4)
Diagnosis: A relatively small Hwniholdtiana,
with depressed shell, rounded peripherally, low
spire and slightly reflected outer lip. The shell
exhibits 3 brownish spiral bands, very weak
growth lines and is smooth and glossy.
Description of Holotype: Shell depressed, 28.1
mm in diameter and 17.2 mm high; smoothly
rounded peripherally, spire low, rising gradually
to height of 8.5 mm with angle of ca. 135°; 4.3
146 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
FIGS. 1-4. Humhiildiiimti eulaliae new species, Metcalf, from the we.st side of the Sierra Santa
Enlalia, eastern Chihuahua, IVIexico. 1-3, holotype (28.1 mm in diameter), 4, paratype a.
whorls, with body whorl moderately descending;
aperture slightly ovate, 13.0 mm wide and 10.6
mm high, inclined at an angle of ca. 45° to the
vertical, columellar portion of peristome cover-
ing about Vs of the umbilicus and outer portion
forming a slightly thickened and reflected lip;
first 2 whorls light tan and glossy with exceed-
ingly fine growth lines except stronger on inner
part of whorl near the suture on second whorl;
after second whorl, low but clearly distinguish-
able growth lines cross entire whorl, occurring
both dorsally and ventrally, but remaining low
and weakly developed, giving the shell a rela-
tively smooth appearance, overall. The shell is
empty and slightly bleached; shell color beyond
the embryonic whorls whitish except for
presence of 3 brownish bands; uppermost band
originating as faint gray, interrupted segments
in center of whorl 3 and becoming more con-
tinuous and brownish in color on whorl 4; middle
band originating as continuous tan band along-
side suture at 2.1 whorls; lower band first
observed slightly below periphery of body whorl
near upper terminus of lip; all bands most
strongly developed on terminal portion of body
whorl near reflected lip.
Paratypes: Three shells (a, h. and c) were ob-
tained in addition to the holotype. Measure-
ments of these, in order a, b, c, are: width: 26.7,
24.9, 20.8; height: 16.9, 14.8, 12.5; whorls: 4.1,
3.6, 3.7. Shells a and c are fresh and shell c (a
juvenile) contains a desiccated body. Both have
broken lips and c retains fragments of a calcare-
ous epiphragm. In the month of March (dry sea-
son) it was, no doubt, sealed by the epiphragm to
a stone. Unlike the holotype, shells a and c have
not suffered bleaching and have a light grayish
brown background color. The brownish bands
are slightly wider and darker in color than in the
holotype (see specimen a in Fig. 4). Faint
gri)wth lines are better discerned on the em-
bryonic whorls than in the holotype; however,
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 147
the shells, overall, have a smooth and slightly
glossy appearance. Shell b is greatly bleached
and coated with calcium carbonate dorsally. It
appears to be fossil or subfossil.
Etymology: The epithet eulaliae refers to the
saint after which is named the Sierra Santa
Eulalia, the type locality.
Type locality: The types and paratypes are
reported by Mr. Wally Lippincott as being taken
on the west side of the Sierra Santa Eulalia in
easternmost Chihuahua, Mexico, near the
border with the state of Coahuila, in an area
centering around 27°12'N; 103°47'36"W. On the
DETENAL 1:50,000 topographic quadrangle
for Guimbalete (G-13, B-44) the locality is indi-
cated by the collector as along walls of a canyon
debouching southwestward about midway of the
Santa Eulalia range. The mouth of the canyon is
1.3 km E of "El Pinolero" and 7.5 km N and 1.5
km E of "Penoles" on the Guimbalete quad-
rangle. The canyon is ca. 2.5 km long, heading
at ra. 1650 m and debouching at ca. 1250 m. Mr.
Lippincott writes (in litt., 26 June 1982): "With-
in the canyon the snails were taken from the
south facing ledges. These ledges were approxi-
mately 10-20 meters above the dry creek bed.
They were characterized by smooth, broken up
stones interspersed between talus areas. The
snails were taken from under the smooth rocks."
Disposition of Types: Holotype: National
Museum of Natural History, USNM 820297;
Paratypes: LIniversity of Arizona 6262 (shell a).
University of Texas at El Paso 8785 (shells 6
and c).
Discussion: The mountains of eastern Chihua-
hua and adjacent Coahuila are almost unknown
malacologically. In the region, two species have
been described that are provisionally assigned
to Humboldtiana: the present one and H. plana
Metcalf and Riskind, 1976. Shells of both these
species are atypical oi Humboldtiana in general.
Further collecting in these areas will probably
reveal other new species and eventually should
lead to an understanding of the relationships of
these unusual shells.
LITERATURE CITED
Metcalf, Artie L. and David H. Riskind. 1976. A New
Humboldtiana (Pulmonata; Helminthoglyptidae) from
Coahuila, Mexico. The Nautilua 90(:3):99-100.
FRESHWATER MUSSELS (BIVALVIA: UNIONIDAE)
OF MONROE COUNTY, WEST VIRGINIA
Michael A. Zeto
West Virginia Department of
Natural Resources
Division of Water Resources
350 North Vance Drive
Beckley, West Virginia 25801
and
John E. Schmidt
West Virginia Department of
Natural Resources
Division of Water Resources
1201 Greenbrier Street
Charleston, West Virginia 25311
ABSTRACT
A survey of the mmsel fauna of Monroe County. West Virginia, was conducted
during the spring of 1983 and 1984. This survey included samples from the Green-
brier River, Indian Creek, and South Fork of Potts Creek. Twelve species of
unionid mussels and Corbicula fluminea were collected from these three water-
sheds, including a new state record, Canthyria collina, which is found in the South
Fork of Potts Creek.
Information on the extant mussel populations
of West Virginia was extremely limited until the
past decade. Mussel surveys conducted during
this period, especially in the past five years, has
greatly enhanced this information. This study
was performed in conjunction with a statewide
148 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
inventory of mussels conducted by the West
Virginia Department of Natural Resources,
Division of Water Resources. This inventory has
investigated approximately fifty percent of the
state's streams with known mussel populations
(Schmidt and Zeto, 1984), yielding 49 naiad
species. Recent studies in the state have been
conducted by Schmidt, Zeto and Taylor (1983)
on the Little Kanawha River Basin, Zeto (1982)
on the Monongahela River Basin, and Clarke
(1982) on the upper Kanawha River. Taylor and
Hughart (1981), Morris and Taylor (1978), and
Taylor (1980) have also conducted taxonomic
surveys on the Elk, Kanawha, and Ohio rivers,
respectively. The only recent published studies
performed in the vicinity of Monroe County
were those conducted by Bates (1971) and Stauf-
fer, Hocutt, and Markham (1980) on New River.
The U.S. Fish and Wildlife Service also con-
ducted a 1983 mussel survey in the study area
(New and Bluestone Rivers) in conjunction with
the U.S. Army Corps of Engineers, Huntington
District. An earlier survey of mussels from the
study area which has not been published upon
was conducted by Stansbery (pers. comm.) in
1964. Many of the species recorded in this study
represent the first published mussel records for
the respective watersheds.
Study Area
Monroe County is located in the extreme
southeast portion of West Virginia. It is
bordered to the north by Greenbrier County and
by Summers and Mercer counties to the west.
Monroe County is bordered by the State of
Virginia to the south and east. The majority of
the county (the western half) lies in the New
River basin. The northern and central portions
of the county are in the Greenbrier River drain-
age, while the extreme eastern section of the
county is in the James River (Virginia) drainage.
The streams specifically concerned in this study
are the Greenbrier River and Indian Creek of
New River, and Potts Creek of James River.
Site 1 is located on the Greenbrier River off
State Route 3, 3.22 kilometers southwest of
Aiderson, Greenbrier County (37°41'56"N x
80°40'()7"W). The river at this location lies en-
tirely in Monroe County for a very short dis-
tance of approximately 0.8 kilometers. Green-
brier River originates in Randolph County and
flows in a generally southwesterly course across
Pocahontas, Greenbrier, Monroe and Summers
counties to its confluence with the New River at
Hinton, Summers County. Greenbrier River is
246.33 kilometers long and falls at an average of
3.14 meters per kilometer. The West Virginia
Department of Natural Resources Greenbrier
River Basin Plan (1983) states that excellent
water quality exists in the river.
Indian Creek rises in the limestone sinks of
south-central Monroe County. The stream flows
in a general westerly direction to its confluence
with New River near Junta, Summers County.
Indian Creek is 54.74 kilometers long. Accord-
ing to the West Virginia Department of Natural
Resources New River Basin Plan (1983), the
stream receives pollution from cropland erosion
and the inadequate disposal of human and/or
animal wastes. Three sites were surveyed on
Indian Creek in Monroe County. These are in
upstream sequence: site 2a at County Route 23
bridge, 1.6 kilometers north of Red Sulphur
Springs (37°3r44"Nx80°46'13"W); site 2b off
County Route 23, 6.44 kilometers northeast of
Red Sulphur Springs (37°33'27"Nx80°45'18"W)
and site 2 c off State Route 122, 2.42 kilometers
west of Greenville (37°33'11"N x 80°42'33"'\\0.
Potts Creek heads in the southwestern corner
of Monroe County and tlows northeastward into
Craig County, Virginia. The stream is in the
James River drainage. The entire portion of the
Potts Creek watershed lying in West Virginia
was surveyed for freshwater mussels, however
mussels were found only in the South Fork.
