JANUARY 30, 1976

THE

NAUTILUS

Vol. 90

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. Arthur H. Clarke, Jr.
Department of Mollusks
National Museum of Canada
Ottawa, Ontario, Canada K 1 A-OM8

Dr. WUliam J. Clench
Curator Emeritus
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. William K. Emerson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 1 0024

Mr. Morris K. Jacobson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 1 0024

Dr. Aurele La Rocque
Department of Geology
The Ohio State University
Columbus, Ohio 43210

Dr. James H. McLean

Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, California 90007

Dr. Arthur S. Merrill
Biological Laboratory
National Marine Fisheries Service
Oxford, Maryland 21654

Dr. Donald R. Moore

Division of Marine Geology

School of Marine and Atmospheric Science

10 Rickenbacker Causeway

Miami, Florida 33149

Dr. Joseph Rosewater
Division of MoUusks
U. S. National Museum
Washington, D.C. 20560

Dr. G. Alan Solem

Department of Invertebrates
Field Museum of Natural History
Chicago, Illinois 60605

Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, Ohio 43210

Dr. Ruth D. Turner

Department of Mollusks
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. Gilbert L. Voss
Division of Biology

School of Marine and Atmospheric Science
1 0 Rickenbacker Causeway
Miami, Florida 33149

Dr. Charles B. Wurtz
3220 Penn Street
Philadelphia, Pennsylvania 19129

KDITOR-IN-CHIEF

Dr. R. Tucker Abbott

Delaware Museum of Natural History
Box 3937, Greenville, Delaware 19807

Mrs. Horace B. Baker

Business and Subscription Manager

1 1 Chelten Road

Havertown, Pennsylvania 1 9083

OFFICE OF PUBLICATION

Delaware Museum of Natural History

Kennett Pike, Route 52

Box 3937, Greenville, Delaware 19807

Second Class Postage paid at Wilmington, Delaware

Subscription Price: $7.00 (see inside back cover)

THE

NAUTILUS

Volume 90, number 1 — January 30, 1976

CONTENTS

Publications Received; Editorial ii

Carl J. Berg, Jr.

Ontogeny of Predatory Behavior in Marine Snails (Prosobranchia: Naticidae) 1

Alex Tompa

Fossil Eggs of the Land Snail Genus Vallonid (Pulmonata: Valloniidae) 5

Thomas M. Duch

Asj^ects of the Feeding Habits of Viripnrvs (ironiinnun 7

Fred G. Thompson

The Occurrence in Florida of the West Indian Land Snail Biilimuhi>i fiuadalupensis 10

Robert A. Wharton

Variation in the New England Pyramidellid Gastropod, Turbomlla nivea (Stimpson) 11

John W. Clark, Jr.

Alvar Nunez and the Snail Rabdotuf^ in Texas 13

Alan Solem

Sjjecies Criteria in Anguispira (Anynisph-d) (Pulmonata; Discidae) 15

Henk K. Mien is

Range Extension of Coralliophila marrati Knudsen (Gastropoda: Magilidae) 23

R. Tucker Abbott

Cittariuni pica (Ti-ochidae) in Florida 24

Alan Solem

Comments on Eastern North American Polygyridae 25

G. L. Mackie

Trematode Parasitism in the Sphaeriididae Clams, and the Effects in Three Ottawa River

species 36

Fred G. Thompson

The Genus Epirobia in Chiapas, Mexico 41

Antonio J. Ferreira

A New Species of Callistochiton in the Caribbean 46

Artie L. Metcalf and Richard W. Fullington

A New Fossil Ashmunella (Pulmonata: Polygyridae) from the Guadalupe Mountains Na-
tional Park, Texas 49

Richard G. Woodbridge, HI

Tentacle-branching in the Periwinkle, Littofimt liftdiva 52

Arthur S. Merrill and Robert L. Edwards (A corrected republication]

Observations on Mollusks from a Navigational Buoy with Special Emphasis on the Sea

Scallop, Placopecten magellanicus 54

STATEMENT OF OWNERSHIP, MANAGEMENT AND CIR-
CULATION (Required by) Act of October 23, 1962: Section
4396. Title 39. United Stotes Cocte, end postal regulation
132-622.

1. Title of publication: THE NAUTILUS.

2. Date of filing, September 25, 1975

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

4. location of known office of publication: Delaware
Museum of Natural History, Kennett Pike, Box 3937,
Greenville, De 19807.

5. Location of the Headquarters of General Business Of-
fices of the Publishers: Delaware Museum of Natural
History, Kennett Pike, Box 3937, Greenville, De. 19807.

6. Names and addresses of publisher, editor, and
manoging editor: Publisher, Mrs. Horace Burrington
Baker, 11 Chelten Rd., Havertown, Pa. 19083. Editor, R.
Tucker Abbott, Delaware Museum of Natural History,
Box 3937, Greenville, De. 19807. Managing editor,
none.

7. Owner: Mrs. Horace Burrington Baker, 1 1 Chelten Rd.,
Havertown, Pa. 19803.

8. Known bondholders, mortgages, and other security

holders owning or holding 1 percent or more of total
amount of bonds, mortgages or other securities: none.
9. Extent and Nature of Circulation:

Average Single
12 Mos Issue

A. Total No. Copies Printed (Net Press 1,000 1,000

B. Poid Circulation

1 Soles through dealers and cor-
ners, street vendors and counter
sales none none

2. Moil subscriptions 631 634

C. Total Paid Circulation 631 634

D. Free Distribution (including samples)

by mail corner or other means 14 14

E. Total Distribution (Sum of C & D) 645 648
F Office use, left-over, unaccounted

and back start subscription copies 355 352

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

net press run shown in A. 1,000 1,000

I certify that the statements mode by me above ore
correct and complete,
(signed) R. Tucker Abbott, Editor

EDITORIAL

Rapid publication of research papers is now
possible, usually within two or three months of
submission of the manuscript, providing the
author pays page charges ($30.00 per page). This
priority does not in any way delay the papei-s
of other authors, since articles with paid page
charges merely increase the normal size of an
issue.

AMU 1976 ANNUAL
MEETING IN COLUMBUS

The annual meeting of the American
Malacological Union will be held Monday,
August 2 (registration) through Friday (field
trip) the 6th on the campus of the Ohio State
University, Columbus, Ohio. Inexpensive but ex-
cellent lodgings. More details in the April issue.

PUBLICATIONS RECEIVED

Humm, Harold J. and Charles E. Lane, editors.
1974. Bioactive Compounds from the Sea.
Marcel Dekker, Inc., N. Y. xiii + 251 pp.
$18.75. Among the 13 chapters resulting from
a 1971 symposium on this subject, some re-
late to toxins carried by marine mollusks,
especially those of dinoflagellates.

Johnson, Richard I. 1975. Simpson's Unionid
Types and Miscellaneous Unionid Types in
the National Museum. Special Occasional
Publ. no. 4, 56 pp., 3 pis. $4.00. Also includes
list of types of B. H. and S. H. Wright.

Olazarri, Jose. Nov. 1975. Hiatoria de la Mala-
cologia en el Uruguay. Foreword b.\' J. .1.
Parodiz. 121 pp., privately printed (115
copies). Montevideo, Uruguay.

Kaicher, Sally Diana. Sept. 1975. Cord Catalogue
of World-wide Shells. Pack 8, Naticidae, part

1. (cards 692-797). Write: 5633-B, 18th Way
South, St. Petersburg. Fla. ;33712.

Walne, P. R. 1974. Culture of Bivalve Molluscs
—.")<• Veal's' Experience at Conwy. 173 pp.. :38
figs., paperback, about $13.75. Fishing News
(Books) Ltd., 23 Rosemount Ave., West By-
fleet, Surrey, England. Details of the mari-
culture of Ostrea edulis. Mytilus edulis. Vene-
rupis decussata. and Mcrcenaria merccnaria
at the government Fisheries Rxperiment Sta-
tion, Conwy [Conway, Wales].

Kay, E. Alison and William J. Clench. 1975.
A Biobibliography of William Harper Peiise,
Malacologist of Polynesia. Nemouria. no. 16,
.")() pp. Gives Pease's life and lists about 660
of his new names, with references. $2.00 from
tlif Delaware Museum of Natural Histoiy,
P.O. li)x 3937. (Ireenville, Delaware 19807.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 1

ONTOGENY OF PREDATORY BEHAVIOR IN MARINE SNAILS
(PROSOBRANCHIA: NATICIDAE)

Carl J. Berg, Jr.

Department of Biology

City College of City University of New York

New York, N. Y. 10031

ABSTRACT
Naticid gastropods (Natica gualtieriana) imre reared throitgh metamorphosis
and presented urith gastropod prey. The first prey were bored by a single well-
formed hole in a stereotyped position. As the animals matured and gained ex-
perience at boring there was no change in the circular distribution of the
boreholes in each whorl but whorl preference changed and the animals became
seemingly less proficient borers.

INTRODUCTION

Marine gastropods of the family Naticidae
are noteworthy because of their predatoi^ habit
of capturing bivalves or snails, boring a hole
through the hard calcareous shell, and con-
suming the soft parts within. There have been
numerous reviews of the controversy concerning
the mechanisms involved in boring (Ziegelmeier,
1954; Carriker, 1961; Fretter and Graham, 1962;
Hyman, 1967; Bernard, 1967) and the position
of the borehole (Ansell, 1960; Reyment, 1966).

While it has been suggested that ex-
periential factors play some role in prey selec-
tion of gastropods (Fischer-Piette, 1935;
Carriker, 1957; Wood, 1968; Morgan, 1972) there
are no studies of the ontogenetic development
of predatory behavior. Such studies are of par-
ticular interest wath those species of naticids
whose development includes a planktonic veliger
stage, during which they use ciliated velar lobes
to filter-feed on phyto plankton. These snails
possess neither a radula nor a proboscis until
after metamorphosis. Veligers are therefore in-
capable of boring and have no experience as
predators. I have found the complete behavior
patterns involved in prey manipulation and
boring to be present upon first experience with
a prey. I have also described how the position
and the quality of the borehole change as the
predators mature.

METHODS
Fourteen veligers of Natica gualtieriana were

collected from the plankton in Kaneohe Bay,
Hawaii, and reared separately in small (55mm
X 15mm) plastic petri dishes containing 20ml
of sea water. The animals metamorphosed
within 24 hours and were provided with a new
dish containing water, sand, and one prey-snail
every second day. Morphologically similar Bit-
ti'um and Rissoella species were offered as prey.
At each change of dish, the shells of the
previous prey were removed and taped to index
cards in sequential order for each predator. As
the A^. gualtieriana grew, larger prey were
provided, up to a maximum of 20 prey per
predator. The position of the borehole was
examined with respect to the longitudinal axis
of the shell and to the plane of the aperture by
determining the whorl in which the hole was
bored, the distance from the tip of the siphonal
canal to the center of the hole, and its circular
distribution. The pooled data were analysed
using standard statistical tests and tests for cir-
cular distribution patterns (Snedecor and
Cochran, 1967; Batschelet, 1965).

The shells from each predator were coated
with gold and examined under a Cambridge
Stereoscan (S4) scanning electron microscope.
Qualitative changes in the shape of the hole
and the amount of radular scraping were noted
for each series of shells.

Young specimens of Natica gualtieriana
Recluz used in these observations are deposited
in the Delaware Museum of Natural History,
no. 103100.

2 THE NAUTILUS

January 30. 1976

Vol. 9(1 (1)

B

FIG. 1. Scanning electron photomicrograph of the firxt
hirchotc made by a newly metamorphosed Natica
gualtieriana. Bar represents 0.1 mm.

RESULTS
Upon first presentation of prey, all newly
metamorphosed A'', giioltieriana bored a single
well -formed hole (Figure 1). There was no
evidence of incomplete boreholes or misplaced
rasping. The first holes were distributed with
mean values of either 273.3° to the right of
the aperture in whorl 2 (Figure 2A) or 114° in
whorl 3 (Table 1). There was no overlap in
the range of distribution for each whorl. The
centers of the holes were located 1.31 mm (Mdso
value) from the tip of the siphonal canal, which
represents (i5"/o (Mdso value) of the distance be-
tween the tip of the siphonal canal and the top

5 10 15

Prey Number
FIG. 2. Distribution of boreholes in prey of N.
gualtieriana. A. Shell of prey, indicating sectors used to
de.tigiiate circular distribution of boreholes around the shell.
A)row indicates position of mean angle <f first borehole in
whorl no. 2. R Distribution of the total sample of boreholes
in whorls no. 2 and no. 3. Arrows indicate mean ixdues
(Whorl No. 2 at sector 6; whorl no. 3 at sector 2). Broad
lines represent 2 angular deviation units. C. Percentage of
holes in each whorl for successive prey. Holes midtmy be-
tween irhorls counted for both whorls.

of the fourth whorl (Figure 3A). Measurements
were not made with respect to total shell
length because the prey were often missing the
initial smallest whorls.

If the total sample of boreholes drilled by the
14 predators is analyzed, distinct patterns
become evident. The holes drilled into the first
20 prey by each of the A^. gualtieriana were not
uniformly distributed around the circumference
of the shell (p < .05). Holes drilled in whorl 2
were located at a mean of 217° to the right of
the aperture, but holes in whorl 3 were only

TABLE 1. Distribution of Natica srualtieriiuia hircholcs in gnstrnpud prey.

Wotson & Williiims

Whorl
Number

A'

Mean
angle

Angular
deflation

Roylcigh z

test for uniform

distribution

P" test fur nil
Hijference in
mean values

First Prev
No. 1

2
3

7
7

273.3°

114°

40.3°
29.3°

p<.a5
p<.01

p < .(fi

Total Prey
No. 1-21)

2
3

9.5
146

217°
60.8°

47.9°
67.t;°

p<.()l
p < .01

p< .001

Vol. 90 (1)

.lanuarv :{(), 1976

THE NAUTILUS 3

Co O

g; 00

-Wtt

+-i

E
E

^

B

-iff

ii

I

20

5 10 15

Prey Number
FIG. 3. Distrihidion of borehates (dmiy the lonyitiidimil
(tr/.s of prey of N. gualtieriana. A. Shell of prey, indicatiiuj
diitance from tip of siphonal canal to center of borehole fa)
and to the top of the fourth whorl (b). Numbers indicate
whorl number, starting from the tip of the siphomU canal.
R Change in distance of borehole from the tip of the
siphonal canal (b) urith successive barings. Dots indicate
median i>alue.^, vertical lines the range of values. Y = 1.011
+ aimX. r = 0.80. C. Change of ratio fa/b) uith .suc-
cessive borings. Dots indicate median vabies, vertical lines
the ninye of m)ue.% Y = 6'.5.63 + 0.29.5 X. ;• = 0.29.

60.8° to the right (Table 1 and Figure 2B).
Although the range of distribution for each
whorl did overlap slightly, the difference in
mean values was significant (p < .001).

There was no significant change in the cir-
cular distribution of boreholes in each whorl
with increased experience or boring. However, a
dramatic change in whorl preference occurred
between the fifth and sixth prey bored (Figure
2C). Five animals switched from boring into
whorl 2 to boring into whorl 3, but only one
animal made the opposite switch. From the sixth
prey on, there was a significantly increased
preference for boring into whorl 3, with p < .01
for the difference from even distribution in
both whorls for prey number 17, 18, 19, and 20
combined.

The increased percentage of holes bored in
the more distant third whorl and the large size
of prey may explain the increase in the distance
between the center of the borehole and the
tip of the siphonal canal (Figure 3B). However,
the ratio of the distance between the tip of the
siphonal canal and the center of the borehole
and the distance from the tip to the fourth

whorl varied only slightly with experience
(Figure 3C).

DISCUSSION

The quality of the borehole and the proficiency
of boring seemed to decrease with repeated
boring. The boreholes became less round in ap-
pearance, indicating that the holes were not
bored perpendicular to the plane of the shell
surface, the walls of the holes were rasped in a
more random fashion, and the holes were not
bored completely through the shell although the
prey was eaten. There was one case of two
holes being drilled in the same prey and cases
of boreholes left incomplete and new holes
formed. In general, it seemed that the predators
became less proficient at boring during early
post-metamorphic development. This may reflect
changes in the sensory systems being used in
determining the suitability of prey and the
position of boring. Such changes would adapt
the animals for preying upon a greater variety
of prey species as they get older.

The position of the borehole is determined by
the way the prey is manipulated and positioned
for boring (Boettger, 1930; Ziegelmeier, 1954).
The behavior appears stereotyped in naticids.
Tactile characteristics of the aperture and
chemicals emanating from it are probably used
as cues by the predators. When shells of
greatly varying shape were given to A^.
gualtieriana. they were bored directly above the
aperture, regardless of the length or width of
the new prey shell. This preferred position lies
over the mantle cavity of the prey snail in its
withdrawn condition. This drilling position
probably confers on the predator certain selec-
tive advantages which have led to its becoming
fixed during evolution. One might explain the
advantages of the preferred site by a com-
bination of factors: 1) By boring on the same
plane as the aperture, the naticid's foot covers
this opening, blocking escape by the prey. 2) By
boring approximately midway along the
longitudinal axis of the shell, the extensible
proboscis, which enters the shell through the
borehole, has a greater probability of reaching
both ends of the shell and removing all of the
meat. Therefore, it probably makes little dif-
ference which part of the prey's body is con-

4 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

FIG. 4. Ytmitij Natica Kualtieriana U mm. in length) fnim
Kaneiihe Bay. Hnwnii, rai.ied in the labdratmy frmn the

ivlujer xtmir. rinfl ii.trd in shell horin;/ nhserrntidns.

sumed first, as Pieron (1933) and Verlaine
(1936) contended.

Since the position of the borehole is the
result of a complex series of behavior patterns
involving prey capture, prey manipulation, and
the actual process of boring, the stereotyped
position of the borehole reflects a stereotypy of
behavior. The stereotyped boring behavior of
naticid gastropods is present upon metamorpho-
sis; no experience is necessary. There is an
increase in the variability of borehole position
and a decrease in the quality of the borehole
during early post-metamorphic development.
These observations contradict Verlaine's (1936)
earlier conclusions based upon boreholes in
shells found on the beach. He suggested that
the naticids learn, by successive drillings, the
position of the gonads under the shells of
bivalves and therefore become more restricted
in their place of boring. This idea has not been
substantiated by my work or that of Bernard
(1967).

The gastropod mollusc A^. gualtieriana and
the cephalopod molluscs Sejria officinaiis and
Octopus cyanea (Wells, 1962; Wells and Wells,
1970) are competent predators upon metamorpho-
sis and, in fact, their behavior becomes more
variable with increasing age. This appears
distinctly different from the fact that ex-
perience is necessary for most vertebrate
predators and for the analogous behavior of nut
opening by squirrels (Eibl-Eibesfeldt, 1951).

ACKNOWLEDGEMENTS
Hawaii Institute of Marine Biology Con-
tribution No. 4620. I am grateful to J. Taylor,
E. Guinther, R. Phillips, and M. Grofik for their
help and to the members of the City University
of New York and American Museum of

Natural Histon,' Animal Behavior-Biopsychology
Training Program for commenting on the
manu.'^'ript.

LITERATURE CITED

Ansell. A. D. 1960. Observations on predation of Venus
strialula (Da Costa) by Natica alden (Forbes). Proc.
Mai. SiK-. Lmvi. 34: 157-164. 1 pi.

Batsehelet, E. 1965. Statistical methuds for the analysis of
problems in animal nrientatiun and certain biological
rhythms. A. I. B. S. Monog., Wash., D.C. 57 pp.

Bernard, F. R. 1967. Studies on the biologj- of the naticid
clani drill Pulinice.i leu'iii (Gould) (Gastropoda Proso-
branchiata). Fish. fles. Bd. Canada Tech. Rept. 42: 1-41.

B(iett(jer. ('. R. 19,30. Die Lage der Bfihrstelle beim Angriff
der Raub.sc'hnecken aus der Familie Naticida. Zeit. Wm.
Z«„l. 136: 45.3-463.

Carriker, M. R. 1957. Preliminar>' study of behavior of
newly hatched oyster drills, Urusalpinx einerea (Say).
./ Eiisha Mitchell Sci. Six-. 73: 328-351.

Carriker. M. R. 1961. Comparative functional morphology
of boring mechanisms in gastropods. Amer. Ziuil. 1:
26.3-266.

Eibl-Eibesfeldt. I. 1951. Beobachtungen zur fortpflanzungs-
biologie und Jungendentwicklung des Eichornchens
[Scitini.i nilgarif: L.). Zeit. Tierij.'ijfc. 8: .370-4i-K).

Fischer-Piette, E. 1935. Historic d'une mouliSre. Observa-
tions sur une phase de desequilibre faunique. Bull. Biol.
Franc. Belg. 69: 153-177.

Fretter, V. and A. Graham. 1962. British Prosobranch Mol-
luscs; their functional anatomy and ecology. Ray Soc.,
Lond. 775 pp.

Hyman. L. H. 1967. Tlie Invertebrates: Mollusca I.. Vol. 6.
Mt>Graw-Hill, N. Y. 792 pp.

Morgan. P. R. 1972. The influence of prey availability on
the distribution and predatory behaviour of Xucella lapil-
lus (L.). ,/. Amm. Ecol. 41: 257-274.

Pieron. H. 1933 Notes ethologiques sur les Gasteropodes
percurs et leur comportment avec utilisation de methode
statistique. Arch. ZahiI. Exper. Gen. 75: 1-20.

RevTnent. R. A. 1966. Preliminary observations on gastro-
jxid predation in the Western Niger Delta. Paleogeog..
Piileorlimntoi. Meoecol. 2: 81-102.

Snedecor, G. W. and W. G. Cochran. 1967. Statistical Meth-
ods. Iowa State Univ. Press., Ames. .593 pp.

Verlaine. L. 19.36. L'instinct et rintelligenoe ches les Mol-
lusques. Les Gasteropodes perceurs de coquilles. Mem.
Mus. Hist. Nat. Belg. 2: ,387-3<M.

Wells, M. .J. 1962. Early learning in Sepia. Zool. S(X. Lond.
Sipnp. 8: 149-169.

Wells, M. .1. and J. Wells. 1970. Observations on the feed-
ing, growth rate and habits of newly settled Octopus
cyanea. ./. Zool. Lond. 161: 6.5-74.

WiKxl. L. 196J<. Physiological and ecological aspects of prey
selection by the marine ga.stropod I'ro.ialpinx einerea
(Prosobranch ia: Muricidae). Malacologia 6: 267-320.

Ziegelmeier, E. 1954. Beobachtungen iiber den Nahrungser-
werb bei der Naticide Lunatia nitida Donovan (Gas-
tropoda Prosobranchia). Helgol. Wiss. Meeresuntersiich. 5:
1-.33.

Vol. 90 (1)

January 30, 197()

THE NAUTILUS 5

FOSSIL EGGS OF THE LAND SNAIL GENUS VALLONIA
(PULMONATA:VALLONIIDAE)

Alex Tompa

Department of Zcwlogy

Duke University

Durham, North Carolina 27706

ABSTRACT
Pleistocene fossil eggs of the land pidmonate genus Vallonia have been iden-
tified on the basis of idtrastructure, mineralogy and size. The eggs are remark-
ably well preserved and show a great deal of swrface detail with respect to their
calcite crystals. Similar comparisons of the ultrastructure of extant snail eggs
unth fossils should allow the identification of many more fossil species.

INTRODUCTION
During the course of my studies on the
mineralogy and ultrastructure of calcareous
land snail eggs. Dr. Claude Hibbard of the
Division of Paleontology, Museum of Zoology at
the University of Michigan, kindly provided me
with some fossil eggs that he had collected.
These eggs had been identified by F. C. Baker
as probably belonging to land snails (un-
published). However, their mineralogy and
ultrastructure had not been investigated. Since
the fossil shell fauna of this locality (Miller,
1968) includes many extant species and genera
whose eggs were recently investigated (Tompa,
1974a), an attempt was made to identify them.

MATERIALS AND METHODS

The eggs came from: 1) the Cudahy Fauna,
Meade County, Kansas, collected just below the
Pearlette ash (restricted), type 0, 600,000 BP
years, Loc. 10 (KU) S'/2NWV4 Sec. 2, T 31S., R.
28 W, Meade County, 2) Meade County, Loc.
UM-Kl-51-Sangamon NW 2 SW'4. Sec. 33, T
34S., R. 29W., and 3) McPherson County, Kan-
sas, Loc. #29, SW'/4 T18S., R4W, = Loc. UM-
Kl-62, Sandahl Local Fauna, Illinoian. The eggs
were untreated or briefly rinsed in distilled
water, then coated with gold and examined
with a JEOL JSM-U3 model scanning electron
microscope. Several eggs were crushed into a
fine powder, packed into Glaskapillaren of 0.5
mm diameter, and examined with x-ray dif-
fraction using CuKa radiation with a Ni filter.

at 35 kV, 15 mA, for 4 hours, with an 11.5 cm
camera.

RESULTS

X-ray diffraction analysis of the recent eggs
of Vallonia ptdchella (Miiller) and V. costata
(Miiller) shows that they are made of calcite;
the fossil eggs examined are also made of
calcite. Table 1 shows the results of
measurements taken of fossil eggs compared
with that of recent eggs of V. pidchella.

Figure 1 is a low magnification of a fossil
egg, showing that it is extremely well preserved,
intact. Figure 2 is a higher magnification of
another fossil egg, while figures 3 and 4 are
of the egg of extant V. pidchella. It should be
noted that the ultrastructural study of the egg
of V. pidchella and V. costata shows no dif-
ference; in fact, it seems that they are not
distinguishable on any basis. A comparison of
figure 2 with figure 3 shows that the two eggs
are identical on the basis of crystal size, shape
and pattern of distribution.

TABLE 1

(Egg type

N

length
(mm)

width
(mm)

height
(mm)

Fossil egg

Vallonia
pulcheUa egg

(10)
(10)

n.h7±().(«

0.66±n.01

0.66+0.04

a62±o.a)

a52±0.03
0..53±0.02

6 THE NAUTILUS

January 30, 1976

Vol. 90(1)

DISCUSSION

Miller (1968) found 3 species of the genus
Vallonia, V. cydophorella Sterki, V. graciliosa
Reinhart, and V. pulchella in the Cudahy
fauna, Meade County, Kansas. Tompa (1974a;
1975) found that the genus Vallonia has eggs
which are distinguishable from all other land
snail eggs examined on the basis of egg size
and ultrastructure, but the two species
examined, V. pitkhella and V. costata were in-
distinguishable from each other. On the basis of

the information presented here, it is concluded
that this fossil egg definitely belongs to the
genus Vallonia, and possibly to V. pulchella.

Pilsbry (1948) states that this genus, con-
sisting of about 25 species, is found in North
America above Mexico, Europe, North and Cen-
tral Asia and Japan. As fossils, vallonias are
known from the Paleocene, Eocene, Miocene and
Pliocene of Europe and Pleistocene of Europe
and America. It is an old group which ap-
parently evolved in Mesozoic time and has
changed very little since the Eocene.

I: . - ^

FK;. 1. SEM iifafnssnl egg. showing remarkable preservatinn itf tstrm-tior. XlOO FIG. 2. View of the surface ofatKithrrfnssit
egg. uiitrmtcd. Nate cri/stnl shape and distribution. X 1260 FIG. 3. Surface «>!/• nf the egg 0/ Vallonia pulchella. X1260. Note
.'<iinil<iritji of shape, size and distribution of crystals n-ith those <f figure 2. FIG. 4. Cross section »/ V. pulchella egg. shomng
that the large crystals are only on the surface layer. X3150

Vol. W (1)

January 30, 1976

THE NAUTILUS 7

The fact that such delicate and fragile objects
as calcified snail eggs should be preserved in-
tact is amazing. Hibbard (1949) describes the
method for their collection. It should be noted
that these snails, V. pvlchella and V. costata
generally deposit a single egg every 24 hours
(Whitney, 1938; Tompa, unpublished). Whitney
(op. cit.) also examined the effect of en-
vironmental changes on their rate of reproduc-
tion.

Fossil eggs much larger than these have also
been reported. Cox (1960) mentioned that large
oval bodies up to 30 mm in length, believed to
be fossil eggs of Filholia elliptica (J. Sowerby)
are found in the Oligocene of England, and that
similar bodies, probably eggs of Limicolaria. oc-
cur in the Miocene deposits of Koru, Uganda.
Hubricht (1952. 1964, 1965) reported eggs up to
3.6 mm in diameter and attributed the several
types found to the genera Discus and
Anguispira and/or Haplotrema. Since then,
Tompa (1974a, 1975) has documented over 35
genera in 17 families of Stylommatophora as
having calcareous eggs. Actually, land snail eggs
can be divided into three categories on the
basis of the degree of calcification of the egg
(Tompa, 1974b): 1) uncalcified, 2) partly
calcified, with discrete crystals dispersed
throughout the jelly, and 3) heavily calcified, or
"shelled," made of fused crystals. Many more
fossil eggs of this third group should be found
after a more careful examination of collections
(1 have seen small fossil snail eggs in collections
of fossil ostracods). A check-list of genera known

to form heavily calcified eggs has been made
(Tompa, 1974a) and should be useful in locating
additional fossil eggs. Moreover, many of these
eggs have already been examined with the scan-
ning electron microscope (op. cit; Tompa, 1975)
which should aid greatly in the identification of
fossils.

LITERATURE CITED

Cox, L. 1960. General characteristics of gastropoda, in
Treatise on Invertebrate Paleontology, C. Moore, ed. Univ.
Kansas Press.

Hibbard, C. 1949. Techniques of collecting microvertebrate
fossils. Gmtrih. Mux. Paleont. Univ. Mich. 8: 7-19.

Hubricht, L. 1952. The fossil snail eggs of the loess. Nau-
tUu.1 66: 33-34.

Hubricht. L. 1964. Some Pleistocene land snail records from
Missouri and Illinois. Sterhiana 13: 7-17.

Hubricht. L. 1965. Pleistocene land snails from Muddy
Creek, Mississippi. Sterlcimia 17: 6.

Miller. B. 1968. Planorbula campestris from the Cudahy
River (Kansas) of Meade County, Kansas, with notes on
the status of subgeneric categories of Planorbula. Mala-
cohigia 6: 253-65.

Pilsbry, H. 1948. Land moUusca of North America. Acad.
Natur. Sci. Phila, Monagr. 3.

Tompa, A. 1974a. The structure and functional significance
of the egg shell of Anguispira alternata (Say) with a sur-
vey of the occurrence and mineralogy of calcified land
snail ^gs. Ph.D. Thesis, The University of Michigan,
Department of Zoology.

Tompa, A. 1974b. The structure of calcareous snail ^gs.
Malac. Rev. 7: 49-50.

Tompa, A. 1975. A comparative study of gastropod egg shell
structure and mineralogy (in preparation).

Whitney, M. 1938. Some observations on the reproductive
cycle of a common land snail. Valhmia pulchella: influ-
ence of environmental factors. Pmc. Ind. Acad. Sci. 47:
299-307.

ASPECTS OF THE FEEDING HABITS OF VIVIPARUS GEORGIANUS

Thomas M. Duch

Bennett College, Millbrook, New York 12545

ABSTRACT

Study has been made on the feeding habits of Viviparus georgianus (Lea)
which were collected from a lentic zone of the Sawkill Tributary of the Hud-
son River. Viviparus feed on diatoms hut cannot break down all diatoms. The
results imply some orientation to diatom clusters, possibly related to a silt-mud
substratum. Aggregation behavior (f Viviparus is described.

8 THE NAUTILUS

January 30, 197fi

Vol. 90

Viviparus georgianus (Lea, 1884) is a fresh-
water prosobranch found generally in eutrophic
lakes, ponds, and slow-moving streams. The
specimens in this study were collected in the
Fall from a lentic zone of the Sawkill
Tributary of the Hudson River at Annandale-
on-Hudson. New York. Vegetative decay was
prevalent in the area, as well as an abundant
brown and green scum covering the surface of a
Slit-mud substratum which, according to Fritch
(1965), represents the diatoms in cluster. It was
on this scum that the animals apeared to graze.

The habitat of this study differs slightly from
that described by Cook (1949). In Cook's study,
Viviparus was confined to areas dominated by
rocks and only a small portion of mud while
Viviparus in this study was generally confined
to areas dominated by thick silt bottom and
few rocks.

This report describes aspects of the feeding
habits of Viviparus georgianus. After general
observations in the field and laboratory during
a period of two years investigations were
limited to: (1) an examination of gut contents;
(2) an examination of a possible substrate
preference; and (3) an investigation of a
po&sible relationship between feeding behavior
and substrate composition.

MATERIALS AND METHODS

The following methods and materials were
utilized for each of the behavioral in-
vestigations; (1) all experimental animals were
acclimated for at least one day before use in an
experiment; (2) the temperature was maintained
at between 20° and 25° C; (3) sterile, filtered
water from the Sawkill was used in all ex-
periments; (4) all apparatus were horizontally
leveled to limit the possible influence of a
geotaxic response; (5) all apparatus were
shielded with black paper to limit the influence
of reflected light; (6) and all experiments were
done separately with and without aeration in
both the Fall and Spring.

Fifty animals were placed in a mild solution
of magnesium sulfate which facilitated dissec-
tion and removal of the gut. After removal of
the gut its contents were flushed with water
and collected for examination. TTie gut effluent

was preserved and examined by the method of
Williams (1964).

The sizeable aggr^ations of Viviparus in
areas characterized by silt-mud and the
decreased concentrations of Vivipanis in other
areas of the Sawkill suggested a pxjssible sub-
strate association. This was investigated by op-
tically dividing a twenty gallon aquarium into
two sections. One section of the aquarium con-
tained sterile washed rock and gravel from the
natural habitat. The other section contained
sterile washed silt-mud from the same general
habitat. Twenty adult animals which had been
starved for ten days were then randomly placed
into the aquarium. The animals were then
allowed to acclimate for one day. The number
of animals in each section were then counted
each hour for a period of seven days. No data
was collected between 12:00 pm. and 7:00 ajn.
In addition, a second group of 20 immature
animals measuring 3-5 mm in diameter were
also used in the experiment.

Observations in the field and in the
laboratory also suggest that Vivipariu'i may
"seek out" clusters of diatoms associated with
the silt-mud substratum. To confimi this sup-
position, the following experiment was per-
formed. A mixed culture of diatoms consisting
primarily of the order Pennales was placed in
random areas on a substratum consisting of
only washed sterile silt. Twenty adult animals
which had been previously starved for a period
of one week were then added to the aquarium.
After an acclimation period of six hours ob-
servations were made of the animal's behavior.
During this time feces were removed to insure
that the animals would not feed on them. In
addition, the distance from diatom clusters was
measured from each animal. Distance
measurements were made at half hour intervals
for a period of twelve hours. At the ter-
mination of the experiment gut analyses were
done on each animal. Two modifications of the
preceeding experiment were done as follows: (1)
washed sterile gravel was substituted for the
silt and (2) the diatom clusters were placed
directly on the slate bottom of an aquaria.

RESULTS AND DISCUSSION
Observations in the field indicate that

Vol. 0(1

January 30, 1976

THE NAUTILUS 9

Vivipmiis in this study tend to aggregate in
silt-mud areas which are dominated by attached
filamentous algae and large clusters of diatoms.
Additional observations lead this observer to
believe that Vivipams may tend to avoid, or
cannot tolerate, conditions where blue-green
algae predominate.

Gut analyses of the animals from the field
showed that Viviparus do ingest and at least
partially break down diatoms and other algae.
Of the diatoms ingested, Merdion, Fragellana
and especially large naviculoid cells were con-
spicuously fragmented, but no specific fragmen-
tation pattern was observed. Other diatoms such
as Gomphonema and Diatoma were not con-
spicuously fragmented. The fragmentation of
only specific groups of diatoms may be related
to the structural features of the diatom fustrule
and the structure of the radular apparatus.
This should be further investigated. Blue-green
algae were absent in a vast majority of the gut
samples, but sparsely present in some samples.
FVagments of filamentous green algae were
found in all samples. In addition, in all of the
above gut samples, a conspicuous amount of a
fine grit was found. The importance of fine
particles of grit in the gut of at least some
gastropods has been demonstrated by Colton
(1908). He noted that in the absence of grit,
food was able to pass through the gut un-
molested. This may also be the case with
Viviparus.

In the laboratory experiments 80% of the
animals congregated and grazed upon the
spread diatoms in the silt sections of the
aquaria. A less intense congregation behavior
was observed when diatoms were provided over
gravel or slate substrata. All animals in the silt
section went through a burrowing behavior af-
ter most of the diatoms were removed. This ob-
servation is not in direct agreement with Cook
(1949) who stated that Viviparus is not an ac-
tive burrower. This behavior culminated in each
animal burrowing to at least half the depth of
its shell. After burrowing, the animals did not
move for a minimum of a half hour. Eleven of
the burrowed animals did not show locomotion
for two days. Gut analyses of the animals
which grazed on diatoms in the silt-aquarium
showed diatom fragmentation which was con-
sistent with the samples from the field. No or

little diatom fragmentation was found in the
guts of animals which were in the exposed slate
aquarium. This would tend to demonstrate that
diatom breakdovm is at least in part related to
the presence of grit in the gut of Vivipams.

In the substrate preference experiments with
no algae present, all animals initially showed a
random behavior and moved about with their
snouts moving from side to side. Six hours after
the beginning of the experiment all of the adult
animals had either moved to the silt side of the
aquaria or remained in the silt-mud side of the
aquaria. Why adults of Viviparus will be
aggregated to sterile silt in the absence of
diatoms was not ascertained. The immature
animals did not show this behavior.

No immediate directed orientation movement
to diatom clusters was observed. Instead, the
animals moved randomly but continuously,
until they came within an average of 10 centi-
meters of a diatom cluster. Thereafter, their
rate of movement intensified in the general
direction of the diatom cluster. Kohn (1961)
pointed out that Viviparus will respond to
organic compounds, and some herbivorous gas-
tropod species are attracted to stimuli em-
anating from food. In addition, Hyman (1967)
also reiterated that chemoreception is well-
developed in prosobranchs. Therefore, it is
possible that the previously mentioned in-
tensified movement may be related to
chemoreception. That is to say, that the initial
feeding behavior is undirected and upon
reaching the immediate area of the diatom
cluster the animal's behavior becomes directed.
Possibly the diatom mass provides a threshold
concentration of some organic stimulus in its
immediate area. Even if this is correct, it can
only be one of the stimuli to which Viviparus
responds when searching for food. The
aggregation response to a predominately silt-
mud substratum with a grit make-up in the ab-
sence of organic matter also may be significant
in locating areas associated with food. This may
then suggest that a possible tactile response or
possibly tactile memory may be involved in
locating an area where focxl may be present.
Tactile memory is well known in marine lim-
pets and chitons although it has not been
reported with Viviparus.

It may be noteworthy to point out that the

10 THE NAUTILUS

January 30. 1976

Vol. 90 (1)

aggregation behavior described in this paper
does not seem to be confined to Viviparus. Bov-
bjerg (1965) has shown that Stagnicola reflexa
tends to aggregate on patches of Spirogifra, and
Calow (1970) has demonstrated that Lymnaea
pereger tends to select green filamentous algae.
In summary, this study tends to show the
following: (1) that Viviparus will feed on
diatoms but cannot breakdown all diatoms; (2)
there is at least some orientation to diatom
masses; and (3) that the orientation may in
some way be related to a silt-mud substratum.

LITERATURE CITED

Bovbjerg, R. V. 196.5. Feeding and dispersal in the snail
Stat/nkiila reflexa (Basommatophora: Lymnaeidae). A/a/o-
coliigia 2: 199-207.

Calow, P. 1970. Studies on the natural diet of Lymnaea
pereger oblusa (Kobelt) and its possible ecological impli-
cations. Proc. Malac. Soc. Lond. 39: 203-215.

Colton, H. S. 1908. Some effects of the environment on
the growth of Lymnaea columella Say. Proceedings of
the Academy of Natural Sciences. Philadelphia. 60:
410-448.

Gx)k, P. M. 1949. A ciliary feeding mechanism in Vivi-
parux (L.) Proceedings of the Malacological Society of
London 27: 265-271.

Fritsch, F. E. 1965. The Structure and Reproduction of the
Algae. Vol. 11. Cambridge University Press. 939 pp.

Hyman. Libbie. 1967. The Invertebrates. Vol. VI. Mollusca
I. McGraw Hill Book Co.. New York. 702 pp.

Kohn, .Man J. 1961. Chemoreception in gastropod molluscs.
American Zoologist. 1: 291-308.

Williams, Louis G. 1964. Possible relationship between
plankton -diatom species numbers and water -quality esti-
mates. Ecology 45(4): 809-823.

THE OCCURRENCE IN FLORIDA OF THE WEST INDIAN LAND SNAIL

BULIMULUS GUADALUPENSIS

Fred G. Thompson

Florida State Museum

University of Florida

Gainesville, Florida 32611

Bulimulus guadalupensis (Brugui^re, 1789) is
widespread in the West Indies where it is
found on most of the Lesser Antilles, all of the
Greater Antilles and many of their satellite
islands. No doubt, its distribution prior to
man's arrival was much more restricted. The
snail adapts to a wide variety of environmental
conditions at low elevations within its present
range. It occurs near human habitation and is
easily disseminated to new areas on live agricul-
tural plants. Thus, it is not surprising that it
has become introduced into southern Florida.

Recently Bulimulus guadalupensis was col-
lected in Florida at three localities by field in-
spectors of the Florida State Division of Plant
Industries: (1) Snead Island, Palmetto, Manatee

Co., October 1969; (2) Eustis, Volusia Co.,
August 1975; (3) 1500 block, W. 7 Avenue,
Hialeah, Dade Co.. July-August, 1975.
Specimens from each of these localities are de
posited in the Florida State Museum. The first
two records involve specimens found at nur-
series on ornamental plants recently imported
from Puerto Rico. Established colonies at these
two places have not been confirmed. The third
locality, in Hialeah, has an established
population where the snail is abundant in a
residential area in lawns and among or-
namental vegetation. The geographic extent of
this population has not been determined. Most
likely the species soon will be found throughout
the greater Miami area.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 11

VARIATION IN THE NEW ENGLAND
PYRAMIDELLID GASTROPOD. TURBONILLA NIVEA (STIMPSON)

Robert A. Wharton

Star Route
Somerset, California 95684

ABSTRACT

Based on the study of a large population of a highly variable species of Tur-
bonilla, and examination of type s])ecimens of T. nivea and T. stricta, it is the
itHthor's opinion that Turbonilla (Turbonilla) stricta Verrill, 1873. is a synonym
of T. (T.) nivea (Stimpson. 1851). The syntype of T. nivea located at the
Academy of Natuml Sciences of Philadelphia is not a typical example of the
species, but is well within the variation observed in a population from. Con-
necticut.

INTRODUCTION

Recent studies on Northwestern Atlantic
species of the genus Turbonilla revealed that
the characters originally used to separate two
of the species, T. (Turbonilla) nivea (Stimpson,
1851) and T (Turbonilla) stricta Verrill, 1873,
are insufficient. As Robertson (1968) noted, the
systematics of the Pyramidellidae is based
solely on shell characteristics. For example,
Verrill (1873), in his original description of T
stricta, stated that it differed from T nivea in
the form of the aperture and lip, and in being
smaller though having the same number of
whorls. Bartsch (1909) separated the two on the
basis of the number of axial ribs on the last
whorl (eighteen on T stricta and twenty-two on
T. nivea), and by a slight difference in the
shape of the aperture. A large population of
Turbonilla from Connecticut exhibited a high
degree of variability in these and other charac-
ters, making the existence of two distinct
species questionable. An examination of types
on deposit at the Academy of Natural Sciences,
Philadelphia (T. nivea syntype, ANSP #20013;
T stricta probable syntype or paratype, ANSP
#78205), confirmed the suspicion that the two
species should be synonymized. The Academy's
single specimen of T nivea was obviously
collected dead, as the shell is quite worn and
even has a drill hole in it. From the variation
shown by the population from Connecticut, and
the poor condition of the T nivea syntype, it is
easy to see how two species were described.

Over six hundred specimens were collected
from a population located subtidally in eel
grass beds off Noank, Connecticut, during 1970
and 1971. Most of the snails burrowed beneath
the sediment throughout the year, and were
seldom seen on the surfece. This may have been
due to a lack of surface materials, since a nearby
population lived beneath dead scallop shells
which littered the surface. Spawning occurred
in late summer, and the young snails grew to a
length of about 2 mm before winter. No growth
was added during the winter, and the shells
became thickened and opaque. Some of the
adult snails also survived the winter. Growth
resumed the following May and June. Ap-
proximately 2 mm of translucent shell material
was added by August. Spawning adults
averaged nearly 4 mm and had 8 to 9 whorls.
Snails dredged offshore from a depth of 30m
were somewhat larger, with more whorls.
Lunatia triseriata (Say) appeared to be the
chief predator of T. nivea at Noank, although it
preferred the less common T verrilli Bartsch.

Sanders (1958) has suggested that at least one
species of Turbonilla is a deposit feeder rather
than an ectoparasite. Because of their
burrowang habits and the scarcity of suitable
pr^y, feeding by T nivea was not actually ob-
served at Noank. Thus the question remains
unresolved, and much more work on this aspect
is needed. There is a well-defined series of
ciliary currents present on the foot, mentum,
and tentacles. These serve to transport substrate
particles over and around the head while

12 THE NAUTILUS

January 30, 1976

Vol. 9() (1)

tOt

to-

la-

<
-z so

o

Q^ 40-

QO

30

to-

10-

12 14 It 18 10 22 24 Zfc 2»
RIBS PfR IVHORL

1
FIG. 1. (iniph ahiiiniiii tlii' iiiinibcr of rihx per ivhnrl in a
xdiiiplc iif i-lll siimls.

burrowing, and might also be used in feeding if
the animal is a selective deposit feeder.

VARIATION

About five hundred snails were examined,
and the number of ribs on the youngest whorl
was counted. Figure 1 shows the result. The
continuous curve shows that this character
should not be used to separate species of the
subgenus Turbonilla. Such variation was due to
differences in both the width of the whorls and
the width of the ribs themselves. Variation in
length and number of whorls per shell did not
affect the variation in number of ribs per
whorl. Shells of the same size also varied in the
number of whorls they possessed. Similarly,
shells with the same number of whorls varied
by as much as one millimeter. The shape of the
ribs was also somewhat variable — even from
whorl to whorl in some specimens. Most were

slender and slightly curved. However, many
specimens had ribs that were straight. The size
of the aperture was measured and found to be
quite variable in this population: from
narrowly elliptical to squarish — though most
commonly broadly oval. Figures 2-6 illustrate
some of the variation in this species. A
representative series, showing the highly
variable nature of this species, was deposited at
the Academy of Natural Sciences of
Philadelphia.