The South Fork of Potts Creek is 9.34 kilo-
meters in length and falls at a rate of 21.66
meters per kilometer. Mussels were located at
two sampling points on South Fork. Site 3a is lo-
cated off County Route 17, 1.6 kilometers north-
east of Waiteville (37°29'03"Nx80°24'50"W),
while site 31) is located further upstream off
County Route 17, 0.8 kilometers west of Waite-
ville (37°28'21"Nx80°25'54"W).
Figure 1 depicts sampling sites where mussels
are located.
Methods
All samiiling sites were examined during nor-
mal or slightly low flow conditions. Each site
consisted of at least one riffle and one pool. The
sites were sampled by walking the banks looking
Vol. 98(4)
October 31, 1984
THE NAUTILUS 149
WEST VIRGINIA
GREENBRIER COUNTY
SUMMERS
COUNTY
MERCER
COUNTY
5 10
SCALE-MILES
FIG. 1. Mussel collection sites in Monroe County, West Virginia. Localities are identified in te.xt.
for shell material, while water scopes were used
in the streams to locate live specimens.
As material was collected in the field, a pre-
liminary species list was compiled on site. Live
specimens were sacrificed and retained only if
suitable dead material was not available. All
collected material was bagged, labeled and re-
turned to the lab for positive identification. Dr.
David Stansbery (The Ohio State University)
aided in the identification of difficult specimens
and confirmed all others. Voucher specimens
have been accessioned in the Ohio State Univer-
sity, Museum of Zoology.
Results and Discussion
A total of 12 species of freshwater unionid
mussels and Corbicula fluminea were collected
during this Monroe County survey (Table 1).
Greenbrier River supported seven species of
mussels, the dominant species being Elliptio
dilatata. Cydonaias tuberculata and Actino-
naias ligamentina carinata. Other species in
Greenbrier River include Alasmidonta margi-
nata, Tritogonia verrucosa. Lampsilis ventri-
cosa and Lampsilis fasciola. All seven species
were collected by Stansbery in 1964, however
Bates reported "negative results" for the Green-
brier River in his 1971 survey. Apparently, the
results of this latter survey were erroneously
reported, as there are currently dense popula-
tions of naiads in the Greenbrier River repre-
senting numerous age classes. Indian Creek also
contained seven species of mussels, with the
population being greatly dominated by Elliptio
dilatata. Other species collected from Indian
Creek include Anodonta grandis grandis, C.
tuberculata, Toxolasma parmis, Villosa iris iris,
L. ventricosa and L. fasciola. Potts Creek con-
150 THE NAUTILUS October 31, 1984
TABLE 1. Freshwater Mussels of Monroe County. West Virjrinia. 1983-1984.
Vol. 98 (4)
Species
Site Number
2a 2b 2c
3a 3b
Anodonta grandis grandis (Say, 1829) X
Strophitus undulatus undulatus (Say, 1817)
Alasmidonta marginata (Say, 1818) X
Irltogonla verrucosa (Raf., 1820) X
Cyclonalas tuberculata (Raf., 1820) XXX
Elliptlo dilatata (Raf., 1820) XXX
Actinonalas llgamentina carinata (Barnes, 182 3) X
Toxolasma parvus (Barnes, 1823) X
Vlllosa iris iris (Lea, 1829) X
Lampsilis ventricosa (Barnes, 1823) XX X
Lampsllis fasciola (Raf., 1820) XXX
Canthyria collina (Conrad, 1837)
Corbicula fluminea (Muller, 177A) XXX
tained two species of unionids of relative equal
abundance. These species are Strophitus un-
dulatus undulatus and Canthyria collina. None
of the species collected is currently listed as en-
dangered, however Canthyria (alias Fusconaia)
collina is currently listed in the Federal
Register (1984) by the U.S. Fish and Wildlife
Service for possible listing as a threatened or
endangered species.
Greenbrier River and Indian Creek both con-
tained seven species of Unionidae, however only
four of these (C. tuberculata, E. dilatata, L. ven-
tricosa and L. fasciola) were common to both
drainages. This variation in species is probably
attributed to the difference in habitat between
the two watersheds.
Greenbrier River is a much larger water body
possessing fairly turbulent water, with a sub-
strate consisting mainly of rocks, cobble and
sand. Indian Creek is smaller in size with calm
water. There is also much more silt in the sub-
strate of Indian Creek due to cropland erosion.
The mussel population existing in the South
Fork of Potts Creek is somewhat a surprise,
since this is an extreme headwater stream
which usually are non-supportive of. mussels.
One of the species, Canthyria collina, found in
this stream is restricted to the James River
drainage, while Strophitus undulatus undulatus
is common to both the Atlantic Costal and
Mississippian mussel faunas. Canthyria collina
represents the first record for this mussel in
West Virginia.
Acknowledgments
The authors would like to extend their great
appreciation to Dr. David Stansbery for his
cooperation and assistance in identification. We
would also like to thank Lee Spencer and Jack
Mumaw for their assistance in collecting.
LITERATURE CITED
1971. Musntl Inoestiyutiont! State of West Vir-
U.S. Bureau of Commercial
Bates, J. M.
ginia, Part I - Section I.
Fisheries. 91 pp.
Clarke, A. H. 1982. Survey of the Freshwater Mussels of the
Upper Kanawha River (RM 91-9.5), Fayette County. West
Virginia, with Special Reference to Epioblasmn tondosa
torulosa and Lnmpsilis alirupta. U.S. Fish and Wildlife
Service, Newton Corner, Massachusetts. 104 pp.
Morris, J. S. and R. W. Taylor. 1978. A survey of the fresh-
water mussels of the Kanawha River of West Virginia.
The Naulilm 92(4):1,'S3-1.55.
Schmidt, J. F. and M. A. Zeto. 1984. Progress Report: West
Virginia Department of Natural Resources Freshwater
Vol. 98 (4)
October 31. 1984
THE NAUTILUS 151
Mussel (Naiad) Population Inventory. Pror. W.V. Acad.
Sci. In Press.
Schmidt, J. E.. IVI. A. Zeto and R. W. Taylor. 198.3. A Survey
of the Mussel Fauna of the Little Kanawha River Basin.
Report of Freshwater Mussels Workshop. 26-27 October
1982. U.S. Army Engineer Waterways Experiment Sta-
tion, Vicksburg, Mississippi. 19ti pp.
Stauffer, J. R., C. H. Hocutt and S. L. Markhani. 1980.
Aquatic Biological Survey of the New River, Virginia and
West Virginia. U.S. Fish and Wildlife Service. Elkins,
West Virginia.
Taylor, R. W. 1980. A Survey of the Freshwater Mussels
of the Ohio River from Greenup Locks Dam to Pittsl)urg,
Pennsylvania. U.S. Army Corps of Engineers, Hunting-
ton/Pittsburg Districts. 71 pp.
Taylor, R. W. and R. C. Hughart. 1981. The freshwater
naiads of Elk River, West Virginia with a comparison of
earlier collections. The Nautilus 95(l):21-25.
U.S. Fish and Wildlife Service, Department of the Interior.
1984. Endangered and threatened wildlife and plants;
review of invertebrate wildlife for listing as endangered
or threatened species. Federal Register 49(100):
21664-21675.
West Virginia Department of Natural Resources, Division
of Water Resources. 1983. Greenbrier River Basin Plan.
97 pp.
1983. New River Basin Plan.
Zeto, M. A. 1982. Notes on the freshwater mussels (Unioni-
dae) of the upper Monongahela River Ijasin West Virginia.
The Nautilus 96(i):rn-l2'-J.
BERMUDA MARINE MOLLUSK TYPE SPECIMENS
TRANSFERRED TO THE SMITHSONIAN
Joseph Rosewater
National Museum of Natural History
Smithsonian Institution
Washington, D.C. 20560
Recently, a number of type specimens of mol-
lusks described by William Healey Dall and Paul
Bartsch were transferred from the Bermuda
Aquarium, Museum and Zoo, Flatt's, Smith's
Parish, Bermuda, to the collection of Recent
MoUusks, Department of Invertebrate Zoology,
National Museum of Natural History, Washing-
ton, D.C.
Since these type specimens were originally
mentioned as being in the Bermuda Museum, or
in the collection of Mr. Arthur Haycock, of Ber-
muda, it is necessary to put on record their new
location for the benefit of malacologists who
may wish to examine them in connection with
research projects. In some cases the numbers of
specimens per species sent from the Bermuda
Museum (Haycock Collection) and labeled as
Cotypes ( = Syntypes or where a Holotype or
Lectotype can be distinguished, Paratypes or
Paralectotypes) exceed the number originally
mentioned by Dall and Bartsch in their publica-
tions. It is probable that Haycock did not
originally send or mention all the specimens he
had available for examination.
The types of the following species are involved
and are listed in order of their publication.
Argyrodonax haycocki Dall, 1911:86 (Ber-
muda: Lectotype USNM 842643; Paralecto-
types USNM "783533). The type lot was de-
scribed by Dall as consisting of one complete
specimen and a single additional valve all in the
collection of Arthur Haycock, Bermuda [later in
the collection of the Bermuda Museum]. In 1979
NMNH received from the Bermuda Museum
two single and unrelated valves of this species
labeled as Syntypes. Recently a complete speci-
men marked "type" was received that matches
Dall's description and measurements and it is
here designated the Lectotype. Argyrodonax
haycocki originally assigned by Dall to the fami-
ly Mesodesmatidae, has the dentition and sculp-
ture of Cumingia and therefore appears to
belong in the family Semelidae.