Shell characteristics alone are generally unac-
ceptable for a clear understanding of specific
differences between species of the subgenus Tur-
bonilla, especially since population studies have
not been undertaken to determine variability
within a species. And until more complete
studies have been done, precise definitions of
the species will be impossible. Lopes (1958) and
Bartsch (1909) have also studied variation in
the shell characteristics (especially spiral in-
cisions) of Turbonilla. However, they were
dealing with other subgenera; and the

4 5 6

FICiS. 2-(;. Fire sperimeiix nf Turbonilla nivea aillected
friiiii Ihc sdtiic Idciililji .ihdirinii mriatidii iritliiii the species.

Vol. ;)() (1)

January :^(), 1976

THE NAUTILUS 13

taxonomic problems resulting from such
variation were less severe because of the
presence of other useful shell characters.

Other possible characters useful for describing
species of Turbonilia are the operculum, which
is elaborately sculptured in some species; the
color of the hypobranchial gland (Robertson,
1968), yellow-green in T. nivea; feeding habits
or host preference; presence (or possible ab-
sence) and form of the stylet; and the presence
or absence of denticles. Such denticles, for
example, are present in T. (PyrgiscusJ verrilli
but absent in T. (T.) nivea. They are quite
similar to the penial denticles figured by Maas
(1964). It is also quite probable that further
studies will reveal that the differences between
at least some species of T. (Pyrgiscus) and T.
(Turbonilia) are generic rather than subgeneric.

The Pyramidellidae as a whole, and the
genus Turbonilia in particular, need a great
deal of study before even some of the basic
taxonomic problems can be cleared up. Other
species of Turbonilia (eg. T. verrilli and T
vinae) should be examined for similar
synonymies. Populations should be studied to
determine variability, and a combination of
other characters should be used in conjunction
with shell morphology to redefine species.

ACKNOWLEDGEMENTS

I wish to express my deepest appreciation to
Dr. Robert Robertson for his assistance on
many aspects of this study. I also wish to
thank Miss Lauren Green for illustrating the
snails; and the faculty and staff of the Univer-
sity of Connecticut Marine Research
Laboratory, Noank, who provided much
assistance during the project. This research was
supported in part by an NSF Graduate
Fellowship from the University of Connecticut.

LITERATURE CITED

Bartsch, P. 1909. Pyramidellidae of New England and the

Adjacent Region. Prof. Bost. Soc. Not. Hist. 34(4): 67-112.
Lopes, H. S. 1958. Sobre Turbonilia (Pi/rgiscus) dispar Pils-

bry, 1897 (Gastropoda, Pyramidellidae). Rev. Brasil. Biol.

18(1): 17-21.
Maas, D. 1964. Liber Cuticularbildungen am Penis von Py-

ramidelliden. Zool. Anz. 173(2): 137-148.
Robertson, R. 1968. Hosts, Spermatophores and the Sys-

tematics of Five East American Species of Odostomia.

s.l. (Pyramidellidae). [Abstract]. Am. Malacol. Urmn Ann.

Repts. "1967" BulL 34: 12-13.
Sanders H. L. 1958. Benthic Studies in Buzzards Bay. I.

Animal -Sediment Relationships. Limnol. Oceanogr. 3(3):

245-258.
Verrill, A. 1873. Rept. U.S. Comm. Fiah nnd Fisheries.

pt. 1: 659.

ALVAR NUNEZ AND THE SNAIL RABDOTUS IN TEXAS

John W. Clark, Jr.

Texas Historical Commission

P.O. Box 12276, Capitol Station

Austin, Texas 78711

In a recent article in TTie Nautilus, Hester
and Hill (1975 : 38) discussed the possible
ethnohistoric account of Alvar Nunez Cabeza de
Vaca referring to the eating of snails in the
Gulf Coastal Plain. In an earlier article, also in
TJie Nautihis (Clark 1973:24) I lamented the
lack of ethnohistoric accounts referring to this
practice among the Texas Indians. Unfor-
tunately, this situation must remain lamented.

Hester and Hill depend on two sources:
Bishop (1933:95) and Krieger (1956:53). The

Krieger article on the food habits of the Texas
coastal Indians unfortunately indicates no
sources other than Cabeza de Vaca and that
somewhat vaguely. The problem of the Bishop
book is that there appears to be considerable dif-
ferences between it and more standard transla-
tions. Unfortunately, neither of these sources
agrees with the Bandelier (1906) translation, the
Covey (1963) translation or the original Spanish
(Nunez 1906 ed.).
There are two passages of the Cabeza de

14 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

Vaca Relaci6n pertinent to the discussion:

1) "Algunas vezes matan algunos venados, y
a tiempos tomaii algun pescado; mas esto es
tan poco y su hambre tan grande que comen
aranas e huevos de hormigas y gasanos e lagar-
tijas e salamanquesas e culebras y biuoras que
matan los hombres que muerden, y comen
tierra y madera e todo lo que pueden auer, y
estiercol de venados y otras coasa que dexo de
contar, y creo aueriguadamente que si en
aquella tierra ouiesse piedras, las comerian
(Nunez 1906 : 70)."

2) "En todo el tiempo que comiamos las
tunas teniamos sed y para remedio desto
beuiamos el (;umo de kis tun;i.s y sacauamosio
en vr\ hoyo que en la tierra haziamos, y desque
estaua Ueno beuiamos del hasta que nos har-
tauamos (Nunez 1906 : 75)."

Covey (1963) translates these passages
following the Spanish closely:

1) "Occasionally, these Indians kill deer and
take fish; but the quantity is so small and
famine so prevalent that they eat spiders and
ant ^gs, worms, lizards, salamanders, snakes
and poisonous vipers; also earth and
wood — anything, including deer dung and other
matter I omit. I honestly believe that if there
were stones in that land they would eat them
(Covey 1963 : 79)."

2) "The thirst we had all the while we ate
the pears, we quenched with their juice. We
caught it in a hole we hollowed out in the
ground. When the hole was full, we drank until
slaked (Covey 1963 : 83)."

The Bandelier translation is similar to that
of Covey.

Obviously, the Spanish word for snail,
"caracol" does not appear in these passages nor
does the word appear in any of the Spanish
language passages dealing with the Mareames
Mariames).

Thus, by examining the original Spanish text
one can see that, although Alvar Nunez
provides much information on the subsistance
of the Mariames and the central Texas coastal
Indians, he does not mention snails. T. C. Hill's
experiment (Hester and Hill 1975 : 38) indicates
that the Indians could have eaten Rabdotus sp.
snails. Likewise, their presence in vast numbers
in certain archeological sites is suggestive. As I

suggested in my 1973 article (Clark 1973:24)
the presence of radulae of these snails in
human coprolites would be the best indication
as to whether these animals were eaten. Un-
fortunately, none have yet been found in
human coprolites from Texas sites or any other
North American archeological sites.

Dr. Vaughn Bryant of the Anthropological
Research Laboratories at Texas A&M Univer-
sity (May 1975: personal communication) has
specifically searched for snail radulae during
the processing of coprolites but has failed to
find any. This may be due in part to the
procedure of sampling the coprolites, the selec-
tion of coprolites for analysis or the possibiliiy
that the Indians did not eat snails. I believe
that at present it is a sampling problem in
that coprolites have not been analyzed which
were associated with snail shell deposits in dry
rockshelters.

In summary, the Bishop (1933) monograph ap-
parently is in error, possibly leading Krieger
(1956) into error. The original Spanish text
(Nufiez 1906) does not mention snails nor do
two of the major translations, thus, there is
still no ethnohistorical evidence from Cabeza de
Vaca and Br>'ant has yet to find hard empirical
evidence for the eating of snails. As of the
moment, all theories are inferential.

LITERATURE CITED

Bandelier, Fanny (Translator). 1904. The Journey of Alvar
Nunez Cabeza de Vaca and His Companions from Florida
to the Ricific 1528-1536. Allerton Book Co., New York.

Bishop, Morris. 1933. The Odyssey of Cabeza de Vaca. The
Century Co., New York and London.

Clark, John W.. Jr. 1973. The Problem of the Land Snail
Genus Rabdotus in Texas Archeological Sites. The Nau-
tUus 87(1): -24.

Covey. Cyclone (Translator). 196:3. .idventures in the Un-
known Interior of America. Collier Books, New York.

Hester, Thomas R.. and T. C. Hill, Jr. 197.5. Eating Land
Snails in Prehistoric Southern Texas: Ethnohistoric and
Experimental Data. The Nautihis 89(2): 37-38.

Krieger, Alex D. 1956. Food Habits of the Texas Coastal
Indians in the Early Sixteenth Centurj-. Bulletin of the
Terns Atrheological Society 27: ■17-.58.

Nufiez Cabeza de Vaca, Alvar. 1906. Relaci6n de los Nau-
fragios y Comentarios de Alvar NtiHez Cabeza de Vaca.
Adelantado y Gobernador del Rio de la Plata. Coleccion
de Libros y Documentos Referentes a la Historia de
America, Tome V. Libreria General de Victoriano Sua-
rez, Madrid.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 15

SPECIES CRITERIA IN ANGUISPIRA (ANGUISPIRA)
(PULMONATA: DISCIDAE)

Alan Solem

Department of Zoology

Field Museum of Natural History

Chicago, Illinois 60605

ABSTRACT

The functioning surface of the penis in Anguispira (Anguispira) shows con-
sistent differences in pilaster pattern among A. alternata (Say, 1816), A. cum-
berlandiana (Lea. 18WI. and A. picta (Oapp, 1920), although the gross ap-
pearance of their genitalia is nearly identical. Investigation of the con-
chologicaliy divergent morphs lumped as A. alternata probably will result in
recognizing several species. The genital difference reported here corresponds
with major shell shape and scuiptwre differences. Radular structure in the
Disddae, as represented by Anguispira, is generalized and differs from the basic
patterns found in the (Jharopidae, Endodontidae, and Helicodiscidae.

INTRODUCTION

The ribbed and unicolored to flammulated
shells grouped as Anguispira and Discus have
been monographed by MacMillan (1940) and
Pilsbry (1948). Comparison of these papers
shows considerable disagreement as to species
limits and affinities, although the generic limits
are the same. MacMillan (1940) relied strictly
on the shell for taxonomic decisions and Pilsbry
(1948: 566) indicated that ". . . fundamental inac-
curacies are involved" in MacMillan's
phylogenies. Preliminary work by H. B. Baker
on the anatomy of various species of Discus
was included by Pilsbry (1948: 599-600) in the
form of a key, together with some anatomical
details on both Anguispira (A.) alternata (Say,
1816) and A. (Zonodiscus) kochi kochi (Pfeiffer,
1845) (Pilsbry, 1948: 568, fig. 304), and, ad-
ditionally. Discus (D.) patulus (Deshayes, 1830)
(Pilsbry, 1948: 599, fig. 327). Subsequently For-
cart (1957) commented on the subgeneric
divisions of Discus; Uminski (1962) revised the
Palearctic species of Discus and summarized the
widely scattered European literature; and
Uminski (1963) reported on the anatomy of
Discus marmorensis H. B. Baker, 1932.

Various discrepancies and contradictions in
these accounts will be discussed elsewhere
(Solem, in preparation). Here, it is sufficient to
point out that the species of Discus have

several longitudinal pilasters within the penis
(Pilsbry, 1948: 599, fig. 327a; Uminski, 1963: 84,
figs. 5-8) and in Anguispira there are only two
pilasters, one very large and the other small
(Pilsbry, 1948: 568, figs. 304C, 304F). There has
not been any detailed study of the anatomy in
different species of Anguispira previously, and
unpublished observations by Hubricht, Grimm
and myself had failed to identify species level
identification features from the external aspects
of ttie genitalia.

During a survey of rare and potentially en-
dangered land snail species of Eastern North
America for the Office of Endangered Species,
it was necessary to investigate the status of the
taxa grouped as Anguispira (A.) cum-
berlandiana (Lea, 1840). MacMillan (1940: 392-
394) and Pilsbry (1948: 586-589) recognized four
subsf)ecies, A. c. cumberlandiana (Lea, 1840)
from Northeastern Alabama and Tennessee; A.
c. alabama (Clapp, 1920) from Northeastern
Alabama; A. c. columba (Clapp, 1920) from
Marion Co., Tennessee; and A. c. picta (Clapp,
1920) from near Anderson, Franklin Co., Ten-
nessee. Clapp (1920) described Anguispira picta
as a full species, and Hubricht (unpublished)
agreed with this opinion on the basis of shell
features.

This paper reports on species level differences
in the terminal genitalia of Anguispira

16 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

(Anguispira) altemata, A. cumberlandiana. and
A. picta. and thus suggests features that can be
investigated to determine the status of the
many forms that have been lumped as A. (A.)
altemata by earlier authors and Pilsbn,- (1948),
but split into several species by Hubricht (1952,
1965. 1968, 1970, 1974) on the basis of field ob-
servations and shell features. Radular teeth of
the same three species are illustrated to show
the basic structures and inter-row support
mechanisms of the central and lateral teeth in
the Discidae.

The field work by Mr. Glenn Goodfriend was
supported by Office of Endangered Species Con-
tract 14-16-0008-764, which also provided for the
excellent anatomical illustrations by Elizabeth
A. Liebman. OES Contract 14-16-0008-965 sup-
ported the page and illustration charges for
publication. The scanning electron microscope
photographs were taken with a Cambridge S4-10
Stereoscan provided to the Field Museum of
Natural History by NSF Grant BMS72-02149.
The SEM prints were prepared by Fred Huys-
mans. The help of Sharon Bacoyanis and Eliza-
beth Liebman in manuscript preparation is
gratefully acknowledged as is the support and
help given this project by the Office of Endan-
gered Species staff, particularly Marc Imlay.

MATERIAL STUDIED

The data on the illustrated material are as
follows :

Atiyuitipira (A.) altemata (Say, 1816). North-
west side of Route 272, 0.4 miles southwest of
Route 270 junction, north side Rich Mountain,
Polk Co., Arkansas. Glenn Goodfriend! Sep-
tember 13, 1973. Field Museum of Natural
History 176186.

Anguispira (A.) cumberlandiana cum-
berlandiana (Lea, 1840). Near Martin Springs
Road, 8 miles south of Monteagle, Marion Co.,
Tennessee at 960 feet elevation. Glenn Good-
friend! September 4, 1974. FMNH 171433.

Anguis-pira (A.) picta (Clapp, 1920). Southwest
side of Buck Creek Cove, 4 miles south of Sher-
wood, Franklin Co., Tennessee at 750 feet
elevation. Glenn Goodfriend! September 6, 1974.
FMNH 171138.

Several additional sets of typical A. alierrmta
were dissected, but are not illustrated, since

they agreed with the structures seen in the
figured material. What appears to be seasonal
variation in the prostate-uterus and develop-
ment of the main pilaster was discovered.
Material collected at the same time of year was
selected for illustration, despite the geographic
incongruence of the A. altemata set.

FIG. 1. Genitalia nf Anguispira; a, Anguispira altemata
altemata (Say. 1816). FMNH ITKlSti. Nmih side of Rich
.Ml.. Polk- Co.. Arkatisas: b, Anguispira picta (Clapp. 1920).
FMNH ITlliS. Buck Creek Cow. south of ShcrwtHid.
Fniiiklin Co., Tennessee; c, Anguispira cumberlandiana
cumberlandiana (Lea. mO). FMNH 17U.iS. About S miles
south of Moulcayle. Marion Co., Tennessee. Scale lines equal
5 mm.

Vol. 9(1 (1)

January 30. 1976

THE NAUTILUS 17

FIG. 2. Penis internal structure and talon in Anguispira:
a, Anguispira altemata alternata (Say, 1816): b, d,
Anguispira picta (Gapp, 1920): c, Anguispira cum-

berlandiana cumberlandiana (Lea. 181,0). Sixde lines as
marked, d yreatly enlarged.

TERMINAL GENITALIA

The apical genitalia of A. altemata and A.
picta are not illustrated, since the ovotestis (G)
and hermaphroditic duct (GD) showed no dif-
ferences from the structures seen in A. cum-
berlandiana (fig. 1 c). All three species have the
tri-lobed talon (fig. 2 d, GT) first reported by
Pilsbry (1948: .568. fig. 304D). A. picta (fig, 1 b)
does have a slightly longer prostate (DG) and
uterus (UT). but this may be a facet of in-
dividual population variation. The very long

spermatheca (S) and slender, fingerlike albumen
gland (GG) also are typical of the Discidae. A.
alternata (fig. 1 a) does have a shorter free
oviduct (UV) than either .4. picta (fig. 1 b) or
A. cumberlandiana (fig. 1 c). There is a slight
variation in the length of the vagina (V), but
because of the angle at which the spermatheca
joins the free oviduct to form the vagina,
measuring the exact length of the latter is very
difficult.

In all Anguispira (Anguispira) examined so

18 thp: nautilus

January 30, 1976

Vol. 90 (1)

far, the vas deferens (VD) emerges abruptly
from the acini bundles of the prostate, narrows
slightly and lies free of the adjacent tubes in
its passage to the peni-oviducal angle, then
reflects apicad to enter the penis (P) through a
simple pore (fig. 2 c, DP). The vas deferens en-
trance is lateral to insertion of the penial
retractor muscle (PR), which, contrary to
previous literature statements, arises from the
diaphragm, not the columellar muscle. In all
cases the insertion of the penial retractor
muscle is on the apex of the penis. The
illustration of A. cumberkwdiumi (fig. 1 r)
suggests that the insertion is slightly lateral in-
stead, but this is an artifact of preservation.
The illustrated specimen was partly retracted
into the shell. As part of the retraction process,
the penis is shifted apicad relative to the origin
of the penial retractor muscle. At full shift the
apex of the penis is bent slightly to the left
and the retractor muscle extends diagonally an-
teriorly, rather than in its normal apical orien-
tation. When fixed in the preservative, this
slight distortion can be misinterpreted as part
of the basic structure unless it is compared
with the condition found in fully expanded
materials.

There is a definite difference in the shape of
the penis, which is caused by the quite
divergent internal pilaster structures (figs. 2 a-
(■). In .4. cunibcHiuKtiinid (fig. 1 c) the penis
tapers almost evenly from apex to atrial junc-
tion (Y). In .4. pirta (fig. 1 b) the penis has an
almost uniform diameter on its upper two-
thirds, then rapidly narrows toward the atrium
on its lower third. A. (dteniata (fig. 1 a) has a
more bulbous penis that narrows slightly
apically, but tapers toward the atrium on its
lower two-fifths. Typically these differences can
be detected, but flattening during dissection or
in the initial preservation process can distort
individual specimens and mislead the observer.

Only by slitting the penis from atrium (Y) to
penis pore (DP) and studying the major
pilasters, can the differences (fig. 2) be seen
clearly and the species differentiated without
question. In A. nUcniata (fig. 2 a) the major
pilaster (PP on left) expands to great size,
tapers very slightly at the apex, and sharply
near the atrium. The second pilaster (PP on

right) is a narrow, much lower, raised ridge
that varies at most slightly in height over its
entire length. In A. picta (fig. 2 h) the major
pilaster (PP) expands much less, even on its
lower third, then narrows greatly toward the
middle, and is a relatively narrow ridge in its
upper half. The second pilaster is lower, wider
on its lower half, then broadens into a semicir-
cular pilaster on its upper half. The second
pilaster itself is composed of less dense tissue.
In A. cumbeiiandiana (fig. 2 c) the main
pilaster is rather high and narrow, without
major size change from near the apex to near
the atrium. The second pilaster is greatly
reduced in height, becoming a wide, nearly flat
patch of fibrous tissue. Near the middle of the
penis in each species, a "pocket" is formed by a
flap of tissue running between the two
pilasters. This is vaguely similar to a structure
found in many Charopidae, but apparently formed
quite differently (Solem, unpublished). All
Aryuispira have vague longitudinal fold ridges
extending from the atrium into the penis base
(figs. 2 (i-c). One or two of these may extend up
alongside the major pilaster, but I have not
dissected enough individuals to determine if the
longer ridge shown for A. cumberlandiana (fig.
2 <■) is an individual variation or represents
another species difference. The different shapes
found in the two large pilasters are charac-
teristic within quite narrow limits and thus
represent species differences.

The above observations are based on studying
five individuals from each population, and on
sampling ten populations from the Middle West
and Eastern United States of A. alternata. The
differences in pilaster structure are constant
and I conclude that they are valid species dif-
ferences. Thus A. picta is distinct from A. cum-
berlandiana. as originally proposed by Clapp
(1920), and both are distinct from A. alternata,
Restudy of dissections that I had made many
years ago of .4. fetyusDni (Bland, 1861) ft-om
Cambridge, Maryland, (specimens courtesy of
Halpli Jackson). .4. niarnrili Walker, 1928 from
Alabama (specimens courtesy of Leslie
Hubricht), and new dissections of A. mordax
(Shuttleworth, 1852) from Well Spring, Camp-
bell Co., Tennessee (FMNH 1.37820, L.
Hubricht! June 5, 1964) show equally different

Vol. m

January 30, 1976

THE NAUTILUS 19

FIG. 3-8. Central and lateral radvlar teeth. Figs. 3-5, 8.
Anguispira pirta (Clapp. 1920). FMNH 1711.18. Fig. 3.
Newly funned central (upper center) and 1st lateral teeth.
llSaX. Fig. 4 Lateral teeth from mid sectimi of radula
shomng functioning of support ridge and anterior flare.
1,260X. Fig. 5. Central (tipper right) and lateral teeth
viewed from anterior angle, erected podtion. 650X. Fig. 8.
Late lateral tooth viewed from low outside angle to show

extent of free anterior margin. l.;il5X. Figs. 6-7.
Anguispira cumberlandiana cumberlandiana (Lea. ISUO). Fig.
6. Central (left) and l.ft lateral near posterior end of radula
showing dual support ridges on central, single support ridge
on lateral, marked anterior flare of lateral. 1,250X. Fig. 7.
Central and early lateral teeth viewed from a high
posterior angle. 6.50X.

20 THE NAUTILUS

January 30, 197fi

Vol. 90 (1)

FIGS. 9-14. Marginal radular teeth. Figs. 9-10. Anguispira
alternata alternata (Say. Ifilf!). Fig. 9. Outer marginals
frciiii high ixinteriar angle. l..iOOX. Fig. 10. Outer marginals
on a creased area to show shape and angle of elevation,
l..iOnX. Fig. 11. Anguispira cumberlandiana cum-
berlandiana (Lea. ISiO). FMNH 17W!.i. Midmarginal. teeth

from II liigh central angle. t;2.5X. Figs. 12-14. Anguispira
picta (Clapp. 1920J. FMNH 17I1M Fig. 12. Transition from
lateral to marginal teeth. IjmX. Fig. 13. Outermost
marginals shoiving splitting of side cusps. 1.250X. Fig. 14.

Oiitprmost marginals from a high nntrrinr angle. l.ll.^X.

Vol. % (I)

January 30. 1976

THE NAUTILUS 21

FIGS. 1.5-18. Radular teeth. Figs. 15-17. Anguispira alter-
nata alternata (Say. 1816). FMNH 176186. Fig. 15. Newly
formed early lateral teeth showing function of basal siipixiii
ridge. 1,050X. Fig. 16. Worn central and early lateral teeth
from anterior end of mdnla. lOOOX. Fig. 17. Lateral teeth.

pilaster patterns in these taxa. Revision of the
Anguispira alternata group is beyond the scope
of this study, but the existence of distinctive
pilaster patterns in some of its more strongly
characterized "races" indicates that several
species are represented, as Hubricht has
suggested previously on the basis of his collect-
ing experiences. An investigation of penis
pilaster structure in this complex can be ex-
pected to yield significant data, despite the lack
of obvious differences in the gross genitalia.

RADULAR STRUCTURE IN ANGUISPIRA

The radulae were prepared using the
techniques outlined in Solem (1972). Published
illustrations have been chosen to demonstrate
the functioning and structure of the inter-row
support system in the Discidae, to illustrate the

1.160X. Fig. 18. Anguispira picta (Oapp. 1920). FMNH
1711S8, Transition from lateral to marginal teeth shouing
shortening of basal plate and reduction of anterior flare.
I.IWX.

pattern of change from lateral to marginal
teeth, and to demonstrate the form of the
marginal teeth. Differences between the three
species are trivial, with A. cumberlandiana (fig.
7) having a smaller central tooth in relation to
the 1st laterals than either A. picta (fig. 3) or
A. alternata (fig. 16) and A. alternata (figs. 15-
17) having a more prominent ectocone on the
lateral teeth than either of the other species.

The rachidian or central tooth of the radula,
marked "r" in figs. 3-7 and 16, has very weak
to weak ectocones, a variably (fig. 7) indented
and sinuated anterior margin, no anterior flare,
and two prominent lateral buttresses on the
basal plate (figs. 3, 6, 7). The first lateral teeth
are immediately recognizable in that they lack
an endocone (fig. 7) and in having the basal
plate buttress only on the outer side of the

22 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

basal plate (fig. 6). In addition, there is a
distinct anterior support flare on the early
laterals that is lacking in the rachidian tooth
(fig. 5). When a tear in the basal membrane
partly separates two rows of teeth (figs. 5-7),
then the basal plate structures and anterior
flares can be observed quite easily. After the
first few lateral teeth, the basal flare becomes
accentuated and somewhat elongated (fig. 8),
with the anterior two-fifths of the tooth free
of the basal membrane. This is the generalized
"helicoid" pattern for inter- row support of the
laterals (see Solem, 1972; pi. 5, figs. 22-23). Figs.
3, 4, and 7 show the stress support system in
various phases of operation. For the rachidian
tooth, the anterior margin is pressed back
against the basal plate and fits right in be-
tween the latei'al buttresses. Fig. 7 shows two
stages in the process: at far left, the anterior
flare is tilted down, but not in contact with the
basal plate, while at far right the flare is in
contact. Fig. 16 shows the interlock system in
full operation even more clearly. The first
lateral teeth differ only in the stronger anterior
flare being pressed partly against the shaft of
the cusp and partly against the outside buttress
(lower left of fig. 4 and center of fig. 15).

This is a highly generalized buttress system
that is widely distributed in the Pulmonata and
yields no information as to the phylogeny of
the group.

Transition from lateral to marginal teeth oc-
curs fairly abruptly (figs. 17-18) and involves
changes in basal plate, anterior flare, cusp
length, and angle at which the cusp is pointed.
Fig. 17, top to bottom, shows the shortening of
the anterior flare, while the different angle in
fig. 18 demonstrates the further progression in
this loss and the then very rapid change in the
length of the posterior section of the basal
plate. The shift is completed vidth the teeth at
the bottom of fig. 18, where the anterior
margin is simply rounded, the cusp is at a
lower angle, the posterior section of the basil
plate is greatly shortened, and the lateral but-
tress on the basal plate is lost. The shift in
angle of the cusp continues to the point shown
in fig. 12, where the cusp is elevated a com-
paratively few degrees from horizontal. At this
point, a weak endocone may appear on some of

the marginals, although most (fig. 11) will have
only a small knob-like protrusion. Newly for-
med marginals (figs. 9, 10) in A. alternata show
no special features, but fig. 10, which was taken
at a curve in the radula, effectively demon-
strates the cusp angle. Outermost marginal
teeth (figs. 13, 14) show irregular splitting of
the ectocone with teeth in successive rows
showing different ectoconal splitting features. In
some individual outer marginal teeth there is a
weak endocone (upper right of fig. 14).

In maintaining a basically bicuspid condition,
the lateral and marginal teeth of the Discidae
differ from those of the Charopidae (Solem,
1974: 167) or Helicodiscidae (Solem, 1975: figs.
6-8) which are essentially tricuspid with often
extreme cusp splitting. The Endodontidae
(Solem, 1973: figs. 6-9, 13-14) also have bicuspid
lateral teeth with bicuspid to tricuspid
marginals, but the inter-row support system
(l(ir. cit.. figs. 6, 14) is very different. The an-
terior margin of the lateral teeth is rounded
and totally lacks an anterior flare, the cusps
are narrower and curved, and support comes by
pressing against the raised posterior tip of the
basal plate ridge. When viewed with optical
equipment, the endodontid and the discid
radulae would look essentially identical, but the
functioning patterns in the two groups are
very different.

SHELL FORM AND GROSS SCULPTURE

Differences in shell form and sculpture be-
tween the nominate taxa of the three species
have been covered quite adequately by Mac-
Millan (1940) and Pilsbry (1948). Aiiguispira
alternata (Say) has a rounded to angulated
periphery on the body whorl and weak to very
strong radial ribs that continue across the
periphery and into the umbilicus. A. cuw-
berlandiana (Lea) has a protruded, thread-like
peripheral keel wath prominent radial ribs that
mntinue across the keel. A. picta (Clapp) has
the radial ribs present on the upper spire, but
absent from the body whorl and with the
protruded peripheral keel smooth and without
any trace of radial ribbing.

Because races of .4. alternata and A. cum-
berlandiana vary greatly in the prominence of
their sculpture, considerable uncertainty con-

;m) (1)

January 30. 1976

THE NAUTILUS 23

tinues to exist concerning the limits to be
assigned sculptural variation within a species.
Thus the decisions by MacMillan (1940) and
Pilsbry (1948) to combine A. picta with .4. cuni-
berlandiana were based on the latitude of
sculptural variation in the morphs lumped as
A. alternata. The demonstration here of dif-
ferences in the penial pilaster patterns be-
tween .4. picta and ,4. cumbcrlamiiana suggests
that investigation of the named forms of A.
alternata that show widely divergent sculpture
may lead to a splitting of that taxon into sev-
eral discrete units.

LITERATURE CITED

Qapp. G. H. 1920. A new species of Pyramidula from Ala-
bama and notes on P. rnmherlandiana with new varie-
ties, ne Nautilii.« 34(1): 23-26, pi. 1.

Forcart. L. 1957. Zur Ta.xionomie und Nomenklatui' von
Gonyodiscus. Discus und Patula (Endodontidae). Arch.
Mali. 86(1/3): 29-32.

Hubricht. L. 19.52 The Land Snails of Pittsylvania Count>'.
Virginia, nie Nautittis 66(1): 10-13.

Hubricht. L. 1965. The Land Snails of Alabama. Sterkiana
17: 1-5.

Hubricht, L. 1968. The Land Snails of Kentucky'. Sterhmnn
32: 1-6.

Hubricht. L. 1970. TTie Land Snails of North Carolina.
Sterkiana 39: 11-1.5.

Hubricht. L. 1974. A Review of Some Land Snails of the
Eiistern United States. Miiliiciil<yical Reriew 7: 33-34.

MacMillan, G. K. 1940. A Monographic Study of the Snails
of the Genera Anguispira and IHsciui of North America,
EAclusive of Mexico. Ann. Carnegie Miis. 27(24): 371-426,
pis. 38-42.

Pilsbry, H. A. 1948. Land Mollusca of North America
(North of Mexiaj). Arad. Nal. Sci.. Philadelphia, Monog.
a 2(2): i-xlvii, .521-1113, figs. 282-.5«.5.'

Solem. A. 1972. Malacological Applications of Scanning Elec-
tron Microscopy. — II. Radular Structure and Functioning.
The Veliger 14(4): 327-336, pis. 1-6, 1 text fig.

Solem, A. 1973. A New (ienus and Two New Species of
Land Snails from the Lau Archipelago of Fiji (Mollusca:
Pulmonata: Endodontidae). The Veliger 16(1): 20-30, 1
table. 21 figs.

Solem, A. 1974. The Shell Makers: Intnidneimj Mdlluxkit.
John Wiley & Sons. 289 pp.

Solem, A. 1975. Polygyiiscvs virginianus (Burch, 1947) a
Helicodiscid Land Snail (Pulmonata: Helicodiscidae).
77k- NautUus 89(3): 80-86, 8 figs.

Solem, A. In preparation. Characteristics of the Land Snail
Family Discidae Thiele, 1931.

Uminski, T. 1962 Revision of the Palearctic Forms of the
(Sen us Discus Fitzinger, 1833 (Gastropoda, Endodontidae).
Ann. Zoo/., Warsaw 20(16): 299-3:34. pis. 3-4.

Umiriski. T. 1963. Taxonomy of AnguLvpira (?) niarmoren.'iis
(H. B. Baker, 19:32) and Notes on the Taxonomy of the
Genera Anguispwa Morse and Difscu.s Fitzinger (Gastro-
poda, Endodontidae). Ann. Zool. Warsaw 21(9): 81-Sl,
19 text figs.

RANGE EXTENSION OF CORALLIOPHILA MARRATI KNUDSEN
(GASTROPODA: MAGILIDAE)

Henk K. Mienis

Department of Zoology, Hebrew University
Jerusalem, Israel

ABSTRACT

Coralliophila marrati Kmidsen. 1956 originally described from off Liberia is
here reported fro in Congo and Angola.

In his report on the molluscs collected during
the Atlantide Expedition to the coasts of
tropical West Africa, Knudsen (1956) described
three new species of the family Magilidae:
Coralliophila jarli, C. kraemmeri and C.
marrati. Although all were based on one or two
specimens, no doubt seems to exist concerning
the specific status of these species.

Coralliophila marrati was based on a single
specimen dredged from a depth of 78 m at 5°

06' N, 9° 34' W off Liberia. Since Knudsen's
description no additional data have been added
to the distribution of C. marrati.

The Zoological Museum of Amsterdam
acquired the second known specimen from Mr.
W. Bergmans. This specimen was collected in
1969 by J. Moret near Pointe Noire, Congo. It
agrees in full detail with the original descrip-
tion of Knudsen (1956: 29, pi. 2, fig. 14). It is
only slightly larger: height 26.7 mm; width 17.1

24 THE NAUTILUS

January 30, 1976

V(.l. 90 (1)

mm (respectively 21.9 and 14.7 mm in the
holotype).

The Hebrew University of Jerusalem
received recently a third specimen from Mr. J.
Bruynseels. This specimen was trawled at a
depth of 73 m on a coral bottom off Moita
Seca, Angola, in 1973. The measurements of this
specimen are: height 22.4 mm and width 14.1
mm. Another specimen from the same locality
is still in Mr. Bruynseels collection.

These two additional records of C. marrati
mean an important range extension in a
southern direction. It is, however, clear from
the known data that systematic dredging along

the coast of tropical West Africa may yield ad-
ditional specimens and localities of this rare
OiniUuiphUa.

I wish to thank Dr. H. E. Coomans and Mr.
R. Moolenbeek for their kind hospitality during
my visit to the Zoological Museum of Am-
sterdam. Thanks are also due to Mr. J. BruvTi-
seels (Belgium) for presenting the Hebrew
University of Jerusalem with one of the dis-
cussed specimens.

LITERATURE CITED

Knudsen. J., 1956. Marine prosobranchs of tropical West
.■\frica (Stenoglosa). Atlantide Report. 4: 7- lid.

CITTARIUM PICA (TROCHIDAE) IN FLORIDA

R. Tucker Abbott

Delaware Museum of Natural History
Greenville, Delaware 19807

Recent reports of living specimens of the
West Indian trochid, Cittarium pica (Linne), at
various localities along the shores of Marathon
and Molasses Keys seem to substantiate the
fact that this species has become established, at
least temporarily, along the Florida Keys.
Whether they were introduced by man from the
West Indies purposefully or accidentally, or
whether they arrived as floating larvae will
probably never be ascertained. Among the
earliest collectors were Mrs. Carol Brunner of
Miami (live, 30 mm.. Molasses Keys, October,
1973), Mrs. Betty Greene of Long Island, N. Y.
(live, 51 mm., oceanside of Ohio-Missouri
Key, March 9, 1974), Gary Magnote of Miami
(live, 80 mm.. East Sister Rock, Marathon, May
1975), and Robert J. L. Wagner of Marathon
(live, several, 100 mm., yacht basin at
Marathon, July 1975).

Clench and Abbott (1943) recorded only dead
shells from the Florida Keys, with the comment
that the species probably died out within com-
paratively recent times, perhaps due to low
temperatures. Verrill (1900) reported a similar
extinction of the species in Bermuda. On the
basis of Helen Randall's (1964) studies on the
growth rate of Cittarium. the 1973 specimens
from Molasses Keys may be assumed to be
about a year and a half old. Wagner's
specimens are about three years old. It is

possible therefore, that Wagner's specimens
came from a natural larval invasion sometime
during 1971 or 1972. Until other young
specimens, say under 10 mm in diameter, are
discovered it will remain a mystery whether or
not these are breeding populations. It will also
be interesting to see if an unduly cold winter
in the future will kill them.

Wagner ((>; Hit.) reported the nearby pres-
ence of "numerous" adult Pnri)um jHitiil(i{Linne).
a common Caribbean species usually thought to
be somewhat uncommon in the Florida Keys.
H. Randall (1964) reported that this snail is a
predator of Cittarium.

There have been sporadic records of large
adults found at various Florida localities, but
these may have been brought in from the West
Indies by fishing boats. A large live specimen
was collected in July 1948 at Dry Tortugas by
R. 0. Smith and was donated tti the U. S.
National Museum.

LITERATURE CITED

Clmvh. \\\ .] :uid R. T. Abbott. 194:J. The Genera Cmrt and
Liviimi in the Western Atlantic. .Inhmtiniia 1(12): M2,
4 pis.

Randall. Helen A. 19&4. A Studj- of the Growth and Gther
Aspects of the Biology of the West Indian Topshell,
Cittarium pica (Linnaeus). Bull. Mar. Sci. Gulf and Carib-
bean 14(.3): .12.1-143.

Verrill. A. E. 1900. Notes on the Geologj- of the Bermudas.
.Amrr. .hmr. Sci. 9(5.3): 313-.340.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 25

COMMENTS ON EASTERN NORTH AMERICAN POLYGYRIDAE

Alan Solem

Department of Z(X)logy

Field Museum of Natural History

Chicago, Illinois 60605

ABSTRACT

Tlic (ictiitulia and mdular i^trncture of several Mesodon aiid Triodopsis from.
Arkansas, Okiahotna and West Virginia are iUustrated and dii<russed in relation
to their potential significance in phyloyenetic studies. Tlic stmrtnre of the
verge, penial pilaster details, penial sheath nni.'irle attachment, and details of
radnlar euspiny are emphamzed.

INTRODUCTION

During a survey of rare and potentially en-
dangered land snail species of Eastern North
America, numerous polygyrid land snails were
collected. Some of these previously had not been
dissected, others were studied in order to check
their affinities and compare their structures
with those of sympatric taxa. Although the em-
phasis here is on species from Arkansas and
Oklahoma, the opportunity is taken to include
information on the West Virginia Triodopsis
(T.) plaiysayoides (Brooks, 1933), since its struc-
tures differ from those found in Triodopsis
(Neohelix) alkdabris alleni (Wetherby, 1883)
and T. (N.) divesta (Gould, 1851). The main pur-
pose of this report is to review shell, genital,
and radular structures that can be confused on
the basis of shell structures and distributional
overlap. It is hoped that further work on their
ecology and relationships will be stimulated.

The field work by Mr. Glenn Goodfriend was
supported by Office of Endangered Species con-
tract 14-16-0008-764, which also paid for the ex-
cellent anatomical illustrations by Elizabeth A.
Liebman. OES contract 14-16-0008-965 provided
the page charges for publication. The scanning
electron microscope photographs of radulae and
jaws were taken by the author with a Cambridge
S4-10 Stereoscan provided to the Field Museum
of Natural History by NSF Grant BMS72-02149
AOL The SEM prints were prepared by Fred
Huysmans. I am indebted also to Leslie Hu-
bricht for loaning material of Triodopsis
platysayoides, to Katy Baker for help with
literature compilations, and to Jayne Freshour

for aid with manuscript preparation. The OES
staff, particularly Marc Imlay, has been most
helpful and encouraging in these efforts.

STATUS OF KNOWLEDGE

Explorations for land snails in Missouri,
Arkansas and what is now Oklahoma were
carried out by James Ferriss in 1900 and 1901,
and then by Henry A. Pilsbry and Ferriss in
1903. The papers by Pilsbry (i903) and Pilsbry
and Ferriss (1907) contain data that is still
essential for any field work in this region,
although their major findings were summarized
by Pilsbry (1940) in his monograph of the
Polyg>Tidae. This work, which synthesizes the
efforts of a century, remains the basic reference
for work on the family. Subsequent faunistic
and descriptive papers by Leslie Hubricht, B.
Branson, L. Lutz and others have provided ad-
ditional distributional records. The conchological
review of Triodopsis by Vagvolgyi (1968), and
the review of the T. fallax group by Wa>Tie
Grimm (1975) contain much useful information.

Potentially the most significant studies are
those of Glenn R. Webb (1952, 1954a, 19.54b,
1959, 1961, 1974) on mating behavior and
anatomy. Unfortunately these papers are dif-
ficult to use. Webb's supraspecific taxa were
ignored by Vagvolgyi (1968) and Grimm (1975).
The subgeneric and sectional names Wilcoxorbis
(Webb, 1952), Aphalogona and Ragsdaleorbis
(Webb, 1954b), Haroldorbis and Shelfordorbis
(Webb, 1959), and the subfamily Ashmunellinae
(Webb, 1954a) are validly proposed taxa and
must be included in any revision of polygyrid
classification.

26 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

The characters that have been used to define
supraspecific categories are few in number.
Mostly they involve alternative states, such as:
penis sheath and retentor muscle (present or

absent); epiphallus (present, absent or vestigial);
duct of spermatheca (slender or swollen); verge
(present or absent); number of major pilasters
inside the penis (one or two); and the size of

a-d

e-h

FIG. 1. ,.S7(('//.s- (if Charkian Pohjgyridae: a-b, Ti-iodopsis
albi)labris alleni (Wctherbii). FMNH 176127. Tenktllcr State
Park. Sequmjah Co.. Okluh<wui: c-d, Mesodon binneyanus
(Pihbni). FMNH J76008. Rich Ml.. Polk Co.. Arkansax: e-f.

Mesodon clausus (Say). FMNH 176220. Calico Hock, hard
Co., Arkan.iax: g-h, Mesodon clenchi (Rehdvrj. FMNH
176059. Mt. Neho State Park. Yell Co.. Arkaiigas. Scale lines
equal ID mm.

Vol. 90 (1)

Januarv 'M). 1976

THE NAUTILUS 27

FIG. 2. Shell o/'Triodopsis divesta (Gotdd). FMNH UfiOHi. Magazine Mt.. Lix/an Co.. Arkaiisa.^. Scale line eqiiah 10 mm.

the papillae in the upper chamber of the penis.
Although Pilsbry (1940: 703) had pointed out
that the finer structure inside the penis should
be investigated, subsequent workers have
ignored this suggestion.

Diodopsis platysayoides and Mesodon clenchi
(Rehder, 1932) had not been dissected
previously, and only fragmentary data had been
published concerning the structures of Ttiodop-
sis divesta and Mesodon dausus (Say, 1821).
New details on the structures of Mesodon bin-
neyanus (Pilsbry, 1899) and Triodopsis
albolabris alleni are presented.

SHELL CHARACTERS

The absence of any major shell differences
between species of Mesodon. Ttiodopsis, and
Allogona that lack apertural barriers has con-
fused students and collectors of the group for
more than a century. Particularly in the
Ozarkian region, several Mesodon and Ttiodop-
sis are conchologically quite similar. They have
differences in the lip and umbilical region, but
most previous illustrations fail to show these
features. New line drawings are presented here
to demonstrate such distinguishing characters.

Triodopsis (Neoheiix) albolabris alleni
(Wetherby) is highly variable in size and color,
ranging as adults from 17-32 mm. in diameter.
The relatively depressed spire, fairly sharp
descension of the body whorl just before the
aperture (fig. 1 a), presence of a thickened
ridge on the basal lip (figs. 1 a, b), and sharply
defined union of the columellar region to the
umbilical covering (fig. 1 b) present a distinct
contrast to the Mesodon (figs. 1 c-h). Triodopsis
(Neoheiix) divesta (Gould) generally is much
smaller in size, mostly 17-21 mm. in diameter.

has a distinctly weaker ridge on the basal lip
(fig. 2 left), shows only slight descension of the
body whorl near the lip, and has a very
gradual merging of the columellar lip into the
umbilical covering (fig. 2 right). Small
specimens of T. a. alleni can be confused with
normal T. divesta, but the differences outlined
above are sufficient to enable identification.

Mesodon binneyamis (figs. 1 c-d) and M. clen-
chi (figs. 1 g-h) differ from each other most ob-
viously in umbilical size, degree of lip reflec-
tion, and body whorl thickness, while M.
clausius (figs. 1 e-f) has a higher spire, narrow
lip, and a more angular insertion of the
columellar lip (fig. 1 J). There is partial size
overlap among these species. M. clausus (10-20
mm. in diameter) normally is smaller than M.
hinneyatiux (16-28 mm.) and M. clenchi (19-23
mm.).

In many places three or more of the above
species are sympatric, at least to the extent of
living on the same slope or in the same ravine.
A compilation of recorded localities in Arkan-
sas, Oklahoma and Missouri for T. divesta, T. a.
alleni, and M binneyanus, for example, showed
that for the 35 T divesta localities, T. a. alleni
also was recorded from 16 of these. Of the 23
localities known for M. binneyanus, T. a. alleni
also has been taken at five, T. divesta at two,
and at an additional two localities, all three
species have been collected. The exact ecological
relationships between these species are
unknown, and a comparative ecological survey
would be well worthwhile.

TERMINAL GENITALIA

The degree to which the terminal genitalia
function in "species recognition" and the extent

28 THE NAUTILUS

January 30, 197fi

Vol. 90 (1)

to which major differences in structures of this
region make hybridization difficult or unlikely
vary greatly from group to group of land
snails. Webb (1952. 1954a, 1954b, 1959, 1961.
1974) has published voluminously on mating
behavior and anatomies of polygyrid snails,
with the cited references only serving as a
locator for his studies. Grimm (1975) reported
evidence of hybridization in the field and many
laboratory crossings among Triodopm, s. .s. The
situation in polygyrids is quite complex. All
this report can do is to focus on some struc-
tural features for future investigation and to
report on some previously undissected species.

leather than present formal descriptions, com-
ments are restricted to comparisons between
structures in order to emphasize features with
potential phylogenetic significance and of use in
classification.

The classic key difference between Mei^adnn
and Ttiodopsis involves the presence in the lat-
ter of a penis sheath (PS) and a continuation
of the penial retractor muscle (PR) from its in-
sertion on the vas deferens (VD) or penis (P)
apex to the penis sheath. This continuation
sometimes is called the "penis retentor
muscle". The length of the sheath varies
greatly, being long in T. plaiysayoides (fig. 3 6),
short in T. divesta (fig. 4 6), and intermediate
in T. a. alleni (fig. 5 a). These differences were

constant in the materials examined. The sheath
in T. plaiysayoides (fig. 3 b) also has a very
unusual muscle attachment, in that it essen-
tially spreads completely around the penis and
onto the inside of the sheath, whereas in the
other species it fastens to one portion of the
sheath wall (fig. 4 b). All Triodopsis dissected
to date agree in having two sections to the penis.
'r\\e upper chamber has one very large pilaster
plus a large microsculpture of papillae, while
the lower chamber, the area below the apex of
the penis sheath, has a series of simple
longitudinal pilasters (PP) that continue into
the atrium (Y). The relative length of the two
chambers varies from species to species (com-
pare figs. 3, 4, 5) and the lower chamber
sometimes shows a distinct difference in
pilaster size below the penis sheath when com-
pared with the area of the penis sheath (com-
pare figs. 3 b. 4 b).

There are obvious and major differences in
the size and spacing of the papillae in the up-
per penis chamber (see figs. 3, 4 and 5). What
has not been recorded previously, is the
variation in apical penis structures. Although
Xolntrema and Neohelix were reported to have
verges (Webb, 1952), any differences in verge
size and form were not recorded or illustrated.
In T. platysnyoides (fig. 3 6) there is no trace of
a verge, while in T. a. alleni (fig. 5 a) the verge

fk;. 3.

Cooper ';

Gciiilnlia (if Ti-iodopsis (T.) platysayoides (Bnmks).
Rdi-k. MniKifidlid C(i.. West Virginia. Leslie

Huhrichl lliStiO: a, tcnnimil iji'ii'dulm: b, iiitcrior af penis
and penis shenlli. Scale lines equal .5 mm.

Vol. f)n (1)

Januarv 30, 197fi

THE NAUTILUS 29

FIG. 4. Genitalia of Triodopsis (Neohelix) divesta (GnuU). minal gcnitatin: b, interior of penis and penis sheath. Scale
FMNH 1/6082, Magazine ML. Logan Co., Arkansax; a, ter- lines eqnal .5 mm.

FIG. 5. Genitalia of Triodopsis (Neohelix) albolabris alleni
(Wetherby) and Mesodon (M.) clenchi (Rehderj: a, c, T. (N.)
a. alleni. FMNH 176127. Tenkiller State Park, SequoyaJi Co.,
Oklalumin. a, interior of peni.s; c, tenninal genitalia: b, d.

M. (M.) clenchi (Rehder). FMNH 176059. Mt. Nebo State
Park, Yell Co., Arkansa.'i; b, juvenile tenninal (/enitalin; d,
ivierior of apical penis region. Scale lines for a-c equal. 5
mm., scale line for d equals 1 mm.

30 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

FIG. 6. Genitalia of Mesodon (M.) clausus (S(niJ. FMSH I7(L'M Calim A'r»A-. hrird Oi.. Arkansas: a, iidiitnlla: b, iiitprior
of penis. Scale lines equal 5 mm.

(PV) is a very large, conical structure with ter-
minal pore. In the often sympatric T. divesta
(fig. 4 b). the verge is a flap-like opening to one
side of the slightly recurved main pilaster and
the pore (PVO) is quite large. The differences
in chamber lengths, papillae size and number,
and verges between T. a. dleni and T. divcsta
probably are sufficient to prevent hybridization.

Equally significant variations can be found in
species of Mesodon. M. clauaus (fig. 6 h) has a
vergic papilla through which the vas deferens
opens and only a single elevated pilaster (P);
M. denchi (fig. 5 d) has two pilasters of equal
size and apparently no vergic papilla; and M.
hinneyanm (fig. 7 e) has two unequal pilasters
that join apically into a flap-like arrangement,
but with the vas deferens entering through a
simple ixire (DP) above the pilaster junction. A
talon (GT) is well developed in M. hinneyanus
(fig. 7 b), but is only a reflexed area in M.
clmisua (fig. 6 a), without being differentiated
from the hermaphroditic duct (GD). All
examined Mesodon had a relatively long vagina
(V), short free oviduct (l^V), spermatheca (S)
with slender shaft, finger-like albumen gland
(GG) and showed no unusual features in the
prostate (DG) and uterus (UT). The ovote.stis
(G) of M. clausus (fig. 6 a) is illustrated, but

most other taxa had this organ in a reduced
stage and it was not studied.

Mesodon binnei/anii.^ (fig. 7) has a very large
penis that is substantially longer than the shell
diameter. Pilsbry (1940: 740. fig. 445, D) used
cross-sections of the penis to establish basic
structures. The more detailed drawings presen-
ted here provide further details of structure.
The apical portion (fig. 7 e) has a short, lower,
second pilaster that gradually merges into the
penis wall. The main pilaster is very high, thin,
and apically forms a flap-like stimulator. In
mid-penis (fig. 7 c) the main pilaster is reduced
in height, thicker, and there are no obvious
subsidiary structures on the penis wall. In the
basal section (fig. 7 d) the main pilaster is
almost circular in shape, becoming flatly ovoid
at the atrium, and there is a complex set of
minor pilasters on the penis wall. Unlike the
situation in M. clausus (fig. 6 b) there is no
pilaster-ft-ee basal area to the penis.

JAW AND RADULAR STRUCTURE

A strongly ridged jaw with denticulated
lower margin is characteristic of the
Polyg>-ridae. No study of jaw variation in rib-
bing or microstructure has been published.
References to the jaw usually are restricted to

V.il. 90 (1)

Janiuirv :M). li»7«

THE NAUTILUS 31

FIG. 7. Genitalia of Mesodon (M.) binneyanus /Pilxhnj).
FMNH 176008. Rich Mt.. Polk Co.. Arkansas: a, tei-mind
!/i'iiitnli<i: b, apical genitalia excltutive of omte.'iti.t: c, in-

terior of mid-penis region: d, interior of basal portion of
penis: e, interior of penis apex. Scale tines equal 5 mm. for
b-e and 10 mm. for a.

a few outline sketches indicating rib numbers
(see Pilsbry, 1940: 912, fig. 522). The jaw of
Triiidopfiis alholabris alleni (figs. 8-10) is
illustrated here to show the typical shape (fig.
8), to demonstrate the wear surfaces on the
denticulated lower margin (fig. 9), and to in-

dicate that the jaw structure is fibrous in
nature (fig. 10). Examples of the other species
studied showed no significant differences. In-
deed, the jaw microstructure is very similar to
that of the helminthoglyptid Humboldtiana
fuUingtoni Cheatum, 1972 from Texas (see

32 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

Solem, 1974: figs. 3-5). Both series of
photographs clearly show the horizontal in-
cremental pattern of jaw growth and demon-

strate the interlocking, basically vertical orien-
tation of the microfibers.

Radular data on polygyrids is equally

^^Kt^^^^tM ^^^^^^^^P9 ^^^^^^^^^ *^^^^p

!Pr

^^H^f^'_^^^^S

ii

wSKtBk

Wi"^^

FIGS. 8-13. .laie and niduhv tfpth. Figs. 8-10. Jaw of
Tri(x)opsis (Nfohelix) albolabris alleni (Wetherby). FMNH
176127. Fig. 8. Kntirc jaw. lower maryiii nt top of fiipirr.
9JX. Fig. 9. Detail if two ridi/es on lower niaryiri atid in-
ter-ridge area. ■i75X. Fig. 10. Fibrous area between tiro
ridges shown in Fig. 9. greatly etdarged. 5.725X. Figs. 11-12.

Radular teeth of T. (N.) a. alleni (Wetherby). FMNH
17(il27. Fig. 11. Transition zone between lateral (upper) and
marginal (lower) teeth near p<isterior end of nulula. ■I7I)X.
Fig. 12. Central (tricuspid) and early lateral teeth. 62.5 X.
Fig. 13. Central and early lateral teeth of Triodopsis (T.)
platysayoides (Brooks). Leslie Hubriclit 11860. 350X.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 33

meagei'. Pilsbry (1940: 703) summarized report-
ed variation in Mesodon, where several species
apparently lack ectocones. I suspect that this is
partly individual variation and partly results
from the deficiencies of optical viewing.
Mesodoii clausus, for example, is supposed to
lack ectocones on all but the outennost
marginals, yet traces can be seen (figs. 26-27)

on the first laterals and there are prominent
ectocones on the outer teeth (figs. 28-29). M
r/(;//.svw does differ in having the cusps on the
outer marginals serrated (fig. 29), but even this
may be subject to individual variation.

The prominence of the side cusps on the
rachidian (central) tooth vary from the large
and conspicuous ones found in M. clenchi (up-

nO%^-

-•^^^^

^

17

FIGS. 14-19. Kadular teeth. Figs. 14-17. Triodopsis (T.)
platysayoides (Bmoks). Leslie Huhrieht IlfiiKl. Fig. 14. Part
nnr itf teeth, not including miter marginals. UOX. Fig. 15.
Tinnsitian zcne between laleral.'i and maniiiials. .!J,.5X. Fig.

16. Outer marginals. 355X. Fig. 17. Outermost marginals.
.i.55X. Figs. 18-19. Mesodon (M.) binneyanus (Pilsbry). FM-
NH 176008. Fig. 18. Outermost marginals. S.S2X. Fig. 19.
Transition betiveen laterals and marginals. Si2X.

34 THE NAUTILUS

January 30. 1976

Vol. 90 (1)

FIGS. 20-25. Rmhdar teeth. Figs. 20-21. Mesodon (M.) bin-
neyanus (Pil.ibryj. FMNH 171101)8. Fig. 20. Central and 1st
lateral teeth. 670X. Fig. 21. Ti-ansitional between lateral
(upper left) and man/inal (lower right) teeth. S95X. Figs.
22-25. Mesodon (M.) clenchi (Rehder). FMNH 176059. Fig.

per left of fig. 22) and THodopsis albolabris
alleni (fig. 12), to a total absence in T.
platysayoideK (fig. 13). M. dmmis (fig. 26) and
M. binneyanua (fig. 20) are intermediate in cusp
prominence. Ectoconal size on the early lateral
teeth correlates with the side cusp prominence on
the central tooth. If the central tooth has
prominent side cusps, the laterals have a
prominent ectocone, and small cusps occur on

22. Central and early lateral teeth. 762X. Fig. 23. Ti-an-
sition between lateral (left) and marginal (right) teeth.
.505 X. Fig. 24. Transitional change in basal plate structure
between laterals (left) and marginals (right) 5-i5X. Fig. 25.
Outermost marginal teeth. SOOX.

both at the opposite extreme (see figs. 12, 13,
20, 22, 26). These same illustrations show that
the pattern of interrow tooth support for the
central and early lateral teeth is nearly iden-
tical. The anterior flare on a lateral tooth un-
der stress fit neatly into a groove on the outer
side of the basal plate on the next anterior
lateral tooth (see figs. 12, 13, 20, 22, 26, 27).
The central tooth has a raised buttress on each

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 35

FIGS. 26-29. Radular teeth of Mesodon dausus (Say). FM-
.\H 176220. Fig. 26. Centnd and fiist lateral teeth. 59.5X.
Fig. 27. Central and early lateral teeth seen from a law

posterior iriewing angle. 1,25'K. Fig, 28. Transition between
laleral and marginal teeth. .J?.5X. Fig. 29. Mid-marginal
and outer marginal teeth. 365X.

side of the basal plate. Because of the angle at
which these photographs were taken, the im-
pression is given that the anterior flare of the
lateral tooth is not or only slightly curved up-
wards. In fig. 23, the angle of view is such that
the upward curve (see left side of photograph)
of the anterior flare is more evident.

The change from lateral to marginal teeth in-
volves a number of alterations. Fig. 11 shows
clearly the higher angle of the cusps in the
laterals (upper), with the change to a much
lower angle in the marginals (lower) occurring
in just a few teeth. Seen in more vertical view
(figs. 14, 1,5, 19, 21, 23, 28), the coherent pattern
of cusp change that involves narrowing and
elongating the mesocone, an increase in ec-
toconal prominence, change in shape for the an-
terior flare, often (figs. 15, 28) a centerwards
shift in angle for the mesocone, and appearance
of a small endocone, is clearly demonstrated.
The change in the basal plate, which involves
shortening, first reduction and then loss of the
support ridge, then gradual elimination of the
anterior flare, is shown in figs. 24 and 28 par-

ticularly well because of the viewing angle (fig.
24) and partly torn radula (fig. 28).

The marginal teeth, particularly the outer-
most (figs. 17, 18, 23, 25, 29) ones, can become
multicuspid, normally show endoconal develop-
ment, and may become quite shortened and
probably are almost without function in
feeding. They are held parallel to the basal
membrane, which is quite in contrast to the
high elevation of lateral teeth (figs. 11, 20).

In terms of basic structure and pattern of
functioning, the radulae examined here show no
major differences between species, much less
between genera. The different angles of view do
permit interpreting functional aspects. Several
species have been illustrated to emphasize their
essential similarity.

DISCUSSION

Particularly within Triodopais, the variation
in verges, papillae of the upper penis chamber,
penis sheath length and muscle attachment,
present characters potentially of high value in
assessing relationshif)s. Radular cusp variation

36 THE NAUTILUS

January 3n. 1976

Vol. 90 (1)

is greater within Mesodon and TriodopsiH than
between the two genera. Shell differences be-
tween the svTnpatric taxti involve growth pat-
terns and rolumellar-umbilical region structures.

Triodopsis platysayoides is a rare and pf)ten-
tially endangered species, but Mefmdun clenrhi
was found to be more widely distributed than
had been suspected and it seems in no danger
of extinction at the present time. The other
species discussed here have wide distributions
and may be considered common at the present
time.

Because the barrier-free Mes^odon and
Tfiodopds of Missouri, Arkansas and Oklahoma
are widely distributed, frequently sympatric.
usually highly variable in size and rolor, they
present excellent potential for studies of
ecological differences under sympatry and for
variational analysis.

LITERATURE CITED

Grimm, F. W. 197.5. Speciation Within the Tiiodapxis fdUu
Group (Pulmonata : Polygyridae)— A Preliminary Re-
port. Bull Amn: Malac. Unimi. Im:. 1974: 23-23, .3 figs.

Pilsbry. H. A. 190.3. Mollusca of Western Arkansas and

.Adjacent States, with a Revision of Paravitrea. Pnc.

Aaul. Nat. Sei.. Philadelphia, 1903: 19.3-214. pis. 9-11.
Pilsbri', H. A. 1940. Land Mollusca of North America

(North of Mexico). Acad. Nat. Sci.. Philadelphia. Monog.

.3. 1(2): iii-vi, 575-994, figs. 278-580.
PiLsbn.'. H. A. and .J. Ferriss. 1907. Mollusca of the Ozark-

ian F^auna. Proc. Acad. Nat. Sci.. Philadelphia. 1906:

.t29-.%7. pis. 20-22, figs. 1-.5.
Solem, A. 1974. On the Affinities of Humhuldtiana fulling-

timi Cheatum. 197Z TYie Veliger, 16(4): .359-.36.5, figs. 1-14.
Vagvolgyi, .J. 1968. Systematics and Evolution of the Genus

Trii}d(ipsis (Mollusca : Pulmonata : Polygyridae). Bull.

Mux. Cmnp. Zmi. 136(7): 145-254, pis. 1-6. figs. 1-27.
Webb, G. R. 1952. A Sexological Revision of Some Trio-

dopsin land-snails, Xidotrema, Neohetic. & WUaixorbis.

(kuitnipiidia. 1(1): 7-8.
Webb. G. R. 19.54a. The Life-histor>- and Sexual .Anatomy

Data on A.'ihmunella with a Revision of the Triodopsin

Snails. Gastropudia, 1(2): 1.3-18.
Webb. G. R. 1954b. Pulmonata, Polygyridae, Polygyrinae :

TTie Sexology and Taxonomy of Seven Species of Land-
snails of the Genus Mesodon. Gastropudia, 1(2): 19-21).

pi. 12.
Webb. G. R. 19.59. Notes on the Sexolog>' of 7>Ti(/'ip.<fi.s. a

New Subgenus, Haraidnrhi^t. and a New Section, She!-

thriliirbi.i. (hxtnipodin. 1(3): 2.3-2.5.
Webb. G. R. 1961. The Phylogeny of American I^nd Snails

with Emphasis on the Polygyridae. Arionidae. and .Am-

monitellidae. Gastrtipadla. l(4-.5): 31-44.
Webb, G. R. 1974. The Sexual Evolution of the Polygyrid

Snails. Gn.'^tmp.dia. 1(9): 8.5-f)0.

TREMATODE PARASITISM IN THE SPHAERIIDIDAE CLAMS,
AND THE EFFECTS IN THREE OTTAWA RIVER SPECIES

G. L. Mackie

Department of Zoology. University of Guelph,

Guelph, Ontario, Canada

NIG 2W1

ABSTRACT

TJiere /.s a seasonal occurrence of rediac of the trematode. CrepidostoniimT
cooperi Hopkins, in the diqestive gland of Musculium securis (Prime) in Britan-
nia Bay of the Ottawa River near Ottawa, Canada. Growth and longevity of in-
fected clams do not appear to be affected hut reproduction is iisiialh/ inhibited.
Similar effects seem to occur in parasitized specimens of Musculium trans-
versum (Scrii) and Sphaerium striatinum (Loman-kl. A rericir if the incidence
of trematode parasitism in Sphaeriidae is given.

INTRODUCTION

While the incidence of trematode parasitism
in Sphaeriidae is well documented (see Table 3),
there is very little known on the effects of this
parasitism. The purpose of this study is to

examine the effects of trematode parasites on
growth, longevity, and reproduction in
Musculiiim securis, Musculium transversum, and
Sphaerium striatinum that were collected
seasonally from Britannia Bay in the Ottawa

!•() (1)

January 30. 1976

THE NAUTILUS 37

River near Ottawa. A review is given to bring
together all studies that relate to trematode
parasitism in Sphaeriidae.

MATERIALS AND METHODS

A standard Ekman grab (L5 cm X 15 cm,
with screen on top) was used to take quan-
titative samples of the population of M. securis.
Grab samples were taken from the 3 to 4 m
depths until at least 30 specimens were collect-
ed. Collections were taken for three years from
May, 1970 to May, 1973 in usually two-week in-
tervals in the summer and one-month intervals
in the winter. A total of 1,764 specimens of M.
securis were examined for trematode parasites.
In addition, 123 specimens of M. transversiim
and 158 specimens of S. striatimim were collect-
ed from the 1 to 3 m depths in the same man-
ner from May to November, 1971 and 1972,
respectively, and examined for parasites. The
lengths (mm, anterior to posterior), heights
(mm, top of umbone to ventral edge), number
of concentric annuli (for S. striatimim only),
and the numbers of brood sacs and larvae per
sac were determined on all specimens (the num-
ber of annuli were not determined for M.
securis or M. trcmsversum because they have
only a one-year life span).

THE STUDY AREA

Fifteen species of sphaeriids are present in
Britannia Bay; M. transversum and S.
striatinum are common species in the 1 to 3 m
depths and M. securis is dominant in the 3 to 4
m depths (Mackie, 1971; Mackie and Qadri,
1973). Other common benthic species include the
oligochaetes, Urwinais undnata and Peloscolex
sp., the amphipods, Hyalella azteca and Gam-
mants fasciatiis, the mayfly, Hexagenia sp.
(especially in the 3 to 4 m depths), the dam-
selfly, Enallagma signatum, the chironomids,
Pseudochironomus, and Dicrotendipes, and the

gastropods, Lymnaea catascopium, Amnicola
limosa, and Valvata tricarinata. The mean sum-
mer temperature (18 C) is reached in mid-June.
Other physical and chemical characteristics of
the water are given in Mackie (1973). Several
species of fish are present in Britannia Bay,
the most common being catfish, Ictalurus punc-
tatus, walleye, Stizostedion vitreum, and pike,
Esox lucius.

EFFECTS OF PARASITISM

The trematodes in M securis and M. trans-
versum were identified as Crepidostomum
cooperi Hopkins, 1931. A specific identification
of the trematodes in S striatinum was not
made but they also belonged to the genus,
Crepidostomum. Redial stages were found
developing only in the digestive glands. No
other life history stages were found. The rediae
contained ophthalmoxiphidiocercariae which
escape into the water and encyst in mayfly
njTTiphs (Gibson, pers. commj. Hopkins (1934)
cites Hexagenia sp. as the second intermediate
host of C. cooperi; this genus is very common
in Britannia Bay, especially in the 3 to 4 m
depths. Adults of C. cooperi are common in
many species of fish, including catfish and
walleye (Gibson, pers. comm.) which are also
abundant in Britannia Bay.

There was a seasonal occurrence of the redial
stage in M. securis (Table 1) and only adults
longer than 3.50 mm were infected. An in-
sufficient number of M. transversum and 5.
striatinum were infected to permit a deter-
mination of seasonal occurrence of parasitism
but only adults longer than 5.00 mm contained
rediae. In M securis, parasitism occurred with
maximum frequency in late July and early
August. The percentages given in Table 1 are
based on infected adults that were alive at the
time of sampling. Empty shells of M. securis
commonly appeared in samples collected in July

TABLE 1. Percentayc of parents of Musculium securis that were parasitized in the simmer months of 1970. mi. 19/2. Only
dams collected in .My. August, and September were para.<titized uith rediae.

1970

1971

1972

July
13

July
29

Aug.
18

July
15

July Aug.
29 3

Sept.
2

July
5

July Aug.
17 20

Sept.
2

22.8

27.8

5.0

ZO

13.3 25.0

4.0

40

20.0 21.8

20

38 THE NAUTILUS

January 'M), 1976

Vol. 9(1 (1)

TABLE 2. Mean lenythx (mm) nf three, species of parasitized and luinparasitized fingernail clams in their last month of life
or with (me anmdxts. The numbers of specimens examined are in jxirentheses.

Species

Nonparasitized clams

Parasitized dams

Mtiscidium secmis
Miisculiuni transversum
Sphaeriitni siriatinum

4.09 (38)
7.81 (24)
10.10 (.32)

4.39 (12)
7.63 (8)
9.77 (5)

and August but it is not known whether
natural causes or parasitism brought about the
death of these clams. Only 16% of M trans-
vermim and 12% of S. stiiatinum were in-
fected. The only parasitized clams of M. trans-
versum were found in collections taken in July
and August and of S striatinum in September
and October.

Adult specimens ofM securis as long as 5.50
mm, of M. transversum as long as 8.13 mm,
and of S striatinum as long as 9.05 mm were
parasitized, suggesting that parasitism did not
affect the growth of clams. Moreover, the mean
lengths of parasitized and nonparasitized clams
did not appear to differ substantially (Table 2),
although it is possible that infected clams had
been parasitized only recently. However, if
development of the intramoUuscan phase
requires only 40 to 50 days, as for many
gorgoderids which also parasitize sphaeriids
(Olsen, 1967), then M. securis and M. trans-
versum would have to be parasitized very
early in life, perhaps even during larval life,
since they require 35 to 60 days to grow from
birth to adulthood (Mackie et al. 1975; Gale,
1969).

Both M. securis and M transversum have a
one-year life span and the adults die in the fall
after producing their young (Mackie et al. 1975;
Gale, 1969). The presence of parasitized adults
of both species during August indicates that the
longevities were not strongly affected by
trematode parasites.

Sphacrium striatinum lives for 18 to 24 months
(Avolizi, 1971) and it was more difficult to
study the effects of parasitism on growth and
longevity because of overlapping generations in
Britannia Bay. However, using annuli in the
shell as an indication of age, adults that were
more than one year old were parasitized but
were of similar size as the noninfected clams
(Table 2). If these clams were parasitized only

recently then parasitism occurred so late that
the growth of the clams would have been
almost complete and any effects of parasitism
on growth and longevity would not have shovm.

Parasitism by C. cooperi appears to have its
greatest effect on the reproductive capacities of
sphaeriids. Of the parasitized adults of M.
securis, approximately 96% were devoid of
brood sacs; the remaining 4% contained brood
sacs but larvae were either absent or poorly
developed. Uninfected adults of the same age
and length class contained 3 to 6 brood sacs
with 2 to 8 larvae per sac. Also, the gonads
could not be found in two parasitized clams.
All other parasitized specimens appeared to
have their gonads intact. It was not determined
if gametogenesis in the intact gonads was
inhibited as in other mollusks (Cheng and
Snyder, 1972).

Of the parasitized adults of M. transversum
and S. striatinum none contained brood sacs
even though nonparasitized adults of the same
size classes were gravid with 2 to 14 larvae in
3 to 6 brood sacs. Gale (1973) also reported the
absence of embryos in parasitized clams of M.
transversum. Cheng and James (1960) attributed
the death of adults of S. striatinum to the
destruction of the clam's hepatopancreas after
repeated infections with Crepidostomum cor-
nutum. Other sphaeriids appear to be similarly
affected. Meier-Brook (1970) found larval
trematodes in Pisidium nitidum, Pisidium sub-
tnirwatum. Pisidium milium, and Pisidium con-
ventus and concluded that Crepidostomum sp.
affects the reproductive ability (and longevity)
of P. nitidum. Heard (1965) reported a lack of
embryos in parasitized specimens of Psidium
casertanum and Pisidium compressum. The ef-
fects of larval trematodes on other bivalve and
gastropod hosts has been reviewed by Cheng
and Snyder (1972).

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 39

REVIEW OF TREMATODE PARASITISM IN
SPHAERIIDAE

Sphaeriids are common intermediate hosts for
several species of digenetic trematodes. Only
two families, the Allocreadiidae and
Gorgoderidae, contain species that require
sphaeriids for development of the sporocyst,
rediae, and/or cercariae.

In the family, Allocreadiidae, miracidia
penetrate the gill filaments and the mantle
where they transform into sporocysts (although
this developmental stage has never been found
(Olsen, 1967)) and then into rediae. The rediae
contain either daughter rediae or cercariae, or

both, with large rediae usually infesting the
hepatopancreas (Olsen, 1967). The cercariae,
having eyespots, a stylet, and thick-walled
excretory vesicle are known as ophthal-
moxiphidiocercariae (Schell, 1970). At least
13 species of allocreadiids use sphaeriids as
the first intermediate host. Table 3 lists the
species of Sphaeriidae in which parasites have
been found and gives the second intermediate
hosts and final hosts for each parasite.

The miracidia of the family Gorgoderidae are
active swimmers and enter fingernail clams in
the incurrent water flowing through the bran-
chial siphon. Upon penetrating and entering the

TABLE 3. Incidence nf trematode parasitism in Sphaeriidae and other hosts nf the parasites.

Sphaemd .s7>frif.s-

Trematode species

Second intermediate host

FmaJ host

Reference

Sphaenmii comeum

Ailocreadnim isoporum

Mayflies

Fish

Dollfus (1949)

S ainteum

Crepidiistomum transmarinum

Mayflies, Amphipods

Salmon (Salm)}

Dollfus {1949)

S. comeum

B}ttu>dera lucxpercae

Cladocera. Qstracoda.

Fish

Wisniewski (1958)

Copepoda

S. Comeum

PhyllixUstumum simile

Odonata. Trichoptera

Bmwn trout (Salmo trutta)

Tliomas (1958)

^haerium nccidentale

AUficreadiuvt neotenicum

None

Beetles (Dytiscus. Anlius)

Crawford (1940a). Peters (1955.
1957). Schell (1970)

S. 'KTulentnlf

Gorgoderim attcnunta

Tadpoles

Amphibians (Rfina. TrituriL-i)

Rankin (19.39)

^haeriian rivicnla

A- isoponmi

Mayflies

Fish

Dollfus (1949)

S liivola

B lucwpercae

Cladocera. Cfetracoda.

Fish

Wisniewski (1958)

Copepoda

^haeninti striatimnn

C)Tpidostn7num ciiniiitum

Mayflies

Crayfish

Ameet (1937), CTieng & James
{I960)

S. stnatinum

Crepidostomum isotmnum

Mayflies

Perch fPerca)

Hopkjns (19.34)

Miwiculium larvstre'

Phyllodistomum stoffordi

Ifemselflies.

Trichoptera

Bmwn Bullhead (letaJiirus nebido-

Schell (1967)

Miuiculium partumeiitm

Gorgndera umplicavn

Snails

sia<)
Amphibians (Rana. Bufn, Am-

byatomn)

Goodchild (1948), Krull (19:15)

M. partumemm

Phyllodistomum caudatum

Unknown

Black Bullhead (Ictalurm melaa)

Beilfuss {1954)

M^isculium secitris

Crepidostomum coopen

Mayflies?

Catflsh (Irtiilurusf^

TTiis study (intermediate and
final hosts not confirmed)

\fusculium tnimversiim

C comutitm

Mayflies

Crayfish

-Henderson (1938). Hopkjns (1934).
Abernathy (19.37)

M. transversvm

C rnnperi

Mayflies

Fish

Hopkins (19.34). Olsen (1%7). This

study
Hopkins (1934)

M. transverstim

Megalogoma wtaluri

Mayflies

Bullheads (Ictalurus. Micropterus.

Noturus)

M. transversum

Phyllodistomum lohrenzi

Trichoptera

Green Sunflsh (Lepnmis cyatiellus)

Beilfuss (1954)

Pisidium ammcum

Crepidtistomum farionis

Mayflies. Amphipods

Salmon (Salmo)

Brown {1927}

Pisidium casertanum

Allocreadium alloneotemciim

Snails

Trichoptera (Limnephilus)

Wooton (1957)

P. casertanum'

C. r/ioperi

Mayflies

Trout (Salvelinus fontinalis)

Choquette (1954)

P casertanum^

Phyllodistomum solidum

Dragonflies

Salamanders (Desmognathus.
Bu rycea).

Goodchild (1943. 1946). Groves
(1945)

P. casertanum'

Bunoderina eucaiiae

Unknovm

Fish (Eucalxs 'inconstans. Umbra
limi)

Hoffman (1955)

IHsidium compressum

C cooperi

Mayflies

Trout (S. fontinalis)

Choquette (1954)

Pisidium ida^ioense

Bunoderella metteri

Trichoptera.

Chironomidae

Tailed Frog (Ascaphus truei)

Anderson, Schell & Pratt {1965)

PiHdium UUjpbnrgi

C cimpen

Mayflies

Trnut IS fnntinalisf

Choquette (19M)

Pi.fi(l)iim mttdum

C cnoperi

Mayflies

Trout (S. fontinalis}

Choquette (1954)

Psidium aubtntncatum

C aioperi

Mayflies

Triiul (S fontinalifj

Choquette (1954)

Pisidium spp.

Phyllodistomum americanum

Ctemselflies,

Trichoptera

Amphibians (Bnfo boreas. Ambys-
ttyma tigrinum)

Crawford (1954)

Pistdtum sp.

Allocreadium lobattan

Amphipods

Fish (Semotilus atromaculata,
Catostomus commercomj

Degiusti (1962)

'Cited by Schell (19«7| as ,W ryckJwlti

' Cited by Goodchild (19431, Groves (194.5), and Choquette (1954) as P. abditum

' Cited by Hoffman (1955) as P. m>V€ixtnucense

40 THK NAl'TILUS

January 30, 1976

Vol. 90 (1)

gills, the miracidia transform to mother
sporocysts. Development of daughter sporocysts
requires 40 to 50 days. The daughter sporocysts
become ventrally located between the inner and
outer lamellae of the inner gills of the clams
and contain fully developed cystocercous cer-
cariae. The cercariae have a tail with a cham-
ber at one end and encloses the larval fluke.
The cercariae are released into the suprabran-
chial chamber of the clam and are then ex-
pelled with the excurrent water through the
anal siphon (Olsen, 1967). At least 7 species of
gorgoderids require sphaeriids as the first in-
termediate host (Table 3).

From a study of Table 3, it is worthwhile
noting that, with the exception of only a few
species, especially C. cooperi. only one parasitic
species has been found in a single species of
sphaeriid. This may indicate that either there is
some degree of host specificity or that an in-
sufficient number of sphaeriid populations have
been examined to show that there is in fact
more than one parasitic species of trematodes
per species of fingernail clam.

ACKNOWLEDGMENTS

The author is grateful to Dr. G. Gibson of
the Canadian Wildlife Services, Environment
Canada, Ottawa, and to Dr. M. Beverley -Burton
of the University of Guelph for identifying the
parasites. A portion of this research was done
at the University of Ottawa, Ottawa, on Grant
No. A-2386 awarded to Dr. S. U. Qadri by the
National Research Council of Canada. A large
portion of the research was supported by the
Research Advisory Board, University of Guelph,
Grant No. 695-16.

LITERATURE CITED

Abernathy, C. 1937. Notes on Crepidnstmnum conudnm
(Osborn). Trans. Am. Microsc. Soc. 56: 206-207.

Ameel, D. J. 1937. The life history of Crepidostomum comu-
tiim (Osborn). .hmr. Fhraxit. 23: 218-220.

Anderson, G. A., S. C. Schell, and I. Pratt. 196.5. The life
cycle of HuiuKhrcUn mvtti'ri (."Miocreadiidae: Bunoderi-
nae). a trematode parasite of Ascaphus tniei. Jmir. Para-
sit. 51: 579-582.

Avolizi, R. J. 1971. Bioma.ss turnover in natural popula-
tions of viviparous sphaeriid clams. Ph.D. thesis. Syracuse
Univ., Syracuse, New York. 154 p. Univ. Microfilm No.
71-23429, Ann Arbor, Michigan.

I5eilfuss, E. R. 1954. TVie life histories of Phi^lndistomum

Idhrfiizi Ijoewen, 1935, and P. caudaium Steelman, 1938
(Trematoda: Gorgoderinae). Jour. Piirasit. 40 (Sect. 2):
44.

Brown. F. J. 1927. On Crepuitistiimum farionis 0. F. Mull.
{=Stfpliani>phiala laureata Zeder), a distome parasite
of the trout and grayling. I. The life history. Parasitology
19: 86-99.

Cheng, T. C. and H. A. James. 1960. The histopathology of
Crepidostomum sp. infection in the second intermediate
host, Sphaerium striatinum. Proc. Helminth. Soc. Wash.,
27: 67-68.

Cheng, T. C. and R. W. Snyder, Jr. 1962. Studies on host-
parasite relationships between larval tremat(xies and
their host.s. I. A review. II. Host glycogen utilization by
the intramollu.scan larvae of Gli/pthetmins pennsylvanien-
sis Qieng and associated phenomena. Trans. Amer. Mi-
crosc. Soc. 81: 209-228.

Choquette, L. P. E. 1954 A note on the intermediate hosts
of the trematode, Crepidostomum coopen Hopkins. 1931.
parasitic in speckled trout (Stdvetinus fontmalt.s Mitchell)
in some lakes and rivers of the Quebec Laurentide Park.
Can Jour. Zool. 32: 375-377.

Crawford. W. W. 1939. Studies on the life histories of Colo-
rado tremattxies. Jour. Parasit. 25 (Sect. 2): 26,

1940a. An unusual case of a sexually mature trema-
tode from the body cavity of a diving beetle. Jour. Para-
sit. 26 (Sect. 2): 32.

194()b. The life historj- of a gorgoderid trematode,

presumably of the genus PhyHodistonmm. Jour. Parasit.
26 (Sect. 2): 38.

Degiusti, D. L. 1962. Ecological and life historj- notes on
the trematode AUocreadium lobatum (Wallin. 1909) and
its occurrence as a progenetic form in amphipods. Jour.
Parastt. 48 (Sect. 2): 22.

Dollfus, R. 1949. Sur une cercaire ophthalmoxiphidiocerque
Cerrarin isopori A. Loess 1894 et sur la delimitation des
Allocreadioidea. Ann. Parasit. 2A: 424-435.

Gale, W. F. 1969. Bottom fauna of Pool 19, Mississippi
River with emphasis on the life history of the fingernail
dam, Sphaerium transversuni. Ph.D. thesis, Iowa State
Univ.. An.es. Univ. Microfilm No. 69-20642, Ann Arbor,
Mich.

1973. Predation and parasitism as factors affecting

Sphaenuni transverum (Say) populations in Pool 19, Mis-
sissippi River. Res. Popul. Ecol. 14: 169-187.

Goodchild, C. G. 1940. The life history of Phyllodistomum
soldum Rankin, 1937 (Trematoda: Gorgoderidae). Jour.
Parasit. 26(Sect. 2): 36.

1943. 'Rie life history of Phyllodistomum solidum

Ranklin, 1937, with observations on the morphologj-,
development and taxonomy of the Gorgoderidae (Trema-
toda). Riol. Bull. 84: 59-86.

1948. .'Additional observations on the bionomics and

life history of Goyndera ami)tiaiv(i IjOo.ss, 1899 Trema-
toda: Gorgoderidae). Jour. Parasit. 34: 407-427.

Groves, R. E. 194.5. An ecological .study of Phylliidistimium
snlidum Rankin, 19:37 (Trematoda: Gorgoderae). Trans.
Ame>: Miavsc. Soc. 64: 112-132.

Heard, W. H. 1965. Comparative life histories of North
American pill clams (Sphaeriidae: Pisidium). Malacologia
2: :381-411.

Vol. 9(1 (1)

January 30, 1976

THE NAUTILUS 41

Henderson. H. E. UW. Hie cercaria of Crepidi>st(imuni
ainiutum ((3sb>rn). Ti'diix. Anier. Microsc. Soc. 57: l(i5-
172.

Hoffman. G. L. 1955. Notes on the life cycle of Bunodem
eiwaliae Miller (Trematoda; AUocreadiidae) of the stickle-
back, Ehicalia inconstans. Proc. Iowa Acad. Set. 62: 638-
639.

Hopkins. S. H. 1934. The papillose AUocreadiidae. A study
of their morpholog>'. life histories, and relationships.
Univ. m. Bull. 32: 47-124.

Krull, W. H. 1935. Studies on the life history of a frog
bladder fluke, Goiyodera amplicava Looss, 1899 (Trema-
toda: Gorgoderidae). Papers Mich. Acad. Sci.. Aii mid
Lettfis 20: 697-710.

Mackie, G. L. 1971. Some aspects of the distribution and
ecolog>' of macrobenthos in an industrialized portion of
the Ottawa River near Ottawa and Hull, Canada. M.Sc.
thesis, Univ. Ottawa, Ottawa, Ontario. 161 p. Available
from Can. Theses on Microfilm, No. 10692, National Li-
brary of Canada, Ottawa.

1973. Biology of Muscidium sectiris (Pelecypoda:

Sphaeriidae) in two temporary forest ponds, a river, and
a permanent pond near Ottawa, Canada. Ph.D. thesis,
Univ. Ottawa, Ottawa, Ontario.

Mackie, G. L. and S. U. Qadri. 1973. Abundance and dis-
tribution of MoUusca in an industrialized portion of the
Ottawa River near Ottawa-Hull, Canada. Jour. Pish. Res.
Board Can. 30: 167-172.

Mackie, G. L.., S. U. Qadri, and A. H. Clarke, Jr. 1976.
Intraspecific variations in growth, birth periods, and
longevity of four populations of Muscidium secu.ris (Pe-

lecypoda: Sphaeriidae) near Ottawa, Canada. Malacologia
15(2): in press.

Meier-Br(K)k, C. Untersuchungen zur biologie einiger Pi-
.'iidi urn — Arten (Mollusca; Eulamellibranchiata; Sphaerii-
dae). Arch. Hydrohinl. Suppl. 38: 73-1.50.

Peters, L. E. 19.5.5. Morphology of the adult and the niii'a-
cidium of a progenetic species of Allocreadium from
water beetles of the family Dystiscidae. Jour. Parasit.
41 (Sect. 2): 26.

1957. An analysis of the trematode genus Alio-

creadium Looss with the description of Allocreadium neo-
tenicum sp. nov. from water beetles. Jour. Parasit. 43:
136-142

Rankin, J. S., Jr. 1939. The life cycle of the frog bladder
fluke, Gonjoderina attenuata Stafford, 1902 (Trematoda:
Gorgoderidae). Amer. Midi. Naturalist 21: 476-488.

Schell, S. C. 1967. The life history of PhiJIiKlt.ttnmum st({f-
fordi Pearse, 1927 (Trematoda: Gorgoderidae Looss, 1901).
Jour. Parasit. 53: .569-.576.

1970. How to Know the Trematodes. Wm. C. Brown

Co. Publ., Dubuque, Iowa. 3.55 p.

Thomas, J. D. 1958. Studies on the structure, life history
and ecology of the trematode Phytbdistomum simUe
Nybelin 1926 (Gorgoderidae: Gorgoderinae) from the uri-
nary bladder of brown trout, Salmo trutta L. Pruc. Zool.
Soc Londtm 130: 397-4.35.

Wisniewski, W. L. 1958. The development cycle of Buno-
dera hiciopercae (0. F. Muller). Acta Parasit. Polon. 6:
289-307 (as cited by Anderson, Schell and Pratt, 1965).

Wooton, D. M. 1957. Studies on the life history of Allo-
creadium alloneotenicus sp. nov. (AUocreadiidae Tre-
matoda). Biol. Bidl. 113: 302-31.5.

THE GENUS EPIROBIA IN CHIAPAS, MEXICO

Fred G. Thompson

Florida State Museum

University of Florida

Gainesville," Florida 32611

The genus Epirobia consists of small slender
urocoptoid land snails that are found character-
istically on limestone in wetter areas of eastern
Mexico and northern Guatemala. The descrip-
tion of two new forms is presented so that they
may be included in a report on the land mol-
lusks of Chiapas by Allyn G. Smith. I wish to
express my appreciation to him for allowing
me to examine pertinent material in the collec-
tions of the California Academy of Sciences
(CAS). Other material cited in this paper is
deposited in the Florida State Museum, Uni-

versity of Florida (UF) and the Delaware Mu-
seum of Natural History.

Epirobia swiftiana alternans new subspecies
Fig. 1, c and d. Fig. 2, a.
Shell. — Elongate fusiform-turreted, thin, tran-
slucent. Spire complete; upper % of spire
gradually tapering to the third or fourth from
last whorl; shell 0.19-0.21 times as wide as
long; narrowly umbilicated. Color light brown
with alternating patches of white ribs. Whorls
19.5-20.5 (20.2 in holotype). Suture moderately
impressed, not crenulate. Embryonic whorls 2.9-

42 THE NAimmS

Jamiarv .'^O. 197B

Vol. 90 (1)

FIG. 1. Epirobia lurida new species, a, hnlntype 16.S mm., b, paratope. Epirobia swiftiana alternans «<»?/' subspecies, c,
hiitiit ijpr. d, pamti/pe.

3.4 (3.1 in holotype), relatively weakly arched,
smooth and nearly equal in size. Following
whorls nearly uniformly rounded at periphery,
more so near sutures. Neck of last whorl round-
ed, below, without any indication of a basal
keel. Whorls sculptured with clusters of narrow,
graceful, sigmoid white ribs. Clusters separated
from each other by nearly equally wide smooth
zones. About 3-10 ribs per cluster and about 5-6
clusters per whorl on lower whorls. Ribs about
half as wide as their intervals. Rib intervals
and smooth zones light brown. Aperture free
from preceding whorl, projecting forward and
offset laterally. Aperture broadly ovate, slightly
higher than wide, slightly oblique; about 0.60-
0.69 times the width of the last whorl.
Peristome white, moderately reflected,
narrowest along posterior comer; widest along
rolumellar margin. Axis hollow and about '4
diameter of whorls. Axis weakly concave within
each whorl; sculptured with weak, slightly
oblique vertical ribs bearing small spines and
nodes that are irregularly sized and spaced.
Measurements in mm of mature specimens

are as follows (measurements of the holotype
are in parentheses): length, 13.0-14.2 (13.8; width,
2.6-2.8 (2.6); aperture height, 1.7-1.85 (1.8);
aperture width, 1.6-1.8 (1.7). (14 specimens
measured).

Type hcality — Chiapas, 4.5 miles north of
Jitotol, 5400 feet altitude HOLOTYPE: UF
22451; collected 6 July, 1965 by Fred G. Thomp-
son. PARATYPES: UF 22452 (12); and Dela-
ware Mus. Nat. Hist. 102474 (1) same data
as the holotype. The type series was found in a
thick cluster of moss growing on the side of a
limestone ledge along a ravine. The area con-
sisted of semi-wet mountain broadleaf forest
which had been partially cut over.

Remarks — This subspecies differs from E S.
suriftiana (Crosse) by being shorter, having
fewer whorls, more embryonic whorls and
having a rounded base on the last whorl. E s.
smftiana is about 18 mm long, has 21 whorls,
including 1.5 embryonic whorls, and the last
whorl is obsoletely subangulate below. The
nominate subspecies is known only from the
type specimen, which comes from an unspecified

Viil. 90 (1)

January 30, 1976

THE NAUTILUS 43

locality (Crosse, 1863; 388-389. 1867: 200-201,
pl.s. fig. 5. Fischer and Crosse, 1878: 407). It
I)r(>bably occurs in Chiapas, as does E. .s. al-

Epirobia lurida >iew species
Fig. 1, a and b. Fig. 2, b.