CiAutnbella somersiana Dall and Bartsch,
1911:278, pi. 35, fig. 2 (Bermuda; Holotype
USNM 842644). This species originally was
described from a single specimen. In 1912 an
additional specimen, so named, was received
152 THE NAUTILUS
October 31, 1984
Vol. 98(4)
from Haycock, and added to the NMNH collec-
tion (USNM 251405, 13.7 mm). The specific
name was considered a synonym of Columbella
mercatoria (Linne, 1758) by Abbott (1974), and
by Radwin (1977).
Aclis bermudensis Dall and Bartsch, 1911:278,
pi. 35, fig. 5 (Bermuda; 2 Paratyjies USNM
228692). Althoug-h the authors indicated that
the Holotype is in the Bermuda Museum, no
specimens of this species were included with the
recent transfer from that source. One of the two
Paratype specimens was illustrated (Bartsch,
1947:2-3, pi. 1, fig. 2) and may be designated as
a replacement if the Holotype cannot be found.
Cerithiopsis ara Dall and Bartsch, 1911:282,
pi. 35, fig. 1 (Bermuda; 3 Synt.'y-pes USNM
221612). 14 additional Syntypes were trans-
ferred recently to NMNH from the Bermuda
Museum (USNM 842645).
Cerithiopsis peso, Dall and Bartsch, 1911:283,
pi. 35, fig. 10 (Bermuda; Holotype USNM
221616). 10 additional Paratypes were recently
transferred to the NMNH from the Bermuda
Museum (USNM 842646).
Cerithiopsis vicoln Dall and Bartsch,
1911:284, pi. 35, fig. 12 (Bermuda; Holotype
USNM 842647). Although originally stated by
Dall and Bartsch (191 1, p. 285) to be based on a
unique specimen, the Holoty^je and 2 additional
specimens (Paratypes USNM 842648) were re-
cently transferred to NMNH from the Bermuda
Museum.
Cerithiopsis io Dall and Bartsch 1911:285, pi.
35, fig. 3 (Bermuda; Lectotype USNM 221615).
The figured specimen is here designated as the
Lectotype. Although only 1 additional specimen
was mentioned as being in the Bermuda Muse-
um, 4 specimens (Paralectotypes USNM
842649) were recently transferred to the NMNH
from the Bermuda Museum.
Type specimens of remaining species de-
scribed by Dall and Bartsch 1911, were already
in the NMNH collection at the time of the trans-
fer described above, and several, also, were
originally said to be represented by Syntypes or
Paratypes in the Bermuda Museum as follows:
Mitrn haycocki Dall and Bartsch, 1911:277, pi.
35, fig. 7 (Bermuda; Syntypes Bermuda Muse-
um; also USNM 221617). [Is Mitrolumna
biplicata (Dall, 1889), Turridae, (Abbott, 1974,
p. 269)].
Turhotiilla (Careliopsis) bermudensis Dall and
Bartsch, 1911:279, pi. 35, fig. 4 (Bermuda; 3
Syntypes: USNM 221614).
Turboyulla (Strioturbonilla) peilei Dall and
Bartsch, 1911:280, pi. 35, figs. 9, 9a(Bermuda; 2
Syntypes: 1 in Bermuda Museum and 1 in
USNM 221610).
TurboniUa (Strioturbonilla) haycocki Dall and
Bartsch, 1911:280, pi. 35, fig. 6, 6a (Bermuda; 4
Syntypes: 2 in Bermuda Museum and 2 in
USNM 221611).
Cerithiopsis movilla Dall and Bartsch,
1911:281, pi. 35, fig. 11 (Bermuda; 2 Syntypes
USNM 221613).
Fissuridea bermudensis Dall and Bartsch,
1911:286, pi. 35, fig. 8 (Bermuda; Syntypes in
Bermuda Museum and USNM 221618). [a valid
Diodora (Farfante, 1943, Johnsonia, vol. 1, no.
11, p. 10)].
Odostomia (Chrysallida) nioha Dall and
Bartsch, 1911:286 (Bermuda; USNM 223284).
Ischnochitnn (Stenoplax) bermudensis Dall and
Bartsch 1911:287 (Bermuda; Holotype USNM
223354). [is Stenoplax rugulata (Sowerhy, 1832)
(Abbott, 1974, p. 397).]
Several additional species were described by
Paul Bartsch (1911) from collections supplied by
Arthur Haycock, from Bermuda. The types of at
least one of these species also were originally
shared between the Bermuda Museum and
NMNH, but no additional specimens were trans-
ferred to the latter:
Cerithiopsis hero Bartsch, 1911:303 (Ber-
muda; USNM 226450).
Cerithiopsis cynthia Bartsch 1911:304 (Ber-
muda; USNM 226449).
Cerithiopsis iontha Bartsch, 1911:304 (Ber-
muda; Bermuda Museum and USNM 226451).
Triphora bermudeyisis Bartsch, 1911:306
(Bermuda; USNM 226452). [Is Triphora turris-
thomae (Holten, 1802) (Abbott, 1974, p. 111).]
Abbreviations used here:
NMNH -National Museum of Natural History.
USNM -United States National Museum, col-
lections of which are in NMNH.
Acknowledgments
I am grateful to Frances Eddy, Bermuda
Museum and Russell H. Jensen, Delaware
Museum of Natural History, for initiating the
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 153
transfer. Harald A. Rehder and Richard S.
Houbrick read and criticized the manuscript.
LITERATURE CITED
Abbott, R. Tucker. I97i. American Seashells. Second Edi-
tion. 663 pp. Van Nostrand Reinhold Co., New York.
Bartsch, Paul. 1911. New Marine Mollusks from Bermuda.
Proceedings of the United States National Museum
41(1861):303-306.
1947. A Monograph of the West Atlantic Mol-
lusks of the Family Aclididae. Smithsonian Miscellaneous
Collections 106(20): 1-29.
Dall, William H. 1911. A New Genus of Bivalves from Ber-
muda. TheNaut}lus 25(8):85-86.
Dall, William H.. and Bartsch, Paul. 1911. New Species of
Shells from Bermuda. Pmeeediiigs of the United States
National Museum 40(182(l):277-288.
Radwin, George E. 1977. The Family Columbellidae in The
Western Atlantic. The Veliger 19(4):403-417.
PRODUCTION OF IMMATURE CORBICULA FLUMINEA
(BIVALVIA: CORBICULIDAE), IN LAKE NORMAN, NORTH CAROLINA
James J. Hall ^
Duke Power Company
Production Environmental Services
Route 4, Box 531
Huntersville, North Carolina 28078
ABSTRACT
The annual production of the immature specunens of the Asiatic clam, Corbi-
cula lluminea, was determined in littoral and sublittoral zones of Lake Norman.
North Carolina, from February 1978 through January 1979. C. fluminea had a
growing season greater than nine months, from 22 March 1978 to 8 January 1979.
The higher mean annual production (516 mg/m') and PIB ratio (26. Jt) o/Cor-
bicula occurred in the littoral zone, while mean annual production and PIB of
Corbicula in the sublittoral zone were 182 mglm^ and 16.i, respectively. The lit-
toral zone had the higher mean Corbicula biomass (20 mg/m^) and density
(SOUOlrn^) compared to the mean Corbicula biomass (11 mg/m^) and density
(891/m') in the sublittoral zone.
The Asiatic clam, Corbicula fluminea (Miiller,
1774), (Bivalvia: Heterodonta: Corbiculidae) was
first discovered in the United States in 1938, on
the shoreline of the Columbia River in Washing-
ton (Burch, 1944). Since 1938, C. fluminea has
successfully overcome physical and ecological
barriers to extend its range from the west coast
to the east coast of the United States (Rodgers
et al, 1979). Corbicula fluminea was first found
in Lake Norman, North Carolina, in August
1972 (T. W. Yocum, pers. commun.). Since that
time, C. fluminea has greatly increased in
number; from 1974 through 1978, C. fluminea
density increased approximately sixty-fold in
Lake Norman (Duke Power Company, unpubl.
data). Their biomass increased from 0.1%
(January 1974) to 85% (October 1978) of the
total benthic biomass collected in the sublittoral
zone of Lake Norman.
Corbicula fluminea are simultaneous herma-
phrodites and incubate their young within the
inner demibranch of the ctenidium. Repro-
duction and release of veligers (non-swimming
planktotrophic larvae) occurs when water
temperatures are above 16°C (Eng 1979), with
an average daily release of 387 (spring) and 320
(fall) veligers per clam (Britton and Fuller 1980).
They have a life span up to seven years and can
attain a shell length of 5.0 to 6.5 cm (Britton and
Fuller 1980: Ingram 1959; Pool and Tilly 1977).
Small clams and veligers are easily taken into
industrial water systems where untreated water
154 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
is used. When the clams are about 1.5 mm in
length, they can attach to the substrate with
their byssus (Goss and Cain 1975). The electric
generating industry is the single largest non-
consumptive user of water, and has encountered
numerous problems with the clams. The most
serious problem is the fouling of cooling con-
densers, which causes high back pressure on the
turbines and consequently reduces turbine effi-
ciency. Cherry et al (1980) state that the most ef-
fective treatment is mechanical removal of
shells and sediments. In some cases, the fouling
is so extensive that it can only be remedied by
closing down the generating unit and manually
removing the clams from the condensers (Goss
and Cain 1975). In addition, problems can occur
in the fire protection service water and emer-
gency reactor cooling systems (Smithson, 1981).
Because of their potential to clog waterlines, in-
terest in the biology of C. fliuninea has been
stimulated by industries that use raw water
(Goss and Cain 1975).
Study Area
A one-year study of the production of C.
fluminea in Lake Norman was initiated in
February 1978. C. fluminea occurred primarily
in the littoral and sublittoral zones and were
near-absent in the profundal zone; therefore,
production was estimated only for the littoral
and sublittoral zones of Lake Norman. Produc-
tion has been defined by Clarke (1946) as the
amount of tissue elaborated per unit area, per
unit time, regardless of its fate. The objectives
of this study were to:
1) describe the life cycle of C. fluminea in Lake
Norman.
2) estimate the production, density, and produc-
tion/biomass ratios of C. fluminea in Lake Nor-
man, in four areas of the lake, at two depth
zones, littoral (~4 m) and sublittoral (~8 m).
Lake Norman (36°26'N, 80°56'W) is located
27 km north-northwest of Charlotte, North
Carolina. The lake was impounded in 1963 and
has a total surface area of 13,156 ha, a max-
imum depth of 36.6 m, and a mean depth of 10.3
m at full pond. Lake Norman is the source of
cooling water for two electric generating plants,
Marshall Steam Station and McGuire Nuclear
Station, and is a source of water for Cowans
Ford Hydroelectric Station (Duke Power Com-
pany 1980). Four locations were selected at both
littoral (~4 m) and sublittoral (~8 m) depths
(represented by X.7 and X.6 location numbers,
respectively) (Fig. 1). These locations are ex-
pected to receive maximum (Location 4), mini-
mum (Locations 2 and 6), and no (Location 8)
thermal effluent from McGuire Nuclear Station
(Duke Power Company 1976).
Methods and Materials
Triplicate Petersen grab samples (258 cm^
each) were taken at all locations at four week in-
tervals from 23 February 1978 through 25 Janu-
ary 1979 (13 sampling periods). The samples
were washed in Wildco sieve buckets (212-/.im
mesh) and preserved in 70% ethanol containing
0.25 g/1 rose bengal stain. Corbicula were sorted
from the bottom samples in the laboratory and
were measured to the nearest 0.5 mm using an
ocular micrometer. Shell lengths were meas-
ured at their greatest anteroposterior dimen-
sion across the valves. All specimens in each
size-class (0.5-mm increments) of Corbicula
were first removed from 70% ethanol, shucked
from their shells, rehydrated in distilled water,
removed from the distilled water, blotted dry,
placed in a pre-weighed crucible, dried at 105° C
for 24 hr, cooled, and reweighed to the nearest
COWANS
DAM
FIG. 1. Locations sampled for Corhinda during the prcxiuc-
tion study on lower end of Lake Norman, North Carolina.
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 155
0.01 mg on a Mettler (Model H542) balance. A
bo(1y length-dry weight least squares regression
equation was calculated from these data.
Production estimates, using dry weights,
were calculated using the size-frequency method
(Hynes 1961, 1980; Hynes and Coleman 1968) as
modified by Hamilton (1969). The estimates
were based on all size classes from the smallest
occupied size class to the largest size class con-
taining substantial numbers (Waters 1977).
Therefore, I used the 6.0-mm size class as the
maximum size class. The annual P/B ratio was
computed as the annual production estimate
divided by the mean standing crop biomass. This
value theoretically indicates how many times
per year the mean population biomass is re-
placed.
Sediment temperatures were taken with a
YSI Model 46 TUC tele-thermometer at every
location and sampling period.
Differences in production estimates could not
be statistically tested, so differences in the C.
Jluminea densities that the production estimates
were calculated from were tested with an analy-
sis of variance procedure after densities were
logarithmically transformed (Elliott 1977). An
F-max test (Sokal and Rohlf 1981) indicated that
variances of C. fluminea mean densities (N = 39
samples) for each location were heterogeneous
at the littoral locations (E-max = 2.76; p<.05)
and were homogeneous at the sublittoral loca-
tions (F-max = 1.43; p>.05). Heterogeneous
variances violates an assumption of the parame-
tric ANOVA, but Keppel (1973) stated that
when equal sample sizes were used, the distor-
tion of the F distribution was relatively slight.
Since sample sizes were equal, a one-way
ANOVA (Sokal and Rohlf 1981) was performed
to determine if there were significant differ-
ences among locations. Significant differences
in C. fluminea mean densities among locations
were tested for using Duncan's Multiple Range
Test (Sokal and Rohlf 1981). Data analyses were
done using the Statistical Analysis System (Barr
ct al. 1979).
Results
Life Cycle
The number of 0.5-1.0 mm size classes domi-
nated the density through(_)ut this study for both
littoral and sublittoral zones (Fig. 2). The
proportion of 0.5 mm clams increased in June,
reflected reproduction in May, which possibly
continued through late November (Fig. 2).
Aldridge and McMahon (1978) found that veli-
gers released in late spring and early summer
2 6.5
6.0
s.s
60
I'M
c/i
S 3.0 I I
73 f EB 78 ?3 MAR Tfl 20 APR 70 18 MAY 78 15 JUN 78 13 JUL 78 10 AUG 78 8 SEP 78 » OCT 78 2 NOV 78 30 NOV 78 78 DEC 78 25 JAN 79
FIG. 2. Length-frequency histcigrams for Curhiculii Jluiiiiiwa collefted in Petersen grab sample.^ from the combined Httoral
and subHttoral zones of Lake Norman (densities are shown as percent occurrence in each size class collected per month).
156 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
are able to reach sexual maturity by the fall. The
high density of small clams (<0.5 mm) from
September through November possibly indi-
cates that higher reproduction occurred in the
fall (Fig. 2). The high reproductive ability of C
fluminea is offset by the high mortality which
is shown to have occurred in the early stages
of growth (veliger to 6.0 mm) preventing all
but a few clams from reaching sexual maturity
(Fig. 2).
Sediment temperatures above 8°C (biological
zero for C. fluminea) (Duke Power Co., unpubl.
data) occurred from 1 April 1978 through mid
January 1979 in the littoral and sublittoral zones
in Lake Norman (Fig. 3).
Regression Analysis
The least squares regression equation In W =
-5.11 + 2.98 (In L), where In W is the natural
logarithm of dry weight in milligrams and In L
is the natural log of body length in millimeters,
was used to calculate dry weight from body
length. This relationship accounted for 99% (R^)
of the variance, and the slope was significantly
different from zero (F,, ,,„ = 3592.0; P<0.0001)'.
Production Estimates
Production estimates were multiplied by two
to account for two generations produced each
year (Hamilton 1969). The bivoltine life cycle of
C fluminea was determined from literature
research (Aldridge and McMahon 1978; Sinclair
and Isom 1963) and data from the C. fluminea
growth study in Lake Norman (Duke Power Co.,
unpubl. data). The littoral zone had the higher
mean annual density (3040/m^) and production
(516 mg/mVyr) (Table 1). The littoral locations
with the highest and lowest densities of C.
fluminea were Locations 2.7 and 4.7 corre-
sponding to the highest (732 mg/mVyr) and low-
est (80 mg/mVyr) production estimates, re-
spectively (Table 1). The average P/B in the lit-
toral zone was 26.4 and ranged from 14.8 to 34.2
(Table 1). There were overall significant density
differences in the littoral zone (F,;,,
13.58;
P<0.0001). Locations 4.7 and 2.7 were signifi-
cantly different from each other and from both
6.7 and 8.7 (Table 2). However, Locations 6.7
and 8.7 did not differ from each other (Table 2).
The mean annual density of C. fluminea in the
sublittoral zone was 70.7% less than that in the
DAYS WHEN WATER TEMPERATURES WERE ABOVE 10°C
(J
o
UJ
a
=>
t-
<
oc
a
z
111
LITTORAL MM)
SUBLITTORAL (v8M)
FEB MAR APR MAY JUN JUL AUG SEP OCT NOV NOV DEC JAN
1978 1979
FIG. 3. Mean monthly sediment tempfratures(°C)forall littoral and suhlittural locations on Lake Norman (23 February 1978
tlirouj^h 25 January 1979). Temperatures above 8°(' ICorhicula biological zero) occurred from late March 1978 through mid-
January 1979.
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 157
TABLE 1. Mean annual densities (no/m'). biomass {mglm'). production (mg/m'j. and turnover ratios (production/mean
liiomass) by zones and locations sampled in Lake Norman for (^irbicuta tJuiiiinea ^<5.U mm in leiig'th.
littoral zone. The mean annual production in the
sublittoral zone was 65% less than in the littoral
zone (Table 1). Production in the sublittoral zone
ranged from 70 to 285 mg/mVyr and densities
ranged from 463 to 1434 m"^" (Table 1). The
mean annual production and density in the sub-
littoral zone were 182 mg/m^ and 891/m^
respectively (Table 1). The P/B in the sublittoral
zone was 16.4, with ratios ranging from 12.0
(Location 4.6) to 18.2 (Location 2.6) (Table 1).