S/ie// — Elongate-t arreted, very slender, 0.15-
0.17 times as wide as long. Spire complete,
uniformly increasing in diameter through the
fourth from last whorl. Moderately thin, only
slightly transparent when alive. Umbilicus
narrowly perforate, visible from oblique view.
Color light yellowish-gray, lusterless, dull, in-
terior of aperture white. Whorls 22.5-25.0 (23.2
in holotype). Suture deeply impressed. Em-
bryonic whorls 3.0-3.2 (3.1 in holotype), smooth,
strongly arched peripherally wath a deeply im-
pressed suture; nearly equal in size. Following
whorls gradually increasing in diameter through
about the eighteenth whorl; sculptured with
regularly spaced ribs. Ribs on lower whorls are
about twice as high as wide, slope obliquely for-
ward and are about one fourth as wdde as their
intervals. There are 35-49 ribs on penultimate
whorls (38 in holotype). Ribs strongly arched in
a reverse sigmoid curve. Periphery of postem-
bryonic whorls strongly rounded on upper spire.
Lower whorls flat sided and almost scalariform.
The flattened periphery is slightly oblique to
the axis of the shell. Base of last whorl round -

FIG. 2. Camera lucida drawings of the coiumeUar striic-
ture in the penultimate whcrrls of a, Epirobia swiftiana
alternans new subspecies and, b, Epirobia lurida new
species.

ed, without indication of a bisal keel. Aper-
ture free from preceding whorl, offset laterally
and extended forward by about V2 diameter of
shell. Aperture broadly auriculate in shape;
about 0.73-0.80 times width of shell; posterior
corner narrowly rounded. Peristome moderately
reflected; narrowest around posterior comer;
widest along baso-columellar margin. Outer lip
sigmoid in lateral profile, corresponding in
outline to curvature of ribs on previous whorl.
Plane of aperture slightly oblique to axis of
shell. A.xis hollow, about Vs diameter of whorls,
nearly straight, slightly twisted in lower whorls.
Axis uniformly wide or slightly concave within
each whorl; sculptured with small granular
spines which tend to form oblique series.

Measurements in mm of mature specimens
are as follows (measurements of the holotype
are in parentheses); length, 15.5-18.3 (16.3); width,
2.4-2.7 (2.6); aperture height, 1.8-2.1 (2.0); aper-
ture width, 1.8-2.1 (1.95).

Pallial organs — The pallial cavity is about 4
whorls long. The kidney is about V4 whorl long,
narrow, reniform sigmurethrous. The secondary
ureter is about equal in diameter to the in-
testine and is tightly bound to the latter. The
heart is about '4 the length of the kidney. The
aorta lies along the ventral margin of the lung
and is weakly branched throughout most of its
length. It divides into 5-6 small arterioles just
behind the mantle collar.

Trophic structures — J avf solid, arcurate.
Salivary glands plumiform, appressed against
the side of the esophagus; short, about half the
length of the pharynx. Salivary ducts about half
the length of the glands. Radular sac short,
coiled in a loop against posterior end of
pharynx. Radular formula 17-1-17 with the
teeth lying in broadly accurate transverse rows
about 390 /^ wide (Fig. 3, b-c). The central tooth
is hexagonal in shape and has a large mesocone
and a small ectocone on each side. The central
is about 19 /i high and 14 ^ wide. The tran-
sition from the laterals to the marginals occurs
at the fifth through seventh rows. The laterals
each bear a large blunt mesocone and a small
ectocone. The mesocone of the seventh tooth and
subsequent marginals is pointed where both the
mesocone and the ectocone are bicuspid.

Muscular system — CoiumeUar retractor long,

44 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

B . i°" .

FIG. 3. Epirobia lurida new species, a, reproductive system exclusive nf the yanml. b, nuhiln. c, (lidiinimntic rieir nf n trans-
verse rn>r of the mdiiln shnviyy the respecfire lyisitiims <if the teeth illu.^lratcd in b.

extending seven whorls into spire; dividing at
the third whorl to give rise to the pedal retrac-
tor basally, the pharyngeal retractor dorsally
and the right and left ocular retractors
laterally. The ocular retractors respectively give
rise distally to the right and left labial retrac-
tors. The pharyngeal retractor divides into four
narrow bands at base of pharynx. Two insert
laterally and two insert basally.
Reproductive System (Fig. 3, a). — The genital

atrium is medium in length, moderately stocky
and opens behind and below the right ocular
tentacle. The right ocular retractor muscle
passes through the penioviducal angle. The
penis is long and slender, being about twice the
length of atrium and has four longitudinal
fleshy folds internally, one of which is larger
than the others along the upper third of the
penis. There is not verge. The apex of the penis
bears a long slender compressed caecum which

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 45

is about twice the length of the penis. The
penis retractor muscle is long and slender. It
originates on the inner wall of the lung about
Vi whorl above the penis and inserts on the
distal end of caecum. The vas deferens is
relatively stocky above the penis and is weakly
enlarged as an epiphallis for a distance about
equal to the length of the penis. It enters the
wall of the free oviduct below the prostate and
oviduct. The spermathecal duct enters the free
oviduct to form a short vagina immediately
above the atrium. The base of the duct is
enlarged into a thick-walled muscular bulb. The
duct is branched distally. The spermatheca lies
appressed against the outer base of the
albumen gland. The spermathecal appendix lies
along the columellar side of the oviduct and
albumen gland. The free oviduct is about 1.5
times the length of the penis, is strongly con-
voluted and becomes moderately wide a little
above the insertion of the spermathecal duct.
The albumen gland lies about four whorls above
the genital atrium and is strongly creased on
its outer surface by the intestine. A talon and
a carrefour are absent.

Tifpe locality — Chiapas, 15.8 miles northwest
of Ocozocoautla on road to Mai Paso, 2700 feet
altitude. HOLOTYPE; UP 22449; collected 20
July, 1965 by Fred G. Thompson. PARATYPES
UP 22450 (116): Delaware Mus. Nat. Hist.
102475 (5); same data as the holotypes; UP
22448 (4), CAS 55555 (30); topotypes. collected 6
October, 1974 by Dennis E. Breedlove. The type
locality is an area covered by a heavy quasi -
rainforest on low, rolling limestone hills. Live
snails were found only on damp moss-covered
limestone boulders.

Remarks — E. lurida is distinguished from
other species of the genus by its flat sided
whorls, its high sigmoid riblets and its slender
straightsided axis with granular spines arranged
in irregular oblique rows. It is similar to E.
pulinigyra (Pfeiffer) from Veracruz in general
aspects of size, shape and whorl count, but the
latter species has evenly rounded whorls, the
riblets are fine threadlike striae and the axis is
convex within each whorl with the rough
granular sculpture confined primarily to the
center of the convexity. E. polygyrella (von
Martens) from Alta Verapaz has shorter, more

strongly rounded whorls, the aperture is nearly
rotund, the axis has slender retracted riblets
that lack granular sculpture and the shell is
smaller.

DISCUSSION

There are seven species and two subspecies of
Epimhia known. Three are recorded from
Veracruz, four from Chiapas, one from Alta
Verapaz, and one was described without any
locality. For a review of the genus see Pilsbry,
1903: 59-66.

Three other snails that were described as
species of Epirobia from northeastern Mexico
are now placed elsewhere. E. coahuilensis Bar-
tsch, 1906, has been referred to Coelostemrna
(ApeHaxis) by Thompson (1971: 301) and E
(Propilsbrya) nelsoni Bartsch, 1906 was elevated
to generic rank as Propilsbrya nelsoni by
Pilsbry (1953: 136). The status of E. (Gyrodon)
mirabilis Pilsbry, 1903a is problematic. It is
known only from a single immature shell, and
its generic status is questionable. Certainly
Gyrodon is very different from Epirobia s.s.

Epirobia (s.s.) contains two species groups.
One group, consisting of E. berendti (Pfeiffer),
E. b. albida (Fischer and Crosse) and E. gassiest
(Pfeiffer), includes species that have relatively
short obese shells. The second group, consisting
of E. s. swijiiana (Crosse), E. s. altemans n.
ssp., E. apiostoma (Pfeiffer), E. polygyra (Pfeif-
fer), E. polygyrella (v. Martens) and E. lurida
n. sp., includes species that are relatively long
and slender.

Previously two taxa were recorded from
Chiapas, E. b. albida and E. gassiesi. Neither of
these is known from a more exact locality than
the state of Chiapas and both belong to a differ-
ent species group than do the two new forms.
E. s. altemans and E. lurida establish the first
exact records of the genus within Chiapas.
They come from an area forming more nearly a
geographic continuum from Veracruz to Alta
Verapaz for the species group to which they
belong.

Epirobia is a member of the family
Eucalodiidae, subfamily Holospirinae because of
its non-decollate shell, solid jaw, trimorphic
radular teeth, the presence of an appendix on
the spermathecal duct, the absence of a verge

46 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

within the penis and the absence of a talon and
a carrefour. It is unique among the eucalodiid
genera for which the anatomy is known by
having a long, slender, compressed penial
caecum, a large muscular bulbous base on the
spermathecal duct, the vas deferens entering the
oviduct wall below the prostrate, and the
mesocones and ectocones of the central and
lateral teeth having large rounded cusps. Un-
fortunately anatomical information is not
available on most other genera within the
Holospirinae, and comparisons are not possible
at present.

The above anatomical characterization of
Epirabia is based exclusively on E. lurida
because of a lack of data on other species.
Strebel and Pfeffer (1880) describe and
illustrate portions of the reproductive system
and the radula recovered from a dried E
apiostoma (Pfeiffer). Pilsbry (1903: 60) expresses
doubt about the identity of the radula. Strebel
and Pfeiffers' description of the reproductive
system are very different from that of E.
lurida, to the extent that doubt about the iden-
tity of their material is even more warranted,

and comparisons involving E. apiostoma cannot
be made at this time. It is possible that
Ejrirobia is a compound genus based on shell
convergences.

LITERATURE CITED

Bartsch. P. 1906. The urocoptid mollusks from the mainland
of America in the collection of the United States Na-
tional Museum. Proc. U.S. Nat. Mus. 31: 109-160; pis.
3-5.

Crosse. H. 1863. Diagnoses d'especes nouvelles. Journal de
Conehylidogie 11: 388-389.

1867. Descriptions d'especes nouvelles. Journal de Con-
chyliolugie 15: 195-203; pi. 4, figs. 1, 4; pi. 5. figs. 2-5.

Fischer, P. and H. Crosse 1878. Miision Scientifique an
Mexiqve et dans L'Amerique Centrale. Moliasques terres-
tres et fluviatiUs. Paris. 1: 1-702; pis. 1-20.

Pilsbr>'. H. A. 1903. Mamml of Conchology: Ser. 2, 15:
1-323; pis. 1-65 1903a. Mexican land and freshwater mol-
lusks. Proc. Acad. Nat. Sci. Phila 55: 761-792; pis. 47-54.
19.53. Inland Moilusca of northern Mexico. II. Proc. Acad.
Nat. Sei. Phila. 105 133-167; pis. 3-10.

Strebel. H. and G. Pfeffer 1880. Beitrag ^ir Kenntniss der
Fauna Mexikanischer Land — urd Susswasser — Conchy-
lien. IV. Hamburg. 1-112; pis. 1-15.

Thompson. F. G. 1971. Some Mexican land Snails of the
genera Cnelostemma and Metastomn (Urocoptidae). B)dl.
Flo. State Mus. 15: 267-302.

A NEW SPECIES OF CALLISTOCHITON IN THE CARIBBEAN

Antonio J. Ferreira'

2060 Clarmar Way
San Jose, California 95128

ABSTRACT
A new frpecies of chiton. Callistochiton portobelensis Ferremi, .sp. nov.. k de-
scribed and figured. Found at Portobelo. Panama (type locality) and off Key
West, Florida, it closely resembles C. elenensis (Sowerby) fi-om the eastern Pa-
cific.

In the Caribbean, the genus Callistochiton
(Carpenter in Dall, 1879) has been thought to
be represented by a single species,
Callistochiton shuttleworthianus Pilsbry, 1893.
In February 1975, while on a collecting trip to
the Caribbean shores of Panama, I came across
several specimens of what subsequent investi-
gation proved to be an undescribed species of
Callistochiton.

Research Associate, California Academy of Sciences.

Class Polyplacophora de Blainville, 1816

Subclass Neoloricata Bergenhayn, 1955

Family Callistoplacidae Pilsbry, 1893

Callistochiton portobelensis new species

Figs. 1-6

Diagno.'iis — Chiton small, less than 1 cm
long, greenish cream color. Anterior valve with
about 12 subdued radial ribs; posterior valve
with none or a few obsolete radial ribs. Mucro

47 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

FIG. 1. Callistochiton portobelensis Ferreira. new speciea.
Paratope. Portnbelo. Panama. 6.7 mm in length.

FIG. 2. Side I'iew of lateral areas of parati/pe.

slightly anterior. Lateral areas bicostate, with
minute tubercles along the posterior margins.
Central areas somewhat diagonally ribbed, and
latticed. Jugal area smooth. Girdle scales cylin-
droid, small, weakly imbricated, outer surface
oval and minutely granulose.

Desmptian of the h-olotype — The specimen,
dried but fully extended, measures (including
girdle) 6.7 mm in length, 3.6 mm in width, and
L2 mm in height. Width to length ratio =
0.53. Jugal angle about 96°. Tegmentum of a
rather uniform greenish cream color, with oc-
casional small darker green blotches peppering
the shell in a random manner; the general sur-
face is microgranular throughout. Anterior
valve shows 12 low-profile radial ribs, better
defined towards the periphery where they seem

more like undulations than ribs on the tegmen-
tum. Posterior valve shows a well defined but
not conspicuous mucro, slightly anterior; the
post-mucro area is moderately concave, with
only the faintest indication of radial ribbing.
Intermediate valves have moderately elevated
lateral areas bearing 2 broad, slightly granose,
low ribs which show no tendency to split; the
space between the two radial ribs is well
defined but shallow. The posterior of the two
ribs in the lateral areas tends to have a few
minute, almost obsolete tubercles along its
sutural edge. The central areas have
longitudinal riblets, about 10 per side,
diagonally disposed by diverging forward as a
whole at about a 20° angle from the midline;
there is no "wedge" figure on valve ii (Ferreira,
1974: 163). The longitudinal riblets are about as
wide as the space that separates them, and
united by some discrete latticing. The central

FIG. 3. Callistochiton ixirtobelensis Ferreira. new species.
Holotifpe. SEM microphotographs (courtesy of Hans Bertsrh)
if girdle scales. Approx. iOOX.

FIG. 4. Girdle scale of holoti/pe. Approx. 500X.

48 THE NAUTILUS

January 30, 1976

Vol. 9(1 (1)

FIG. 5. Detail of girdle scale of hololt/pe. Approx. 1500X.

5».><.

loo A

FIG. 6. Callistochiton portobelensis Ferreira, new species.
Holotype. Radula (Camera lucida drawing).

sculpture becomes obsolete towards the jugal
area, which is mostly smooth. The ar-
ticulamentum is white but, by transparency,
shows some occasional small dark blotches. In-
sertion teeth are straight edged except at the
corners where they tend to be a bit thicker and
rounded. There is no clear cut festooning or
scalloping in any of the teeth. Slit formula 11-
1-9. The slits correspond well with the tegmen-

tal undulations or ribs. Sutural laminae are
sharp, semioval, short, and continue with no
visible demarcation or notch with the sinusal
lamina. Sinus is relatively shallow. Eaves
short and solid. The callus inside valve viii is
suffused with dark-brown pigmentation. The
girdle has a uniform width of 0.5 mm; it is the
same color as the tegmentum but softly banded
with green. The scales measure about 80fj in
length. They are weakly imbricated, standing
close together like cobblestones on a pavement.
Somewhat cylindrical in shape, their sides (jux-
taposed, and therefore hardly visible in the un-
disturbed girdle) are neatly ribbed vertically,
while its outer (distal) surface, oval in outline,
and slightly convex is minutely pustulose. (Figs.
3, 4, 5). The radula measures about 1.6 mm in
length, and has 44 rows of teeth. The median plate
(tooth) is wider anteriorly (30/i) with a very
thin blade, markedly narrowed medially (12^^),
and again somewhat dilated posteriorly to ter-
minate rapidly in a blunt point. The in-
termediate (first lateral) plate has a small
superiorly recurved uncinated growth at the
outer-anterior comer. The uncinate (second
lateral, major lateral) plate has a long and
thick (25ji X 8fi) tubercle inwardly directed,

, and a unicuspid blade, about 52fi long by 25ji
wide, with a small posterior notch (Fig. 6).

Type material — Holotype (disarticulated
valves, excised fragments of the girdle, and
mounted radula) and a paratype (Figs. 1, 2),
are deposited with the California Academy of
Sciences, Department of Invertebrate Zoology
(CASIZ Type Series 679 and 680; CASIZ Type

. Slide Series 493 and 494). Color slides of some
paratypes are deposited with the California
Academy of Sciences, Department of Zoology
(CASIZ Color Slide Series nos. 3259, 3260, and
3261).

The paratypes vary in size from 5.1 mm to
6.9 mm in length. They all have the same
general coloration (with one exception— a
uniform brick-red specimen, with faint
creamish banding of the girdle), and some
irregular, small, greenish blotches. Paratypes
deposited with the Los Angeles County Museum
of Natural History, United States National
Museum of Natural History (USNM no. 710720),
Academy of Natural Sciences of Philadelphia,
and in my own private collection.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 49

Type locality — 5 km west of Portobelo
(latitude 9° 30' N; longitude 79° 42' W),
Panama. The specimens were all collected on
February 15, 1975, by myself, in about 1 to 10
feet of water, under rocks or fragments of old
coral resting on sand. They came from two
collecting stations (AJF 222, and 223), about 1
km west of Portobelo (1 specimen, 5.5 mm
long), and 5 km west of Portobelo (10
specimens, including the here designated
holotype), respectively. The species is called por-
tdbelenm in reference to its type locality, Por-
tobelo.

Fiirther distribution — Another specimen of
Callistochiton porta belensis was found by the
author on April 28, 1975, while diving from
aboard the R/V Cord Reef with the Steinhart
Divers of the California Academy of Sciences,
in 5 m of water by the Northwest Channel
(latitude 24° 30' N; longitude 81° 54' W), off
Key West, Florida. The specimen measures 9.0
mm in length. This finding extends the known
range of C. portobelensis some 1,000 miles north-
ward.

Discussion — Callistochiton portobelensis bears
little resemblance to C. shuttleworthiamis, the
only member of the genus Callistochiton hither-
to known in the Caribbean (KAAS, 1972). In-
stead, in size, color, general shape, sculpture of
the tegmentum, and girdle scales, C por-
tobelensis is remarkably similar to
Callistochiton elenensis (Sowerby, 1832) from
the tropical eastern Pacific. Compared with ran-
domly selected specimens from several lots of C.
elenensis in my collection, C portobelensis was
found to differ by 1) its smaller size, 2) a much

more subdued sculpturing of the valves, par-
ticularly of the radial ribs in valves i and viii,
3) a more rounded and smoother jugal area, 4)
no "upswept" valves (see Thorpe in Keen,
1971:875), and 5) thicker longitudinal riblets,
separated by narrower interspaces.

Still, the affinities between C. portobelensis
and C. elenensis are so close as to make them
sibling species. Likely, they evolved from the
same parent population and became
geographically isolated by the emergence of the
isthmus of Panama in the Pliocene.

ACKNOWLEDGEMENTS
I wish to express my appreciation to Hans
Bertsch of the Donner Laboratory, University of
California, Berkeley, for the SEM microphoto-
graphs; and to the Steinhart Divers of the
California Academy of Sciences, and to Beta
Research Oceanographic Laboratories, for their
assistance in several phases of this work. I
wish further to give my thanks to Allyn G.
Smith of the Department of Geology of the
California Academy of Sciences for his valuable
critical comments of the manuscript.

LITERATURE CITED

Ferreira, Antonio J. 1974. The genus Lepidozona in the
Panamie Province, with the description of two new spe-
cies. The Veliger. 17(2): 162-180, 6 pits. Berkeley. Cali-
fornia. October 1.

Kaas, P. 1972. Polyplacophora of the Caribbean Region.
Studies on the Fauna of Curacao and other Caribbean
Islands, vol. 41. no. 137. 162 pp.. 247 text figs., 9 pits.
Martinus Nijhoff. TTie Hague. July.

Keen, A. Myra 1971. Sea Shells of Tropical West America:,
Marine Mollusks from Baja California to Peru. 2nd ed.
Stanford University Press, xiv -I- 1064 pp., ca. 4000 figs.,
22 color pis. September 1.

A NEW FOSSIL ASHMUNELLA (PULMONATA: POLYGYRIDAE) FROM THE
GUADALUPE MOUNTAINS NATIONAL PARK, TEXAS

Artie L. Metcalf

Department of Biological Sciences

University of Texas at El Paso

El Paso, Texas 79968

and

Richard W. FuUington

Dallas Museum of Natural History

Fair Park Station

Dallas, Texas 75226

ABSTRACT

A new species of fossil polygynd hnid snail. Ashmunella nana, is described.
The .species is known only from depo.sits of Pleistocene age in the southern

50 THE NAUTILUS

January 30. 1976

Vol. 90 (1)

Guadalupe Mountains, Culberson County, Texas. An associated molluscan fauna
in these deposits is recorded and remarks are made concerning Oreohelix
socorroensis Pilsbi-y.

INTRODUCTION

Pine Spring Canyon in the southern
Guadalupe Mountains, Culberson County, Texas,
has received considerable attention
malacologically. It is the type locality of
Holospira montivaga breviara Pilsbry, 1946, of
Holospira pityis Pilsbry and Cheatum, 1951, and
of Ashmunella kochi amblya Pilsbry, 1940. The
canyon is now in a central position in the
Guadalupe Mountains National Park.

Exposed in walls of Pine Spring Arroyo are
thick alluvial deposits that contain fossil
mollusks. On slopes of the canyon above the
arroyo there are fossiliferous colluvial deposits.
At the locality reported here, there are two
strata of nibbly oolluvium (to be referred to,
hereafter, as "lower rubble" and "upper rub-
ble") separated by reddish silt, containing scat-
tered, subrounded stones. The rubble is
predominantly of small, sharply angular
limestone fragments of the type interpreted by
Galloway (1970 : 245), in the Sacramento Mts.
(120 km to the northwest, in New Mexico), to
be periglacial deposits of frost rubble. It seems
probable that the upper rubble was deposited
during the latest Wisconsinan Glaciation. The
reddish deposits probably represent a paleosol
appertaining to an interstade or interglaciation
and the lower rubble seemingly represents
either an earlier Wisconsinan or still earlier
time when periglacial conditions existed in the
mountains.

The molluscan fauna found in the lower rub-
ble comprises, among others listed below, Ash-
munella rhyssa (Dall) and a new species,
described below. Neither species is known to
live in the Guadalupe Mts. at present and the
latter seems to be an extinct species. A. r.
rhyssa still flourishes in the Sacramento Moun-
tains. In the upper rubble a different Ash-
munella, A. kochi amblya Pilsbry, occurs. This
species presently inhabits Pine Spring Canyon
and other parts of the southern Guadalupe Mts.
The sequence suggests that the two former
species of Ashmunella became extinct in the
Guadalupe Mts. between the times of deposition

of the lower and upper rubbles and that A.
kochi amblya appeared in the mountains during
the time of the latest glaciation. [Vagvolgyi
(1974 : 143) suggested that the subspecies amblya
might better be synonymized with the nominal
subspecies.]

Ashmunella nana new species
Figs. 1-3

Description of Holotype: Shell small (for
genus), moderately depressed, 10.6 mm in
diameter, 5.0 mm high; body whorl rounded
peripherally and descending only slightly; um-
bilicus round, deep, contained 5.4 times in
diameter; aperture obliquely oriented, 3.2 mm
in oblique distance between inner comers of
lip; aperture bearing four denticles; parietal

FIGS. 1. 2. Hi)li>t!/pe of Ashmunella nana new upecies (10.6
mm diameter). FIG. 3. Aix'rtiiml view nf paratype of A.
nana.

Vol. 9() (1)

January 30, 1976

THE NAUTILUS 51

tooth oblique, simple, 1.7 mm long, .4 mm high;
palatal tooth rectangular, 1.1 mm long and .5
mm high, basal lip with two teeth, both com-
pressed, 1.0 mm apart, upper tooth rising .6
mm and lower tooth rising .2 mm above inner
rim of lip; lip slightly expanded and recurved,
grooved behind; first 1''4 whorls smooth, except
for minute pits; succeeding whorls finely
wrinkle-striate to last half of body whorl, which
bears ca. 26 low but distinct ribs, better
developed dorsally and progressively thicker
distally; total number of whorls, 4.75.
Etymology: nowa =dwarf (L., fem., subst.).

Variation: For fifty paratypes from the type
locality, the following measurements (mm) and
proportions were obtained (mean outside paren-
thesis; range inside parenthesis); Diameter:
10.07(9.1-11.2); Height: 4.53(4.0-5.2);

Diameter/Height: 2.21(1.98-2.47); Width of Um-
bilicus: 1.96(1.4-2.5); Diameter /Width of Um-
bilicus: 5.17(4.32-6.50); Length of Parietal Tooth:
1.51(1.2-1.8); Length of Palatal Tooth: 1.24(0.7-
1.5); Number of Whorls: 4.86(4.6-5.25). All
specimens' observed had four denticles (except
where exfoliated), which showed only minor
variation in shape and size. There was variation
in degree of ribbing, ranging from few ribs to
specimens in which most or all of the body
whorl bore ribs dorsally and peripherally.
Measurements of four specimens taken ca. 60 m
southeast of the type locality (see below) fell
within the limits enumerated above.

Comparisons: A. nana is among the smallest
of Ashmunellas. The only members of the genus
reported to be as small are A. proxima harveyl
Pilsbry (Pilsbry, 1940 : 959) with a specimen
reported as being 10.3 mm in diameter and 5.0
mm high and A. intricata Pilsbry (Pilsbry,
1948 : 203) with specimens recorded as 9.6 and
10.6 mm in diameter and 4.7 and 4.8 mm high.

A. nana seems to bear little resemblance,
conchologically, to any known species of Ash-
munella, living or fossil, from the region east of
the Rio Grande Valley. In general shape and in
number and arrangement of denticles it resem-
bles the A. proxima Pilsbry complex of the
Chiricahua Mts., Arizona. However, A. nana is
much less tightly whorled, less angular
peripherally and is much more ribbed than
members of the proxima complex. A close

relationship with this distant group seems
unlikely.

In contrast to A. nana, in regard to size, is
A. kochi amblya, which may exceed diameters
of 20 mm. Thus, one of the largest and one of
the smallest of Ashmunellas have inhabited
Pine Spring Canyon. A. nana seems to bear lit-
tle relationship either to A. kochi amblya or to
the other living species of the Guadalupe Mts.,
A. edithae Pilsbry and Cheatum and A.
carlsbaderms Pilsbry. The wide, shallow um-
bilici of the latter three species are in marked
contrast to the narrow, deep umbilicus of A. nana.

Type Locality: Texas, Culberson Co.,
Guadalupe Mts., Pine Spring (Canyon, 3.2 km (2
mi.) WNW of village of Pine Springs. 104° 50'
45" W Long, 31° 54' N Lat; 1912 m (6270 ft.)
elevation. Deposits are exposed in banks of a
small arroyo of high gradient, tributary, from
the west, to the main arroyo of the canyon.
Deposits occur ca. 30 m west (on east-facing
slope) and up-slope from a right-angle bend in
the main arroyo (changing from west to north,
up-canyon). This sharp bend is .65 km (.4 mi.)
south of the "H" in "Devil's Hall" (U.S.G.S.
Guadalupe Peak, Texas, 15 min. topographic
quadrangle, 1933).

Types: Holotype, Acad. Nat. Sci., Philadelphia
338703; Paratypes: ANSP 338704; Dallas
Museum Nat. Hist. 4400; The Delaware
Museum Nat. Hist. 100700; University of
Arizona 17382; Museum of Arid Land Biol., U.T.
El Paso 4165, 4170.

ASSOCLVTED FAUNA

In association with A. nana and A. r. rhyssa,
the following species of snails have been taken
in the lower rubble: Cochlicopa lubrica (Miiller),
Gastrocopta pilsbryana (Sterki), Pupilla
sonorana (Sterki), Pupilla blandii Morse,
Vallonia gracilicosta Reinhardt, Vcdlonia per-
spectiva Sterki, a succineid, Holospira nwn-
tivaga breviara Pilsbry, Discus cronkhitei
(Newcomb), Helicodiscvs eigenmanni Pilsbry,
Retinella indentata (Say), Hawaiia minuscula
(Binney), Zonitoides arboreus (Say), Striatura
meridionalis (Pilsbry and Ferriss), Vitrina
pellucida alaskana Dall, Oreohelix socorroensis
Pilsbry and Humboldtiana ultima Pilsbry.
Recent collecting by Fullington shows that all

52 THE NAUTILUS

January 30. 1976

Vol. 90 (1)

these species except probably the Oreohelix still
occur in the Guadalupe Mts. but several species
now occur only at higher elevations.

Oreohelix socorroensis was taken in both the
lower and upper rubble. It also occurs in
alluvium along Pine Spring Canyon Arroyo.
Probably specimens of 0. yavapai compactula
G)ckerell reported by King (1948 : 145) were of
this species. 0. socorroensis has been found, as
a fossil, in the Sacramento and San Andres
Mts., New Mexico, and in the FYanklin, Hueco
and Guadalupe Mts., Texas. It still lives in the
Gallinas Mts. in central New Mexico. It is
surely allied to the 0. yavapai Pilsbry complex
of northern New Mexico and Arizona, especially
to 0. yampai neomexicana Pilsbry. However,
elucidation of relationships probably would in-

volve a taxonomic revision of the entire yavapai
group, a task not undertaken lightly.

LITERATURE CITED

Gallaway. R. W. 1970. The full-glacial climate in the south-
western United States. Ami. Assoc. Amer. Geogr. 60:
24.5-2.56.

King. P. B. 1948. Geology of the southern Guadalupe Moun-
tains. Texas. U.S. (kol. Sun: Prof. Pap. 215: 1-183.

Pilsbry, H. A. 1940. Land Mollusca of North America
(North of Mexico). Acad. Nat. Sci. Philadelphia Monogr.
1(2): vi + .575-994.

Pilsbr>'. H. A. 1948. Inland mollusks of northern Mexico. -
I. the genera Humlxjldtiana. S(jnorella. Oreohelix and
Ashmunella. Proc. Acad. Nat. Sci Philadelphia 100:
185-203.

Vagvolgyi. J. 1974. Eight new Ash man el hu-; from the S(juth-
western United States (Pulmonata: Polygjridae). Proc.
Biol. Soe. Washington 87: 139-166.

TENTACLE-BRANCHING IN THE PERIWINKLE, LITTORINA LITTOREA

Richard G. Woodbridge, III

Ekjx 111, Princeton .Junction,
New Jersey 08550

Abnormalities in mollusks have been noted
by many observers and are the subject of a
treatise by P. Pelseneer (1920). In gastropods,
supplementary or multiple tentacles have been
noted in several cases, but, as Pelseneer noted,
they are moi:e common on one side than the
other. Branching has been particularly noted in
Littorina. Pelseneer's own observations may be
summarized as follows:

Jeffreys (1862) noted a specimen of L. littorea
which had two tentacles branched. He also com-
mented in reference to a supplementary ten-
tacle observed in a specimen of L. ohtusata.
that the extra tentacle is not far removed from
the normal one.

Hanko (1912) in a paper delineated the
varieties of tentacle-branching which have been
observed in Nasmrius mutahilis (L).

Crabb (1927) studied forked tentacles in the
pond snails Physa gyrina and Lymnaea
stagnaJis appressa.

Wong and Wagner (1956) reported on the ef-
fect of ultraviolet light on the tentacles (among
other things) of Oncomelania nosophora and 0.

quadrasi. Exposure to ultraviolet light causes
abuornial growth structures in many individuals
of these species. However, abnormal tentacles
tended to be lost over a period of time.

Davis, Moose & Williams (1965) described a
specimen of a hybrid Oneomelauia with ten-
tacle abnormalities and stated "It is known
that the tentacles of Oneomelania are prone to
abnormal branching." The authors suggested
that inheritance might be involved in tentacle
branching.

Richards (1969) in an important paper
showed that inheritance appears to play a part
in tentacle branching of the freshwater
pulmonale mollusk Biomphalaria glabrata.

While observing 50 living periwinkles which
had been selected for experimental purpose
from near the low tide mark of the intertidal
region of Northwest Harbor, Deer Isle, Maine,
the summer of 1971, the writer noticed one
specimen with a bifurcated tentacle (fig. 1).
Subsequently, four collections of periwinkles,
consisting of 1,026 living specimens were
examined with the following results:

Vol. 9<) (1)

January 30, 1976

THE NAUTILUS 53

TABLE 1. Tentacle-branching in the Littirrina

Species

L littorea

L )itdis (saxatilis)

L. nbtiixata

TABLE 2.

Date

(1971)

July 27

July 2!-)

July -St) (lot 1.)

July 30 (lot 2.)

Ntimber nf

Indi I'idualK

Nuted

1
5
3

Number Obseiiied

100
303
318
305

1,026

Tentacle
Left Right

Number with
Forked Tentacles

2
4
3
1

10

The periwinkles with the forked tentacles
were subsequently brought back to the writer's
laboratory aquariums in Princeton, New Jersey,
for continuing observation. In contrast to the
findings of Wong and Wagner (1956) on the
ultraviolet light induced tentacle growth ab-
normalities in Oncomelania. the branched ten-
tacles of these periwinkles appeared permanent
and stable, certainly as "normal" as normal
tentacles, for the period of over eleven months
during which they were under observation.

Each fork of a tentacle shows independent
activity. Both forks in the tentacle shown in
drawing 1 moved separately and conducted in-
dependent searching movements. This was also
true in specimen 8, which was surprisingly
prehensile in appearance and movement.

Small forks in numbers 4, 5 and 6 showed

more independence of motion than the smaller
forks of numbers 2 and 7.

Microscopic examination of numbers 1 and 8
showed no difference internally or externally in
the organization of the forks. Tentacle forks are
organized tissue and certainly not "cancer-like."
Number 10 was the only case found with
multiple forking.

A further analysis of lot 2 collected on July
30 containing 305 specimens gave the following
results of the 18 abnormal specimens (5.9%):

TABLE 3.

Tentacle Abnormality

Missing
Short
Bent
Forked

Totals

Left Tentacle

1

12
0

_0

1.3

Right Tentacle

1
1
2

J_
5

FIGS. 1-10. Ahnnrmnl branching in the tentacles of Litto-
rina littorea (Linn').

No periwinkles were observed in which both
tentacles appeared to be abnormal.

It should be noted that forking is not restricted
to the phylum Mollusca but occurs in other in-
stances involving the regeneration of structures.
In the case of lizards which cast off their tails to
escape being eaten, regeneration occurs in such a
manner as to give a forked tail.

It is possible that the bites of very small fish
in some instances do not remove but only in-
jure the tentacles of periwinkles in such a man-
ner that regeneration results in similar forking.

LITERATURE CITED

Crabb, E. D. 1927. Genetic experiments with pond snails
Lymnaea and Physa. Amer. Naturalist 61: 54-67.

Davis, G. M., Moose, J. W. and Williams, J. E. 1965. Abnor-
mal development in a hybrid Oncomelania (Gastropoda;
Hvdrobiidae). Malacotogm 2: 209-217.

Duprey. cf. Jeffreys. 1883. Proc. Zool. Soc. London, p. 122.
Ref. in Pelseneer.

Hanko, B. 1912. Uber Missbildungen bei Nassarius mutabilis
(L.). Zoo/. Aiaeiger 39: 719-723.
Jeffreys. 1862. British Conchology 3: 373.

Pelseneer, Paul. 1920. Les Variations et Leur H^redite
chez les Mollusques, L'Academie Royale de Belgique.

Richards. C. S. 1969. Genetic Studies on Biomphalaria
glabrata: Tentacle and eye variations. Malacologia 9(2):
.327-338.

Wong, L. W. and Wagner. E. D. 1956. Some effects of ul-
traviolet radiation on Oncomelania iwsophora and O.
quadrasi. snail intermediate hosts of Schistosoma Japoni-
cum. Ti-nns. Amer. Micro. Sue. 75: 204-210.

54 thp: nautilus

January 30. 1976

Vol. 90 (1)

•OBSERVATIONS ON MOLLUSKS FROM A NAVIGATION BUOY

WITH SPECIAL EMPHASIS ON THE SEA SCALLOP

PLACOPECTEN MAGELLANICUS

Arthur S. Merrill

National Marine Fisheries Service

Middle Atlantic Coastal Fisheries Center

Resource Assessment Investigations

Oxford, Maryland 21654

and Robert L. Edwards

National Marine Fisheries Service

Northeast Fisheries Center
Woods Hole, Massachusetts 02543

ABSTRACT

Tuwlve species of postlarval mollusks were found among fouling organisms
collected from a navigation buoy. Length data for the three most abundant
species, Placopecten magellanicus, Anomia aculeata. and Mytilus edulis. were
analyzed in an attempt to explain normal and log-nonnal frequency distribution
patterns. Molluscan community relationships on the buoy were closely observed
and reported. The ocean bottom under the buoy was sampled by dredge, and
the population composition of mollusks on the bottom did not include the
postlarval forms found on the buoy.

INTRODUCTION

Many objects floating at the ocean's surface
eventually acquire an imposing community of
sessile marine organisms. An impressive body of
literature exists with reference to such fouling
organisms (Woods Hole Oceanographic In-
stitution Contribution No. 580, 1952). In this
paper, we present the results of a study of the
mollusks attached to an ocean buoy. One
specific purpose of this study was to learn more
of the early life history of the sea scallop,
Placopecten magellanicus (Gmelin).

United States Coast Guard navigation buoys
come in many shapes and sizes. Those for ocean
duty are usually made up of a suf)erstructure
carrying a Ught and a bell or whistle, a cylin-
drical float chamber, and a stabilizer to hold
the buoy upright. They are anchored to large
blocks of concrete by heavy chain.

Immediately upon launching, buoys become
attractive bases for colonization by marine
organisms. The organisms which settle, survive,
and grow are, for the most part, species which
are able to attach themselves securely. When

' Published previously in the October issue, Vol. 98. No. 4.
in an unsatisfactorj' manner, due to editorial carelessness,
and re-published correctly here without cost to the sub-
scriber.

the buoy is returned for cleaning and servicing,
the entire community of organisms can be con-
veniently observed and sampled. The outside
buoy surfaces are subjected to strong tidal
currents and wave action, which restrict at-
tachment to those organisms with the most
tenacious holdfasts. The inside of the stabilizer
tube (Fig. 1) offers a more sheltered en-
vironment with considerable, but gentler, water
exchange as the buoy surges up and down. Here
are found the densest populations, and here the
struggle for space is readily observed (Merrill,
1965).

FIG. 1. Ti/pwal iimngation buoy. Arrow indicates the
sheltered, inner portion of the stabilizer tube.

Vol. 90 (1)

January 30, 197(i

THE NAUTILUS 55

METHODS

The collection was taken from the Nantucket
Shoals Lightship (NSLS) buoy. The buoy was
placed on station October 8, 1957, at N. lat.
40°33'; W. long. 69°28', 1 mile north of the
Nantucket Lightship, and returned to the Coast
Guard Base at Woods Hole for cleaning and
repairs on May 10, 1958. It offered a par-
ticularly attractive fouling community for
study, since the buoy had been on station for
only a limited time (7 months), and during a
period when many species with pelagic larvae
were not spawning (the winter months).

The NSLS buoy is 24 ft long and its greatest
diameter is 9 ft. About half of the buoy is sub-
merged when in position. Collecting was restrict-
ed to the area 8 ft inward from the mouth
(bottom) of the buoy stabilizer, which is 2 ft in
diameter (see arrow. Fig. 1). This area, ap-
proximately 50 sq ft, was carefully scraped and
then wire-brushed to loosen many small in-
dividuals still hidden in crevices. The total sam-
ple of l'/2 gal (12 pt) was taken to the
laboratory for sorting, study, and analysis.

Since the buoy had been out of water about
3 weeks, the fouling community had dehydrated
slowly and was in excellent condition for collec-
tion and study. Much of the material consisted
of sizable thin pieces of rust (Fig. 2) with
animals and plants attached in their original
positions.

Measurements of mollusks were made to the
nearest 0.1 mm wath the aid of an ocular
micrometer. The greatest overall size, height or
length was used as the basic measurement.

.1 i

FIG. 2. A piece of iron n/st removed from within the
stabilizer tube of a buoy. The material dried slowly and a
number of organisms can be seen adhering in their original
positions.

Hydrographic data for the area were
available from the nearby lightship.

To compare the population of the buoy with
that of the bottom below, the area was dredged
on May 26, 1958, about 2 weeks after the buoy
was brought in. A 10-ft-wide sea scallop dredge
with a ^/4-inch stretched mesh liner was towed
from the Bureau of Commercial Fisheries
Research Vessel Albatross HI to make the
collection. The contents of a 5-min tow which
covered approximately 15,000 sq ft of bottom
area were analyzed.

RESULTS

Three species of pelecypods — the sea scallop,
Plaeopeden rnagellanicus, the jingle shell,
Anornia aculeata, and the common, blue mussel,
Mytilus edulis — dominated the community
found on the buoy. Because the two latter
species were so numerous, a 1-pt subsample (of
the 12-pt total sample) was taken and all
specimens were counted and measured. The
length-frequency distributions obtained of the
three most common mollusks are shovra in
Figure 3. As a check on the validity of this
subsample, all molluscan species in the total
sample, except the numerous A. actdeata and
M. edulis, were also counted and measured.
Figure 4 shows the frequency distribution of P.
rnagellanicus found in the total sample.

The frequency distributions in Figures 3 and
4 are strongly skewed to the right and only
that for M. edulis is obviously polymodal. In
the subsample, there were 731 P. rnagellanicus
with a range in size of 0.5-13.2 mm and a mode
at about 3 mm; 2,217 A. aculeata with a range
of 0.5-14.0 mm and a mode at about 4 mm; and
1,550 M. edulis with a range of 0.4-24.3 mm and
obvious modes at about 1.7 and 2.8 mm (Fig. 3).
In the total sample, there were 9,806 P.
rnagellanicus with a range of 0.5-13.4 mm and
modes at about 2.5 and 2.8 mm (Fig. 4).

The mussel produces a stout and intricately
woven byssus, and the jingle shell a short
thickened byssal plug, both of which are
capable of holding shell remains securely to a
substrate after drying. The thin byssal threads
of scallops become brittle upon drying and
break easily. Therefore, the size-frequency data
presented in Figure 3 for the mussel and jingle

56 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

5 6 7 e 9 10

LENGTH IN MILLIMETERS

FIG. 3. Size -frequency distribution of the three cvmmun moltiusk sjjccws found on the Nantucket Shoals Lightship buoy (1-
pt subsample).

shell are pwssibly more representative of the
total sample than for the scallop. Propor-
tionally, there were fewer small PUicopecten in
the pint subsample than in the total sample,

and the mode was about 0.5 mm higher. Ap-
parently, some of the smaller scallops settled to
the bottom of the original scrapings before the
aliquot was obtained. However, aside from these

<

O

a

2

U.
O

q:
lij
m

s
1}
z

LENGTH IN MILLIMETERS
FIG. 4. Size-frequency distribution of the sea scallops found on the Nantucket Shoals Lightship (moy.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 57

TABLE 1. Frequency by size of the

•nolhisk

,s taken from

the Nantvcket Shoals Lightship buoy

Specie*

Size i til III)

Total 1

Range

0-1

1-2

2-3

;5-4

.1-.5

,5-1;

6-7

7-8

8-9

f>-10

>10

Live

Dead

in size

iV.i.

No.

Nil.

No.

A',..

A'..,

No.

No.

No.

A'o.

Nil.

Nil.

No.

in m

GASTROPODA

Mitrella lunata Say

I

13

12

12

41

3

1.4- 46

Lacuna nerttnidea dduld

7

6

13

1

03- 1.8

Spiratella lesueuri D'Orbigny

2

9

1.7

Anachis avara Say

1

1

1.4

Unidentified

0

2

0.3

PELECYPODA

Placopecten mayellaniais Gmelin

148

1,845

.3,4:33

a 174

868

425

371

275

154

86

27

9,806

0,5-13.2

P. magellanicus (dead)

118

84

23

4

1

9

1

233

2.0- 69

Anomia aculeata Gmelin

:S6

2,4CKJ

3,axi

4.608

4,452

3,516

2,472

2,160

l,.50O

732

468

26,604*

108-

0.,5-13.0

Mytiliis edidis Linnaeus

744

3,792

.3,144

1,824

1,284

1,452

1,248

1.5.36

840

636

•2,100

18,600-

04-24.3

M edulis (dead)

204

1,800

396

60

34

48

12

12

12

2,568-

0.4- 83

Hiatella arctica Linnaeus

4

14

14

6

5

3

1

1

48

2

1.1- 9.3

Anadara ovalis Bruguiere

1

1

2.5

Teliina agUis Stimpson

1

1

0.9

Periploma papyratium Say

1

1

1.1

.5.5,120

2,915

-Calculated from i 12 aliquot of total sample.

minor differences, the scallop size-frequency
distribution in the aliquot (Fig. 3) is similar to
that in the total sample (Fig. 4).

All the moUusks collected from the buoy are
listed in Table 1, together with their size-
frequency by 1-mm groups. The size-frequency
of the shells of dead P. magellanicus and M.
edulis is also given. The total number of A.
aculeata and M. edulis is estimated on the
basis of subsample counts. TTie total number of
living mollusks from the 50-sq-ft area was
55,120 or an average of 7.7 individuals per
square inch.

The material obtained by dreding the bottom
under the buoy was compared with the sample
from the buoy (Table 2). The bottom was of a
mud-sand texture; the sand dollar,
Echinarachnius parma, proved to be the com-
monest species of the area with over 1,200 cap-
tured. Some of the larger gastropods such as
Lunatia heros and Buccinum undatum were
present in fair numbers, and there were many
dead double valves of the bivalve, Arctica islan-
dica. The molluscan faunal composition of the
bottom was completely different from that of
the buoy except that it contained a few large
sea scallops. None of the same larval mollusk
species that had settled on the buoy found their
wav to the bottom in this area.

TABLE 2. Number of live and dead mollusks collected in
the dredging of a 5-min tow on May 28. 1958, in the area
of the Nantucket Shoals Lightship buoy.

Number of specimens
*«"«« Live Dead

Gastropoda

Cotus pygmaea Gould

Nassari.us trivittatus Say

Buccinum undatum Linnaeus

Lunatia heros Say

Crepidula plana Say'
Pelecypoda

Placopecten magellanicus Gmelin'

Artica islandica Linnaeus'*

Ensis directus Conrad"*

Astarte castanea Say

Venericardia borealis Conrad

Modiolus modiolus Linnaeus

Anomia simplex d'Orbigny

Spisula solidissima Dillwyn''

1

5

8

3

62

60

74

64

78

0

6

1

8

125

0

5

2

0

5

0

1

1

1

0

9

1

- This species had deposited numerous egg cases on the in-
terior of practically every dead valve of the mahogany clam
{Arctica islandica).