No significant differences in mean densities
were detected among the four sublittoral loca-
tions (F,3 152) = 1.06; p>0.37) (Table 2).
Discussion
Production estimates were made only on the
clams <6.0 mm in length, so they probably
slightly underestimate the production of the
whole population, but the method is most
reliable when very low densities of larger
TABLE 2. Duncan's Multiple Range Test of Corbicula
Jluminea geometric mean densities {nolm') at each location
in the littoral and sublittoral zones. Densities subtended by
the same line were not significantly different at the five per-
cent level.
DUNCAN'S MULTIPLE RANGE TEST
SUBLITTORAL LOCATIONS
GEOMETRIC MEAN
DENSITIES (N0/M2)
UTTORAL LOCATIONS
GEOMETRIC MEAI
138
179
IC MEAN
iSlTlES (N0/M2) 2890 202 692 11
organisms are omitted (Waters 1977). High P/B
ratios in both littoral (26.4) and sublittoral (16.4)
zones probably result from high reproduction by
C. fluminea ^6.5 mm and high mortality of the
clams <6.0 mm, as shown by the ability of only a
few clams to reach the 6.5 mm size class (Fig. 2).
The increase in density of C. fluminea in each
represented size class, except for 0.5 mm, in
December 1978 and January 1979, is assumed to
indicate growth of the sexually immature clams
(<6.0 mm) during the winter months. Corbicula
fluminea 8.0 mm or larger in Lake Norman
grew a maximum of 10 mm during a one-year
growth study (June 1978 to June 1979) (Duke
Power Co., unpubl. data). They ceased to grow
when the water temperatures was between 8.8
(1 January 1979) and 6.5°C (17 January 1979)
and resumed growth in March when the water
temperatures reached 10-11°C. Corbicula
fluminea reach sexual maturity during their
first year at a length ranging from 6.5 to 10 mm
(Aldridge and McMahon 1978; Sinclair and Isom
1963). Britton et al. (1979) stated that Corbicula
in Texas could grow year-round, with water
temperatures ranging from 8 to 33°C and that
veligers released in the fall continued to grow
during the winter reaching 10-12 mm in length
by April. They also stated that larger clams
showed little growth, tmt more field work was
needed for growth during the winter season.
Leveque (1973) used three methods (Bojsen-
Jensen, instantaneous rate of individual growth
and mortality, and instantaneous rate of popula-
tion growth) to estimate production of C.
158 THE NAUTILUS
October 31. 1984
Vol. 98 (4)
africana in Lake Chad, in Chad, Africa. The an-
nual production estimate (1080 mg/m^) of C.
africana {> 8.0 mm) was 107 and was 500%
higher than the production estimates for C.
fluminea (0.5 to < 6.0 mm) in the littoral and
sublittoral zones of Lake Norman, respectively.
Leveque worked with a population of C.
africana having three cohorts. He reported that
the monthly densities of clams {> 8.0 mm)
ranged from 35 to 100/m-' while the density of
clams (> 6.5 mm) collected in Lake Norman
ranged from 0 to 20/m^
Cohort P/B of C. africana in Lake Chad
ranged from 1.7 to 2.5 and are much lower than
the P/B in Lake Norman's littoral (26.4) and
sublittoral (16.4) zones. Corhicula JJuminea's
higher P/B in Lake Norman suggests that this
population had greater recruitment or a greater
population growth rate than C. africana..
The P/B of C. fluminea in Lake Norman can
be expected to drop as the clam's population
becomes better established with a higher per-
centage of larger clams being present in Lake
Chad. As the density of larger clams increases,
production of C. jluminea in Lake Norman can
also be expected to increase.
Acknowledgments
I wish to express my gratitude to the follow-
ing for their assistance with the collecting: T.
W. Bowen, D. A. Braatz. K. A. Eaton, L. W.
Pace, T. J. Wilda, and P. S. Wingo. Also I am
very grateful to R. L. Green (designer of the
project), E. F. Jones, and D. W. Revill for their
assistance in the collections, who all lost their
lives in a boating accident on Lake Norman, 7
January 1980. I am also appreciative of Dr. T. C.
Folsom for the computer programming and
analyses, W. M. Rash for assistance on the
figures, and J. A. Brotherton for typing the
manuscript.
LITERATURE CITED
Aldridge, D. W. and R. F. McMahon. 1978, Growth, fecun-
dity, and bioenergetics in a natural population of the
Asiatir freshwater clam, Corhicula maniiensis I'hilippi,
from north central Texas. Jour. Moll. Stud. 44:4i)-70.
Barr, A. J., J. H. Goodnight, J. P. Sail. W. H. Blair and D.
M. Chilko. 1979. SAS U.'ser's Guide. 1979 edition. SAS In-
stitute, Raleigh, NC. 494 p.
Britton, .1. C. and S. L. H. Fuller. 1980. The freshwater
bivalve Mollusca (Unionidae, Sphaeriidae, Corbiculidae) of
the Savannah River Plant, South Carolina. National Envi-
ronmental Research Park, Savannah River Plant. M. H.
Smith and I. L. Brisbin. ed. SRO-NERP-3. 37 p.
Britton, J. C, D. R. Coldiron, L. P. Evans, Jr., C. Golightly.
K. D. O'Kane, and J. R. TenEyck. 1979. Reevaluation of
the growth pattern in Corhicula fluminea (Mialler). Pp.
177-192. In: J. C. Britton, ed. Proc. First Int. Corhicula
Symp. Tx. Christian Univ. Res. Found. Publ., Fort Worth,
TX. 313 p.
Burch, .]. Q. 1944. Checklist of western American moliusks,
family Corbiculidae. Minutes Conchological Club Southern
California, no. 36:18.
Cherry, D. S., J. H. Rodgers, R. L. Graney and J. Cain. 1980.
Dynamics and control of the Asiatic clam in the New
River, Virginia. VPI-SU. Va. Water Resour. Res. Cent.
Bull. 123:1-72.
Clarke, A. L. 1946. Dynamics of production in a marine area.
Erol. Monogr. 16:321-335.
Duke Power Company. 1976. McGuire Nuclear Station Units
1 and 2. Environmental Report, Operating License Stage.
Vols. 1 and 2. Revision 6. Charlotte, NC.
1980. McGuire Nuclear Station consolidated
overview baseline year 1978-1979. Duke Power Company,
Charlotte. NC. 187 p.
Elliott, ,]. M. 1977. Some methods for the statistical analysis
of samples of benthic invertebrates. Sci. Publ. No. 25.,
Freshwater Biol. Assoc, Ferry House, U.K.
Eng, L. L. 1979. Population dynamics of the Asiatic clam,
Corhicula fluminea (Muller), in the concrete-lined Delta-
Mendota Canal of central California. Pp. 39-68. In: J. C.
Britton, ed. Proc, First Int. Corhicula Symp. Tx. Chris-
tian Univ. Res. Found. Publ, Fort Worth, TX. 313 p.
Goss, L. B. and C. Cain, Jr. 1975. Power plant condenser and
service water system fouling by Corhicula. the Asiatic
clam. Pp. 11-17. In: L. D. Jensen, ed. Biofouling Control
Procedures. Technology and Ecologj' Effects. Marcel
Dekker, New York. NY. 113 p.
Hamilton. A. L. 1969. On estimating annual production.
Limnol. Oceanogr. 14:771-782.
Hynes, H. B. N. 1961. The invertebrate fauna in a Welsh
mountain stream. Arch. Hydrohiol. 57:344-388.
1980. A name change in the secondary produc-
tion business. Limnol. Oceanogr. 25:778.
Hynes, H. B. N. and M. J. Coleman. 1968. A simple method
of assessing the annual production of stream benthos.
Limnol. Oceanogr. 13:569-573.
Ingram, W. M. 1959. Asiatic clams as potential pests in Cali-
fornia water supplies. Jour. .Am. Water Works Assoc.
51:363-370.
Keppel, G. 1973. Liesign and analysis: A research handbook.
Prentice-Hall, Inc., Englewood Cliffs, NJ. 658 p.
Leveque, C. 1973. Dynamique des peuplements biologie et
estimation de la production des Mollusques benthiques du
Lac Tchad. Hydrohiologia 7:117-147.
Pool, D. and L. J. Tilly. 1977. A model to determine growth
rate of Corhicula. Presented First Int. Corhicula Symp.
1:11 p.
Rodgers, J. H., D. S. Cherry, K. L. Dickson <and J. Cains.
1979. Invasion, population dynamics and elemental ac-
cumulation of Corhicula fluminea in the New River at Glen
Lyn, Virginia. Pp. 99-110. In: J. C. Britton, ed, Proc. First
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 159
Int. Corbicula Symp., Tx. Christian Univ. Res. Found.
Publ., Fort Worth, TX. 313 p.
Sinclair, R. M. and B. G. Isom. 1963. Further studies on the
introduced Asiatic clam Corbicula in Tennessee. Tenn.
Pollut. Board, Tenn. Dept. Public Health, Cordell Hull
Building, Nashville, TN. 76 p.
Smithson. J. .A.. 1981. Control and treatment of Asiatic
clams in power plant intakes. Annu. Meet. Am. Power
Conf.. Decatur. Illinois. 43:1-18.
Sokal, R. R. and R. J. Rohlf. \m\. Bdmu'tiy. Freeman, San
Francisco. 859 p.
Waters, T. F. 1977. Secondary production in inland waters.
Adv. Ecol. Res. 10:91-164.
THE BORING CLAM, PENITELLA CONRADl (BIVALVIA: PHOLADIDAE)
IN NEPHRITE FROM MONTEREY COUNTY, CALIFORNIA
Edward C. Wilson (vid George L. Kennedy
Natural History Museum of Los Angeles County,
Los Angeles, California 90007 and
U.S. Geological Survey, Menlo Park, California 94025
ABSTRACT
Cobbles and boulders of nephrite jade collected subtidally and on Pleistocene
marine terraces in Monterey County, California, contain numerous teardrop-
shaped burrows typical ofpholadid clams. Most burrows examined were vacant or
occupied secondarily by nestling clams and other organisms. One burrow con-
tained valves of a primary borer, Penitella conradi Valenciennes, and represents
the first record ofpholadids boring nephrite. Emendation of the widespread belief
that pholadids burrow only by mechanical abrasion seems justified.
In May, 1982, one of us (Wilson) was aston-
ished to recognize a vacant pholadid burrow in a
slabbed cobble of nephrite jade (Fig. 1) offered
for sale at Gorda, Monterey County, California.
Inquiry disclosed that the cobble had been col-
lected by divers off the coast nearby between
Jade Cove and Willow Creek (Fig. 2). Subse-
quently, more than 100 burrows in cobbles and
lioulders of nephrite from the same area were
observed by us, including some reportedly from
local Pleistocene marine terraces. Such burrows
are common enough to be considered a minor
nuisance by the local jade dealers. Most of the
burrows were empty or occupied secondarily by
the nestling clams, Hiatella arctica (Linnaeus,
1767) or Pefricola carditoides (Conrad, 1837),
and other organisms. One burrow (Fig. 3) how-
ever, contained shells (Fig. 4) of a primary
borer, the pholadid Penitella conradi Valen-
ciennes, 1846, a species that ranges from
Washington to Baja California Sur on the west
coast of North America.
In addition to the pholadid burrows, unoc-
cupied cup-shaped depressions with diameters
as great as 80 mm occur on the surfaces of some
of the nephrite boulders (Fig. 5). They are
' -?" jrv^ji^^X
FIG. 1. Cut piece of nephrite cobble showing longitudi-
nally sectioned pholadid burrow surrounded by dark halo.
LACMIP hypotype 2480. Inset: latex cast made from this
burrow. Both Figs, x 1.
160 THE NAUTILUS
121° 29'
October 31. 1984
121° 26'
Vol. 98 (4)
FIG. 2. Map showing general location of study area in
California (in.set) and more detailed map of the Plaskett
Point-Cape San Martin region, Monterey County, where
pholadid-liored nephrite jade occurs.
similar in shape and size to those formed by the
sea urchin, Strongylocentrot-us Brandt, 1835.
Nephrite
Between Plaskett Point and Cape San Martin,
near Gorda, Monterey County, California (Fig.
2), nephrite crops out as lenticular masses asso-
ciated with a complex of serpentine, schist,
graywacke, and shale usually referred to the
Franciscan Formation of Mesozoic age (Crip-
pen, 19.51). F\^bbles, cobbles, and boulders de-
rived from this formation, including nephrite,
[)r()vide a substratum for epifaunal and infaimal
marine organisms.
FIGS. .S-4. 3 (upper), portion of nephrite cobble with
pholadid burrows. Collection of Mrs. Peggy McCain, x 0.."). 4,
|iaired valves of Penitella conradi removed from burrow
shown by arrow in Fig. 3. LACMIP hypotype 2481. x2.0.
FIG. .S. Nephrite Ixjulder showing small pholadid burrow
openings and large surface depressions probably formed by
cchinoids. Boulder is 91 cm high. Collection of Mr. Kenneth
Comello.
Nephrite is a silicate mineral with a legendary
toughness that is due to an internal structure of
filamentous crystals arranged in a dense, felt-
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 161
like pattern, making it both difficult to break
and to work. All of the nephrite cobbles and
boulders with burrows tested by us have a hard-
ness of between 5 and 6 on the Mohs scale and a
specific gravity of 3 to 3.44. This would seem to
be an inhospitable substratum for infaunal
organisms.
Burrows
All of the burrows in nephrite seen in cross-
section have the typical teardrop shape of phola-
did burrows (Figs. 1, 6). Selected latex casts of
other burrows in the nephrite show that they
have similar shapes. No burrows were seen with
shapes that are typical of boring clams other
than pholadids. The size of the burrows is
variable, with entrances that range from 1.5 to
4.5 mm in diameter. The largest burrow has a
depth of 36 mm and a maximum width of 16
mm. A darkened halo around one of the sec-
tioned burrows is as much as 7 mm wide (Fig. 1)
and strongly suggests chemical alteration of the
nephrite. The hardness in the discolored zone,
however, is unaltered. Halos around burrows in
mudstone formed by the boring mytilid Litho-
phaga Roding, 1798, considered to be a chemical
borer by most workers, were attributed to
subaerial weathering by Warme and Marshall
(1969).
The specimen of Pent tella conradi (Fig. 4) was
taken from a subtidally collected nephrite cobble
(Fig. 3). The valves are of an adult animal with
FK;, r,, ( ut piece of nephrite cobble showing longitudinally
sectioned pholadid burrow. Collection of Mr. Kenneth
Comello. Inset: latex cast made from this burrow. LACMIP
hypotype 2482. Both Figs, x 1 .0.
callum and are 13 mm long (without siphono-
plax). The shells are not misshapen, as is the
case with some pholadids that bore into hard
substrates, but the concentric ridges on the
anterior slope are very tightly packed.
Discussion
"Members of the family Pholadidae bore into
stiff clays or muds, shales, friable or soft rock,
shells, poor grade cement, wood, nuts, or other
plant products" (Turner, 1969). The implication
of "soft rock" is that it is either sedimentary or
relatively nonresistant to erosion. However,
pholadids infrequently have been reported bor-
ing into volcanic and metamorphic rocks. Bor-
ing generally is considered to be mechanical and
not chemical in nature. On the basis of wear pat-
terns on pholadid shells, Kennedy (1974) con-
cluded that mechanical rasping of the burrow
wall was done primarily with the fore edge of
the last concentric ridge of the anterior slope.
The mechanics of boring in numerous species of
pholadids was discussed by Roder (1977).
Reports of two researchers (Smith, 1969;
Haderlie, 1976, 1979, 1980) contradict the tra-
ditional view that pholadids bore only mechan-
ically.
The process of boring by Penitelln conradi
was studied by Smith (1969). After examination
of California abalone shells bored by this
species, he concluded that "the role of mechani-
cal abrasion by P. conradi is minor . . . The
boring process in P. conradi proceeds mainly by
chemical dissolution of the calcareous sub-
strate". He suspected that epithelial glands in
the mantle were used for chemical dissolution of
the abalone shell.
Smith (1969) also observed that during the
characteristic rocking motion of the pholadid
boring cycle, the mantle of P. conradi was in
contact with the anterior burrow wall as far as
the maximum diameter of the burrow and that it
simultaneously covered most of the anterior
portions of the valves. Apparently a biochemical
secretion was being deployed to the calcareous
substrate by specialized cells in the mantle. The
mantle was then withdrawn and the rotation
cycle initiated, during which the mechanical
abrasion occurred.
Haderlie (1976, 1979, 1980) reported that P.
conradi and six other species of pholadids bore
162 THE NAUTILUS
October 31, 1984
Vol. 98 (4)
into siliceous sediments of the Monterey Shale
in Monterey Bay, California. The rocks were
reported to be chert and to have a hardness of
seven on the Mohs scale.
The presence of burrows of P. conradi in
nephrite seems to substantiate the findings of
Smith (1969) that the species uses chemical
assistance for boring and Haderlie (1976, 1979,
1980) that it somehow bores into substrata much
harder than its shell. Further studies are
necessary to elucidate the method of substratum
dissolution.
Acknowledgments
We are grateful to Mrs. Peggy McCain of
Beverly Hills and to Messrs. Kenneth Comello,
"Jade Ron", and Robert York of Gorda for allow-
ing us to examine specimens from their collec-
tions. Dr. A. R. Kampf, Curator of Mineralogy
at the Natural History Museum of Los Angeles
County, verified the identification of the
nephrite. Drs. J. H. McLean, D. R. Lindberg, L.
N. Marincovich, E. J. Moore, and R. D. Turner
reviewed the manuscript.
The shells of Penitella conradi and selected
specimens of nephrite with pholadid burrows
are in the Natural History Museum of Los
Angeles County, Invertebrate Paleontology
Section (LACMIP) as hypotypes 2480-2482.
LITERATURE CITED
Crippen, R. A., Jr. 1951. Nephrite jade and associated rocks
of the Cape San Martin region, Monterey County, Cahfor-
nia. California Division of Mines and Geology, Special
Report, io-A:7-18.
Haderlie, E. C. 1976. Destructive marine wood and stone
borers in Monterey Bay, p. 947-953. In Sharply, J. M. and
A. M. Kaplan, editors, Proceedings of the Third Interna-
tional Biodeqradation Symposium. Applied Science Pub-
lishers, London.