' Found attached inside large dead shells, usually Lunatia
heros.

' The heights of these in millimeters were 59.9, 85.2, 117.8,
131.7. 1.57.4, 164.7; one upper valve, 28.2
'' The animal lives in the substratum, consequently not
adequately collected by the type of dredge used.

DISCUSSION
Each species exhibited patterns of preference
in utilizing the substrate within the 8-ft length

58 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

of buoy tube. The spat of Mytilus, for example,
first attached directly to the substrate, and
later tended to aggregate and intermingle their
byssal threads to form colonies. Even thou^
the mussel may detach and reestablish
elsewhere (Field, 1922), our observations showed
that in some cases unusually dense masses of
byssal threads may entrap certain segments of
a population. As a result, some mussels became
smothered, or grew at a slower rate than neigh-
boring specimens. Anomia spat attached directly
to solid substrate, preferring crevices, but did
attach to all other available surfaces. Individual
Hiatella were randomly distributed and grew
competitively within aggregates of mussels, or
freely on open substrate. The spat of Plcwopec-
ten showed a marked preference for areas that
were free from other mollusk association. The
smallest scallops, those under 1 mm, were in-
variably attached to the filaments of bryozoa,
to the byssal threads of Mytilus, or directly to
shells, where they could move about freely.
Scallops over 1.5 mm were generally attached to
solid substrate, far removed from other
organisms, when possible.

Young sea scallops do not seem to compete
well in fouling communities. The mantle is ap-
parently easily injured, and evidence of serious
shell malformation was seen in situations where
other organisms were in close proximity to the
scallop. This was particularly noticeable when
an occasional larger specimen had been trapped
within the byssal maze of a Mytilus colony.
Young Anomia, Mytilus. and Hiatella, unlike
Placopecten, adjust to the necessity for living
close to other organisms. Anomia conforms
easily to close contact; if an obstacle in the im-
mediate area interferes with normal develop-
ment, the individual will change shell symmetry
and become elongate in any plane which offers
the opportunity for further growth. Mytilus and
Hiatella suffer least from close contact,
probably because their siphons, not their mantle
edges, are most exposed. However, both species
are known to exhibit shell distortion in con-
ventional habitats — Hiatella in peat and coral
burrows, and Mytilus in dense colonies.

Baird (19.53), in examining many "bushy"
organisms obtained from dredgings, found only
the bryozoan Gemellaria to be a consistent host

for settling sea scallop larvae. He suggested the
possibility of a direct relationship between
Gemellaria and Placopecten in the larval
ecology of the scallop. In light of our ob-
servations, we wash to amend this slightly. Ap-
parently when the scallop spat settles, it is too
delicate to take advantage immediately of bot-
tom substrate, composed entirely of particulate
matter continuously shifting with the bottom
currents. Thus, those that land on sedentary
branching plants and animals, or any other
hard .mrface on or above the ocean floor which
offers freedom of shell movement on all sides,
may have a distinct survival advantage.

It should be noted that, as with Placopecten.
many of the smallest individuals of Mytilus and
Anomia were attached to bryozoa and to byssal
threads; however, just as many of the smallest
were attached to solid substrate. From ob-
servations on the distribution of these species
in the buoy, it appears that all are able to
disengage themselves and travel some distance
—the mussels to aggregate, the scallops to
spread out, and the jingle shells to seek any
solid substrate available. Mytilus and Anomia
appear to fix more or less permanently at an
early age, while Placopecten and Hiatella may
continue to disengage from time to time.

Several of the smallest scallops from the buoy
measured as little as 0.5 mm. The prodissoconch
measured about half this size, so these smallest
specimens had approximately doubled in size
since settling. To our knowledge, these are the
smallest metamorphosed sea scallops ever col-
lected.'

After death, the ligamental structure in the
hinge of the scallop continues to hold the valves
together, but gaping. In this condition, sea
scallop valves tend to tangle in filamentous
bryozoa or amongst the byssal threads of the
mussels. There were 233 dead specimens of
scallops in the total population, the mode at
about 2.0 mm. Size-frequencies for the dead and
live scallops (Table 1) show similar curves
which suggests that valves do not remain long
in the buoy after death. The pint sample con-
tained 214 dead mussels (Fig. 3, dotted line),

' We have since taken from buoys scallops as small as 0.3
mm. the prodissoconchs having barely a fringe of dissoconch
growth.

Vol. 90 (1)

January 30, 1976

THE NAUTILUS 59

many of them of smaller size. In fact at about
1.2 mm, more dead than live mussels were
counted. Some of these were found trapped in
aggregates of mussels, while many were found
partly or completely buried in the light layer
of fine silt and debris that builds up in the
buoys. The great mortality in the smallest
mussels occurred over a period of time, judging
from the various degrees of shell decomposition
observed. The top and bottom valves of A.
acideata? soon separate after death and shell
remains are quickly flushed from the buoy;
hence, dead specimens are rarely found.

In order to discuss growth, the time of set-
ting must be ascertained with some degree of
accuracy. It is possible to determine quite
closely the spawning season (and hence the
probable time of setting) for two of the major
species on this buoy. Observations on the
spavraing of sea scallops have been made by
several investigators. These observations have
been summarized by Dickie (1955, p. 848) and
show that the spawning period, for all
geographical areas, may extend from mid-July
to early October. From extensive study, we can
definitely state that scallop spawning in the
offshore area of Cape Cod occurs between late
September and the middle of November.
Allowing as much as an extra month in the
larval state, all spat should have settled by
mid-December. This means larvae of the sea
scallop could, and probably did, settle on the
buoy during the first few weeks after it was
placed on station, and, judging by the
similarity of their population structures, so did
the other species as well.

In Milford Harbor, Connecticut, spawning of
M. eduiis is restricted to those months when
the temperature is approaching and above 60°F^
(Engle and Loosanoff, 1944). In "Marine Fouling
and Its Prevention" (Woods Hole Oceanographic
Institution, Contribution No. 580, 1952), early to
late June is indicated as the beginning of the
breeding season for Mytilus at Woods Hole,

Massachusetts. Mytilus larvae, then, must have
been in the water after the buoy was placed on
station, and, because of the low temperatures
that prevailed, there could have been no further
sets in the spring before the buoy was taken
off station. No spawning information is
available for A. aculeata, but the size-frequency
distribution suggests that the spat of this
species settled about the same time as the other
two species.

Both M edulvi and A. acvleata showed signs
of polymodal distribution not obvious in P.
magellanicus. The use of probability paper in
an attempt to define polymodal distribution as
outlined by Harding (1949) failed to show any
significant secondary set or group for the sea
scallops. However, similar analysis of the
Anomia data indicated possible modes at 3.7
mm and 7.2 mm, and for the mussel at 1.6 mm,
2.8 mm, 7.0 mm, and possibly others. This
suggests that, within the spavming period, one
strong set of sea scallops and two or more
heavy sets for the other two species settled on
the buoy.

From observations of the buoy material, there
is indirect evidence that more than one group
of larvae settled. For instance, many small
Anomia were seen attached to larger shells of
the same species; a small Anomia and a small
Mytilus were found attached to the inner valve
of a much larger dead mussel; and there were
many instances in which one organism grew
upon another in such a way as to suggest that
it set some time after the other. Indirect
evidence can also be found in the data; for in-
stance, the smallest mussel was 0.4 mm and the
largest just under 25 mm — far too much dif-
ference in growth, it is felt, for a single set.

The average and maximum sizes of the four
common species of pelecypods found in the buoy
were:

' Abbott in the second edition of American Seashelk (1974.

p. 452) follows Winckworth, 1922, and others, in calling this

species squamida Linne, 17.58.

' Temperature records for the time and locality involved in

this study are available in published form (Day, 1959a;

1959b).

Average

Maximum

Placopecten magellanicus

Z9 mm

13.2 mm

Mytilus eduiis

a9 mm

24.5 mm

Hiatella arctica

3.7 mm

9.5 mm

Ammia aculeata

4.5 mm

13.2 mm

The averages represent shell growth for 6 to 7
months after setting, and during the coldest
months of the year. The maximum sizes at-
tained are an indication of the amount of

60 THE NAUTILUS

January 30, 1976

Vol. 90 (1)

growth that can be achieved under the existing
conditions.

The location of the NSLS buoy is such that
pelagic bivalve larvae could be transported from
many coastal areas, and this could effectively
extend the setting season. The currents that
sweep over Nantucket Shoals undoubtedly carry
planktonic larvae originally spawned in many
different estuaries and bays of the Massachu-
setts coast, as well as from a large area of the
Gulf of Maine. It seems most reasonable to
suggest that, for Mytilus at least, the peak of
setting may have occurred for several weeks af-
ter the buoy was on station. Initial settlers
would have had less competition from their own
kind, as well as a warmer and longer period in
which to grow.

It should be pointed out that a factor such as
overcrowding might lead to arrested growth.
Arrested growth in one segment of the
population might yield a mode that possibly
could be interpreted as indicative of age.

The strongly skewed size distributions of
Figure 3 deserve further mention. Such
distributions are not uncommon in youthful
populations of many organisms, and can con-
ceivably arise in one or more ways, including
(1) simple differences in growth due to time of
setting, especially when spatfall occurs over a
period of time associated with a change in tem-
perature; (2) decreased grow1;h rate for later
arrivals due to increased density and com-
petition; and/or (3) some characteristic of the
buoy that causes unusual mortality (or loss to
the buoy) amongst the larger individuals.

The sea scallop size-frequency is well fitted
by a log-normal transformation, as can be seen
in Figure 5. The length -frequencies of Mytilus
and Anomia are not so well fitted, perhaps
because more than one set is represented in the
data. However, since any one or any com-
bination of the factors mentioned above can
result in a log-normal distribution, this trans-
formation does not of itself shed additional
light on the subject.

It would appear that the observed skews can
be largely attributed to setting over a period of
time during which sea surface temperatures
were cooling. The possibility that many Mytilus
and Anomia settled after temperatures were too
cool for any further significant growth cannot

ID

s

I 2 3«56789I0

LENGTH IN MILLIMETERS

P'IG. 5. Size-freqtiency distribution of the xea scallops
found on the Nantucket Shoals LighUhip buoy plotted on
semilngarithmic paper to produce the symmetry of a log-
normal curve.

be dismissed. The problem is worthy of further
study, and material from buoys may be par-
ticularly useful in this respect.

SUMMARY

1. All the mollusks within an area of 50 sq
ft were collected from within the stabilizer tube
of a heavy duty navigational buoy. Twelve
species were recovered from approximately
55,000 mollusks that made up the fouling
population. Three species, Placopecten
mayellanicus, Anomia aculeata, and Mytilus
edulh were found in the largest number.

2. The ocean bottom under the buoy was
dredged, and the population composition and
structure were found to be completely different
from the buoy population.

3. The population structure and the in-
terrelationships of species in the mollusk com-
munity were closely observed. Methods of at-
tachment and distributional patterns, par-
ticularly patterns of preference in utilizing sur-
face area, are discussed in some detail.

4. Analysis of the length-frequency
distribution, using probability paper to define
polymodal groups, suggested one heavy set of P.
mayellanicus and two or more of A. aculeata
and M. edulis.

5. Taking into consideration the season and

Vol. m (1)

Januarv 30. 1976

THE NAUTILUS 61

length of time the buoy was on station (7 months
from October 8. 1957, to May 10, 1958) and
using available evidence regarding the time in
which sea scallops and mussels spawn, it was
possible to predict that these species had settled
on the buoy before the first of the year. Hence,
growth was related to the size-frequency
distribution after that time.

6. Size-frequency graphs for the three com-
mon species on the buoy show that large num-
bers of small individuals form obvious modes
and that a persistent but diminishing number
of larger specimens spread over a considerable
range; i.e., the major modes for the three
species are skewed to the right. Possible reasons
for such size-frequency distribution are
discussed.

ACKNOWLEDGMENTS
We wish to acknowledge the cooperation of
the Commander of Base, U. S. Coast Guard
Station, Woods Hole, Massachusetts, and other
base personnel who assisted in the collection of
samples. The writers are grateful to Dr. L. B.
Slobodkin for helpful suggestions relative to
distribution of animals.

LITERATURE CITED

Baird. F. T. Jr. 1953. Observations on the early life his-
tory of the giant scallop (Peclen magellanmut). Maine
Dep. Sea Shore Fish., Res. Bull. No. 14, pp. 2-7.

Day, C. G. 1959&. Oceanographic observations, 1957, east
coast of the United States. U.S. Fish Wildl. Serv., Spec.
Sci. Rep.-Fish. No. 282, 123 pp.

Day, C. G. 1959b. Oceanographic observations, 1958, east
coast of the United States. U.S. Wildl. Serv., Spec. Sci.
Rep.-Fish. No. 318, 119 pp.

Dickie, L. M. 1955. Fluctuations in abundance of the giant
scallop, Ptacnpecten magellanicus (Gmelin), in the Digby
area of the Bay of Fundy. J. Pish. Res. Board Can.,
12: 797-857.

Engle, J. B. and V. L. Loosanoff. 1944. On the season of
attachment of larvae of Mytilva edulis Linn. Ecology.
25: 433-440.

Field, 1. A. 1922. Biology and economic value of the sea
mussel, Mytihis eduiu!. U.S. Bur. Fish... Bull. 38: 127-259.

Harding, J. P. 1949. The use of probability paper for the
graphical analysis of polymodal frequency distribution.
J. Mar. Biol. Assoc. U.K.. 38: 141-1.53.

Merrill, A. S. 1965. The benefits of systematic biological
collecting from navigation buoys. ASB Bull.. 12: 3-8.

Winckworth. R. 1922. Note on the British Species of
Anomia. Proc. Malacological Soc. London, 15(1): 32-34.

Wcx)ds Hole Oceanographic Institution. 19.52 "Marine Foul-
ing and Its Prevention." U.S. Naval Inst., Annapolis, Md.
Prepared for Bur. Ships, Navy Dep., by Woods Hole
Oceanogr. Inst., Contrib. No. 580). 388 pp.

62 THE NAUTILUS

January 30, 1976

THE BEST OF THE

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was felled by a clam dropped on his head by a
seagull in 1925.

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APRIL 1976

THE

NAUTILUS

Vol. 90

No. 2

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. Arthur H. Clarke, Jr.
Department of Mollusks
National Museum of Canada
Ottawa, Ontario, Canada K1A-0M8

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Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. William K. Emerson

Department of Living Invertebrates

The American Museum of Natural History

Newr York, New York 10024

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Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

Dr. Aurele La Rocque
Department of Geology
The Ohio State University
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Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, California 90007

Dr. Arthur S. Merrill
Biological Laboratory
National Marine Fisheries Service
Oxford, Maryland 21654

Dr. Donald R. Moore

Division of Marine Geology

School of Marine and Atmospheric Science

10 Rickenbacker Causeway

Miami, Florida 33149

Dr. Joseph Rosewater
Division of Mollusks
U. S. National Museum
Washington, D.C. 20560

Dr. G. Alan Solem

Department of Invertebrates
Field Museum of Natural History
Chicago, Illinois 60605

Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, Ohio 43210

Dr. Ruth D. Turner

Department of Mollusks
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. Gilbert L. Voss
Division of Biology

School of Marine and Atmospheric Science
10 Rickenbacker Causeway
Miami, Florida 33149

Dr. Charles B. Wurtz
3220 Penn Street
Philadelphia, Pennsylvania I9I29

EDITOR-IN-CHIEF

Dr. R. Tucker Abbott

Delaware Museum of Natural History
Box 3937, Greenville, Delaware 19807

Mrs. Horace B. Baker

Business and Subscription Manager

1 1 Chelten Road

Havertown, Pennsylvania 1 9083

OFFICE OF PUBLICATION

Delaware Museum of Natural History

Kennett Pike, Route 52

Box 3937, Greenville, Delaware 19807

Second Class Postage paid at Wilmington, Delaware

Subscription Price: $7.00 (see inside back cover)

THE

NAUTILUS

Volume 90, number 2— April 27, 1976

CONTENTS

Notices; Review (of R. T. Abbott) iv

Gale G. Sphon

The Mitridae of the Galapagos Islands 63

Robert S. Voss

Observations on the Ex»logy of the Florida Tree Snail, Liguus fasciatus Muller ) 65

Walter B. MiUer

New Species of Sonoreiia (Pulmonata: Helminthoglyptidae)from New Mexico and Texas 70

Clyde A. Henry

The Commensal Clam, Paramya subovata Bivalvia: Myidae) and Thdassema hartrmni
(Echuroidea) off Galveston, Texas 73

John Ogle

The Occurrence of the Date Mussel Lithophaga bisulcata (Mytilidae) in Living Oysters, off
Galveston, Texas 74

G. L. Mackie, S. U. Qadri andA. H. Clarke
Reproductive Habits of Four Populations of Musculium securis (Bivalvia: Sphaeriidae) near
Ottawa, Canada 76

Leslie Hubricht

The Genus Fontigem from Appalachian Caves (Mesogastropoda: Hydrobiidae) 86

Warren S. Landers

Reproduction and Early Development of the Ocean Quahog, Arctica islandica, in the
Laboratory 88

Publications Received 92

NOTICES

WESTERN SOCIETY OF MALACOLOGISTS
The ninth annual meeting of the Western
Society of Malacologists will be held from June
23—27, 1976, on the Asilomar State Conference
Grounds, Pacific Grove, California. The program
will feature contributed papers, symposia,
displays, shell auction and field trips. Send
inquiries to Mr. Clifton Martin, 324 Kennedy
Lane, Oceanside, California 92054.

1976 AMU MEETING

The meetings will be held on the campus of the
Ohio State University, Columbus, with
registration Monday afternoon (Aug. 2) and the
opening of the sessions that evening. Air-
conditioned rooms with private bath at the
University Residence Halls are only $11.00 per
single and $15.00 per double occupancy. Banquet,
Thursday, Aug. 5; Field Trip, Friday, the 6th.
Amateur night will feature a shell book auction
and bazaar. Forms will be mailed to members in
May. Inquiries: AMU '76, Museum of Zoology,
Ohio State University, 1813 North High Street,
Columbus, Ohio 43210.

REVIEW

THE BEST OF THE NAUTILUS. A bicenten-
nial Anthology of American Conchology. By
Abbott, R. Tucker (editor). 1976. viii 4- 280
pp. American Malacologists, P.O. Box 4208,
Greenville, Delaware 19807. $13.95.

In this Bicentennial year it is most appropriate
to look back over "the best of the Nautiliwi."
Dr. R. Tucker Abbott, current editor-in-chief of
the Nautilius has done this for us, and for our
pleasure and enlightenment he has assembled a
special volume to serve both as a source of
some classic studies in early American con-
chology and of some historically interesting
papei-s not available to those who do not have
a complete set of the Nautilus. Not only
original papers are included, but brief notes,
news items, obituaries, advertisements and ex-
change offers (but don't answer any of them!)
are sprinkled throughout. There is something

here for everyone— reports for the serious stu-
dent, advice for the shell collector, warnings for
the environmentalist, nostalgia for the anti-
quarian, oddities for the curious, and humor for
everyone. Even verse is included. Everyone will
appreciate "Salute to the Nautilus.", a verse by
Henry Dodge, the only piece not originally
published in the Nautilus, and the only item of
recent date. Stress is given throughout the
volume to the romance of shell collecting and
the human side of malacology.

Coverage is the first 40 years of publication
(1886-1926), out of a total of 90 years, begin-
ning with a reproduction of the postal card
which formed issue No. 1 of Volume 1, then
known as The Conchologists Exchange, and
Pilsbry's introduction to the Nautilus, beginning
with Volume 3.

Selections are grouped according to
geographic areas— the Atlantic Coast, the Pacific
Coast; the major habitats— land, fresh-water,
marine; foreign collecting; departed friends;
and miscellaneous. Familiar names of the giants
of conchology— Pilsbry, Sipipson, Johnson,
Clench, Henderson, Roper, Morse, Winkley,
Keep, Fred Baker, Frank Baker, Oldroyd, Eyer-
dam, Ferriss, Frierson, Cockerell, Goodrich,
Walker, etc. appear on every page. Many ar-
ticles are prefaced with editorial notes of a
biographical nature.

Illustrations include a color plate of 11
selected, colorful marine, freshwater, and land
shells, many drawings of shells, diagrams of an-
tique apparatus (in the ads), and reproduction
of the original figures illustrating each article.

Having read through many volumes of the
Nautilus for my own studies, and as official
abstractor for Biological Abstracts over a long
period of time, I can assure the reader that
Tucker Abbott has made a most interesting
selection of material to exemplify what profes-
sional and amateur conchologists and
malacologists were doing, thinking, and writing
to advance the study of mollusks over the first
40 years of the Nautilm. and to share with us
the excitement they experienced.

Ralph W. Dexter
Dept. of Biological Sciences
Kent State University
Kent, Ohio

IV

Vol. 90 (2)

THE NAUTILUS

63

THE MITRIDAE OF THE GALAPAGOS ISLANDS

Gale G. Sphon

133 W. Channel Rd.
Santa Monica, Calif. 5X)402

ABSTRACT
Eleven species of Mitridae are known to occur in the Galapagos archipelago.
Of these, thrve are endemic. The range of Mitra mitra is extended to include
the Eastern Pacific. The generic or s^ibgenenc standing of four species is
changed. A new secies, Subcancilla edithrexae, is described from the Galapagos
Islands.

The family Mitridae ranks as one of the
largest in the molluscan phylum. Cemohorsky
(1970) recorded over 800 valid species and
stated that 2624 names had been proposed. The
majority of mitrids are found in the Indo-
Pacific. In the Eastern Pacific, I recognize
about 30 valid species. Within the Galapagos
Islands, this number is reduced even further.
As far as I have been able to determine there
are only eleven species occurring in the ar-
chipelago.

First, a new record for the E^astem Pacific:
Mitra (Mitra) mitra (Linnaeus, 1758). In the
Indo-Pacific this is a very common species, but
Eastern Pacific records are based on only three
specimens, one adult living specimen taken off
the coast of Costa Rica and two adult, but
dead, specimens dredged by Jacquline and An-
dre DeRoy in the Galapagos. The DeRoys re-
tained one specimen for their own collection
and deposited the other at the Charles Darwin
Research Station. The Costa Rican specimen is
in the collection of the Los Angeles County
Museum of Natural History.

The next species is Mitra (Isara) effusa
Broderip, 1836. Mitra effusa is not common
anywhere within its range from Mazatlan, Mex-
ico, to Ecuador and the Galapagos. However, it
has been dredged in several locations in the
Galapagos by the DeRoys. Cemohorsky (1970)
synonomized the subgenus Isara with Mitra s.s.
However, the shape of the shell with its droop-
ing lip is distinct enough to warrant its separa-
tion as a valid subgenus.

The third species is evidently endemic to the
archipelago. This is Mitra (Mitra) gausapata
Reeve, 1845. Keen (1971) placed this species in

the subgenus Strigatella. I am here reassigning
it to the subgenus Mitra based on the radula
and shell morphology. Apparently this is one of
the sand-dwelling Mitra and occurs subtidally
throughout the archipelago. It appears to be
relatively common within its restricted range.

The fourth species is Mitra (Mitra) crenata
Broderip, 1836. Again, the subgenus is changed
here from Strigatella to Mitra s.s. Specimens I
have seen indicate that it is probably a good
species and not the young of something else,
even though at the present time the radula is
still unknown. The range of the species is from
Guaymas, Sonora, Mexico, south to and
throughout the Galapagos Islands.

Its authors put Subcancilla sphoni (Shasky
and Campbell, 1964) in the subgenus Strigatella.
Keen (1971) questioned this. Neither the shape
nor the spiral sculpture are characteristic of
Strigatella and it is here changed to the genus
Subcancilla. It ranges fi-om Guaymas, Sonora,
Mexico, to the Galapagos Islands.

The sixth species is a common intertidal
species throughout most of its range, from the
head of the Gulf of California to Peru.
However, Mitra (Mitra) lens Wood, 1828 is rare
in the Galapagos. To my knowledge it has only
been taken once in the Archipelago at Academy
Bay, Santa Cruz Island by Carmen Angermeyer
in 1964. This specimen is now in the American
Museum of Natural History. Mitra lens, also,
should be removed from the subgenus
Strigatella and placed in the subgenus Mitra on
the basis of the radular structure.

The seventh species is the only true
Strigatella in the Eastern Pacific and this is
Strigatella tristis (Broderip, 1836). This is prob-

m THE NAUTILUS

April 30. 1976

Vol. 90 (2)

FIG.l. Subcancilla edithrexae Sphon, iiew speaas. Huluti/ije
Length 22.6 mm. Width 9 mm.

ably the most common Eastern Pacific Mitra. It
ranges from the head of the Gulf of California,
south to Ecuador and the Galapagos Islands.

Although Strigatella is a large group, all
the members resemble one another in their
pyriform shape. Some authors have used Striga-
tella as a genus, and I tend to agree with them
even though there is little difference in the
radula of Mitra s.s. and Strigatella.

The next three species all belong to the genus
Thala. The type locality for Thala gratiosa
(Reeve, 1845) is the Galapagos and it has a
much larger range than the others, namely
from the Gulf of California to Panama. It has
also been, mistakenly, called Thala solitaria (C.
B. Adams, 1852). T. solitaria occurs from

- 1

\'j

Banderas Bay, Mexico, to the Galapagos and
was described from Panama. The true Thala
solitaria is one of the rarer Eastern Pacific
miters. The third species of Thala is T. jean-
cat eae Sphon, 1969 and it is known only fi-om
a half dozen specimens from the Galapagos.

The eleventh and last mitrid species is new
to science, and I take great pleasure in naming
it in honor of a very dear friend, Miss Edith
Rex.

Subcancilla edithrexae Sphon, neir species
Shell of moderate size, to 22 mm in length;
shape ovate with raised reddish brown ribs
about one quarter to one half the width of the
white interspaces; periostracum thin and
brownish; interspaces marked by numerous ir-
regular growth lines; columella with 3 or 4
plications; spire attenuate, angle acute; aper-
ture narrow, slightly more than half the shell
length; Radula formula 1-1-1; Triangular -shaped
rachidian wider than hi^, with 6 cusps, the
center 4 being of equal size and prominent, the
outer ones being one-third as large, a small
denticle present on the ends nearest to laterals;
laterals with eleven cusps, the two outer ones
mere denticles, next six progressively larger
nearing the median tooth; third cusp from the
median largest; innermost two reduced in size;
lateral tooth plate basically rectangular in
shape with slight curve to lower portion.

The holotype was collected by the Ameripagos
Expedition, in 10-20 feet of water on March 25,
1971. The type locality is Punta Alfaro, Isabela
Island, Galapagos Islands, Ecuador. It is
deposited at the Los Angeles County Museum
of Natural History (LACM 1735). There are
numerous paratypes in the following institu-
tions and private collections: American Museum
of Natural History; California Academy of
Sciences; Charles Darwin Research Station;
and several private collections.

/

FIG. 2. Radrtla of Subcancilla edithrexae Sphon. new
species (from a paratype).

LITERATURE CITED

Cernohorsky. W. 0. 1970. Systematics of the families

Mitridae & Volutomitridae (Mollusca : Gastropoda). Buil.

Aukland Inst, and Mus. no. 8, pp. 1-190 -I- iv, 18 pits.
Keen. A. M. 1971. Sea Shells of Tropical West America.

Stanford Univ. Press, Stanford, Calif, pp. 1-1064 -t- xiv.

Dlust rated.

Vol. 90 (2)

THE NAUTILUS

65

OBSERVATIONS ON THE ECOLOGY OF THE FLORIDA TREE SNAIL,
LIGUUS FASCIATUS (MULLER)

Robert S. Voss

Department of Ecology & Evolutionary Biology

Student Union P.O. Box 9743

Tucson, Arizona 85720

ABSTRACT

Four South Florida populations of Liguus fasciatus were studied over an
eight month period. Growth ivas calculated by means of size frequency diagrams
and age class groupings, and was found to be roughly linear. L. fasciatus
hatches at a size of 7 mm, grows aproximateiy 10 mm per year, and reaches
sexual maturity in its fourth year at a size of about ^8 mm. Copulation occurs
in the months of July. August and early September, and nesting follows in late
September. Mass mortality of adult snails was observed soon after nesting. The
young emerge with the rains in April and May, but are fully developed long
before. Tree snails are eaten by many vertebrates and invertebrates, and preda-
tion may exert a powerful selective pressure on this species. L. fasciatus
displays a marked preference for smooth barked host tree species, preferential
listings of which are included. L. fasciatus is not an endangered species in South
Floiida.

Liguus fasciatus (Mtiller) is a tree snail of
Antillean origins which probably arrived from
Cuba shortly after the emergence of the Florida
peninsula in the late Pleistocene. In Florida, L.
fasciatus is found exclusively in hammocks,
assemblages of tropical hardwood trees scattered
island-like in the 'Glades and pinewoods of the
extreme southern part of the state. Hammocks
provide Liguus protection from fire, predators,
cold spells, and dessication.

The species exhibits great variability in color-
ation of the shell which is often of striking
beaut>'. Consequently this snail has long been
popular with collectors, and an enormous
literature exists dealing almost exclusively with
its systematics and zoogeography. Surprisingly,
little has been published on the ecology of L.
fasciatus. What has been published on the sub-
ject consists largely of scattered notes, or pass-
ing references in larger, systematic works
(Pilsbn,- 1946, Simpson 1929, Weber 1953, etc.).
The best account to date is in a popular article
by Davidson (1965), but the ecological literature
on this snail is, as a whole, exceedingly sketchy.

It is hoped that this paper will help to fill this
gap.

METHODS

This study was carried out over an eight -
month period from August 1969 to March 1970
during which weekly field observations were
made. Attention was centered on four Liguus
populations, three on the east coast of Florida
near Miami (Matheson, Brickell, and Timm's
Hammocks) and one on the eastern edge of the
Big Cypress Swamp (Pinecrest #5, Pilsbn' 1946)
about fiftj' miles west of Miami.

Snails were sighted and collected either by
hand or with the aid of a "Lig pole", three in-
terlocking four foot aluminum tubes with a cup
on the end into which the snail was shovfed.
Measurements of living snails were taken in
the field: total length from the apex of the
shell to the base of the aperture.

Eggs were incubated in one-pint Mason jars
kept outdoors and occasionally sprinkled with
water. Young were maintained for short periods

66 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

in an indoor terrarium and provided with wet
bark on which to feed.

All of the dead shells on several square
meters of forest floor were collected for preda-
tion studies. When studying tree preference, the
hammock was "walked" and all trees closely
scrutinized for snails.

RESULTS AND DISCUSSION

Reproduction: Ligmis fasciatus mates in the
summer primarily in the months of July,
August and early September, which is the rainy
season. I have, however, observed copulating
pairs as late as September 20. Snails on trees
and on the ground often appear to follow the
mucus tracks of others, and individuals may
locate each other prior to mating in this way.
Mating was only observed on tiees. A long in-
terval of intertwining precedes copulation.

Gestation takes from three to six weeks, and
at the first heavy rain the snails descend to lay
their eg^. The nesting procedure is as follows:
the snail anchors pjart of its foot on the base of
the tree, and tentatively stretches out across
the leaf litter. Reassured, it releases its hold,
and begins probing the humus for a suitable
nest site. This operation may occupy some half
hour or more. After locating a spot, the snail
begins to pull itself into the humus by exten-
sions and contractions of the foot until only the
apex of the shell remains above ground. Here it
hollows out a nest in the earth consisting of a
vertical tunnel, 10 to 15 mm in diameter, which
widens to form a chamber for the eggs. The
depth of the nest varies from 40 to 50 mm. The
entire nesting process lasts between 59 and 75
hours, during which time the snail is extremely
vulnerable to terrestrial predators.

In 1969, snails were observed laying eggs only
from 14-27 September. The peak of ^g laying
activity was from the 14th to the 19th, after
some exceptionally heavy rains. Of nineteen
snails observed nesting in Matheson Hammock
on September 16, the range in clutch size and
mean clutch size was 14-19-30 eggs. The range
in size and average size of nesting snails was
40-48.3-60 mm. No correlation was observed be-
tween size of snail and clutch size. The eggs of

L. fasciatus are oval, 6.5-8.0 mm long and 5.5-
6.0 mm wide, brittle, and pinkish brown
(Ridgway's Color Guide's Light Vinaceous Fawn
(Weber 1953)) in color.

Many snails die soon after nesting. This is
evidenced by the disproportionately large
numbers of freshly dead snails observed for a
month or so after the egg laying period, a phe-
nomenon also noted by Simpson (1920). This
field observation was later verified by examin-
ing size frequency diagrams (Figs. 1 arid 2).
Here, it is seen that the number of snails per
size range drops off considerably for sizes
greater than 48 mm, the average size at
nesting, indicating low post -reproductive sur-
vivorship. High post-reproductive mortality may

1

10

A

^ 8

W

n

1 \

c

1 \ A

! 6

/ \

o

/ \

fc 4

/ \

n

/\ / \

E

/ V L

3 2

c

\ / \

1 1 1 > 1

10

20 30

size (mm)

40

50

FIG. 1. Size frequency distribution of a sample of 52
LiguusyroTW Tlmm 's Hammock.

c
in

i)
n

E

C

10

20

30 40 50 60

size (mm)

FIG. 2. Size frequency distribution of a sample of SU
Mgwjsfrom Brickell Hammock.

Vol. 90 (2)

THE NAUTILUS

67

function to reduce competition between non-
productive adults and their potentially produc-
tive young.

Hatching occurs after the first heavy rains in
April or May apparently due to increasing
warmth and moisture, as the snails are fully
developed after six weeks (Weber 1953). Snails
removed from the egg by me after fifteen
weeks, and provided with wet bark to feed on,
began to grow immediately; snails left in the
^g did not hatch for another three months.
The newly hatched young measure 6.0-7.0 mm
long.

Aestivation and Feeding: During the winter
months from November to March, the dry
season in southern Florida, Liguus fasciatus
secretes a mucus seal which cements the shell
to the tree, protecting the animal from dessica-
tion. During this time the shell does not grow.
Upon resumption of feeding with the spring
rains, shell growth begins anew, and a growth
line appears where lip growth ceased during
the winter. By counting the number of these
grow^th lines, the age of the snail can be deter-
mined with a fair degree of accuracy. Occa-
sional winter rains may occur, and after these
snails may be seen feeding for a while before
resuming aestivation.

Liguus fasdatus is largely nocturnal, and is
most active after heavy rains which soften the
confervoid algae (Simpson 1929) and lichens on
which it feeds. This grovrth is abundant on tree
bark, the normal substrate for L. fasciatus. and
the feeding snail cuts visible swaths in this
growth as it moves.

Growth: In an organism such as Ligmis
fasciahis in which reproduction is seasonal,
discrete generations are present, and these
generations should appear as peaks of size fre-
quency when the measurements of large
numbers of individuals from a given population
are graphed. Such was found to be the case,
and graphs of size versus frequency for the
Timm's and Brickell Hammock populations are
given in Figures 1 and 2. Peaks represent suc-
cessive generations and the distance between
them a years growth. Averaging the data from
the two populations, and assuming that the
young hatch at a size of 7 mm, it is found that
L. fasciatus grows approximately 9 mm the

TABLE 1. Aivrage size of snails frmn three hammnrks
grmiped accirrding to anniud growth marks (total length in
mm.) M = Matheson Hammock; B = Bnckell Hammock;
T = Timm's Hammock; in the column "mean growth"
the snails assumedly hatched at 7 mm.

YEAR

M

Hammock
B

T

^fean size

Mean grovth

1

18

23

18

19.6

12.6

2

28

30

29

29.0

9.4

3

34

43

36

37.6

&6

4

49

49

42

46.6

9.0

first year, 14 mm the second, 11 mm the third,
and 7 mm the fourth. Measurements throughout
were taken from the apex of the shell to the
base of the aperture.

A second method employed in estimating
growth was that, of grouping the snails by an-
nual growth marks (discussed in the preceding
section), and averaging the sizes of individuals
in each group. Year class averages calculated
by this method (Table 1) yield the following
figures for growth: first year 13 mm, second
year 9 mm, third year 9 mm, fourth year
9 mm.

Data derived from both of the above methods
were plotted on the same graph (Figure 3), and
growth (measured as total length) was found to
be approximately linear. Mean size of nesting
individuals was found to be 48 mm, and by
locating this size on the line fitted to the data
points in Figure 3, it is found that reproduc-
tion occurs at the end of the fourth year of
growth.

Tree Preference: While observing tree snails,
it was noted that they displayed a marked
preference for certain tree species. This ten-

• growth mark

o srze frequency
40

20

10

age (years)
FIG. 3. Size (total length) vs age for Liguus. Date derived
from size frequency diagrams and age class groupings.

68 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

TABLE 2. Host trees of 50 liguus from "nrnm's Hammock

Number of snaiia

Hott tree species

34

Tamarind Lysitoma bahamensis

5

Poisonwood Metupium torifera

3

Jamaica Dogwood Piscidia pisdpula

2

Paradise Tree Simarouba glauca

2

Tetmzygia bicolor

2

Live Oak Quercvs virginiana

1

Stxangler Fig Ficus awrea

1

dead wood

TABLE 3. Host trees of 21 Liguus from Matheson
Hammock

Number uf snails

Host tree species

7 Strangler Fig Ficus aurea

2 Paradise Tree Simarouba glauca

2 Seagrape Coadoba uvifera

1 Mastic Ma,st ichodendron foetidissimum

1 Live Oak Qiiercus virginiana

1 Jamaica Dogwood Piscidia piscipula

7 Miscellaneous (ground, palmetto leaves,
dead wood, etc.)

dency has been noted before in the literature
(Simpson 1929, Craig 1973), but quantitative
data has not been made available.

The host trees of 50 Liguus fascial us were
tallied, and the results are given in Table 2
(Timm's Hammock). In this hammock, 65% of
the snails were found on Lysiloma, 9% on
Metopium, and 6% on Piscidia with the remain-
ing 20% being found sparingly on foiu" other
species.

The host trees for 22 Liguus fasciatus from
Matheson Hammock are listed in Table 3. In
this hammock, Lysiloma and Metopium are ab-
sent or scarce. The trees most frequented in
this case were F^us (32%), Simarouba (9%),
and Cocoloba (9%). An unusual number of
snails were found on atypical substrates on the
day when this survey was made.

Other trees on which I have commonly
observed Liguus are the Mastic (Mastich-
odendron foetidissimum), and the Guava
(Psidium guajava). Citrus groves in or near
hammocks are often found to contain numbers
of tree snails. Simpson (1929) found L. fasciatus
on cypress trees (Taxodium), and White But-
tonwood (Conocarpus erecta) in fresh and salt
water swamps respectively. It seems unlikely
that these represented breeding populations ron-

sidering the terrestrial nesting habits of these
snails. It is possible that Simpson's specimens
were isolated individuals accidentally dropped
by birds, or snails which had wandered away
from hammocks in the dry season, to be later
isolated by rising water.

It appears from the preceding data that L.
fasciatus strongly prefers certain tree species
over others. In each case, the preferred species
are smooth barked trees. On such trees there is
an abundance of algal growth on the bark, the
smooth surface of which permits the snail to
crawl easily, and presumably permits a long,
unobstructed sweep of the radula. It should be
noted however, that L. fasciotns will feed over
any smooth algae covered surface including con-
crete walls and the sides of wooden outhouses
(personal observations).

Predation: In southern Florida, Liguus
fasciatus is preyed upon by a wide variety of
vertebrates and invertebrates. While the con-
tribution of L. fasciatiui to the food budget of
individual predator species may be small, their
cumulative effect on tree snail populations may
be quite large.

The carnivorous gastropod Euglaruiina rosea
has long been known to devour L. fasciatus.
and Baker (1903) observed that it likewise
devours the much larger native tree snail
Orthalicus. Davidson (1965) observed and
photographed E. rosea predation on L. fasciatus.
E. rosea seems to be primarily a terrestrial
species associated with rocky substrates, but I
have often observed it on concrete walls, and it
may climb trees as well.

Pilsbr>' (1946) stated that he had "seen no
evidence that the tree snails are molested by
native birds", but friends have repeatedly
observed Blue Jays (Cyanocitta crista semplei)
devouring L. fasciatus. and I have frequently
noted broken shells in areas where other
predators are scarce. Further, the condition of
many freshly broken empty shells is ttx) intact
for any but a beaked animal to have removed
the snail.

Rats have often been reported as a m^or
predator on L. fasciatus. Pilsbry (1946) believed
that they would soon exterminate these snails
in all accessible hammocks. Timm's, Matheson
and Brickell hammocks have been surrounded

Vol. 90 (2)

THE NAUTILUS

for many years by human habitations, however,
and their snail populations continue to thrive.
Clench (1975) has suggested the ameliorating ef-
fec-ts which domestic cats and dogs may have
on the hammock rat populations, and contends
that rats may indeed prey rather heavily on L.
fasciatus.

The native land hermit crab, CoenoMta
dypeatus may also prey on tree snails. David-
son (1965) observed possible predation on L.
fasciatus by this crab, but in a fit of an-
throp(jmorphic compassion removed the crusta-
cean before it could eat (?) the snail. I have oc-
casionally seen crabs of this species inhabiting
tree snail shells in Brickell Hammock, but as
Coernibita wall occupy any suitable empty
gastropod shell it encounters, this cannot be
taken as proof of predation.

The land crab Cardisoma guanhumi may also
eat L. fasciatus, for its burrows are often sur-
rounded by the broken shells of this species.
Rhoads (1899) reported that L. fasciatus is
"eaten by tree crabs which bite the shell in
half during their winter hibernation". He cites
the occurrence of broken basal portions
cemented on trees as evidence. This seems an
unlikely hypothesis as Cardisoma does not
climb, and Coenobita, a good climber, seems too
small to break a snail shell in two: Davidson's
photograph shows Coenobita inserting its claws
into the aperture. I would imagine that Rhoad's
"tree crate" are in fact raccoons or oppossums
which frequently climb and have been reported
as preying on L. fasciatus.

Of 189 empty tree snail shells collected in the
leaf litter of Matheson Hammock (where all of
the above predators occur), 52% of the shells
were intact, indicating natural death or Eu-
glandina predation: ^% of the shells were
crushed leaving only the apex, suggesting rac-
coon, oppossum, rat, or crab predation. The re-
maining 10% were broken open on one side
only, suggesting predation by birds. These con-
clusions are only speculative, but if the sample
was a representative one, then it indicates that
nearly half of tree snail mortality is due to
predation, which must then be viewed as a
powerful selective force impinging on Ligmts
populations. K so, and if a significant number

of predators locate L. fasciat-us visually, then
the elaborate banding patterns of this snail
may have a much greater adaptive significance
than has been hitherto recognized. This is a fer-
tile field for further research.

Contrary to the cries of alarmist conserva-
tionists, Liguus fasciatvis does not appear to be
an endangered species in South Florida. It is
quite commonly found in the tropical hammocks
of the area, and these hammocks are largely
preserved within the county, state and federal
parks. It is true that certain local and rare
color varieties have been exterminated by col-
lectors and developers, but the species as a
whole continues to thrive.

ACKNOWLEDGMENTS

I wish to thank my parents. Dr. Gilbert L.
and Mrs. Nancy A. Voss for their constant
assistance and encouragement. I would also like
to thank Mr. Arthur Peavy, Director of Dade
County Parks, for permission to work with tree
snails in the county parks; Mr. John C. Eckhoff
for his enthusiasm and assistance: Mrs. Rita
Sturgeon of the Florida Department of
Agriculture: the Rosenstiel School of Marine
and Atmospheric Sciences for the use of its
library. I also extend my thanks to Dr. William
J. Clench for critically reviewing the
manuscript, and to Dr. Walter B. Miller for his
helpful suggestions.

LITERATURE CITED

Baker. F. C. 1903. Shells of land and water. A. W. Mum-
ford. Chicago.
Clench. W. J. 1975. Personal communication.
Craig, A. K. 1973. A new record for Ligmis: the Boynton

Beach colony. The Nautilus 87: 83-85.
Davidson, T. 1965. Tree snails, gems of the Everglades. Nail.

Geographic Mag. 127: 372-387.
Pilsbry, H. A. 1946. Land moUusca of North America. 2:

37-102.
Rhoads, S. N. 1899. Annotated list of land and fresh water

shells recently collected in the vicinity of Miami. Florida.

The Nautilus 13: '&-i7.
Simpson, C. T. 1920. In Lmver Florida Wilds. New York.
Simpson, C. T. 1929. The Florida tree snails of the genus

Lnjum. Prx. U.S. Nat. Mu.f. 73: 1-44.
Weber, J. A. 1953. Nests of the Florida tree snail.

Every ladf.'iNai. HkL Mag. 1: 63-65.

70 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

NEW SPECIES OF SONORELIA (PULMONATA: HELMINTHOGLYPTIDAE)

FROM NEW MEXICO AND TEXAS

W alter B. Miller

Department of Biological Sciences, University of Arizona,
Tucson, Arizona 85721

ABSTRACT

Two new species of land snails of the genus Sonorella (metcalfi and todseni)
a?-e described from Dona Ana Cminty, New Mexico, and El Paso County, Texas.

Sonorella orientis Pilsbry, 1936, was first col-
lected in 1897 by C. H. T. Townsend in
Fillmore Canyon, Organ Mountains, Dofia Ana
County, New Mexico, as stated by Pilsbry and
Ferriss (1905). The type lot, including live
snails, was cc^Uected by Ferriss and Pilsbry in
1922, at Dripping Springs in Ice Canyon, Organ
Mountains, just south of Fillmore Canyon, and
was described as a subspecies of Sonorella
hachitana (Dall, 1895) by Pillsbry (1936). I col-
lected it in Fillmore Canyon on 7 June 1965,
but was unable to obtain live specimens for
dissection. Subsequently, Artie L. Metcalf, of
the University of Texas at El Paso, sent me
live specimens from several localities in
Fillmore Canyon, Ice Canyon, and Rock Springs
Canyon. Dissection of several series of
specimens revealed that the reproductive
anatomy differed significantly from that of S.
hachitana. This information, plus evidence ob-
tained in my laboratory (unpublished hybridiz-
ing experiments) that S hachitana is ap-
parently an obligate calcicole, with peculiar
nutritional or growth factor requirements, were
considered sufficient to infer probable reproduc-
tive isolation and accordingly, Bequaert and
Miller (1973) raised S. orientis to specific rank.

Since 1967, Artie Metcalf and Thomas Todsen
have continued to collect in the Organ Moun-
tains, as well as in the San Andres Mountains
to the north, the Dona Ana Mountains to the
west, and the Franklin Mountains to the south.
They have kindly sent me many specimens
from their collections. Examination of shell
characteristics as well as reproductive anatomy
of the collected specimens reveals the presence
of two new species of Sonorella, one in the
Franklin Mountains and one in the Dona Ana
Mountains. I take great pleasure in naming
these new species after their discoverers. Dr.

Artie L. Metcalf of the Department of
Biological Sciences, University of Texas at El
Paso, and Dr. Thomas K. Todsen, of the White
Sands Missile Range, New Mexico. I also wish
to thank the Commander, White Sands Missile
Range, and his staff for permitting this scien-
tific exploration of the San Andres Mountains.

Sonorella metcalfi new species
Figs. 1 and 4
Description ofholotype. Shell depressed -globose,
heliciform, thin, glossy, light tan, with chestnut
spiral band on the well-rounded shoulder; um-
bilicate, the umbilicus contained 10 times in
the diameter and about '4th covered by the
reflected columellar lip. Embryonic shell of \Vz

V\C.\. Sonorella metcalfi. new species. W. R Miller. IHstal
reproductive xtntctures. Drawing made from stained whole
mount. Ahhreriatians: ec ep'phallic caecum: ep cpiphallus;
to free in'iditct: og ovidncnl gland: pe /lents: pr penial
retmctor: ps penial .<iheath: pt pro.'itate: sd spermathecal
duel: va iiigina: vd vas deferens: ve verge.

Vol. 90 (2)

THE NAUTILUS

71

FIG. 2. Sonorella todseni, new species, W. B. Miller. Distal
reproductive structures. Drawing made from stained whole
mount.

whorls, silky -smooth, not glossy, with light,
radial ripples and traces of descending, spiral
threads atxjve the suture, visible at about 10 X
to 20X magnification. Post-embryonic whorls
marked with light growth wrinkles. Last fourth
of body whorl with light, incised spiral lines,
most pronounced near shoulder. The peri-
ostracum has a silky, lustrous appearance. The
last whorl descends abruptly to the slightly ex-
panded peristome. Aperture oblique, rounded,
slightly wider than high, with margins converg-
ing; parietal callus thin. Shell measurements, in
mm: diameter 19.8, height 12.0, umbilicus 2.0,
AVa whorls.

Reproductive anatomy. The ovotestes, her-
maphroditic duct, seminal vesicle, albumen
gland, spermoviduct, spermatheca, and sper-
mathecal duct are typical of the genus. The
penis contains a long, thin cylindrical verge
bluntly rounded at its tip; the verge is slightly
less than half as long as the penis. A penial
sheath covers the distal half of the penis.
Epiphallus very thin distally, the distal end
embedded in the penial retractor muscle, then
enlarging proximally to its junction with the
vas deferens and the short, free, epiphallic
caecum. Vagina about '/4th the length of the
penis. Lengths, in mm, as follows: Penis 13;
penial sheath 6.5; verge 6; epiphallus 14;
epiphallic caecum 0.8; vagina 10.

Type Locality. North Franklin Mountain, El

Paso Co., Texas, in a northwest arm of
Fusselman Canyon, above spring. Latitude 31°
53.7' N, longitude 106° 29.0' W; elevation ca
5300 feet. Collector: Artie L. Metcalf, 11 May
1972.

Tyj^e Material. Holotype, United States Na-
tional Museum No. 760816. Paratypes: Delaware
Museum of Natural History, No. 99172;
Academy of Natural Sciences of Philadelphia,
No. 338227; Museum of Arid Land Biology,
U. T. El Paso, No. 4374, and the author. No.
59:38.

Distribution. Sonorella metcalfi is found in
the Franklin Mountains of Texas and in the
southernmost part of the Organ Mountains of
New Mexico. It has been collected at the follow-
ing localities: Franklin Mountains: (1) Several
localities in Fusselman Canyon, (2) Tom Mays
Park, 0.2 mi SW of West Cottonwood Spring,
(3) West slope of South Franklin Mountain, at
ca 5500 feet. Organ Mountains: head of Finley
Canyon at ca 6000 feet. All collections by Artie
L. Metcalf.

Sonorella todseni new species

Figs. 2 and 4

Description of holotype. Shell depressed-
globose, heliciform, thin, glossy, light tan, with
narrow, chestnut spiral band on the well-
rounded shoulder; umbilicate, the umbilicus
contained 7 times in the diameter and only
slightly covered by the reflected columellar lip.
Embryonic shell of IV2 whorls, dull with minute
radial ripples on which are superimposed many
spirally descending and ascending interrupted
threads and granules. Postembryonic whorls
marked with light growth wrinkles and
granules, the granules becoming absent on the
body whorl. The periostracum has a silky,
lustrous appearance. The last whorl descends
abruptly to the slightly expanded peristome.
Aperture oblique, rounded, slightly wider than
high, with margins converging; parietal callus
very thin. Shell measurements, in mm:
diameter 17.9, height 9.6, umbilicus diameter
2.6; 4' 4 whorls.

Repi-oductive anatomy. Ovot«stes and prox-
imal accessory structures as in other Sonorella.
The penis contains a long, thin, unevenly cor-
rugated verge tapering to a pointed tip; the

72 THE NAUTILUS

April 30, 197f;

Vol. 90 (2)

5mm

K1G.3. Sonorella orientis Pilahry. Distal reproductice.
structures. Dramng made from stained whole mount.

verge is about V3 the length of the penis. A
penial sheath envelops the distal third of the
penis. Epiphallus thin, the distal part embedded
in the penial retractor muscle; a very short,
free, epiphallic caecum is present. Vagina about
'4 the length of the penis. Lengths in mm, as
follows: penis 8, penial sheath 2.5, verge 5.5,
epiphallus 6.5, epiphallic caecum 0.7; vagina 6.

Type Locality. Dona Ana Mountains, Dona
Ana Co., New Mexico, on NW slope of Dona
Ana Peak (NW '4, SW '/i, NE %, Sec. 25, T 21
S, R 1 E); elevation ca 5300 feet. Collector:
Artie L. Metcalf, 28 August 1972.

Type Material. Holotype, United States Na-
tional Museum No. 760817. Paratypes: Delaware
Museum of Natural History, No. 99171;
Academy of Natural Sciences of Philadelphia,

No. 338228; Museum of And Land Biology,
U. T. El Paso No. 2809; private collection of
the author. No. 5973.

Distribution. Sonorella todseni is known only
from the Dona Ana Mountains of New Mexico,
a small, detached outlier of the Organ Moun-
tains, just north of Las Cruces. It was orig-
inally collected on 1 October 1967 by Dr.
Thomas L. Todsen (ALM #850; WBM #5023), a
small lot of shells only. Subsequently, a lot con-
taining one live adult was collected by Edward
Stern and Artie Metcalf on 23 January 1969
(WBM #5103). The type lot, consisting of many
live adults as well as shells only, was collected
by Artie Metcalf on 28 August 1972.

Remarks. Compared to S. metcalfi, S. todseni
has a generally smaller, lower, more widely um-
bilicate shell, with the umbilicus less covered
by the reflected- columellar lip. Fresh shells
tend to show heavier granulation under high
magnification. It is in the anatomy that dif-
ferences are more easily discerned. S. todseni
has a coarsely corrugated verge, tapering to a

FIG. 4, T(rp row, Sonorella todseni, new .•species, W. R
Miller. Middle row, Sonorella metcalfi, mw species, W. R
Miller. Bottom row, Sonorella orientis Pilsbry.

Vol. 90 (2)

THE NAUTILUS

73

pointed tip; the walls of the penial chamber
surrounding the verge are relatively smooth. S.
meicalfi has a nearly smooth, cylindrical verge,
bluntly rounded at its tip; the walls of the
penial chamber surrounding the verge are
thickened, glandular, and finely corrugated.
Although dimensions of anatomical structures
show much variability, certain length ratios,
such as verge/penis (ve/p), vagina/penis (va/p),
and penial sheath/penis (ps/p) appear to be
consistent and diagnostically useful. Approx-
imate values of these ratios are: S. todseni.
ve/p %, va/p Vi, and ps/p '4; S. meicalfi, ve/p
'/2, va/p ^4, and ps/p '-2.

Both 5. meicalfi and S. iodseni appear to be
closely related to S. oneniis Pilsbry 1936, and
all three species probably speciated relatively
recently from a common ancestral population.
S orieniis (Figs. 3 & 4) has a usually larger,
widely umbilicate shell. It has a long, coarsely
corrugated, tapering verge, in a smooth -walled,
capacious penial chamber with ve/p ca ^'3, va/p
ca 1 or >1, and ps/p ca Vj. S. orieniis is found
throughout the Organ Mountains except perhaps
the southernmost part (Finley Canyon) where S.

meicalfi is found; the possibility of their being
sympatric there needs to be confirmed by addi-
tional collecting and dissection. It is also found
in the San Andres Mountains (confirmed by
dissection, WBM#'s 5978 and 5983) where it has
been collected on Salinas Peak by Thomas
Todsen and Artie Metcalf (MALB-3145, WBM
5978) on 10 September 1972 and in Ash Canyon
by Artie Metcalf (MALB-3156, WBM 5983) on
23 September 1972. Shells from Sierra Blanca
Mountain (Pilsbry, 1936) and the Sierra Vieja
of Texas (Oieatum, Fullington, and Pratt, 1972)
may also be S mieniis but need to be ron-
firmed by dissection.

LITERATURE CITED

Bequaert, J. C. and W. B. Miller. 1973. Tlie mollusks of the

arid Southwest with an Arizona checklist. University of

Arizona Press. Tucson, Ariz. 271 pp.
Cheatum, E. P., R. Fullington, and L. Pratt. 1972.

Molluscan records from West Texas. Sterkiana 46: 6-10.
Pilsbry. H. A. 1905. Mollusca of the southwestern states. I:

Umcoptidae; Helicidae of Arizona and New Mexico. Proc.

Ac(id. Nat^ Sci. Ph iM.elph la 57: 257.
Pilsbry, H. A. 19.36. TTie eastern limit of Simtrrella. The

Nautilus 49(4): 109-110.

THE COMMENSAL CLAM, PARAMYA SUBOVATA

(BIVALVIA: MYIDAE) AND THALASSEMA HARTMANI

(ECHUROIDEA) OFF GALVESTON, TEXAS

Clyde A. Henry

Texas A&M Marine Laboratory

Building 311, Fort Crockett

Galveston, Texas 77550

Studies of macrobenthic assemblages offshore
Galveston, Texas, have revealed the presence of
the commensal bivalve, Paramya subovata
(Conrad, 1845). The highest concentrations of P.
subovata were found in May 1975 in the
Bolivar Roads entrance channel (13.5 m depth)
at 29° 19' 15" N. Lat. and 94° 38' 42" W. L:)ng.
A total of 242 living specimens, ranging in
length from 1.5 to 6 mm, were collected at this
site in five replicate spade corer samples. The
average calculated abundance was 745/m^ The

specimens agree with the description in Abbott
(1974, p. 537, Fig. 5989).

Jenner and McCrary (1970) reported
Paramya subovaia to be commensal specific
with the echiuroid worm, Thalassema hartmani
Fisher, 1947. T. hartmani has also been found
during the present study. At the Bolivar Roads
entrance channel site in May, a total of 261 in-
dividuals of T. hartmani were collected with an
average calculated abundance of 805/m^. Though
direct observations of the commensalistic

74 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

behavior of Paramya aubvvata were not made,
this non-leptonid bivalve has rarely been found
during the present studies in the absent of T.
hartmani.

Ladd (1951) and Ladd, et al. (1957) reported
dead specimens of Fnrnmya subnvata from the
Lydia Ann Channel in the vicinity of Aransas
Pass, Texas. As far as I am able to ascertain,
this is the first report of the occurrence of liv-
ing specimens of Paramya mibovata from Texas,
other than a beach-stranded specimen found
alive after a hurricane on Galveston West
Beach (Ode' and Speers, 1970). Thalassema hart-
mani is also previously unreported from Texas
coastal waters. I would like to thank Dr. R.
Tucker Abbott who mnfirmed the identification
of Paramya subovata (Del. Mus. Nat. Hist. no.
102595) and encouraged the development of this

report. This research was supported by Contract
No. IX) A RES DAC W64-7.5-()070 from the
Waterways Experiment Station, U. S. Army
Corps of Engineers."

LITERATURE CITED

.Abbott. R. T. 1974. American Seashetls. Second Edition, Van
NfKtrand Reinhold Co.. N.Y.. 6&3 p.

•Jenner. C. E. and A. B McC"rar>'- 1970. f\iramya aubovata,
a OTmmensal with the echiuroid Thalassema hartmani
Ann. Kept. Amer. Mai. Union. 1969. p 42.

I..;idd. H. S. 19.51. Brackish-water and marine assemblages of
the Texas Coast, with special reference to mollusks.
hibls. hist. Mar. Sci.. Umii Tmus. 2(1): 129-163.

Ladd. H. S., J. W. Hedgpeth, and R. Post. 19.57. En-
vironments and facies of existing bays on the central
Texas mast. In H. S. Ladd (ed.) Treatise on Marine
Ecology and Paleoecology. Vol. IL Paleoecology (leol. Soc.
r/Mmrr.Wem. 67, .599-639.

Ode'. H. and A. B. Speers. 1971). Notes concerning Texas
beach shells. 71'j-as Omchalugist 6(8): 83.

THE OCCURRENCE OF THE DATE MUSSEL, LITHOPHAGA BISULCATA

(MYTILIDAE), IN LIVING OYSTERS

OFF GALVESTON, TEXAS

John Ogle

(College of Marine Science
Texas A&M University
Galveston, Texas 77550

ABSTRACT
The date mussel, Lithophaga bisulcata, was found boring live oysters
Crassostrea virginica and Ostrea equestris at three petroleum platforms off
Galveston, Texas. A specimen of Lithophaga aristata found boriny into Ostrea
equestris is reported from Galveston.

In the course of conducting survival and
growth studies of commercial oysters
(Crassostrea mrginka Gmelin, 1791) at an off-
shore oil platform in the Northwest Gulf of
Mexico, it was noted that the oysters had been
burrowed by the date mussel Lithophaga
bisulcata (Orbigny, 1842). Experiments during
the past 2 years (1973-1974) were undertaken to
determine the feasibility of culturing oysters off-
shore in the Gulf of Mexico, utilizing
petroleum platforms for suspension culture.
These experiments, under the direction of Dr. S.
M. Ray', have utilized platform B of the Atlan-
' Head of M(K)dy College of Marine Science.

tic Richfield Company located 8 miles offshore
from High Island, Texas, east of Houston in ap-
proximately 10 m of water. The salinity varies
from 23 to 31 ppt over the year with an
average of 26 ppt. Temperature varies from 14°
to 29°C with a yearly average of 22°C. Mussels
were first noted during June 1974 in oysters
that had been suspended at the platform for 17
months. Ten oyster shells were carefully broken
apart and the number of mussels determined
(Table 1) on three different occasions.

Shell boring pholad clams identified as
Diplothyra .'imithi Tryon, 1862 were also found
in the oysters, two examined in June, five in

Vol. 90 (2)

THE NAUTILUS

75

TABLE 1. Intensity of mussel infestntivm in C. virginica.

Size of mussels (mmj

A l<erage oyster No. of mussels

Date size (vimj fH-r oyster Average Range

June 1974

98

Sept. 1974

93

Dec. 1974

106

24
21
13

7

6

12

2-12
2-19
4-21

September and three in December of 1974. The
pholad borers were all from oysters suspended
in the upper 4 m of water. The boring mussels
were found in oysters suspended throughout the
water column.

No borers were noted during the 16 months
prior to June 1974 that oysters were suspended
offshore. It is suggested that both species of
borers settled during the summer of 1974. Bur-
rows of L. bisulcata were found in all parts of
the oyster shell as indicated by the radiograph
(Figure 1). The greatest number of mussels was
found anterad, close to the umbo, possibly due
to the greater thickness of the shell in this
area. In some cases the burrows penetrated into
the interior cavity of the shell. Several oysters
were actively depositing shell material in
response to the boring activity of the mussels
(Figure 2).

In November 1974, oysters occurring nat-
urally on oil platforms were collected utilizing
SCUBA. Both Ostrea equestris Say, 1834 and C.
virginica were collected at depths of 6-12 m
from a platform 12 miles south (173°) of the
Galveston lighthouse. No date mussels were
found, but burrows were observed in both speci-
mens of C. virginica collected. Ostrea equestris,
the only oyster species observed on another oil
platform 29 miles south (173 ) of the Galveston
lighthouse occurred in the water from 12 to 21
m. Eleven 0. equestris examined were infested
with an average of three to five L. bisulcata. In
addition, one specimen of Lithophaga aristata
(Dillwyn, 1817) 24 mm long was found.

Ode' and Speers (1970) report L. bisulcata
from old oyster valves at Port Aransas, Texas
and less commonly at Galveston. They report L.
aristata from Port Aransas and Port Isabel,
Texas, in rocks. The author is unaware of any
account of L. bisulcata burrowing into living
oysters. Turner and Boss (1962) report this
species as burrowing into living corals and into
"living shells such as Strombus" (p. 112). Both

C. virginica and 0. equestris were found U) be
burrowed by L. bisulcata in this study. The
species L. aristata has been reported to burrow
into Ostrea as well as a variety of other shells
(Turner and Boss, 1962) including the shell
plates of a chiton (Bullock and Boss, 1971).
These findings thus represent a new pest of

FIG. 1. Radiograph of oyster shell (actual size) shoumg
location and position of infesting musseb L. bisulcata.

FIG. 2 Photograph showing blisters on interior of shell
due to infestation by the mussel L. bisulcata (white rec-
tangle represents one cm).

76 THE NAUTILUS

April 3(3, 1976

Vol. 90 (2)

the Virgfinia oyster (Craxsostrea virginica) that
will be of concern to persons attempting to
culture oysters commercially in offshore waters
of the Gulf of Mexico.

ACKNOWLEDGMENTS

Appreciation is expressed to Captain J.
Roberts for the use of his boat Starfish, to his
son Mr. J. Rf)berts for Captaining the vessel,
and to Mr. T. Bullington and Mr. D.
McLaughlin for assistance in data collection.
Drs. D. V. Aldrich and W. J. Wardle reviewed
the manuscript and offered many helpful sug-
gestions and constructive criticism. Appreciation

is also expressed to the people at Public Health
Department in Galveston for doing the X-ray
and to Mr. J. Kelsey for aid in the darkroom.
Voucher specimens are deposited in the
Delaware Museum of Natural History, no.
106621.

LITERATURE CITED

Bullork. R. C, and K. J. Bok.s. 1971. Lithnphaga aristala in

the shell plates of Chitons (Mollu-sca). BrvviKi-a. Miis.

Comi). ZiiiiL No. 369, 10 p.
Ode. H.. and A. B. Speers. 1970. Notes concerning Te.xas

beach shells. Tex. Gmchot. 6(6): 59.
Turner, R. D.. and K. J. Boss. 1962. The genus Lilhophaga

in the Western Atlantic. JoAn,s(mia 4: 81-116.

REPRODUCTIVE HABITS OF F^OUR POPULATIONS OF

MUSCULIUM SECURIS (BIVALVIA: SPHAERIIDAE)

NEAR OTTAWA, CANADA'

G. L. Mackie,^ S. U. Qadri

and

A. H. Clarke

Biology Department

University of Ottawa

Ottawa, Ontario, Canada

National Museum of Natural Sciences

National Museums of Canada

Ottawa, Ontario, Canada

ABSTRACT

Comparative reproductive habits of populations of Musculium securis (Prime)
in two temporary forest ponds, a river and a permanent pond near Ottawa,
Canada were determined fivm .samples collected seasonally for one to three
years, and from laboratory and field experiments. Gametogenesis is most active
during the summer months. Spermatogenesis and oogenesis usually occur
simultaneously although protogyny is often apparent. Four to ten brood sacs
per inner gill are produced but only two to four sacs usually mature. Only 31
to 63% of the larvae in each brood sac are viable from the fetal stage of
development. The average litter size produced varies from 2.1 to i.8 indiindiials
per parent. Intrapopulation variations in reproduction are moye pronounced in
temporary than in permanent aquatic habitats. Interpopulation transplants of
M. securis indicate that reproductive habits may be adoptively modified.

The present study was planned to show the
extent of intrapopulation and interpopulation
variations in several reproductive aspects of
Musculium securis. The reproductive aspects ex-
amined were seasonal gonad activities, number
of brood sacs and larvae per sac (brood size).

' This contribution summarizes a portion of a thesis sub-
mitted by the senior author in partial fulfilment of the re-
quirements for the Ph.D. degree. University of CXtawa, 1973.

' Present address: Department of Zoology, University of
Guelph. Guelph, Ontario, Canada.

and the number and sizes of litters produced.
Four populations of M. securis were examined,
two from temporary forest ponds, one from a
river, and another from a permanent pond.

To distinguish between species of Musculium
and Sphaerium, van Cleave et al. (1947) have
given data to indicate that Musculium species
might have larger brood sizes than Sphaerium
species. Herrington (1962) suggested a need for
data on more species before evaluating the
significance of differential fecundities. Gale
(1969) suggested the use of standardized pro-

Vol. 90 (2)

THE NAUTILUS

77

cedures and the analysis of seasonal field col-
lections to show the extent of intraspecific
variations before evaluating the diagnostic value
of differential reproduction.

STUDY AREAS
Detailed descriptions of the study areas have
been given in Mackie (1973). Briefly, the two
temporary ponds, called Carp Pond and Greely
Pond, are located at Carp and Greely, Ontario,
and are situated in deciduous forests. The domi-
nant tree species at the ponds are white elm,
(Ulmus americana), willows (Sdix spp.), red
maple (Acer rubrimi). and trembling aspen
(Popuhis tremulflides). Carp Pond covers an
area of approximately 15,000 m^ with a maxi-
mum depth of 1 m and Greely Pond, 90,000 m^
with a maximum depth of 0.8 m. Miisculium
seciiris is the most common macroinvertebrate
in Carp Pond but Sphaerium (Mcidentale is ap-
proximately twice as numerous as M. seciiris
in Greely Pond. Both ponds are usually dry
from August to November. The mean summer
temperatures {18°C) of the ponds are usually

reached near mid-May.

The permanent aquatic habitats are located
in Britannia Bay of the Ottawa River near Ot-
tawa and at Lac Bourgeois in the Gatineau
Hills near Hull, Quebec. Fifteen species of
sphaeriids are present in Britannia Bay where
M. securis is the dominant species in the mud
of the 3-4 m depths (Mackie and Qadri, 1973).
Lac Bourgeois, with an area of approximately
90,000 m^ appears to contain only one sphaeriid,
M. fteciiris. which attains its largest densities on
the east shore under the shade of several small
willow trees. The mean summer temperatures
(18°C) of Britannia Bay is reached in mid -June
and of Lac Bourgeois in early June. Only
Britannia Bay contains fish; catfish (Ictalurus
punciatus). walleye (Stizostedion mtreum). and
pike (Esox lucius) are among the common fish
species. Seasonal fluctuations in several physical
and chemical characters of the water in each
habitat have been given by Mackie (1973).

MATERULS AND METHODS

The reproductive habits of each population

examined were seasonal gonad activities,

numbers of brood sacs and larvae per sac

(brood size), and numbers and sizes of litters

produced. These aspects were determined from
seasonal field collections and from adults main-
tained in the field and in the laboratory.

Seasonal Field Collections— From May 1970
to May 1973, 50-100 clams were collected twice
a month in the summer and once a month in
the winter from Carp Pond and Britannia Bay.
Greely Pond and Lac Bourgeois were visited
monthly for one year.

Random quantitative samples were taken
from Britannia Bay with a standard Ekman
grab (15 x 15 cm, with screen on top) and
qualitative samples from the remaining habitats
with an ordinary domestic sieve. The sizes of
the samples needed to show differences between
means of litter sizes at P = 0.05 were deter-
mined from the sample size formula of Simpson
et al. (1960, p. 196). The specific dates of collec-
tions and the sample sizes may be found in
Mackie (1973).

All clams used for reproductive studies were
preserved immediately in 70% ethanol. Since
some clams often prematurely aborted their
young, individuals longer than approximately 3
mm were isolated and put into vials containing
70% ethanol. Clams to be used for histological
examination were first narcotized in 10%
sodium nembutal (van der Schalie, 1963), fixed
in Bouin's fluid, and then preserved in 70%
ethanol. For each clam in the seasonal field col-
lections, lengths and heights were measured to
two decimal places in millimeters wnth a Preci-
sion Tools and Instruments Co. Ltd. microscope
micrometer, model 14.

Seasonal gonad activities were determined
from stained sections of gonads from 4 or 5 in-
dividuals of most field collections. Only
specimens prepared for histological examination
were used. Tlie shells of parents and extra-
marsupial larvae were removed by hand. After
dehydrating, clearing and embedding in paraf-
fin, the soft parts were sectioned to a thickness
of 8 microns. Sections were stained with Harris'
haematoxylin and oounterstained in alcoholic
eosin.

The numbers of brood sacs and their brood
sizes were determined for both the left and
right inner demibranchs. Usually the embryos
were so small that their numbers could not be
determined accurately. Therefore, data were

78 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

recorded for only fetal, prodissoconch, and
extra -marsupial larvae. Tlie lengths of all
shelled larvae were also recorded. Since 99% of
the extra -marsupial larvae were viable (as
shown from growth studies), their numbers
were taken as a valid measure of litter sizes
produced by M. securis. Note that the brood
size is the number of larvae per brood sac
while the litter size produced is only the
number of extra-marsupial larvae per litter or
the number of young bom at one birth.

The numbers of litters produced by parents
were determined by back-calculation of brood
sacs; this technique has been described by
Mackie, Qadri and Clarke (1974a). Only parents
which had completed growth were used to
determine the numbers of litters produced.
Parents that had completed growth could
usually be identified by the formation of a
black deposit on the margin of their shells.

Maintenance of M securis in the laboratory
and field— Reproductive studies on adults main-
tained in the laboratory and field were done to
complement those in seasonal field collections.
Growth tubes, prepared from 45 mm diam. x 70
mm ht. plastic vials (Mackie, 1973), were used
to maintain adults in the field. Racks, made
from 1 cm thick plexiglass sheet, were con-
structed to hold twenty growth tubes.

A rack of twenty tubes was put into each of
Carp Pond, Britannia Bay, and Lac Bourgeois
on May 9, 1972 (Greely Pond was not in-
vestigated because it was first examined on
June 6, 1972). Each growth tube contained one
newborn M. securis and substrate (1 cm deep)
from the habitat in which the tube was placed.
The lengths of adults were measured at approx-
imately two week intervals until their deaths.
Newborns were counted and removed as they
appeared in each tube. The numbers of litters
produced by each parent were also noted.

Interpopulation transplants were performed
to determine if the sizes and numbers of litters
produced by M. securis adults were environmen-
tally or genetically controlled. Newborn M
securis from each habitat were isolated and
maintained in growth tubes in all habitats (ex-
cept Greely Pond) including its own. Lengths of
clams were measured at approximately two
week intervals until their deaths. The litter

sizes and the numbers of litters produced were
also recorded.

Adults from Cai:p Pond, Britannia Bay, and
Lac Bourgeois were also maintained in the
laboratory. Since M. securis would grow only in
the presence of tree foliage, only substrate and
leaves from Carp Pond were used. "Pyrex"
dishes 100 mm diam. x 50 mm ht. were used as
growth dishes. Five M. securis newl»ms from
each habitat were put into each of three dishes.
Thiree replicates were made of each dish con-
taining 5 M seairis, 50 g of air dry Carp Pond
soil, 2 g of air dry white elm leaves, and
chlorine-free tap water. The lengths of adults
were recorded at frequent intervals and the
total number of young produced in each dish
was recorded.

A student's t test. (Simpson et ai. 1960, p.
176) was used to determine significant dif-
ferences between population means at P = 0.05.

RESULTS AND DISCUSSION

Seasonal Gonad Activities. The gonads of

newborns are small and often difficult to locate.
Primary oocytes are often seen in newborns
that have estivated and/or hibernated in Carp
Pond and Greely Pond but neither oogenesis
nor spermatogenesis is strongly apparent (Fig.
1-1) when serial sections of the gonads are ex-
amined. Gametogenesis does not appear to
begin until growth of adults ensues in the
spring. At this time the ovary appears to be in
further stages of development than the testis
(Fig. 1-2). Throughout May, June, and early
July, both fully developed ova and sperms are
present but there is no evidence of increased
gonad activity with time (Fig. 1, -3, A, -5, -6).
Spermatogonia and spermatocytes are readily
visible and usually fill the entire follicular cav-
ity. It is not until late July that sper-
matogenic activity appears to be maximum
(Fig. 1-7). In late-July -specimens the sper-
matozoa are usually found in the central lumen
of the testicular follicles (Fig. 1-7) where the
tails of the sperms are clearly visible (Fig. 1-8).
Frequently the testis is so large in these late
July specimens that the ovary cannot be
located.

In specimens over 4 mm in length collected
between November and April from Lac

Vol. 90 (2)

THE NAUTILUS

79

1

4'

4^ * .^ i J

'''f?

"v*!'

#f

.t
%*

y
\

%.

'4f.

^

.» M^^

*.^

%%

FIG. 1. Photomicrographs of seasonal gonad activity in
Musculium securis in Carp Pmtd. DO develivping (Kigonia. I
intestine. K) primary oocytes. ST spermatozoa, STT tails of
spermatozoa, SY spermatocytes.

1. October 10. 1970. Length of parent 1.70 mm. 380X.

2. May 20. 1971. Length of parent S.S5 mm. 380X.

Bourgeois, the testicular follicles show evidence
of a decided reduction in spermatogenesis and
primary oocytes are usually absent in the
ovaries. The central lumens of the ovaries and
testis are devoid of gametes so that
gametogenesis probably does not occur during
the winter months.

Although there are variations, gametogenesis
is first apparent in adults of lengths 2.00-2.50
mm. The testis greatly dwarfs the ovary in
adults larger than 5.50 mm. On the basis of the
earliest appearance of primary sacs, eggs are
first fertilized in adults of lengths of 2.00-2.50
mm.

Numbers of Brood Sacs and Brood Sizes.
Demibranchs within a parent usually contain
the same number of brood sacs. A maximum of
three brood sacs per demibranch (i.e. six brood
sacs per gill) are usually found but four brood

3. May 30. 1971. Length of parent 3. 76 mm. 380X.
I June U. 1971. Length of parent 165 mm. 380X.

5. .June 28 1971. Length of parent 5.22 mm. 380X.

6. July 12 1971. Length of parent 5.68 mm. 380X.

7. July 26, 1971. Length of parent 5. 75 mm. 95X.
8 Same as no. 7 but 380X.

sacs also occur, although very rarely. The total
number of brood sacs per gill varies with the
size and age of the parent (Fig. 2).

During the summers of 1970 and 1971, only
parents longer than 4.00-4.50 mm in the Carp
Pond population contained 6 brood sacs (Fig.
2a). By late June extra-marsupial larvae are
present but 6 brood sacs also occur indicating
that a total of 8 brood sacs (i.e. 2 primary, 2
secondary, and 4 tertiary) are produced. This is
probably the average maximum number since
only four brood sacs per gill (i.e. 2 secondary,
and 2 tertiary) are found in parents taken at
the end of July. In 1972 when the pond did not
dry up, the same phenomena occurred (as ex-
emplified by results from Greely Pond, Fig. 2b)
and new sacs were not produced in later sum-
mer. Therefore, the extended aquatic season has
little effect on the total number of brood sacs

80 THE NAUTILUS

April 30. 1976

Vol. 90 (2)

2 4 6|2 4 c,\! A S\l 4 6|2 4 e|2 4 e{2 4 S
TOTAL NUMBER OF BROCD SACS
M10 I M20 1 M3C I J14 I J2e | J12 | J2S
DATES SAMPLES COLLECTED

2 4 G|2 4 6|2 4 6|2 4 S|2 4 G|2 4 S|

TOTAL nUMBER Ot BROOD SACS
M28 I Jll 1 J24 I J1S 1 J29 I All I
DATES SAMPLES COLLECTED

fee

(/)

UJ

SB

<
u

2 4 6|2 4 6[2 4 6|2 4 e|2 4 e|2 4 6|2 4 S
TOTAL NUMBER OF BROOD SACS

J6 I J18 I J7 I J23 I A6 I A19 | S2
DATES SAMPLES COLLECTED

FIG. 2. Total number of brood aaat per inner gill in parents
collected between (a) May 10 and July 26, 1971 from Carp
Pond, (b) June 6 and September 2. 1972 from Greely Pond.
(c) May 28 and August _ 11. 1971 from Britannia Bay. (d)
May 8 and September 20. 1972 from Lac Bourgeois. Each

produced although more brood sacs mature (i.e.
4 brood sacs per gill remained in 1970 and 1971
adults but 2 remained in the 1972 adults).

Six brood sacs are uncommon in individuals
from the Britannia Bay population and are
found only in July (Fig. 2c). There appear to be
no major differences in the total numbers of
brood sacs between 1970, 1971 and 1972 popula-
tions of Britannia Bay. Usually a total of six
brofxl sacs are produced but only two brocxl
sacs mature and four remain immature at the
end of the summer. Clams of lengths 2.00-3.50
mm represent slow-growing adults (Mackie,
Qadri, and ('larke, 1974b) which usually pro-
duce a total of only four brood sacs (Fig. 2c).

24S|246|246|246 24G|24S
TOTAL NUMBER OF BROOD SACS

M8 |'M2eI J13 I J6 I AS I S20
DATES SAMPLES COLLECTED

size class represents a 0.1f9 mm increment in shell length
(i.e. 1 = IH).J,9 mm.. 2 = 0.50-0.99 mm. .1 = 1.00-H9 mm.
.... 12 = 5..'}0-5.99 mm. 13 - lengths greater than 6.00
mm). Rni'h interval (m the ordinate aris als(i represents
100%.

Six brood sacs per gill are most common in
adults longer than 4.50 mm in Lac Bourgeois
(Fig. 2d). At least 8 brood sacs are produced by
many parents since one litter of e.xtra-
marsupial larvae is released and 6 brood sacs
still remain by mid-September. Some parents
celease another litter of extra-marsupial larvae
in the fall and many still have 6 brood sacs per
gill. Therefore, some parents of Lac Bourgeois
produce as many as 10 brood sacs per gill.

The number of larvae in brood sacs of
parents from each population are given in
Table 1. Primary sacs are not included because
the embryos were too small to be counted ac-
curately. The total number of larvae increases

Vol. 90 (2)

THE NAUTILUS

81

TABLE 1. Sizt^ (if lutein in nmrsntpial chamber and hruad sizes of Musculium securis in four habitats for each year of
collection. Only parents in which all larvae were present and from which no extra-marsupial larvae had been released were
examined.

Carp Pond

Greelu
Pond

Britannia Bay

Lac Bourgeois

197V

1971

/972

wn

1970

1971

1973

1971

1972

Extra-marsupial larvae

3.0° (25)'

40 (40)

■26 (28)

2.7 (28)

2.4 (18)

ai (15)

2.4 (16)

3.8 (14)

4.8 (20)

in branchial chamber

110'

1.61

0.90

0.84

0.&3

1.44

0.»J

1.48

1.56

Prodissocoiich larvae

4.8 (25)

5.5 (40)

50 (28)

54 (28)

3.9 (18)

4.1 (15)

34 (16)

5.1 (14)

6.0 (20)

in tertiary sacs

1..35

1.57

2.01

1.70

i.:s

1.36

0.77

1.92

2.13

Fetal larvae in

6.8 (25)

7.4 (40)

7.3 (28)

6.8 (28)

5.6 (18)

6.1 (15)

5.6 (16)

7.4 (14)

7.8 (20)

secondary sacs

1.64

1.12

2.07

1.29

1.23

1.23

1.02

1.18

220

' Mean litter or brood size.

' Number of specimens examined.

'Standard deviation of the mean.

TABLE 2. Percentage of Musculium securis parents producing mie, two. and three liters in each of four habitats for each
year of collection. The percentages are based o'n back-calculation of brood sacs in parents that had completed growth.

Carp Pnnd

Greely Pond

Britannia

Bay

La£ Bourgeois

Year of
Collection

N-
(25)

No. of Litters
One

64.0

Two
36.0

No. of Litters
N One Two

N

No. of Litters
One Two

No. of Litters
N One Two 'Riree

1970

No collections

(19)

84.2

15.8

No collections

1971

(40)

45.0

55.0

No collections

(17)

88.4

11.6

(30) 38.5 53.2 8.3

1972

(30)

6.8

93.2

(31) 13.0 87.0

(16)

81.1

18,9

No collections

° Number of specimens examined.

with age of the parent indicating that the
generative performance increases with age.

Numbers of Litters Produced. Table 2 gives
the percentages of adults that produced one,
two, or three litters in each population for each
year of study. A maximum of three litters were
produced by a single parent. Variations in the
numbers of litters produced within and among
populations are discussed later in this paper.

One litter was usually produced in the
growth tubes placed in Carp Pond, Britannia
Bay, and Lac Bourgeois and in the laboratory
growth dishes (Table 3). A maximum number of
three litters was produced in all maintenance
studies. The results were obtained by noting the
presence or absence of newborns in the growth
containers at approximately two week intervals.
Analyses of parents from seasonal field collec-
tions show that in a few instances two litters
of extra-marsupial larvae occur together, par-
ticularly when the litter sizes are small.
Therefore, it is possible that two litters may

have been produced within two weeks in the
growth containers. If this occurred then a maxi-
mum of six litters was produced. However,
studies on the numbers of brood sacs produced
show that usually four sacs, and rarely five, are
formed in each inner demibranch. Therefore,
the maximum number of litters most likely pro-
duced in the growth containers was four.

Sizes of Litters Produced. Since only extra-
marsupial larvae are released, their numbers
represent the sizes of litters produced. Table 4
gives the sizes of the first litters in all popula-
tions for each year of study and of second lit-
ters in populations of which at least 35% of the
parents produced two litters. The sizes of the
first and second litters of prodissoconch and
fetal larvae in sequential parents are also in-
cluded in Table 4. Sequential parents are those
parents that represent a stage in the sequential
development of each litter of extra-marsupial
larvae. That is, the sizes of the first and second
litters of prodissoconch and fetal larvae that

82 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

TABLE 3. Numbers and sizes of Utters prodveed by Musculium secuiis adtdts maintained in growth containers in three
habitats and in the Utburatirry. Means sidescored by the same line we nut significantly different at P = 0.05.

Papulatvm* trangptanled into:
L/ic Bnurgcuix fntm:

Lac Bourgeois (control, N = 18)"
Carp Pond (N = 16)
Britannia Bay (N = 15)

Carp Pond from.
Lac Bourgeois (N = 16)
Carp Pond (Control. N = 17)
Britannia Bay (N = 14)

Britannia Bay from:
Lac Bouritjeois (N = 16)
Carp Pond (N = 17)
Britannia Bay (Control, N

18)

Adults maintained in the

Laboralorj'
Carp Pond
Lac Bourgeois
Britannia Bav

Nu

one
litter

mber 0/ Ihreitla

Prvduciiv

tun
lillm

first
litter

a6

Average Siifx
o/lMen

Kectmd
litter

a9

Total .Vum»er

Bom per .Ave.

Pareut and

Standard

Deitatum t )

2

16

7.1 (1.8)

10

6

3.0

a4

43 (2.5)

2"

0

0.2

0

0.2 (0.4)

6

10

a2

5.3

6.5 (20)

5

12

42

2.6

60 (22)

1'

0

0.1

0

01 (0.1)

0

16

43

a9

a2 (1.7)

0

17

3.7

ai

6.8 (25)

10

8

28

a7

4.5 (1.2)

0

15

as

4.2

aO (21)

0

15

4.0

5.1

9.1 (28)

9

6

a3

4.7

5.5 (1.7)

"Twenty specimens were put into eac)i habitat but only N number survived.

'Calculated as (Size of first litter X proportion of parents pnjducing only one litter) + (Total number of young born X

proportion of parents producing two litters).

■ Of the adults that survived, one or two produced young.

represent the first and second litters of extra-
marsupial larvae were counted in parents from
three successive field collections.

The results (Table 4) show that the sizes of
the first and second litters of each larval stage
are similar (P > 0.05) but there are usually
significantly larger numbers (P < 0.01) of fetal
larvae than of prodissoconch larvae which in
turn are numerically larger (P < 0.01) than e.x-
tra-marsupial larvae. Clearly, the results in-
population consistently produced fewer (P <
tion often differed (P < 0.05) among habitats,
the extra-marsupial stage.

Table 3 indicates that there is some genetic
TOntrol of litter size since the Brittania Bay
population consistently produced fewer (P <
0.05) young in all transplants than did other
populations of the same transplants. However,
there also appears to be some environmental
control of litter size since the tt)tal number of
young produced by parents of any one popula-
tion often differed (P < 0.05) among habitats.

Intraspecific variations in reproductive
habits of Musculium securis. There is some
variation in the seasonal gonad activities be-
tween slow- and fast-growing adults (Mackie,
Qadri, and Clarke, 1974b) in Britannia Bay. In
slow-growing adults gametogenesis is first ap-
parent in length classes 2.00-2.50 mm but in
fast -growing adults gametogenesis is not ap-
jiarent until clams are of lengths 3.00-3.50 mm.

Cametogenesis and fertilization appear to
continue until the death of the individual in all
populations but is most active in the summer
months. Similar observations have been reported
by Okada (1935) for M. japonicum. Okada (op.
cit.) also noted that spermatogenesis is most ac-
tive in clams measuring 3-7 mm in length and
(M)genesis in those measuring more than 8 mm;
protandrous maturation of M. juponwum is
therefore suggested. The results of the present
study indicate that ova and sperm mature at
approximately the same time although primary
oocytes (ova lying free in the ovarian cavity)
are often present before spermatids; therefore.

Vol. 90 (2)

THE NAUTILUS

83

TABLE 4. Sizes of fii'st and second litters per (fill and the percent viability of larvae in seqttential parents (defined in
text) of Musculium securis in four habitats for each year of adlection.

Types of Litters

(iirp Pond

(hrclif
Prnii

Britannia Bay

Uir li>Uf>iei)ix

1970

1971

1972

1972

1970

1971

19T2

1971

1972

Fii-st Larval litters

in sequential parents

ELxtra-marsupial larvae

aO" (25)'

4.0 (40)

2.6 (28)

Z7 (18)

24 (18)

ai (15)

2.4 (16)

28 (14)

4.8 (20)

LIO-

1.61

(1.91

0.84

0.8;^

1.44

0.90

1.48

1.56

Prodissoconch larvae

4.7 (31)

5.3 (:«)

5.5 (36)

5.4 (20)

4.0 (23)

a9 (22)

a8 (16)

4.8 (30)

6.0 (34)

1,26

\M

1.70

1.30

0.93

1.72

1.29

1.84

1.78

Fetal larvae

7.0 (37)

6.9 (38)

7.4 (37)

7.0 (22)

5.9 (28)

5.8 (12)

6.1 (25)

67 (23)

7.6 (34)

1.67

1.77

2.27

1.91

0.99

1.56

1.20

1.29

2.02

% viability

45

58

37

39

41

58

;s

57

6:3

Second larval litters
In sequential parents

Eidra-marsipial

larvae

2.1 (9)

ai (14)

2.4 (a5)

2.4 (.34)

4.2 (1.5)

0.11

0.88

077

0.74

Insufficient

1.27

No

Prodiss(X'onch larvae

4.6 (25)

5.0 (55)

4.8 (.50)

61 (42)

Size

6.6 (31)

Data

1.30

1.44

1.93

1.95

of

L99

Fetal larvae

61 (34)

6.6 (50)

7.4 (.50)

7.8 (45)

Sample

80 (32)

1.51

1.67

2.11

2.16

2.30

% viability

34

47

32

31

52

' Mean litter or brood size.

' Number of specimens examined.

'Standard deviation of the mean.

'% viability = (extra -marsupial larvae, tetal larvae) X

100.

protogyny may occur in some individuals.
Simultaneous maturation of gametes also seems
to occur in Sphaerium simile (Zumoff, 1973)
and M. paiiumeium (Thomas, 1959).

Intraspecific variations in seasonal gonad ac-
tivity is also present in other sphaeriids. Foster
(1932) suggests that maximum size adults of S
striatinum are sterile and reproduction occurs
in the winter months; Avolizi's (1971) data in-
dicate that reproduction in this species occurs
until the death of the animal with peak
reproduction in spring and fall but Monk (1928)
found that reproduction of S. striatinum is at a
peak during the summer months.

There is very little intrapopulation variation
in the total number of brood sacs produced per
parent from one year to the next. However, in-
terpopulation variations in brood sac production
are present. Individuals in Britannia Bay usu-
ally produce a total of six brood sacs while
those in other papulations usually produce
eight, and occasionally ten (Lac Bourgeois),
brood sacs. Of these totals, only two to four (oc-
casionally six) brood sacs mature. Therefore, the

potential total number of litters (six to ten) is
probably rarely achieved, although Heard (1974)
suggests that M. securis can "produce several
litters over a life span of several years".

A significantly larger number (P < 0.05) of
extra -marsupial larvae occurred in 1971 than in
1970 or 1972 in Carp Pond, Britannia Bay, and
Lac Bourgeois. There are no significant dif-
ferences (P > 0.05) in the numbers of pro-
dissoconch larvae nor of fetal larvae between
the 1970, 1971 and 1972 populations of Carp
Pond and Britannia Bay nor between 1971 and
1972 populations of Lac Bourgeois. The numbers
of each larval stage in Greely Pond adults are
similar to those in Carp Pond adults in 1972.
Smaller numbers (P < 0.05) of prodissoconch lar-
vae and of fetal larvae are produced in the
Britannia Bay population than in other
populations. Lac Bourgeois parents produced
larger (P < 0.05) numbers of extra-marsupial lar-
vae in 1972 than did other populations in the
same year and similar numbers (P < 0.05) of
prodissoconch and of fetal larvae as Carp Pond
and Greely Pond in the last two years of study.