1979. Range extension for Penitella fitchi
Turner, 1955. The Veliger 22(1):85.
1980. Stone boring marine bivalves as related to
the geology of Monterey Bay, California, p. 231-248. In, V
International Congress on Marine Corrosion and Fouling.
Graficas Orbe, Madrid.
Kennedy, G. L. 1974. West American Cenozoic Pholadidae
(Mollusca: Bivalvia). San Diego Society of Natural History.
Memoir S:\-\27.
Roder, Heinrich. 1977. Zur Beiziehung zwischen Konstruk-
tion und Substrat bei mechanisch bohrenden Bohrmus-
cheln (Pholodidae, Teredinidae). Senckenbergiana
niantuna 9(3/4):105-213.
Smith, E. H. 1969. Functional morphology of Penitella con-
radi relative to shell-penetration. American Zoologist
9(3):869-880.
Turner, R. D. 1969. Superfamily Pholadacea Lamarck, 1809,
p. N702-N741. In Moore, R. C, editor. Treatise on Inverte-
brate Paleontology, Part N, vol. 2, Mollusca 6, Bivalvia.
Geological Society of America and University of Kansas,
Lawrence, Kansas.
Warme, J. E. and N. F. Marshall. 1969. Marine borers in cal-
careous terrigenous rocks of the Pacific coast. American
Zoologist 9(3):765-774.
THE MIDWESTERN NAIAD UNIOMERUS TETRALASMUS
IN WEST VIRGINIA
Ralph W. Taylor
Department of Biological Sciences
Marshall University
Huntington, West Virginia 25701
ABSTRACT
Uniomerus tetralasmus is typically considered to he a midwestem species. Two
locality records for this species within the State of West Virginia constitute a
significant increase in its known range. Additional notes on habitat, age and size
of individuals, and population densities are included.
Murray and Leonard (1962), Parmalee (1967),
and LaRocque (1967) all give a geographic dis-
tribution for Uniomerus tetralasmus that
generally centers around the Mississippi River
valley. LaRocque (1967) gives the easternmost
localities: one from the Scioto River in central
Vol. 98 (4)
October 31, 1984
THE NAUTILUS 163
Ohio and a second locality from the Licking
River in central Kentucky. David Stansbery
(pers. comm.) has a recent single specimen from
the headwaters of the Muskingum River system
in eastern Ohio. I have been unable to find any
previous record of this species occurring in
West Virginia. This paper presents data on two
localities within the state.
Locality #1
Three Ohio River specimens of U. tetrala^niui;
are currently housed in the Marshall University
Malacological Collections. All are from the same
locality (River Mile 178.1) at the upstream end
of Halfway Island near Parkersburg, West
Virginia. They were found as fresh dead shells
and therefore cannot be sexed. Their measure-
ments are as follows.
These specimens obviously represent a stable,
though small, population. These are the only
specimens found even though many collecting
trips to this area have been made in recent
years. One specimen was collected in 1979 and
the other two in May 1982. Little can be said
about the habitat where they were found as they
were dead and had been washed or carried
ashore. They were, however, in the vicinity of
the long sand and gravel bar that extends
upstream from the island.
Locality #2
This locality is a far more interesting find for a
variety of reasons. First, it is represented by a
population of literally hundreds of living speci-
mens; secondly, the population is located in a
rather small (less than .5 acres) farm pond; and
thirdly, it is anyone's guess as to how they ar-
rived and became established there. This small
pond is located about 65 km east of the Ohio
River. It is, however, close to the Kanawha
River, but the lower Kanawha has been essen-
tially devoid of mussel life for many years
(Taylor, 1983). The pond is located on private
property near the village of Scott Depot, Put-
nam County, WV.
Discussion
In July of 1984, Ms. Brenda West, a graduate
student at Marshall University, brought in
several large mussels to be checked for parasites
as part of a Parasitology lab. The shells were
brought to me for identification; they proved to
be Uniomerus tetrnlasmus. I sought and got in-
formation on the location of the pond and
returned to the site in September. I and a stu-
dent, Mr. Chris Estep, surveyed the pond using
SCUBA gear to ascertain the size of the popula-
tion, the pond depth, type of substrate, and the
habitat preference of any of the mussels in the
pond. What we found is as follows:
1. U. tetralasmus is the only naiad currently
living in the pond.
2. It is a spring-fed pond and is quite cold
even though local daily temperatures at
this time of year average around 30°C.
3. The substrate consists in places of fine
clean sand and pebble-size gravel. In other
places there is a 30-40 cm thick layer of
silt.
4. The mussels seem to have no preference as
to substrate. In many instances they are
buried in the sand and gravel under the
silt.
5. Individuals show no preference for depth
as they appear to be equally distributed
throughout the pond from the deepest part
(approximately 3 m) to water less than 10
cm deep.
6. They are present in large numbers.
7. They are reproducing as several size and
age classes are represented in the series
collected.
The Putnam County pond specimens were col-
lected 11 September 1984. They were returned
to the laboratory where the soft tissues were
removed and preserved for future study. None
of the 32 live-taken specimens dissected showed
any evidence of being gravid with glochidia even
though this is very close to the dates when
Utterback (1916) reported finding gravid U.
tetralasmus in Missouri.
These specimens are quite large. Ten speci-
mens were arbitrarily selected to show the size
164 THE NAUTILUS
October 31, 1984
Vol. 98(4)
and age class range. These data are included in
the following chart.
Specimen tt L. H. W. Apprnx. Aije.
1 149 mm Tl mm 48 mm 14
2 145 mm 72 mm 47 mm 15
3 148 mm 73 mm 49 mm 12
4 136 mm 66 mm 43 mm 10
5 127 mm 61 mm 39 mm 10
6 120 mm 58 mm 38 mm 9
7 111 nmi 56 mm 36mm 10
8 105 mm 53 mm 33 mm 8
9 101 mm 51 mm 32 mm 9
10 96 mm 49 mm 31 mm 8
Most of the specimens are in the 140-150 mm
size class. Utterback's (1916) largest figured
specimen was 80 mm long and Murray and
Leonard (1962) figured a 4V2 inch (= approx.
115 mm) specimen.
The current owner of the pond property, Mr.
E. D. Hardman, has owned the farm for 30
years and the pond was present when he pur-
chased the land. The age of the pond is
unknown. It is man-made with an earth dam.
The occurrence of U. tetraldsmtis in West
Virginia is quite a surprise for several reasons.
It is well outside the previously known range.
The large size of the Putnam County pond speci-
mens and also the large number of individuals
appear to indicate that living conditions are not
marginal. They can live and do remarkably well
under these environmental conditions.
One must now ask, how did it get there? The
only reference to a host fish species was given
by Sterns and Felder (1978). They used anecdo-
tal evidence and concluded that the Golden
Shiner was the host fish for U. tetralasmus in
Louisiana. The Golden Shiner's range does not
come to within a thousand miles of the State of
West Virginia. Glochidia could have been
brought in attached to bait minnows which had
originally been seined in some southern or mid-
western stream. Several naiadologists suspect
that larval clams may be distributed as a result
of being attached, via byssel threads, to aquatic
birds' feet and then releasing in a different pond
at a later time.
It would appear that in order to address the
many unanswered questions about this popula-
tion we must first determine what fish is serving
as a larval host. Are there other populations in
similar ponds in the immediate area? When is,
and what is the length of, the breeding season
for this species in this area? It is hoped that
some light will be shed on these questions as I in-
tend to monitor this population for years to
come.
Voucher specimens have been placed with the
(^hio State University Museum of Zoology and
Marshall University Malacological Collections.
LITERATURE CITED
LaRocque, A. 1967. Pleistocene Mollusca of Ohio. Ohio
Dept. of Nat. Res., Div. of Geological Survey. Bull. 62
(part 2): 113-356.
Murray, H. and A. Leonard. 1962. Unionid Mussels in
K(insn.s. Univ. of Kansas Press. 184 p.
Parmalee, P. 1967. The freshwater miuisels of Illinois.
Illinois State Museum. 108 p.
Sterns, E. and D. Felder. 1978. Identification of host fishes
for four species of freshwater mussels. Anwr. Midland
Nat. 100:233-236.
Taylor. R. 1983. A survey of the freshwater mussels of the
Kanawha River from riverhead to rivermouth. U.S. Army
Corps of Engineers, Huntington District. 62 p.
Utterback, W. 1916. The Naiads of Missouri. /I mcr. Midhmd
Nat. 4(6):244 pp.
NEWS
OF SEA AND SHORE, a popular magazine
on shelling, has ceased publication after thirteen
fruitful years of serving amateur conchologists.
Tom Rice, the editor, will continue his Sheller's
Directory of Clubs, Books, Periodicals and
Dealers and his Catalog of Dealers' Prices for
Marine Shells. He will also expand his activities
at the "Of Sea and Shore Museum" in Port
Gamble, Washington. Tom will join the editorial
staff of the new popular magazine, "Shells and
Sea Life" which is headed by Steve Long and
Sally Bennett (505 East Pasadena. Phoenix, AZ
85012). If you were a subscriber to Of Sea and
Shore, and are owed numbers, you will be sent
Shelh and Sea Life as substitutes. Tom's last
number was vol. 13, no. 2. We all thank him for
giving the general public such an interesting
magazine on shelling and wish Shells and Sea
Lfe a prosperous and long future.