84 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

Significantly more (P < 0.(X)5) parents pro-
duced two litters in 1972 than in previous
years of study in Carp Pond (Table 2). The
1972 increase is attributable to the extended
aquatic season since the data was obtained
from parents sampled in August and Septemter
when the pond was usually dry. The data for
1970 and 1971 were obtained from parents col-
lected at the end of July, just prior to the
disappearance of water from the pond. Parents
of Carp and Greely Ponds produced the same
proportions of one and two litters in 1972. A
larger proportion (P < 0.005) of parents produce
one litter in Britannia Bay than in other
habitats. No differences are obsei-ved in the
proportion of parents producing one and two
litters in Lac Bourgeois, Carp Pond, and Greely
Pond although a small percentage of parents
produce three litters in Lac Bourgeois. The ex-
tended aquatic season had no apparent affect
on the numbers of litters produced by in-
dividuals in the Britannia Bay and Lac
Bourgeois populations.

The results from the transplant studies (Table
3), suggest that the Britannia Bay population
may be adaptively modified with respect to the
number of litters produced. That is, with two to
four weeks lag in rate of temperature increase
in Britannia Bay (Mackie, 1973), the population
has less time than other populations to produce
additional litters. Hence, there is greater sur-
vival value to select for one litter than for
several litters of which only one can be pro-
duced.

Gale (1969) proposes that more discretion is
needed in comparing the numbers of embryos
in various species since differences may reflect
seasonal or parental size class variations; also
purported differences between species may be
due to differences in procedures used by various
investigators. The present study indicates that
brood sizes of M. necuris vary greatly within
and among habitats, primarily because of dif-
ferences in larval mortalities. However, there
appears to be less variation in the brood sizes
of secondary sacs within and among populations
with similar habitats. Therefore, the numbers of
fetal larvae alone (and probably embryos) ap-
pear to be more valid measurements for deter-
mining differential fecundities among species

within similar habitats than are numbers of
extra -marsupial or prodissoconch larvae.

The data (Table 3 & 4) also indicate that
both intrapopulation and interpopulation varia-
tions in litter sizes are present. Within the
Carp Pond, Britannia Bay, and I>ac Bourgeois
populations, the sizes of litters released are
significantly larger in the second year of study
than in the first. These higher values may in-
dicate the response of M. securis to replace
those individuals that had been removed for life
history analyses by the author in the previous
year of study. The removal of specimens by the
author are interpreted as representing a mor-
tality factor that is not normally present in the
populations. If this interpretation is correct, M.
securis compensated for the high mortality by
producing large litters in the following year.
This appears to be achieved, not by producing
more eggs (since the total number of fetal lar-
vae per* parent remained relatively constant),
but by maintaining a greater survival rate
(reflected in % viability. Table 4) of larvae
already produced. In this context, the sampling
efforts of the authors apparently had little
ultimate effect on the litter sizes produced
since the litter sizes in the third year of study
are not significantly different from those in the
first year (Table 4). This is a valid interpreta-
tion if the large amount of rainfall in 1972 did
not cause reductions in the litter sizes pro-
duced.

The viability of M. securis larvae from the
fetal stage of development ranges from 37% to
63% in the first litter and 31% to 52% in the
second litter, depending on the year of study
and the habitat. Since the number of embryos
probably exceeds the number of fetal laiTae, the
percent viability of larvae from point of fer-
tilization of the egg is probably smaller. The
data (Table 4) also indicate that M. seairis
produces a certain number of eggs, this number
being genetically fixed. This is suggested from
the similar numbers of fetal larvae (approx-
imately 7.0) of the first litters in Carp Pond,
Greely Pond and Lac Bourgeois. The Britannia
Bay population produces significantly smaller
numbers (P < 0.01) of fetal larvae per sec-
ondary brood sacs than other populations. This
implies that either a high mortality of embryos

Vol. 90 (2)

THE NAUTILUS

85

occurs in the Britannia Bay population or that
the population is genetically distinct with
respect to egg production and indicates that the
litter size can be modified adaptively. Support
for adaptive modification of litter size is seen
in the results from the transplant studies
(Table 3). The Britannia Bay population pro-
duced significantly smaller (P < 0.05) litter
sizes in all transplants than did other popula-
tions of similar transplants.

Avolizi (1971) has also studied larval
viabilities but presented his data in terms of
"embryonic mortality"; the maximum embryonic
mortalities of S. stnatinum and S. simile are
90% and 77-65%, respectively (i.e. larval
viabilities of 10% and 23-35%, respectively).
Avolizi (op. cit.) suggests that "the dying off of
younger stages contributes to the nutrition
of... embryos which survived". The litter sizes
of S stnatinum and S simile at birth range
from 1-2 for both species.

The annual ratio of selection of M. securis
(i.e. number of young bom annually per
average adult) varies widely within and among
populations. For example, the Carp Pond
population in 1970 and 1972 and the Greely
Pond population in 1972 had an annual ratio of
selection of ABOUT 5:1; this ratio increased to
about 7:1 in the 1971 Carp Pond population.
With only one litter, the Britannia Bay popula-
tion has a low annual ratio of selection of
about 2-3:1 while parents in Lac Bourgeois
have the highest annual ratio of selection (8:1).

Analyses of results obtained from seasonal
field collections and the maintenance of adults
in the field and laboratory (Table 3) indicate
that the annual ratio of selection is a function
of density dependent and independent factors.
This is also suggested from the results obtained
by Mackie's (1973) ecological studies on the ef-
fects of such factors as intraspecific and in-
terspecific competition, temperature, and pollu-
tion on the growth and reproduction of M.
securis. Similar conclusions are reported by
Avolizi (1971) for S. simile and S. striatinum.
Burky (1968) has demonstrated that the annual
ratio of selection of Ferrissia riindaris varies
from 35 : 1 in an eutrophic habitat to 8:1 in an
oligotrophic stream.

Heard (1974) describes five types of reproduc-

tive cycles in Sphaerium and Musculium. The
Type II cycle describes reproduction of M.
seruri.s in the Britannia Bay and Lac Bourgeois
populations where there are two or three
periods of fertilizations and births every year.
However, neither of the five cycles defined by
Heard (1974) describe reproduction of M. securis
in the Carp Pond and Greely Pond populations.
In conformity with Heard's (1974, Table 41)
criteria, the reproductive cycle of the latter two
populations can be described as having a life
span of approximately one year, semelparous
reproduction with one litter (or two litters in
one birth period) per year, rarely a fall and
winter incubation period, and only one birth
period (summer).

ACKNOWLEDGMENTS

This research was supported by the National
Research Council of Canada, Grant No. A 2386
awarded to S.U.Q. and by a Postdoctorate
Fellowship awarded to G.LH. by the National
Museums of Canada.

LITERATURE CITED

Avolizi, R. J. 1971. Biomass turnover in natural populations
of viviparous sphaeriid clams. PhD dissertation. Syracuse
Univ.. Syracuse. New York, 150 p.

Burk\'. A. J. 1968. Biomass turnover, energy balance and in-
terpopulation variation in the stream limpet, Ferrissia
riiidaiis (Say), with special reference to respiration,
growth, and fecundity. PhD dissertation, Syracuse Univer-
sity.

Foster. T. D. 1932. Observations on the life history of a
fingernail shell of the genus Sphaerium. J. Morph. 53:
473-497.

Gale, W. F. 1969. Bottom fauna of Pool 19, Mississippi
River with emphasis on the life history of the fingernail
clam, Sphaerium transversum. PhD dissertation, Iowa
State Univ.. Ames, Iowa 233 p.

Heard. W. H. 196.5. Comparative life histories of North
American pill clams (Sphaeriidae: Pisidium). Malacologia
t 381-411.

1974. Manuscript of "Comparative life histories of

fingernail clams (Sphaeriidae: Sphaerium and
Miisndium)" . MalacoUjgia 15: (In press).

Herrington, H. B. 1%2. .A revision of the Sphaeriidae of
North America (Mollusca: Pelecypoda). Misc. Publ. Mus.
Zool. Univ. Mich., No. 118, 1-74.

Mackie, G. L. 1973. Biology of Museuliym secm-is
(Pelecypoda: Sphaeriidae) in two temporary forest ponds,
a river, and a permanent pond near Ottawa. Canada.
PhD dissertation, Ottawa Univ., Ottawa. 17.5 p.

Mackie. G. L. and S. U. Qadri. 1973. Abundance and
distribution of Mollusca in an industralized portion of

86 THE NAUTILUS

April 30. 1976

Vol. 90 (2)

the Ottawa River near Ottawa-Hull, Canada. J. Fish. Res.

Ba. Canada 30: 167172.
Mackie, G. L, S. U. Qadri, and A. H. Clarke. 1974a.

Development of brood sacs in Mvsculiian securis

(Pelecypoda: Sphaeriidae). The Nautilus 88: 109-111.
19741. Intraspecific variations in growth, birth

periods, and longevity of four populations of Muscidium

securis (Pelecypoda: Sphaeriidae) near Ottawa. Canada.

Malariihigia: (In press).
Monk. G. R. 192& The anatomy and life-history of a

freshwater mollusk of the genus Sphaerium. J. Morph.

45: 473-503.
Okada. K. 1935. Some notes on Muscidiwn heterodon

(Pilsbry). a freshwater bivalve. III. Fertilization and

segmentation. Sci. Rpt. Tohoku Imp. Univ.. Ser. i. Biol.
10: 467-483.

Simpson. G. G., A. Roe. and C. R. Lewontin. Quantitative
ZtKiltyy. Harcourt, Brace and Co.. New York, 440 p.

Thomas. G. .1. 1959. Self-fertilization and production of
younginasphaeriidclam. TheNautilu.<t 72: 131-140.

van Cleave, H. J., A. G. Wright, and C. William Nixon.
1947. Preliminary observations on reproduction in the
molluscan genus Musculium. The Nautilius 61: 6-11.

van der Schalie, H. 1953. Nembutal as a relaxing agent for
mollusks./l»«. Midi Nat. .50: 511-512

Zumoff. C. H. 1973. The reproductive cycle of Sphaeriwri
simUe. Biol. Bull. 144: 212-228.

THE GENUS FONTIGENS FROM APPALACHIAN CAVES
(HYDROBUDAE: MESOGASTROPODA)

Leslie Hubricht

4026 a5th Street
Meridian, Mississippi 39.301

ABSTRACT
Fontigens holsingeri Hubricht from Hnnnan Cave, Randolph Co.. West
Virginia, and Fontigens turritella Hubricht from McClung Cave. Greenbrier Co..
West Virginia are described as new species. Additional geographical records are
given for Fontigens orolibas Hubricht. Fontigens aldrichi (Call & Beecherj.
Fontigens tartarea Hubricht. and Fontigens nickliniana (Lea).

Fontigens holsingeri new species

Fig. lA

Description: Shell small, conical, diameter
about 65% of height, thin, translucent, dull,
pale yellowish -horn; umbilicus open, about 0.1
mm. in diameter; nuclear whorl nearly flat,
later whorls regularly increasing in size, well
rounded with very deep sutures, each whorl
lightly appressed to the preceding whorl;
sculpture of numerous inconspicuous growth
lines; aperture ovate, vertical, may or may not
be appressed to the preceding whorl; lip thin,
sharp, with a very slight thickening within.
Operculum paucispiral, thin, of about 3.5
whorls, hyaline, the nucleus being located about
one-half way between the center and the lower
right margin. Animal unpigmented and blind,
verge unknown.

Height 1.7 mm., diameter 1.1 mm., aperture
height 0.6 mm., aperture width 0.5 mm., um-
bilicus diameter 0.1 mm., 4.5 whorls. Holotype.

Distribution: West Virginia: Randolph Co.:

stream in Harman Cave, 0.5 mile southwest of
Harman (Type locality) (J. R. Holsinger & D. C.

B

FK;. \.\. Fontigens holsingeri Hubricht. hotott/pe. Length.

1.7 mm.

FIG. IB. Fontigens turritella Hubricht. holotype. Length. 1.9

mm. Drawings courtesy Field Museum of Natural History.

Chicago, with thanks to Elizabeth Liebman for her skilled

efforts.

Vol. 90 (2)

THE NAUTILUS

87

Culver, colls.), holotype 170893 and paratypes
170392 Field Museum of Natural History, other
paratypes 42560 and 43635 collection of the
author; stream in Bazzle Cave, 1.0 mile south-
southeast of Harman (J. R. Holsinger & D. C.
Culver, colls.). Pocahontas Co.; stream in Pidd-
ling Pit Cave, 10 miles north-northeast of Mar-
lington (J. R. Holsinger, R. Baroody, & R.
SwenSvSon, colls.); stream in Marthas Cave, 0.9
miles southwest of Hillsboro (David Culver &
David Newson, colls.).

Remarks: Fontigens holsingeri is most closely
related to F. eryptica Hubricht; differing in be-
ing larger, with more rounded whorls, and a
more open umbilicus. Fontigens tartarea
Hubricht, which is found in the same area dif-
fers in its flatter whorls and shallower sutures.

Fontigens turritella new species

Fig. IB

Description: Shell small, conical, turreted,
diameter about 48% of height, thin, pale straw
colored, translucent, dull; nuclear whorl
depressed, giving the shell a truncated ap-
pearance, later whorls regularly increasing in
size, well rounded with deep sutures; sculpture
of very weak growth lines and spiral lines;
aperture ovate, vertical, lightly appressed to the
preceding whorl; lip thin, sharp, with a very
slight thickening within, not reflected in the
columellar region. Operculum paucispiral, thin,
hyaline, of about 2.5 whorls, the nucleus located
left of center. Animal unpigmented and blind.

Verge with three lobes, the upper lobe
slender, cylindrical, less than one-third the
length of the other two lobes, and attached
near the base of the center lobe; the center
lobe and the lower lobe are joined together
along most of their length, with only their tips
separate, they excede in length the diameter of
the shell; the center lobe contains the sper-
mathecal duct, the other lobes contain much
smaller ducts of unknown function.

Height 1.9 mm., diameter 0.9 mm., aperture
height 0.5 mm., aperture width 0.5 mm., 5.5
whorls. Holotype.

Distribution: West Virginia: Greenbrier Co.:
stream in McClungs Cave, 2 miles northeast of
Maxwelton (Type Locality) (John Rutherford;
Leslie Hubricht, colls.), holotype 170891 and

paratypes 170890 FMNH, other paratypes 38272
and 40694, collection of the author; stream in
The Hole Cave (Gibbs Eiitrance Section), 2
miles east of Frankford (J. R. Holsinger, D.
Culver, P. Starr, S. Peck, & D. Newson, colls.).

Remarks: Fontigens turritella differs from all
the species knovwi from Appalachian caves ex-
cept F. nickliniana (Lea) by its elongate shape,
its height exceeding twice the diameter. From
F nickliniana it differs in its verge, in its
smaller size, in its truncated spire, and more
slowly increasing whorls.

Fontigens aldrichi (Call & Beecher)

Pnhidina obhisa Lea. 1841. Proc. Amer. Phil. Soc. 2: 34.
(Not. P obtma Troschel. 1837).

BythinMa aldnchi Call & Beecher. 1886. Bull. Washburn
Coll. Lab. Nat. Hist. 1: 190-19i

Amnicola aldrichi aldrichi (Call & Beecher). Hubricht, L.
1940. Nautilus 53: 118-119.

Snails found in springs and caves from north-
western Virginia north to Maryland are not
distinguishable from snails found in the eastern
Ozarks of Missouri. The spring form with eyes
and dark gray pigment were collected at the
following localities: Virginia: Highland Co.:
spring, 0.7 mile southwest of Mustoe; spring, 1.3
miles north of Mustoe. Both of these springs
are in the headwaters of the Jackson River.

The blind unpigmented cave form was found
at the following localities: Virginia: Bath Co.:
stream in Butler Cave, 1 mile north of Bums-
ville (J. R. Holsinger, T. Vigour, & L. Vinzant,
colls.). Frederick Co.: stream in Ogdens Cave,
3.5 miles west-northwest of Middletown.
Maryland: Washington Co.: beneath stones,
large spring, 0.4 mile south of Little Heiskell
Quarry (F. Wayne Grimm, coll.).

It is probable that during the Pliocene, Fon-
tigens aldrichi lived in springs in the northern
United States but was forced south by the
Pleistocene glaciers. Because the kind of springs
in which it lived were covered over by till, it
was not able to move back into its old range
and has survived only in the Appalachians, the
eastern Ozarks, and if the type locality for
Paiudina obtusa is correct, in Ohio.

Fontigens orolibas Hubricht
Fontigens orolibas Hubricht. 1957. "Hie Nautilus 71: 9.

88 THE NAITILUS

April 30, 1976

Vol. 90 (2)

An unpigmented form of this species, which
may or may not have eyes, has been collected
in the following caves: Virginia: Warren Co.:
stream in Skyline Caverns, 2 miles south of
Front Royal. Giles Co.: stream in Smoke Hole
Cave, Newport (J. R. Holsinger & H. R. Steeves.
colls.): stream in Tawneys Cave, near Newrport;
stream in Stames Cave, 3.5 miles south-
southeast of Narrows (J. R. Holsinger & S.
Hetrick, colls.). Tazewell Co.: stream in Hugh
Young Cave, 1.5 miles southwest of Liberty Hill
(J. R. Holsinger, coll.).

Fontigens tartarea Hubricht

Fontigenstartann Hubricht. WWA Nautilas76: 140.

Since this species was described it has been
found living in the following caves: West
Virginia: Tucker Co.: stream in Harpers Cave,

5 miles southeast of Hendricks (J. R. Holsinger

6 D. C. Culver, colls.). Randolph Co.: stream in
Simmons-Mingo Cave, 1.5 miles southwest of
Mingo (R. B. Williams, coll.); stream in Bowden
Cave, 7 miles east of Elkins (J. R. Holsinger &
D. C. Culver, colls.). Monroe Co.: stream in In-
dian Draft Cave, a few miles south of Wayside
(J. R. Holsinger, D. C. Culver, & R. Baroody,

rolls.); stream in Rock Camp Cave, 1.6 miles
south of Rock Camp; stream in McClungs Cave,
Zenith.

Specimens from EJowden Cave are ven- small:
height 1.2 mm., diameter 0.7 mm., and are
probably the smallest freshwater snails known
from the eastern United States.

Fontigens nickliniana (Lea)

Palidina mcklinUma Lea. 1839. Trans. Amer. Phil S()c n
s. 6: 92.

Fimtiyens nickliniana (Lea). Pilsbrv. 1933. Nautilus 47:
12.

What appears to represent a blind, white,
cave form of this species has been collected at
the following localities: Went Virginia: Monroe
Co.: stream in Hunt Cave, near Sinks Grove (J.
R. Holsinger, coll.). Virginia: Lee Cx).: stream in
Gallohan Cave No. 1, 6.5 miles southeast of
Rose Hill (J. R. Holsinger, coll.); stream in
Spangler Cave, 3.5 miles west of Jonesville
(J. R. Holsinger, coll.); pool in Smiths Milk
Cave, 7 miles southeast of Rose Hill (.1. R.
Holsinger, D. C. Culver, colls.). The verge has
not been e.xamined from any of these lots. It is
very difficult to kill cave hydrobiids relaxed.

REPRODUCTION AND EARLY DEVELOPMEINT OF THE OCEAN QUAHOG,
ARCTICA ISLANDICA, IN THE LABORATORY

Warren S. Landers

National Marine Fisheries Service

Middle Atlantic Coastal Fisheries Center

Milford. Laboratory

Milford, Connecticut 06460

ABSTRACT

The ocean quahng. Arctica islandica, mmnaily spawns in summer in southern
New Enyland. Attempts to ripen these bivalves out of season in the labomtory
produced limited success. Clams obtained from the Rhode Island fishery in late
winter and kept in seawater ranging from 10°C to 15°C ripened significantly in
five weeks, but clams subjected to the same temperatures, plus supplemental
feeding with cultured algae in the fall, failed to produce gametes. Ripe clams
could not be induced to spawn by rapidly increasing temperature, rapidly
decreasing temperature, changing the salinity, or by sperm suspension. Fer-
tilization and the per cent developfnenl of stripped eggs to n^mnal latToe were
significantly increased when the eggs were exposed to dilute ammonium
hydroxide before fertilization was attempted. The eggs developed to the veliger

Vol. 90 (2)

THE NAUTILUS

89

larral stage best at a temperature of about 15°C. The larvae were reared to
metamorphosis at 12°C ± 2°C. Early straight-hinge stages have an unusually
long hinge line. Older larvae have low-profile tmbones that barely rise above
the hinge line; consequently, the larval outline is always round. Larvae
metamoi-phose most commonly at a length of 190-200\ji The color throughout
larval development ranges frojn colorless to a pale yellow.

During World War II a modest fishery for
A)Ttica islaudica (Linne), the ocean quahog,
sometimes called the mahogany clam, developed
off the coast of Rhode Island, but, because
other bivalve species more familiar to the con-
sumer were still plentiful, this fishery did not
expand significantly in the post-war years.
Recently, a decline in the abundance of the
more popular bivalves has spurred the govern-
ment and industry to explore the possibility of
using ocean quahog populations more efficiently
(Mendelsohn, Parker, McRae, King and Joyce,
1970). The general distribution and abundance
of these clams in the Middle Atlantic Bight
have recently been established (Merrill and
Ropes, 1969), and it is apparent that these
stocks represent a potentially valuable resource.
The purpose of this paper is to describe recent
attempts at the Milford Laboratory to develop
rearing methods for the developmental stages of
the ocean quahog as an aid to understanding
the dynamics of its natural populations and the
response of the clam to its environment.

GAMETOGENESIS

TTie reproductive cycle of Arctica in Rhode
Island waters has been described by Loosanoff
(1953). Spawning begins in late June or early
July, when the bottom water temperature over
the clam beds is about 13°C, and continues ac-
tively into early October. By late October few
animals with ripe sex products are found. After
what may be a recovery or "resting" period of
about a month, gametogenesis resumes and con-
tinues into December. While this activity slows
down with the advent of winter water tem-
peratures, both male and female clams can be
found with some morphologically mature sex
products. The gradual warming of the water in
the spring initiates a period of rapid
proliferation of sex cells until, by the end of
June, many individuals are ready to spawn.

This sequence of reproductive events suggests
that it should be easy to ripen ocean quahogs
for spawning in the laboratory during much of
the year. My attempts to accomplish this, to
date, have had only limited success, however. In
one instance, clams were obtained from the
fishery off Rhode Island in late March 1971.
The state of gonad development at this time
was as described by Loosanoff (1953); i.e. most
animals contained identifiable sex products, in-
cluding some mature eggs and active sperm, but
their numbers were small and the gonads far
from being full. These animals were kept in
flowing, unfiltered seawater at temperatures
that ranged between 10°C and 15°C. By the end
of April, the abundance of sex products had in-
creased substantially, and, when the gonad was
opened, it produced the runny appearance that
is associated with ripeness in field stocks of
this bivalve in late June. The clams remained
in this environment throughout the spring and
summer. Sex products continued to accumulate,
producing white, distended gonads. This ap-
pearance persisted until late October when a
decrease in the volume of sex products became
apparent and many of the remaining eggs ap-
peared to be breaking down.

In late November 1971, a new group was ob-
tained from the same fishery. These included a
few females with old disintegrating eggs and a
few with new, developing eggs. There were also
a few males with small numbers of motile
sperm. Most clams had empty gonads, however.
All were kept in the laboratory at 10°-15°C in
unfiltered, flowing seawater. Half of them were
additionally fed continuously with cultured
algae and the other half were not. Once a
month, thereafter, gonads fi-om each batch were
examined for sex products.

By mid-March 1972, it was apparent that
neither of the treatments had produced any
quantity of ripe gametes. Gametogenesis ap-

90 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

peared to have been stimulated to some extent
in those clams getting the supplemental algae,
but with no consistency within the group as a
whole, i.e., there were some individuals with lit-
tle or no identifiable sex products. It appeared
from these two trials that gametogenesis in the
ocean quahog can be accelerated experimentally
in the laboratory by simulating summer tem-
peratures only at certain times of the year.

AVAILABILITY AND DEVELOPMENT
OF EGGS

Loosanoff (1953) was unable to spawn ripe
ocean quahogs in the laboratory using stimuli
that work for many other bivalves. These
stimuli included a rapid increase in water tem-
perature, addition of suspensions of sex prod-
ucts, and changes in salinity. He did observe un-
provoked spawming in conditioning tanks on
two occasions, but could not relate these to any
obvious environmental condition. My own at-
tempts at various times, using the same kinds
of stimuli during the summer and early fall,
when the clams contain the most, and,
presumably, the ripest sex products, corroborate
Loosanoff 's observations. In addition,
stimulation with rapidly decreasing tem-
perature, a technique which was described by
Posgay (1953) as a dependable way to induce
spawning in sea scallops (Placopecten
magellanicus), and which we too found to work
well with this species, also failed to cause
spawning in ocean quahogs, even though these
two bivalves live in the same range of water
temperature in nature and spawn at about the
same time of the year.

Loosanoff (1953) states that the stripped ^gs
of the ocean quahog cannot be fertilized because
the germinal vesicle remains intact even after
the eggs are placed in seawater. I found that a

few stripped ^gs can be fertilized directly with
stripped sperm, but tliat more eggs can be fer-
tilized if they are treated with dilute am-
monium hydroxide before the sperm are added.
The ammonium hydroxide treatment is one that
Loosanoff and Davis (1963) used on certain
refractory species, and consists of adding 3 ml
of 0.1 NH4OH for every 100 ml of egg culture,
to a clean suspension of stripped eggs. After
the required length of exposure, the ^gs are
washed on a screen repeatedly with filtered,
UV-irradiated seawater and resuspended in the
same kind of water. The stripped sperm are
then added.

Table 1 shows the effects on Arctka eggs of
exposure to dilute NH4OH for different lengths
of time. The effects are measured in terms of
the per cent development of normal ^gs to
normal straight-hinge, veliger larvae at
12°C±2°C. The term "normal eggs" is defined
here as those eggs which after being stripped
from the gonad have, or quickly assume, the
round, solid appearance that characterizes most
naturally-spawned bivalve ^gs.

In two of the three experiments, there was
some fertilization and development of untreated
eggs, but the per cent development of treated
^gs was almost always higher and, in the best
exposure times, about three times higher than
in the controls. Exposure times between 5 and
15 minutes appear tf) give good results.

The ocean quahog is a cold water species. The
adults soon die if kept in water of 70°F (Tur-
ner, 1949). One might expect, therefore, that
their eggs would also be intolerant of high tem-
perature. Table 2, which summarizes the results
of two experiments in which the effects of dif-
ferent temperatures on the development of eggs
treated with ammonium hydroxide for 15
minutes were observed, shows this to be so.

TABLE 1. Per cent devclc/pment to the veliger stage of Arctica islandica eggs expose to NH,OH for different lengths of
time prior to feriilizatum.

Experiment

Exposure

time in

minut

es

number

0

5

10

15

20

30

60

1

4

12

8

10

11

2

1

12

11

27

6

3

0

13

13

7

2

Average

5

12

10

17

8

7

2

Vol. 90 (2)

THE NAUTILUS

91

TABLE 2. Per cent development to the nelifier ittcii/e at different temjxratures nf Arctica islandica eggs erpused to NH,OH
for 15 minutes prior to fertilization.

Experiment

Water

temperature

number

lO'C

15°C

20°C
2
3
2

23°C

1

2

Average

10
27
18

26
21
24

0
0
0

Variations from the prescribed temperatures
were about ±1°C in these experiments. At tem-
peratures of 20X and above development of the
eggs to normal larvae is adversely affected.
Visual examination showed that fertilization
and early cleavage were as successful at the
high temperatures tested as at the lower ones,
but before the veliger stage was reached, most
of the embryos died. Per cent development of
eggs at 10°C and IST was approximately the
same but the rate of development was slower at
10°C. At 15°C veliger larvae were present at 48
hours after fertilization but not until about 72
hours at 10°C.

GROWTH OF THE LARVAE

Larvae were grown to metamorphosis
twice — once at lOT and once at 12°C, using
the method described by Loosanoff and Davis
(1963). A mixture of Monochrysis and Isochrysis
was used as food.

The development of the larvae from straight-
hinge to metamorphosis is, in general, un-
distinguished, with no arresting morphological
features which would serve to distinguish the
larvae from those of many other bivalves in the
plankton. With that in mind, only certain
characteristics which appear to be typical of
Arctica development are described.

The earliest, fully-shelled, straight-hinge lar-
vae average about llOfi long (parallel to the
hinge line) and 80^4 high (Fig. 1). The hinge line
is longer than that of most straight-hinge
bivalve larvae and, at this stage, averages
slightly more than SO^t In this respect the lar-
vae are similar to those of the blue mussel,
Mytilus edulis. The color is light yellow to
almost colorless. A noticeable concavity in the
hinge line is apparent in some larvae, but in
the majority it is straight. In a resting position
the larvae appear to be bilaterally symmetrical,
with little or no skewness.

FIGS. 1-3. Larval development in the ocean quahog.. Arctica
islandica. FIG. 1. Early straight -hinge larva. 110 ji fony.
FIG. 2. Late straight-hinge and early umbone larvae, 150 ii
Umg. FIG. 3. Mature larva approaching metamorphosis, 180
fi lo)ig.

92 THE NAUTILUS

April 30, 1976

Vol. 90 (2)

At a length of 150^^ the straight hinge line is
still a prominent feature in many lar\ae, but
has begun to be replaced in others by a convex
hinge line (Fig. 2). Umbones are present but
are small and of low profile and, consequently,
do not impinge on the gradually rounding
outline of the shell.

At a length of 175-180^ it is apparent that
the larvae have changed only in size and not at
all in shape, since the silhouette is still round.
In certain perspectives the umbones appear to
project very slightly above the hinge, but from
most angles they lie about even with the
slightly convex hinge line. A few larvae begin
to metamorphose at this size and can be seen
creeping along the substrate, but the most com-
mon larval length at metamorphosis is 190-200fi.

The length of larval life at both 10°C and
12°C in the laboratory was about 60 days.
Because the bottom water temperature over the
clam beds off Rhode Island does not exceed
15°C during the breeding season (Loosanoff,
1953), the slow growth of the larvae in the
laboratory at the experimental temperatures
may be accurately reflect the rate of growth of
the larvae in the field. This would force the
larvae to remain in the plankton for weeks,
possibly subjecting them to prolonged predation
and widespread dispersal, a consideration in the

proper management of the resource if it is ever
utilized lo its fullest extent.

ACKNOWLEDGMENTS

I thank Mr. George Morrison of the En-
vironmental Protection Agency Laboratory,

Narragansett. Rhode Island, for providing me
with the adult clams used in this study, and
Mr. James B. Hughes of this laboratory for
making the illustrations.

LITERATURE CITED

Loosanoff, V. L. 19.5.3. Reproductive c>'cle in Cxfprina is-
Iwidica. Biol. Bull 104(2): 146-1.5.5.

Loosanoff, V. L. and H. C. Davis. 1963. Rearing of Bivalve
Mullusks. In Russell, F. S. (ed.) Advan. Mar. Biol. 1:
M.36.

Mendelsohn, J. M.. P S. Parker, E. D. McRae, F. J. King
and A. H. Joyce. 1970. TTie ocean quahog — a bountiful
clam. F(x>d Product Development 4(7): 90, 92, 97.

Merrill, A. S. and J. W. Ropes. 1969. The general distribu-
tion of the surf clam and ocean quahog. Proc. Nat. Shell-
fi.th. Assoc. 59: 4045.

Posgay, J. A. 1953. Sea Scallop Investigations. In Sixth Re-
port on Investigations of the Shellfisheries of Massachu-
setts. Mass. Dept. Conservation, Div. Marine Fisheries,
pp. 9-24.

Turner, H. ,J. 1949. The Mahogany Quanaug Resources of
Mas.sachusetts. /« Report on Investigations of Methods of
Improving the Shellfish Resources of Massachusetts. Mass.
Dept. Conservation, Div. Marine Fisheries, December 31,
1949, pp. 12-16.

PUBLICATIONS RECEIVED

Ros, Joandomenec. 1975. Opistobranquios (Gastro-
poda: Euthyneura) del litoral iberico. Investi-
gacion Pesquera, vol. 39, no. 2, pp. 269-372, 4
pis. (3 in color). Barcelona, Spain. Ecology, foixi
preferences, and brief synonymies of 102 spe-
cies of littoral opisthobranchs from Spain and
Tangiers.

Taylor, John and Jerry G. Walls, 1975, Courriea.
288 pp., numerous color photos, wall chart in-
cluded. T. F. H. Publications, New Jersey
$14.95. Despite a number of spelling mistakes
and a few misidentifications, this is the best
buv in Cowrie books for amateurs.

Humfrey, Michael. 1975. Sea Shells of the West
Indies. 351 pp., 20 text figs., 32 colored plates.

Taplinger Publishing Co., N. Y. $19.95. This
book is very similar to Caribbean Seashells by
Wamike and Abbott, but has more colored
plates, and 48 species not in the latter. How-
ever, 272 species found in Caribbean Seashells
are not included. The drawings are copies from
Caribbean Seashelh and American Sea.thelL%
first edition. The nomenclature does not in-
clude changes and updatings found in the se-
cond, 1974, edition of American Seashelh.
Abbott, R. Tucker. 1976. Seashells. 160 pp., 184
color pis. Bantam Books, Inc., N. Y. Paperback,
$1.9.5. Introduction to the shells of the
seven seas.

INFORMATION FOR SUBSCRIBERS

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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.

The Delaware Museum of Natural History

has extensive modern facilities and equipment
for the housing and curating of voucher
specimens. Material should be accompanied by
the identification, locality data and its
bibliographic reference. There is no charge for
this permanent curating service, and catalog
numbers, if desired, will be sent to authors
prior to publication.

JULY 1976

THE

NAUTILUS

Vol. 90

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. Arthur H. Clarke, Jr.
Department of MoUusks
National Museum of Canada
Ottawa, Ontario, Canada K1A-0M8

Dr. WUliam J. Clench
Curator Emeritus
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. William K. Emerson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

Mr. Morris K. Jacobson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

Dr. Aurele La Rocque
Department of Geology
The Ohio State University
Columbus, Ohio 43210

Dr. James H. McLean

Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, California 90007

Dr. Arthur S. Merrill
Biological Laboratory
National Marine Fisheries Service
Oxford, Maryland 21654

Dr. Donald R. Moore

Division of Marine Geology

School of Marine and Atmospheric Science

10 Rickenbacker Causeway

Miami, Florida 33149

Dr. Joseph Rosewater
Division of MoUusks
U. S. National Museum
Washington, D.C. 20560

Dr. G. Alan Solem

Department of Invertebrates
Field Museum of Natural History
Chicago, Illinois 60605

Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, Ohio 43210

Dr. Ruth D. Turner

Department of MoUusks
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. Gilbert L. Voss
Division of Biology

School of Marine and Atmospheric Science
1 0 Rickenbacker Causeway
Miami, Florida 33149

Dr. Charles B. Wurtz
3220 Penn Street
Philadelphia, Pennsylvania 19129

EDITOR-IN-CHIEF

Dr. R. Tucker Abbott

Delaware Museum of Natural History
Box 3937, Greenville, Delaware 19807

Mrs. Horace B. Baker

Business and Subscription Manager

1 1 Chelten Road

Havertown, Pennsylvania 1 9083

OFFICE OF PUBLICATION

Delaware Museum of Natural History

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Box 3937, GreenviUe, Delaware 19807

Second Class Postage paid at Wilmington, Delaware

Sut>scrlptlon Price: $7.00 (see Inside back cover)

THE

NAUTILUS

Volume 90, number 3 — July 21, 1976

CONTENTS

Review (of W. K. Emerson and M. K. Jacobson) vi

Wayne Leathern, Peter Kinner and Don Maurer

Northern Range Extension of the Florida Marsh Clam CyrenoidaJloTidana

(Superfamily Cyrenoidacea) 93

David Bickel

Two New species of Non-marine Mollusca from the Fort Union Group

(Paleocene) of North Dakota and Montana 94

Artie L. Metcalf and David H. Riskind

A New Humboldtiana (Pulmonata: Helminthoglyptidae) from Coahuila, Mexico 99

Raymond W. Neck and Richard W. Fullington

Anomalous Land Gastropods from Texas (Polygyridae and Urocoptidae) 101

Leslie Hubricht

Notes on Some Land Snails of the Eastern United States 104

Alan Solem

Status oiSuccinea ovalis chittenangoensis Pilsbry, 1908 107

Fred E. Wells

Growth Rate of Four Species of Euthecosomatous Pteropods

Occurring off Barbados, West Indies 114

J. A. Gardner, Jr., W. R. Woodall, Jr.,
A. A. Staats, Jr. and J. F. Napoli

The Invasion of the Asiatic Clam {Corbicula manilensis Philippi)

in the Altamaha River, Georgia 117

N. V. Subba Rao and S. C. Mitra

Succiyiea nun New Name for Siwcinea arboricola Rao, 1925

(Stylommatophora: Succineidae) 125

BOOK REVIEW

Emerson, William K. and Morris K. Jacobson.
1976. Guide to ShelU: Land, Frej^hunter, and
Marine, fi-om Nova Scotia to Florida, .wiii + 482
pp., 47 pis. (16 in color). Alfred A. Knopf, N. Y.
Hardcover, $17.50; paperback, $8.95.

This husky little guide with its attractive il-
lustrations and entertaining, as well as accurate,
text should be a pcjpular sheller's reference book
to the common shells of the seashore, streams and
woods of eastern United States. Numeroas keys
to all of the species covered in the book, and a
wealth of etymological data for the lovers of the
origin of names, are outstanding features.

The selection of the 524 species of marine
shells, except for a few dozen species requiring a
microscope for identification, will help the
amateur, although other similar books treat with
many more. Most useful under this one cover are
several hundred, rather well-illustrated, land and
freshwater mollusks.

Somewhat of a drawback created by the book
designer is the use of difficult-to-remember ro-
man numerals for the plates (XLII, XXXK,
etc.), and the main species not being put in
boldface type. The origin of the scientific names
is very well done, but, parenthetically, Helicina
clappi was named after the venerable land-shell
taxonomist, George Hubbard Clapp, and not for
the Cape Cod shipworm specialist, William F.
Clapp. Amateurs and some professionals will be
dismayed over the re-arrangement of the scien-
tific names of the Biisycon whelks. The il-
lustrated holotype of Linnaeus' pervermm (The
Nautilus, vol. 53, pi. 7) is almost identical to what
they label as kieneri. Nonetheless, this is a very
praiseworthy shell book.

R. Tucker Abbott
Delaware Museum of Natural HiMory

THE NAUTILUS
Back Volumes 1 through 40

High quality reprintings are now available from
our office. The cost of the handsomely bound set,
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available separately for $12.00 (paperbound).

Oothbnund, vols. 1-40 (with Index) $482.00

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THE B^ST OF THE

W*1

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american malacologists

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A handsome, durable hardback edition bound in .simulated
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ized end papers. A dozen well-known shells are shown in
full color. Only $13.95.

Bicentennial Presentation Qipy

Only a few numbered copies are available and only by ad-
vanced .subscription; each is handdated. numbered and per-
sonally autographed by the editor to the individual pur-
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facturing This elegant book, in simulated leather, is
matched with a specially designed, presentation slip box.
SKlKl.

VI

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 93

NORTHERN RANGE EXTENSION OF THE FLORIDA MARSH CLAM
CYRENOIDA FLORIDANA (SUPERFAMILY CYRENOIDACEA)

Wayne Leathern, Peter Kinner and Don Maurer

College of Marine Studies

University of Delaware

Lewes, DE 19958

The small bivalve, Cyrenoida floridana (Dall,
1896), was collected in the Canary Creek Marsh,
Delaware, at 38°48'45" north latitude and 75° 10'
west longitude. In May 1975, 15 samples were col-
lected in connection with a marsh productivity
study. On the average, 12 specimens were found
in every 1/4 m^ sample. The clams attaining a
length of 9 mm occurred most abundantly among

FIGS. 1-3. Cyrenoida floridana (DalL 1896) from Canary
Creek, Delaware. 1, hinge of left valve. X200. 2, hinge of
right valve. X200. 3, dorsal view of bivalve. XlOO.

the layer of detritus at the base of the marsh
grasses.

The range for C. floridana had previously been
reported from Georgia to southern Florida (Dall,
1896). This constitutes a northern range extension
of approximately 900 km and crosses a major
zoogeographic boundary (Abbott, 1968; Cerame-
Vivas and Gray, 1966). The description of these
specimens agrees with Abbott (1974, p. 466, fig.
5385).

To ascertain more information about the den-
sities and ecology of C. floridana, 15 stations
tent and volatiles, sand, silt and clay. Eh, and
altemiflora (tall and dwarf), S. patens, and
Dii^tichlis .'ipicata zones. The percent of water con-
tent and volatiles, sand, silt and clay. Eh, and
surface salinity were sampled at each location.
A 0.1 m^ sample of sediment taken from the base
of each of the grasses was sieved over a 1 mm
screen and the number of C. floridana was
recorded.

The area with the highest density of C.
floridana was the D. spicata (15.0/0.1 m^) zone.
The dwarf S. altemiflora (3.0/0.1 m^) area was
the only other area where appreciable numbers of
individuals were found. A few specimens were
recorded in the -S. patens and S. altemiflora
zones.

Of the environmental data collected only the
percentage of volatiles and water content showed
any association with the observed densities of C.
floridana. The D. spicata and dwarf S. alter-
niflora had mean water contents of 238.4 (± 81.5)
and 273.8 (± 104.1), respectively, while the tall S.
altemiflora value was only 80.7 ± 26.7. The per-
centage of volatiles was also higher in the D.
spicata (-210.0 ± 7.4) and dwarf S. altemiflora (21.8
± 8.5) areas than in the creekside tall Spartina
(6.76 ± 2.02).

94 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

From this limited evidence it may be specu-
lated that the high water content of the sedi-
ments containing C. floridana may be impor-
tant in facilitating the life functions between
daily inundations in the marsh areas where it
lives. The high volatile content of the sediments
inhabited by C. floridana should be examined
more closely for its possible nutritive role.

The stem densities in the D. apicata and dwarf
S altemijhra zones are far greater than those in
the tall S. atternijlora. This may be very impor-
tant in stabilizing the sediment and lessening the
effect of light and temperature on marsh surface
containing the clam (Kraeuter and Wolf, 1974).

At the suggestion of Dr. R. Tucker Abbott, who
kindly verified the identification (Del. Mus. Nat.
Hist., No. 102,538), we offer a figure to supple-

ment the illustration in Abbott (1974). We would
like to thank our colleague, Mr. Phil Averill, who
collected and brought these specimens to our at-
tention.

LITERATURE CITED

Abbott. R. T.. 1968. Seashells of North America. A Golden

Field Guide. Golden Press, N. Y., pp. 268.
Abbott. R. T., 1974. American Seashells. Second Edition. Van

Nostrand Reinhold Co., N. Y., pp. 66a
Cerame-Vivas, M. J., and I. E. Gray. 1966. The distribution

pattern of benthic invertebrates of the continental shelf

off North Carolina. Ecology 47(2): 51-52.
Dall, William Healey, 1896 On the American species of

Cyrenoidea. The Nautilus 10(5): 51-52.
Kraeuter. J. N. and P. L. Wolf. 1974. The relationship of

marine macroin vertebrates to salt marsh plants. In:

R. J. Reimold and W. H. Queen, eds. Ecology of Halophytes.

Academic Press, N. Y., pp. 449-462.

TWO NEW SPECIES OF NON-MARINE MOLLUSCA FROM THE FORT
UNION GROUP (PALEOCENE) OF NORTH DAKOTA AND MONTANA

David Bickel

Minot State College
Minot, North Dakota 58701

ABSTRACT

Two new species of fossil freshwater moUusks are described from the Paleo-
cene Tongue River and Sentinel Butte Formations of North Dakota and Mon-
tana. Eupera missouriensis n. sp. is a pisidiid clam related to K formosa (Meek
and Hayden). Bellamya campjaniformis n. sp., a vimparid snail, occurs in the
lowei' and middle Tongue River Formation and possibly in the Paskapoo Fcrr-
mation of Alberta.

INTRODUCTION

Pioneering work on Fort Union mollusks and
stratigraphy was done by F. B. Meek and F. V.
Hayden between 18.56 and 1860. Meek (1876) sum-
marized the p)aieont<)l()gy of the region and listed
about 25 non-marine species of mollusks then
known to occur in the Paleocene of the Williston
Basin. With the exception of studies in the
Saskatchewan portion of the basin summarized
by Russell (1974) and other, scattered reports,
most data on Paleocene mollusks of the Northern

Great Plains has come from work in other
sedimentary basins.

This report of two new species is part of a study
of Williston Basin mollusks initiated in 1971 and
due for publication in the near future. TTie
results are based on collections from about 130
localities in eastern Montana and western North
Dakota selected to provide the best stratigraphic
and geographic coverage of the Fort Union
Group.

The Fort Union Group along with the lowest

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 95

member of the predominantly Eocene Golden
Valley Formation includes all the strata of
Paleocene age in the Wil listen Basin. The
Ravenscrag; Formation is the synonymous
lithostratigraphic term for the northern margin
of the Fort Union sequence in .Saskatchewan
(Russell, 1974). In eastern Montana the earliest
Paleocene is included in the Tullock Formation
which sets on top of dinosaur-bearing beds of the
Cretaceous Hell Creek Formation and is
overlain by the Lebo Formation. Together, the
two reach thicknesses of over 600 ft. In North
and South Dakota these two rock units cannot be
easily separated and the sequence is termed the
Ludlow Formation with possible subdivision into
Tullock and Lebo Members in some areas. The
Ludlow Formation in North Dakota and
southeastern Saskatchewan intertongues with a
marine equivalent, the Cannonball Formation,
which represents a last resurgence of the
Cretaceous epicontinental sea that crossed North
America. Up to 700 ft. of the non-marine Tongue
River Formation overlays the Lebo-Ludlow for-
mation in Montana and westernmost North and
South Dakota, and the Cannonball Formation
over much of western North Dakota. The
Saskatchewan portion of the basin includes only
the lowest part of the Tongue River Formation
and older rocks. Over much of North Dakota and
parts of eastern Montana up to 650 ft. of the Sen-
tinel Butte Formation overlays the Tongue River
Formation and represents the most extensive
unit of Upper Paleocene strata in the basin. At
scattered localities in western North Dakota rem-
nants of the lower member of the Golden Valley
Formation reach maximum thicknesses of 65 ft.
The Paleocene-Eocene boundary is placed at the
contact of the upper and lower members of this
formation based on paleobotanical evidence
(Hickey, 1972).