- R. Tucker Abbott
Vol. 98 (4)
October 3 L 1984
THE NAUTILUS 165
CONSTRAINTS TO ADAPTIVE RADIATION IN
DEPOSIT-FEEDING PELECYPODS
David Nicol
Box 14376, University Station
Gainesville, FL 32604
ABSTRACT
Deposit-feeding pelecypods must be mobile, infaunal animals confined to a soft
bottom. Because of these constraints, deposit feeders are never rock or wood
borers, shell-cemented to the bottom, or. as adults, attached by a byssus. Primitive
suspension-feeding pelecypods prrjbably gave rise to deposit feeders during the
early Ordovician.
Deposit-feeding is a specialized mode of ob-
taining food and is found in about 13,000 living
species of animals. It occurs only in animals with
both mouth and anus and occurs mainly in coelo-
mates but also is found in a few pseudocoelo-
mates. Deposit-feeding is not found in the most
primitive multicellular animals (Nicol, 1981).
Deposit-feeders must be mobile solitary animals.
Nicol and Jones (in press) have noted that de-
posit-feeding animals are of small to moderate
size. Whales, giant squids, and other truly large
animals are not deposit feeders.
The majority of living species of pelecy]3ods
are suspension-feeders, but the protobranchs
and some tellinaceans are deposit-feeders. De-
posit-feeding pelecypods are restricted to a soft
bottom and are all infaunal. The protobranchs
are ideally suited for life in the oozes of the
abyssal and hadal regions (2,000 m or greater
depths) and are the dominant group in the deep
sea (Knudsen, 1970). Deposit-feeding pelecy-
pods have not invaded fresh water, but it is dif-
ficult to explain this fact. These pelecypods are
of small to medium size, rarely attaining a
length of more than 100 mm (Nicol, 1964). This
appears to be true of fossil as well as living
species. Living deposit-feeding pelecypods are
rapid burrowers that have a low to moderate
convexity; they do not have the inflated valves
of Glos.^us or Meiocardia. which are slow bur-
rowers (Nicol, 1983). Because mobility is neces-
sary, the shells are never thick or massive, and
ornamentation is either lacking or subdued.
Spinose shells, as in Arcinella. are never pre-
sent. Unlike some species of the pectinaceans
and ostreaceans, they are either equivalved or
only slightly inequivalved. Deposit-feeding pele-
cypods have retained the primitive dimyarian
condition of the adductor muscles. The necessity
of mobility and infaunal life also prevents
deposit feeders from being shell-cemented to the
bottom or byssally attached as adults. Rock bor-
ing, wood boring, and nestling are all unavail-
able adaptations to deposit feeders but are
found in some suspension feeders. No commen-
sal species occur in deposit-feeding pelecypods,
and none has symbiotic algae in the mantle.
None of them is able to swim. The mobile in-
faunal life of deposit feeders places many mor-
phologic and habitat constraints on these
pelecypods. For example, all of the proto-
branchs show less adaptive radiation than the
arcaceans, which can be burrowers (infaunal),
semi-infaunal, attached by a byssus (epifaunal),
or, in one rare instance, rock boring.
The mud-grubbing deposit feeder is commonly
thought to be a primitive animal. The first
deposit-feeding pelecypods were protobranchs
that appeared in the earliest Ordovician. How-
ever, the Order Actinodontoida appeared in the
middle Cambrian and includes the Modiomorphi-
dae, Cycloconchidae, Lamellodontidae, Carydi-
idae, and Lyrodesmatidae (N. J. Morris, 1967).
These pelecypods do not resemble protobranchs
and were probably suspension feeders. It is like-
ly that early in the evolution of the pelecypods a
primitive suspension-feeding stock gave rise to
the deposit-feeding protobranchs at about the
beginning of the Ordovician.
It is often difficult to interpret the type of
166 THE NAUTILUS
October 31, 1984
Vol. 98(4)
feeding a group of extinct invertebrates had, but
I cannot see that any of the rostroconchs were
deposit feeders. Their thick shell and convex
form must have made their mobility as adults
difficult; they were most likely all suspension
feeders (Nicol, 1982). In a recent article on the
Hyolithida and its relatives, Yockelson (1984)
thinks that these extinct molluscs were detritus
(deposit) feeders. However, he admits that the
elongate conical shell would make it difficult for
these animals to move about. For this very
reason, I would think that deposit feeding would
be an unlikely mode of feeding in these animals.
From observations on living detritus or deposit-
feeding animals, it appears that they are not
primitive but specialized animals. In multi-
cellular animals, deposit-feeding probably arose
after herbivores and suspension-feeders, and
possibly after scavengers and carnivores as
well.
LITERATURE CITED
Kimrlsen, .1. 1970. The systematics and biology of abyssal
and hadal Bivalvia. Galatkea Report Vol. 11, Danish Sci.
Press. Copenhagen. 240 pp., 20 pis.
Morris, N. J. 1967. Chapter 17. IVIoUusca: Scaphopoda and
Bivalvia. p. 469-477. in: The Fossil Record: A SyTnposium
with Documentation. Geol. Soc. London.
Nicol, D. 1964. An essay on size of marine pelecvpods. Jour.
Paleo. 38:968-974.
1981. A survey of deposit-feeding animals. Flor-
ida Scientist 44:123-126.
1982. Some characteristics of extinct major
groups of animals. Florida Scientist 45:76-80.
1983. Shell shape and burrowing habits of
marine pelecypods. Florida Scientist 46:120-12.5.
Nicol, D., and D. S. Jones. The comparative size of deposit-
feeding animals. Florida Scienti.'it (in press).
Yochelson, E. L. 1984. Speculative functional morjjhologj'
that could not function: The example of Hyolithes and
Biconulites. Malacologia 25:255-264.
OBITUARY
We regret to announce the sudden death of
Dr. Zinaida A. Filatova, a well-known and well-
liked Russian malacologists, on June 11, 1984, in
Moscow, USSR, at the age of 78. She was born
October 8, 1905, in Simferopol, USSR. She suc-
ceeded her professor, L. H. Zenkevich, as head
of the Benthic Laboratory at the Shirshov Insti-
tute of Oceanology in 1972 and retired in 1979.
She published over 120 papers on deepsea mol-
lusks, her last issued in 1984 on "New Data on
the Abyssal Monoplacophora from the Pacific
and South Atlantic Oceans" (with Moskalev and
Starobogatov). She was internationally re-
nowned for her personal kindness and excellent
scientific contributions. A more complete ac-
count was published in "Shells and Sea Life",
(Phoenix, Arizona), vol. 16, no. 8, p. 118.
-R. T. Abbott
/^
Q~y9^~oa^
INFORMATION FOR SUBSCRIBERS
The annual subscription rate for The Nautilus
is $15.00 for individuals (foreign $18.00) and
$20.00 for institutions (domestic or foreign).
Subscriptions may begin in January. Send check
or money order made out to "American Mala-
cologists" to the Business Manager, P.O. Box
2255, Melbourne, Florida 32902-2255, U.S.A.
Back issues from volume 72 to date are ob-
tainable from the Business Manager. Volumes 1
through 71 (if available) may be obtained in
reprint or original form from Kraus Reprint
Co., Route 100, Millwood, New York 10546.
Advertising rates may be obtained from the
Business Manager or Editor.
CONTRIBUTORS
Mamcscripts: 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 re-
quired, to facilitate reviews. Tables, numbered
in arable, should be on separate pages, with the
title at the top. Legends to photographs should
be typed on separate sheets. Explanatory terms
and symbols within a drawing should be neatly
printed, or they may be pencilled in on a translu-
cent overlay, so that the printer may set them in
8 pt. type. There is a charge of 50 cents per
word for this extra service. All authors or their
institutions will be charged 50 cents per line of
tabular material and taxonomic keys. The pub-
lishers reserve the right, seldom exercised, to
charge $45 per printed page.
An abstract should accompany each paper.
Reprints are available at cost to authors.
When proof is returned to authors, information
about ordering reprints will be given. They
are obtained from Economy Printing Co., Inc.,
R.D. 3, Box 169, Easton, Maryland 21601-9430.
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 identifi-
cation, locality data and its bibliographic
reference. There is no charge for this perma-
nent curating service, and catalog numbers, if
desired, will be sent to authors prior to publica-
tion.
WANTED - OLD SHELL BOOKS
Will pay good prices for libraries, second- Phone (1-305-725-2260) or write: R. Tucker
hand books and reprints on mollusks, shells Abbott, American Malacologists, Inc., P.O.
and conchology. Back numbers of The Box 2255, Melbourne, FL 32902. Free ap-
Nautilus, vols. 40-71 wanted, $1.50 each. praisals.
.^:
american malacologists, mc.
PUBLISHERS OF DISTINCTIVE BOOKS ON MOLLUSKS
THE NAUTILUS (Quarterly)
MONOGRAPHS OF MARINE MOLLUSCA
STANDARD CATALOG OF SHELLS
INDEXES TO THE NAUTILUS
(Geographical, vols 1-90; Scientific Names, vols 61-90)
REGISTER OF AMERICAN MALACOLOGISTS
AC Mr
FF :
100c<Ai/iL Na;^: ;.iREET
CHARLESTOV^Ai, ivlASS.
MBL WHOI LIBRARY
lt'!iii;iiiiiip;iii;i
UH 17Y