Sediments comprising Fort Union Group
strata, with the exception of the Cannonball For-
mation, were deposited in an alluvial system of
numerous streams flowing generally eastward
across broad coastal lowlands left from the mid-
continent seaway. The sediments occur generally
as semi-consolidated silts, clays, fine sandstones,
and the lignite beds that command current atten-
tion as a source of abundant coal. The strata are

often calcareous although true limestone and
marlstone units are rather infrequent. Jacob's
(1973) discussion of depositional environments of
the Tongue River Formation provides a basic in-
sight into the environments responsible for much
of the non -marine Fort Union sequence.

Register of localities— The species described
here occur at only 8 of the many localities ex-
amined, thus both are infrequent or rare in the
Williston Basin.

Locality l.-NW 1/4, SW 1/4, sec. 7, T. 143 N.,
R. 79 W., Burleigh Cx)., N. Dak., middle Tongue
River Formation. 2.-NW 1/4, sec. 30, T 142
N., R. 78 W., Burleigh Co., N. Dak., lower Tongue
River Formation. 3.-SW 1/4, sec. 12, T. 144 N.,
R. 84 W., Mc Lean Co., N. Dak., upper Tongue
River Formation. 4.-NE 1/4, SW 1/4, sec. 1, T.
140 N., R. 81 W., Burleigh Co., N. Dak., lower
Tongue River Formation. 5.-SE 1/4, NW 1/4,
sec. 28. T. 148 N., R. 100 W., Mc Kenzie Co., N.
Dak., upper Sentinel Butte Formation. 6.— SE
1/4, NE 1/4, sec. 26, T. 148 N., R. 100 W., Mc Ken-
zie Co., N. Dak., upper Sentinel Butte Formation.
7.-NE 1/4, NW 1/4, sec. 10, T 12 N., R. 51 E.,
Prarie Co., Mont., lower Lebo Formation. 8.—
sec. 7, T. 135 N., R. 88 W., Grant Co., N. Dak.,
upper Tongue River Formation.

Family Pisidiidae
Genus Eupera Bourguignat

Eupera is represented in the non -marine
Paleocene of the Williston Basin by the following
taxon and "Sphaerium" fomiosum (Meek and
Hayden). Yen (1946) referred a Lower Cretaceous
species from Alberta and Wyoming to the genus
and noted that Eupera also occurs in the Eocene
of North America.

Eupera missouriensis new species

Figs 1-4

Description— Shell medium size, elongate, in-
flated, greatest thickness along mid-length: beaks
large, raised, umbo extending forward to anterior
one-fourth of length; hinge extending over most
of shell length; dorsal margin convex, joining
posterior margin at a rounded angle; posterior
high; posterior margin truncate, joining ventral
margin at a prominent but rounded angle; ven-
tral margin convex, merging with rounded
anterior margin; anterior margin meeting hinge

96 THE NAUTILUS

July 21. 1976

Vol. 90 (3)

line to form a rounded angle; anterior end low;
posterior outer surface crossed by a rounded and
indistinct ridge extending from beak to base of
posterior margin; surface above ridge flattened or

slightly convex; growth lines fine, irregular,
growth cessation intervals marked by coarse
lines; right valve (RV) cardinal t(X)th slender,
posterior tip bent slightly ventrad below umbo,

fu f^ ti ^ ^ t

FIG. 1, Eupera missmriensis n. sp., exterior ofHolati/pc (USNM 2Jn()TS) Xi; FIG. 2, .some sperimni. interior of Hi ilalype X4;
FIG. 3, Eupera mi.ssourien.sis /!. .sp. exterior of Paratype (USNM /JOdTD) XJ,: FIG. 4, same specimen, interior of Rinit ype Xi;
FIG. 5, Bellamya campaniformis n. sp.. apical mew nf Holotype (USNM ^tlOHD) XI. .5: FIG. 6, Bellamya campaniformis n. up.,
HoUitype X1.5: FIG. 7, same specimen, basal view of Holotiipv XI. 5: FIG. 8, Bellamya campaniformis n. sp.. series of 21
piiratjfpex summarized in Thble 1, X'A

Vol. 90 (3)

July 21. 1976

THE NAUTILUS 97

anterior portion merging into hinge; cardinal
teeth (LV) two, short, slender, situated below um-
bo; posterior lateral tooth (RV) slender, length
about one-fourth of shell length; anterior lateral
teeth (RV) two, short, cusps forming lip-like bor-
der for pocket, inner lateral curved, bulging into
shell cavity; anterior and posterior laterals (LV)
single, thick, raised, cusps prominent and
situated near mid-length.

Types and measurements— Uolotype USNM
22(X)78 a right valve measuring, length 7.1 mm.,
height 5.5 mm.; Paratype USNM 220079 a left
valve measuring, length 8.1 mm., height 6.4 mm.

T>ff>p locality-SE 1/4, NW 1/4, sec. 28, T. 148
N., R. 100 W., Mc Kenzie Co., N. Dak. North Unit
of Theodore Roosevelt Memorial Park at 2340 ft.
above mean sea level. Sentinel Butte Formation.

Age and ra^ye— Middle through late Paleocene
age. Eupera missouriensis occurs in the Tongue
River Formation along its eastern margin and in
the Sentinel Butte Formation in the Little
Missouri Badlands of western North Dakota. It is
a dominant element only in the assemblages from
the Sentinel Butte localities. Specimens have been
collected at Localities 3, 4, 5, 6, and 8.

Remarks— Eupera missouriensis can only be
confused with the equally uncommon but smaller
species, Eupera fmyttosa (Meek and Hayden). It is
more elongate than E. foitnosa and possesses a
rounded posterior ridge that is flanked by areas
that appear flattened relative to the rest of the
shell surface. The posterior surface of E. fonnosa
is not broken by a ridge and its posterior margin
is more rounded and merges with the ventral
margin in a gentle curve. Eupera fomiosa ap-
pears ovate in outline while E. missouriensis ap-
pears more triangular. Growth lines on E for-
mosa are more regular than those of E.
m,issouriensis. Eupera formosa has a slightly
more fragile shell, and Williston Basin localities
indicate that it inhabited rather heavily

vegetated and quiet water in floodbasin areas.
Eupera missouriensis has been collected from
units interpreted as channel, point bar, levee or
crevasse splay deposits. It appears that the two
species occupied different habitats in the alluvial
system, with E. missouriensis more closely
associated with stream channels, possibly living
in quiet reaches along shore. Specimens suited to
adequate study of hinge structure are seldom
recovered from the fine enclosing matrix,
however the hinge structures of E formosa are
generally more delicate that those of E
mmouyiensis and the cusp of the posterior
lateral (LV) is toward the posterior while on E
niissou lien sis it is central on the tooth.

Family Viviparidae

Subfamily Bellamyinae

Genus Bellamya Jousseaume

Examination of numerous lots of living African
and Asian Bellamyinae in the U. S. National
Museum and Field Museum of Natural History
confirms Dwight Taylor's assignment of this and
many other Late Cretaceous and Paleocene forms
to the Bellamyinae.

Bellamya campaniformis new species

Figs. 5-8
Description— SheW medium to large,
trochiform, heavy; spiral angle 70° -90° on first
five whorls, declining to 50° on later whorls;
shell width about three-fourths of height, width
and height nearly equal in juveniles; whorls 4 to
6' 2, juvenile whorls nearly flat to slightly convex,
adult whorls slightly to moderately convex; junc-
ture of whorl base and periphery angular,
marked by a narrow raised carina on juvenile
whorls, whorl base convex; sutures lightly im-
pressed, often slightly to distinctly below keel of
preceding whorl; body whorl large, comprising
more than two-thirds of shell height; aperture

TABLE 1. Ranges of measurements and proportions of three size groups of Bellamya campaniformis n. sp. Upper, middle, and
lower rows of Figure 8 show measured specimens arranged in the respective groups.

Number of
specimens

7

7
7

Height (mm )

10.8-18.4
21.0-29.8
31.2-42.6

Width (mm.)

12.9-17.0
18.6-23.7
25.1-28.9

Number of
whorls

4.0-4.7
47-5.3

5.1-65

Width

Height

1.19- .92
.88-.77
.81 -.67

98 THE NAUTILUS

July 21. 1976

Vol. !)() (3)

ovate tx) roundly triangular, large, equal to abjut
60% of shell height in juveniles, about 45% in
mature specimens; peristome and growth lines
prosocline, forming a 40° angle with spire axis;
peristome periphery and base simple, convex, col-
umellar lip attached, thickened, slightly reflected
near base; columella imperforate; growth lines
prominent, straight or slightly sinuous, and
crossed by 1 to 6 or more fine, evenly spaced,
spiral ridges.

Type^ and meafiurementa—Holotype USNM
22(T(IS0 height 32.7 mm., width 25.1 mm., aperture
height 15.5 mm., whorls 6; Paratype USNM
220081 height 25.1 mm., width 20.8 mm., aperture
height 12.4 mm., whorls 5. Nineteen other
paratypes (Figure 8 and Table 1) are retained in
the aiithor's collection.

Tifpr lorality-BaW Butte, NE 1/4, SW 1/4, sec.
1, T. 140 N., R. 81 W., Burleigh Co., N. Dak. Gray
buff sandstone about 2090 ft. above mean sea
level. Tongue River Formation.

,4(/f and range— Mid Pala)cene, lower 300 ft. of
the Tongue River Formation along its eastern
margin m North Dakota (Localities 1, 2, 4, and
possibly 7) and the Paskapoo Formation of Alber-
ta.

Remarka—Bellamya campaniformifi differs
from Bdlainija refusa in having a higher spire, a
greater number of whorls, and whorls that are
much less a)nvex. Bellamita retma lacks the
spiral sculpture and keeled periphery of B. cam-
IxudfonHi.s. Both species have similar peristomes
and share the tendency for shoulders to be formed
on the first three whorls.

Bdlantya rampanifonnk has a thicker walled
and heavier shell than Paludotrochus trochiformis.
It lacks the two prominent and equally spaced
spiral ridges that are insistent features on
the spire whorls of P. twchiformvi. The spiral
angle of P. frochijonni.s varies only from 80° to
70° during ontogeny giving the spire a straight -
sided, trochoid .shape while the spiral angle of B.
campanifiinnis decreases during ontogeny produc-

ing a spire with convex sides. The number of
whorls are about the same for the two species. A
distinct shoulder at the top of early whorls per-
sists onto the fourth whorl of P. trochifomiis
while the shoulder on B. camjxinifonnii^ is
generally less distinct and fades out on the sec-
ond or third whorl. Palndotrochn.^ tmchifdnnis
hius a perforate collumella and generally a thin-
ner columellar lip than B. canijxinifomiui.

Tozer (19.56) referred to Bcllamya rrtnsa
.specimens from the Paskapoo Formation
(Paleocene) of Alberta that agree with B. cam-
jKitiifiinnk. The description and illustrations give
the diagnostic characters of this species, however
his material was not e.xamined.

The species has been collected from sand and
clayey silt units interpreted as channel, point
bar, and floodbasin deposits. Its limited oc-
currence does not permit a full analysis of its
ecology, however it apparently lived in habitats
associated with larger streams or at least flowing
water as opposed to ponded floodbasin habitats.

LITERATURE CITED

Bii-kfl. I). Ut?:). Non-marine mollusks and two new species of
I'ixiiimm from the Tongue River Formation (Paleooene),
North Dakota. Thi- Nmitilus 87: i:?-18.

Hickey, L. .J. 1972. Stratigraphic summary- of the Ciolden Val-
ley Formation (Paletx.-ene— Eocene) of western North Da-
kola, p. 105-122. In Ting. F. T. C. ed. Depositional environ-
ments of the lignite-bearing strata in western North
Dakota. Nmih Dakota Geol. Sttrv. Miic. Ser. 50 VM p.

.lacob. A. F. 197.1 Depositional environments of Paleocene
Tongue Kiver Formation, western North Dakota. Amer.
Aanar. Pet ml. Ccol. Bull. 57: l(i:»- 10.52.

Meek, F. B. 1876. .\ report on the invertebrate Cretaceous
;uid Tertiary fossils of the Vpper Mi.ssouri countr^^ l'. S.
dfdl. Sun: Terr. (Hayden Survey) 9: «29 p.. Ah pis.

Russell, L. S. 1974. Fauna and airrelation of the R;ivenscrag
Formation (Paleocene) of southwestern Saskatchewan.
Life Sci. Contrib. Ruy. Ontario Mux. 102: .'J2 p.

Towr. K. T. HF)!!. Uppermost Cretaceous and PalecK-ene non-
mannc molluscan faunas of western Alberta. (!<'iil. Siirr.
Oimiila Mem. 280: 12.5 p., 9 pis.

Yen. T, C, 1910. On lower Cretaceous fresh-water mollusks of
Sage Creek. Wyoming. Notutae Nature 166: 1-13.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 99

A NEW HUMBOLDTIANA (PULMONATA: HELMINTHOGLYPTTDAE)

FROM COAHUILA, MEXICO

Artie L. Metcalf

Department of Biological Sciences

University of Texas at El Paso

El Paso, Texas 79968

and David H. Riskind

Resource Management Section

Texas Parks & Wildlife Department

Austin, Texas 78701

ABSTRACT

A new species of land snail, knovm only from shells, is described and placed
pmvvdomdly in the genus Humboldtiana (Pulmonata: Heiminthogiifptidae).
Humboldtiana plana differs from other knoum species of Humboldtiana in its
greatly flattened and highly gmnulose shell. It is presently knoum only from
the Sierra Santa i^o.sa in north-central Coahuila, Mexico.

INTRODUCTION

The species of land snail described herein was
collected by Riskind from the higher, northern
slopes of the Sierra Santa Rosa, north-central
Coahuila, Mexico, in 1975. Generic allocation of
the species to the genus Humboldtiana cannot be
done with certainty as living specimens have not
been obtained in two collecting trips requiring
strenuous climbs. The shell is much more de-
pressed and granulose than in any known species
of Humboldtiana. However, Humboldtiana is the
only genus of large, banded helicacean snails
known in the region and it seems likely that this
species is a conchologically modified representa-
tive of the genus or of a new, related genus in the
family Helminthoglyptidae.

There are few published records of Hum-
boldtiana from Coahuila. However, the genus has
been recorded from both the extreme north (H
taylori Drake by Drake, 1951: 95 and by Solem,
1954: 6) and the extreme southeast (H.
nuevoleonis Pilsbry by Pilsbry, 1948b: 192). Thus,
it seems likely that the genus also occurs in
many of the intervening mountain ranges in the
state such as the Sierra Santa Rosa. Drake (1951:
93) assigned shells from archaeological deposits in
Frightful Cave in the Cuatro Cienegas Basin of
central Coahuila to H. montezuma Pilsbry.

Humboldtiana plana new species

Figs. 1-.3

Description of Holotype: Shell thin, flattened,
with spire rising only slightly above shoulder at

an angle of ca. 150°; whorls 4.1, with body whorl
expanding greatly and angular peripherally;
aperture elongate-lunate, its height 1.4 times
its width; columellar peristome reflected, cover-
ing half of umbilicus; outer lip thin, broken; em-
bryonic whorl smooth; second whorl with small
granules in center; remainder of shell, both above
and below (including umbilical area) with
numerous large, whitish granules, irregularly
distributed, smaller on older whorls and ranging
from 0.3-0.9 mm in length (averaging ca. 0.5 mm)
on the body whorl, some arranged in irregular
rows of two to twelve granules; dark reddish-
brown color of first IV2 whorls continues on as a

FIGS. 1-3. Holotype of Humboldtiana plana »<■?/• .fpeetes (U3.6
mm diameter) in laternJ. durftal and ventral xriews.

100 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

band in central dorsal part of whorls I'': to 2'-2,
greatly expanding thereafter to cover inner half
of whorl 4, this band 10.8 mm wide at lip; two
additional bands arise on first part of whorl 4,
one above and one below peripheral angularity;
remaining surface of shell brownish-gray except
for the numerous whitish granules; internal sur-
face of aperture dark reddish-brown, slightly
iridescent. Etymology: From planus (L.), flat, in
relation to morphology of shell.

Variation and Measurements: Only four
relatively complete shells of H. plana have been
obtained (numerous fragmentary specimens were
observed). Part of the thin-shelled body whorl has
been broken away in one paratype and some
breakage has damaged the lip of the holotype,
which is, otherwise, the best-preserved of the four
shells. In two specimens with undamaged
peristomes, the outer lip is slightly thickened and
recurved and columellar peristome extends over
most of the umbilicus. Probably the type died
shortly before forming the thickened peristome
seen in these paratypes. In one paratype the
nuclear whorls are slightly more elevated than in
the type. Measurements for the type (listed first)
and two paratypes are as follows: Diameter of
shell, 43.6, 40.1, 40.5; Height of shell, 19.8, 21.0,
18.8; Aperture width, 25.1, 25.4, 25.1; Aperture
height, 17.8, 16.0, 15.5; Number of whorls, 4.1, 4.3,
4.2.

Types: Holotype, Delaware Museum of Natural
History 106681; Paratypes: University of Arizona
6220 and University of Texas at El Paso 4651 and
4653.

Localities of Collections: Holotype and two
paratypes (UA 6220, UTEP 4651): Mexico,
Coahuila, Mcpo. de Muzquiz, Sierra Santa Rosa
near the summit of the Rincon de Maria (28°28'
N; 102°04' W). Ca. 2207 m elevation in sheltered,
mesic cleft with northern exposure in a massive
limestone cliff. Associated plants include such
mesophytic species as the ferns Woodsia sp.,
Polypodium erythrolepis, the fir, Abies coahuilen-
sis, and species of Tilia, Philadelpkus and

Heuchera. Collected on 23 August 1975 by
Riskind, T. Wendt and E. Lott. On 24 April 1975
a paratype (UTEP 4653) was collected by Riskind
and T. Wendt on the north slope of the same
mountain at an elevation of 1700 m in an area of
extensive stabilized limestone talus in oak
woodland (predominantly Quercus glaucoides).

COMPARISONS AND DISCUSSION

The flatness and angularity of the shell of H.
plana is much greater than in any Humboldtiana
known to us. The degree of granulation is ex-
treme for the genus but may be approached by
that of H. peryranulosa Solem from Durango.
Solem (1955: 42) noted granules 0.05-0.75 mm
long in H. peiyranulosa. Illustrations (Solem,
1955: Figs. 1-3) show these to be more uniformly
distributed over the surface than in H. plana.

Some members of the polygyrid snail genus
Ashmunella living in talus of limestone rocks
have become greatly flattened and carinate.
Pilsbry (1948a: 587) quoted notes (A. G. Wether-
by) indicating that the greatly flattened and
carinate Anguispira cumberlandiana (Lea) in-
habited crevices between layers of limestone
rocks. Perhaps flattened shells are of adaptive
value in such habitats.

LITERATURE CITED

Drake, R. J. 19.51. Humboldticma tayhri. new species, from

northern Giahuila. Rev. See. Malacoi Carlos de la Torre 8:

93-96.
Pilsbry, H. A. 1927. TVie structure and affinities of Hum-

Mdtiana and related helicid genera of Mexico and Texas.

Priic. Acad. Nat. Sci. PhUadelphm 79: 165-192.
Pilsbry. H. A. 1948a. Land Mollusca of North America (North

of Mexico). Acad. Nat. Sci. PhUadelj^ia Monogr. 3, 2(2):

xlvii -f- .521-1113.
Pilsbry. H. A. 1948b. Inland mollusks of northern Mexico.

I. The genera Humboldtiana, Stnwrella, Orenhelix and

Aithmunella. Proc. Acad. Nat. Sci Philadelphia 100:

185-203.
Solem, A. 1954. Notes on Mexican mollusks. I: Durango,

Coahuila and Tamaulipas, with description of two new

Humhdldtiaiia. The Nautilus 68: :i-10.
Solem. A. 1955. New and little-known Helicidae (Mollusca.

Pulmonata). The Nautilus 69: 40-44.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 101

ANOMALOUS LAND GASTROPODS FROM TEXAS
(POLYGYRIDAE AND UROCOPTIDAE)

Raymond W. Neck

Texas Parks and Wildlife Department

John H. Reagan Building

Austin, Texas 78701

and

ABSTRACT

Richard W. FuUington

Curator of Invertebrate Zoology

Dallas Museum of Natural History

Dallas, Texas 75226

Anomaloics shells of several land gastropod species from Texas include scalari-
form Mesodon thyroidus thyroidus, Mesodon roemeri and faulty shell regenera-
tion in Holospira oritis, Holospira mesolia, and Polygyra texasiana texasiana.

SCALARIFORM MONSTROSITIES
A loosely-spired Mesodon thifl-oidus thyroidus
(Say), (Fig. 1) was collected in deep woodlands
near White Rock Creek, Dallas Co., on 22 June
1974, by Bruce Boardman. The whorls are
acutely raised with the spiral lines deeply incis-
ed. The shell wall from the embryonic whorl
through the antepenultimate whorl is quite
thin. The general appearance is that of a highly
turret«d shell. The shell measures 16.5 mm in
height and 19.6 mm at greatest diameter, giving
a H/D ratio of 0.84. Average figures previously
reported for this species (Cheatum & Full-
ington, 1971: 29) are 20 mm and 12-13 mm for
an average H/D ratio of 0.60-0.65.

A turreted Mesodon roemeri Pfeiffer (Fig. 3)
was given to one of us (RWN) on 24 May 1972
by Don W. Kaufman, who collected it in an
open woodland floodplain along Barton Creek
within Austin, Travis Co. The specimen was
alive and appeared normal; it was later found
dead in the labortory in early August. Death is
believed to be the result of improper care
rather than associated effects of the anomalous
shell form. The shell measures 18.8 mm in
height and 23.0 mm greatest diameter (H/D
ratio = 0.82); normal height for a shell of that
diameter is about 12 mm (Cheatum & Full-
ington. 1971: 20-21), resulting in a H/D ratio of
0.52. The shell wall of this specimen of M.
roemeri does not appear to be thinner than in
normal specimens of this species.

These similar anomalies of two species of
Mesodon were found independently from widely
spearated localities. The only shell anomaly
reported for these two species previously involv-

ed several specimens for thyroidus (Bland in
Tryon, 1867; Wetherby, 1895; Archer, 1934) and
a single sinistral specimen for roemeri (Pratt,
1965).

These two specimens, representing two species
which are most easily distinguished by differing
H/D ratios, appear to be very similar. However,
they are referrable to their respective taxa by
application of other differences between these
two species (Neck, upub. data). The Dallas Co.
specimen exhibits the following characteristics
of thyroidus: 1) almost immediate expansion of
upper lip, 2) the erect nature of the lip as it
approaches the umbilicus, 3) coarse growth lines
and 4) ochre band behind the lip. The Travis
Co. specimen exhibits the following
characteristics of roemeri: 1) delay of f)eristome
expansion until upper lip merges into palatal
lip, 2) lip flattened as it approaches umbilicus,
3) fine growth lines and 4) yellowish band
behind lip. Additionally, each site contains only
individuals of the respecive species of Mesodon.

The high-spired roemeri is noticeably larger
than the high-spired thyroidus. In eastern
Travis Co. and Bastrop Co. (central Texas)
where these two species occur sympatrically,
throidus is slightly larger than roemeri. The
smaller size of the Dallas Co. throidus may be
the result of marginal habitat near the edge of
its geographical range.

Without detailed breeding and controlled ex-
periments, we can only speculate as to the
cause of these two anomalous shell conditions.
A similar anomaly was reported in Helix asper-
sa Muller from a California garden (Herzberg,
1966); breeding of this individual failed to pro-

102 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

ll

5 6

8

10

#

11

duce the anomaly in either F, or Fj gen-
erations. Similar turreting has been reported
for at least two sf)ecies of Littorina (Davis,
1972; Rosewater, 1972). The effect in thsee two
species, however, did not involve an increase in
shell height, only a turreting effect.

In the two Mesodr)H individuals reported
herein, the cause, whether genetic or en-
vironmental, affected shell growth from the
time of hatching, possibly before. The small size
of the protoconch makes it impossible to deter-
mine if the turreting effect began in the
earliest stages of embryogenesis although this
would a priori appear to be most likely as all
post-nuclear whorls are affected. Rosewater
(1972) reported specimens of Littorina scahra
angulifera Lamarck with both immediate and
late turreting, i.e. changes involving all whorls
and only the last two. Oldham (1931) attributed
the occurrence of high-spired Arianta ar-
bustorum (L.) to injuries by parasitic mites;
neither Mesodon shell appears to have the de-
formed shell structure which accompanies such
a malformation.

M. thj/roidus (Fig. 2) and M. memeri (Fig. 4)
are members of the same subgenus (Mesodon s.
str.) but are placed in different species groups
(Filsbry 1940: 704 et seq.). As these two species
undoubtedly share considerable common genetic
material, the turreted anomalies could be
genetic in origin, either through similar muta-
tions or through similar rare recombinations of
certain alleles. The possibility of some en-
vironmental factor affecting expression of nor-
mally buffered (non-expressed) genes cannot be
ruled out but is considered unlikely. Both shells
have the normal number of whorls {bVi-bVt).

FAULTY SHELL REGENERATION

Gastropods are effectively protected from en-
vironmental perturbations by their calcreous
shells. When an injury cracks or destroys a
part of the shell, regeneration of the injured
portion must occur. Terrestrial gastropods are

FIGS. 1-2. Mesodon th.vToidus (Scalarifiinn. Numiatl
FIGS. 3-4. Mesodon roemeri (Scaiariform, Nnrmal)
FIGS. 5-7. Abnormal Holospira oritis
FIGS. 8-9. Abiiiirmnl Holospira mesolia
FIGS. 10-11. Abtwrmal Polygvra t. texasiana

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 103

particularly effective in rapid regeneration of
shell material (Wagge and Mittler, 1953).
Sometimes regeneration of an injured shell
results in oddly-formed shells.

A dead shell of Holospira otitis (Fig. 5-7)
Pilsbry & Cheatum with two complete aper-
tures (Fig. 3) was collected 26 July 1974, deep
in South McKittrick Canyon, Guadalupe Moun-
tains National Park, Culberson Co., by Ray
Garza. The shell measures 14.6 mm in height
and 4.8 mm at greatest diameter. The shell con-
tains nine whorls but several apical whorls
have been lost. Entire shells of this species
measure 13''2-154 whorls and 15-20 mm in
length (Cheatum & Fullington, 1973: 40). The
breakage may have occured some time
following death as the shell material is not
weathered to the same degree as the rest of the
shell. The body whorl of the snail was filled
with soil and debris when found.

The entire body whorl except for the original
aperture and 2.5-3.0 mm behind it had been
torn away. A new body whorl and partial
peristome were secreted with the original neck
cavity being filled by the columellar lip of the
new aperture. The new shell secretions were
rough and irregular; now new ribs were formed
on the new basal whorl. The basal lip of the
new aperture was split by the presence of rem-
nants of the original whorl; thus, the animal
emerged between the palatal wall of the second
aperture and the jagged edge of part of the
original body whorl. A similar double-aperture
example of Cylindrella agnesiana C. B. Adams
is illustrated by Cooke (1895: 252, Fig. 160A).
In this case, the body whorl was undamaged
with destruction restricted to previous whorls.
The second aperture was constructed completely
separate from the first. The most likely source
of the original shell injury was attempted
predation by some unknown animal (most likely
rodent). Apparently, the shell was dropped and
the animal was unharmed or only slightly in-
jured as it survived to produce the illustrated
repair work.

On 19 October 1974, several living and dead
shells of Holospira mesolia Pilsbry (Fig. 8-9),
were collected (by RWN) 4.6 km west of
Sanderson, Terrell Co., on the north side of U.S.

90. Attention was drawn to one shell due to its
shorter height (17.0 mm vs. 23.7 for normal
shell). The smaller size was due to the loss of
several whorls as a resullt of an injury similar
to that suffered by the above individual
reconstructed about Wt whorls before producing
the extremely flat expansion of the peristome
which is characteristic of this species. The final
''4 whorl is moderately ribbed in the manner
typical of the body whorl of this species. The
first reconstructed whorl which is partially
underneath the remnant apical portion of the
original whorl is unsculptured and much thin-
ner than normal. The injury, however, either
occured before the snail matured and con-
structed an aperture or was so massive that
the original aperure was also destroyed. Com-
parison of the shortened shell with a normal
shell revealed the loss of four complete whorls
(if the injured individual matured previous to
injury).

An additional example of shell repair was
collected (by RWN) on 30 August 1974, at the
Bi-ackenridge Field Laboratory of the Universi-
ty of Texas at Austin within the Austin city
limits. The shell involved is a Polygyra texas-
iana texasiana (Moricand) (Fig. 10-11) which
had lost about H of its body whorl. The site of
the original aperture was discernable by the
presence of the parietal tooth which was ap-
parently not totally built up at the time of the
injury. The snail, however, did not reconstruct
any of the body whorl. It simply constructed a
new reflected lip complete with two teeth, one
basal and one palatal. A new parietal tooth
was also constructed. The diameter of the shell
as found measured 8.1 mm; before injury, the
original shell measured about 9.5 mm.

These three shells exhibit three responses to
somewhat similar injuries. The differential
responses of the two Holospira resulted fi'om
differential injuries. The response of the P. t.
texasiana may indicate a basic difference be-
tween the Polygyridae and the Urocoptidae in
the physiological response to shell regeneration.

All specimens described herein are deposited
in the Dallas Museum of Natural History
Mollusca collection. Reprint requests are
directed to the Museum.

104 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

LITER ATI 'RE CITED

Archer, A. F. 1934. Sinistral land snails from Ann Arbor, Mi-
chigan, ne NautiliLs 47: 148-149.

Cheatum, E. P. and R. W. Fullington. 1971. The aquatic and
land moUusca of Texas. The Recent and Pleistocene mem-
bers of the gastropod family Polygyridae in Texas. Dallas
Mus. Nat. Hist. 1(1): 74 pp.

1973. The Recent and Pleistocene members

of the Pupillidae and Uroooptidae (Gastropoda) in Texas.
Ibid. 1(2): 67 pp.

Cooke, A. H. 1895. Mollusca. In: The Cambridge Natural His-
tory. Ed. by S. F. Harmer and A. E. Shipley. 3: 1-459. Mac-
millan & Co., London.

Davis, D. S. 1972. An unusual form oi Littorina littarea Linne'
found in Nova Scotia. The Nautilus 86: 87.

Herzberg, F. 1966. An anomaly of a Helix aspersa shell which

failed to appear in successive generations (Mollusca: Pul-

monata). Veliger 8: 190.
Oldham, C. 1931. Some scalariform examples of Arianta car-

bustorum infested by parasitic mites. Pruc. Maiac. Soc

Umdtm 19: 240-242.
Pilsbry, H. A. 1940. Land mollusca of North America (north

of Mexico). Acad. Nat. Sci. Phil. Manogr. 3, vol. L at. 2.
Pratt, W. L., Jr. 1965. Sinistral Mesodon roemeri. The Nauti-
lus 78: 143-144.
Roeewater, J. 1972. Teratological Littorina acalera angidifera.

The Nautilus 86: 70-71.
Tryon, G. W., Jr. 1867. Scientific intelligence. Amer. J. Qmch.

3: 104-106
Wagge, L. E. and T. Mittler. 1953. Shell regeneration in some

British molluscs. Nature 171: 528-529.
Wetherby, A. G. 1895. New records of reversed American

Helices. The Nautilus 9: 94.

NOTES ON SOME LAND SNAILS OF THE EASTERN UNITED STATES

Leslie Hubricht

4026 35th Street
Meridian, Mississippi 39301

ABSTRACT

The examination of type and other material has made it necessary to change
the status of a number of specific and subspecific names: Polygyra septemvolva
volvoxis and P. s. febigeri are synonyms of P. cereolus; Polygyra latispira is a
synonym o/ Triodopsis vultuosa; Guppya miamiensis is a form o/ G. gundlachi;
Glyphyalinia burringtoni is a synonym of G. wheatleyi; G. roanensis is a
synonym of G. cumberlandiana; G. umbilicata is a valid species; Paravitrea
walkeri is a synonym of P. umbilicaris; P. smithi is a synonym of P.
petrophila; Anguispira alternata paucicostata is a synonym of A. mordax;
Helicodiscus enneodon is a synonym of H. multidens; Megapallifera is raised to
genus; and Gastrocopta tappaniana is a valid species.

The examination of material in the Academy
of Natural Sciences of Philadelphia (ANSP), the
Museum of Comparative Zoology (MCZ), the
University of Michigan Museum of Z(x)logy
(UMMZ), the Carnegie Museum (CM), and
material in the author's collection has made it
necessary to change the status of a number of
specific and subspecific names.

Polygyra cereolus (Miihlfeld)

Helix cereolus J. C. Megerle von Miihlfeld, 1818,
Gesellschaft naturforschender Freunde zu

Berlin, Magazin etc., 8: 11, pi. 2, fig. 18a, b.
Helix volvoxvi "Parreyss" Pfeiffer, 1846, Sym-

bolae ad Hist. Heliceorum, 3: 80.
Helix carpenteriana Bland, 1860, Ann. Lye. Nat.

Hist. N. Y. 7: 138.
Helix febigeri Bland, 1866, Amer. Journ. Conch.,

2: 373, pi. 21, fig. 10.
Polygyra septemvolva \3S . floridana Hemphill, in

W.G. Binney, 1892, 4th suppl., Bull. Mus.

Comp.Zool.22: 184.
Polygyra cereolus (Miihlfeld), Pilsbry, 1940, Acad.

Nat. Sci. Philadelphia Mono. 3, 1: 582.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 105

Fdhfgjfra cereolus form carpenteriana (Bland),

Pilsbry. ibid. 1: 585.
Polygi/m cereolus floridana Hemphill, Pilsbry,

ibid. 1: 586.
Polygyra septemvolva volvoxis (Pfeiffer), Pilsbry,

ibid. 1: 590.
Polygyra septemvolva febigeri (Bland), Pilsbry,

ibid. 1: 591.

The presence of an internal lamella which
Pilsbry used Xa distinguish P. cereolus from P.
septemvolva Say is not a valid specific charac-
ter. P. cereolus has larger caliber whorls and a
smaller umbilicus than P. septemvolva. Very
depauperate specimens less than 7 mm in di-
ameter are very difficult to identify, but such
specimens are rare. When the two species occur
together, as they sometimes do, they can be
sorted without too much difficulty. Very large
lots will usually contain the complete range of
variation in size, sculpture, and degree of angu-
lation of the periphery; so that it does not
seem wise to attempt to recognize subspecies.

Triodopsis vultuosa (Gould)

Helix vultuosa Gould, 1848, Proc. Boston Soc.

Nat. Hist. 3: 39.
Tiiodopsis vultuosa (Gould), Pilsbry, 1940. Acad.

Nat. Sci. Philadelphia Mono. 3, 1: 818.
Polygyra latispira Pilsbry, 1896, Proc. Acad. Nat.

Sci. Phila., p. 16; 1940, 1:622.

The holotype and paratype (ANSP) of Polygyra
latispira are immature Triodopsis mdtuosa. An
immature specimen of T. vultuosa in lot ANSP
172794, from 2 miles northeast of Neches, Ander-
son Co.. Texas, Wheeler & Archer, colls, agrees
with the types of P. latispira.

Guppya ^ndlachi form miamiensis Pilsbry

Helix gundlachi Pfeiffer, 1840, Archiv. f. Naturg.,

1:250.
Guppya miamiensis Pilsbry, 1903, The Nautilus

17: 77.
Guppya gundlachi (Pfeiffer), Pilsbry, 1946, Acad.

Nat. Sci. Philadelphia Mono. 3, 2: 244.
Guppya miamiensis Pilsbry. Pilsbry, ibid. 2: 244.

Guppya miamiensis differs from G. gundlachi
only in the absence of spiral sculpture. I believe
it to be only a form of G. gundlachi.

Glyphyalinia wheatleyi (Bland)

Zonites wheatleyi Bland, 1883, Ann. N. Y. Acad.

Sci. 2: 368, fig. 1.
Glyphyalinia bwringtoni Pilsbry, 1928, The

Nautilus. 41: 83.
Retinella wheatleyi (Bland), Pilsbry, 1946, Acad.

Nat. Sci. Philadelphia Mono. 3, 2: 272.
Retinella burringtoni (Pilsbry), Pilsbry, ibid. 2:

266.
Glyphyalinia wheatleyi (Bland), Hubricht, 1964,

Sterkiana 13: 12.

There is no difference in the shells between G.
ivheatleyi and G. burringtoni, and recent studies
show that the anatomical differences are not con-
stant. B<jth types of penis may occur in the same
lot and intermediates are sometimes found.

Glyphyalinia cumberlandiana (Clapp)

Polita cumberlandiana Clapp, 1919, The Nautilus,
33:8.

Retinella (Glyphyalus) cumberlandiana roanensis
H. B. Baker, 1930, Proc. Acad. Nat. Sci.
Philadelphia, 82: 203, pi. 9, figs. 7-9; Pilsbry,
1946, Acad. Nat. Sci. Philadelphia Mono. 3, 2:
271.

Retinella cumberlandiana (Clapp), Pilsbry, 1946,
ibid. 2: 269.

Glyphyalinia cumberlandiana (Clapp), Hubricht,

1964, Sterkiana 16: 7.

Glyphyalinia roanensis (H. B. Baker), Hubricht,

1965, The Nautilus 78: 133.

By going on my collecting trip through the
Southern Appalachians in May instead of June, I
discovered that G. cumberlandiana. which I had
considered to be a rare species, was rather com-
mon. As a result, I was able to collect a good
series which enabled me to better understand the
species. H. B. Baker's treatment of R. cumberlan-
diana was based on small specimens of G.
wheatleyi and R. cumberlandiana roanensis
which I consider a synonym of cumberlandiana.

Glyphyalinia umbilicata (Singley)

Zonites indentatus var. umbilicatu^ Singley, in
Cocherell, T. D. A. 1893, Brit. Nat., 3: 81. 1899;
The Nautilus \2: 120.
Specimens collected in Dallas, Texas, were

dissected and found to be more closely related to

106 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

G. hdicola Hubricht than to G. indentnta (Say),
a!th()up;h the shell looks like a rather large G. in-
dentdta with a more open umbilicus. Judging by
the shells I have seen, umhilirata appears to be
widely distributed in Texas, but more anatomical
studies of Te.xas material iu-e needed. This species
has been called Rctinella indentata paucHirata
(Morelet) by H. B. Baker and H. A. Pilsbry. But
piiurilimta was described from Guatemala and its
anatomy is unknown. For this reason it seems un-
wise to use the name of a species so g«)graphical-
ly distant in a group with such deceptive shells.

Paravitrea umbilicaris (Ancey)

(kiMrodonla rnultidentata umbilicaris Ancey,

1887, Conch. Exch., 1:55.
Gmtri,d(»ita imlkcri Pilsbry, 1900, Proc. Acad.

Nat. Sci. Philadelphia, p. 146.
Paravitrea (Paravitreops) walkeri dentata H. B.

Baker, 1929, Uc Nautilus. 42: 88.
Pararitrca walkeri (Pilsbry), Pilsbry, 1946, Acad.

Nat. Sci. Philadelphia Mono. 3, 2: 362.
Paravitrea indkeri form dentata H. B. Baker,

Pilsbry, 1946. ibid. 2: 363.

The three specimens in the type lot (UMMZ).
and a good series of topotypes which I c-nllected,
show that this species is not related to P.
multidentata (Binney) but is identical with P.
walkeri form dentata. Thus P. umbilicaris will
replace P. walkeri form dentata and the
lamellate form will become P. umbilicaris form
walkeri. The type locality for P. umbilicaris is
Alleghany Springs, Blount Co., Tenn., which is a
former Spa at a sulfur spring on the side of
Chilhiiwf'e Mtn., al)()ut 11 miles southwest of
Maryvillc.

Paravitrea petrophila (Bland)

Zimites petrophila Bland, 1883, Ann. N. Y. Acad.

Sci. 2: 369, fig. 2.
Vitrea {Pararitrea) smithi Walker, 1928, Terr.

Moll. Ala., p. 88, fig. 120.
Paravitrea petrophiln (Bland), Pilsbry, 1946,

Acad. Nat. Sci. Philadelphia Mono. 3, 2: 385.
Paravitrea i^mithi (Walker). Pilsbry, ibid. 2: :384.

The holotype (UMMZ) and paratype (CM) could
not be found; but specimens which I nillected
at what I believe to be the type locality, and
which agree with the original description, are

depauperate P. petrophila. P. smithi should be
placed in the synonomy of P. petrophila.

Anguispira mordax (Shuttleworth)

Helix mordax Shuttleworth, 1852, Mittheil.

Naturforsch. Ges. Bern, Nr. 248-9, p. 195.
Anguispira altemata paucicostata Kutchka, 1938,

The Nautilus 52: 12, pi. 2, fig. 2. Pilsbry, 1948,

Acad. Nat. Sci. Philadelphia Mono. .3, 2: 581.
Anguispira altemata mordax (Shuttleworth),

Pilsbry, /frirf. 2; .581.
Anguiapira mordax (Shuttleworth), Hubricht, L.,

1968, Sterkiana 32: 5.

The holotype and two paratypes (CM) of A.
altemata paucicostata were examined. Ihe
paratypes are typical A. inoiriax. and the
holotype is an aberrant specimen of the same
species.

Helicodiscus multidens Hubricht

Helicodiscus multidens Hubricht, 1962, Vie

Nautilus 75: 102.
Hpiicodiscu.'< enneodon Hubricht, 1965, The

Nautilus 79: 6

Recent collecting has shown that H. multidens
and H. enneodon intergrade and therefore H. en-
neodon should be placed in the synonomy of H.
niultidens.

(Jen us Megapaliifera Hubricht

Megapallifera new subgenus, Hubricht, 1956,

Nautdiis 69: 126.

Megapallifera was originally described ;U5 a
subgenus of Pallifera to contain Pallifera
ntutabilis Hubricht (type species), P. iceatherbifi
W. G. Binney, and P. ragsdalei (Webb). Much col-
lecling hiis been done in the Philomycidae since
this subgenus was described and no intergrada-
tion with Pidlifera .s'..s. has been found. The large
size and basic chevron color pattern of all species
causes them to be confused with Philomycus. I
feel that Megapallifera should be raised to the
status of gen us.

Gastrocopta tappaniana (C. B. Adams)

Pupa topixiiiunio "Ward" C. B. Adams, 1842, in

Thompson's History of Vermont, p. 158.
Gastrocopta tappaniana (C. B. Adams), Pilsbry,

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 107

1948, Acad. Nat. Sci. Philadelphia Mono. 3, 2:

889.

Joseph C. Bequaert & Walter B. Miller, 1973,
Moll. Arid Southwest, Univ. Arizona Press, Tuc-
son, Ariz., p. 89) state that the holotype (MCZ) of
Gdstracopta tappaniana is a typical G. pentodon
(Say) and that there is only one species. I have
examined this specimen and can state that it is
not G. pentodon, but represents G. tappaniana as
understood by Pilsbry and others. I have e.xamined
a good many lots of G. pentodon and G. tappa-

niana and have had no difficulty in separating
them. Large series in river drift have sorted
readily.

H. A. Pilsbry (1939-1948, Acad. Nat. Sci.
Philadelphia Mono. 3) reported a number of
species, notably Sterkia ei/riesi rhoadsi (Pilsbry),
fi-om Dismal Key, Lee Co., Florida. However,
Dismal Key is not in Lee Co., but in Collier Co. It
is one of the Ten Thousand Islands and is located
several miles southeast of (iioodland.

STATUS OF SUCCINEA OVALIS CHITTENANGOENSIS PILSBRY, 1908

Alan Solem

Department of Zoology

Field Museum of Natural History

Chicago, Illinois 60605

ABSTRACT

Dissection and SEM radular study of the rnorph described as Succinea ovalis
chittenangoensis Pilsbry. 1908, suggest that this is a marked genetk mutation of
Succinea ovalis Say, 1817, charactenzed by one shell feature and an apparent
specialization in ecology. A summary of its varying abundance and ecology is
presented. Comparisons of genital and radular structure are made unth the sym-
patric Oxyloma decampi gouldi Pilsbry, 19^8 and S. ovalis jrom Illinois.

INTRODUCTION

Pilsbry (1908) determined the identity of
Succinea ovalis Say, 1817, and described a popula-
tion from Chittenango Falls, Madison County,
New York, as a new subspecies, Succinea ovalis
chittenangoensis Pilsbry, 1908. The differen-
tiating features were the elongated shell spire
and larger size in comparison with typical
populations. The original data essentially were
republished in Pilsbry (1948). Subsequently
Hubricht (1972) and Wayne Grimm (letters) have
suggested that chittenangoensis is a distinct
species.

As part of a survey of rare and potentially
endangered land snail species of Eastern North
America for the Office of Endangered Species

(hereafter OES), the status of this taxon was in-
vestigated. The field work by Alan Solem and
Glenn Goodfriend was supported by OES Contract
14-16-0008-764, which also provided for the
illustrations by Ms. Claire Kryczka. OES Con-
tract 14-16-0008-965 covered the page and il-
lustration charges. The scanning electron mi-
croscope photographs were taken from Cambridge
S4-10 Stereoscans during cooperative research
with the American Dental Association and an in-
strument provided the Field Museum through
NSF Grant BMS72-02149. I am indebted to Glenn
Goodfriend, Arthur Qarke, Leslie Hubricht,
Wayne Grimm, George Najarian, Fred Huysmans,
Dorothy Karall, Elizabeth Liebman, and Sharon
Bacoyanis for assistance with various phases of
this project. The financial support given by the

108 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

Office of Eiidangered Species and the National
Science Foundation is gratefully acknowledged.

ECOLOGY AND ABUNDANCE

The initial collection of S. o. chittenangoensis
occurred August 27, 1905, and was "on a sloping
weedy talus near the foot of the falls." According
to Pilsbry (1908:49), "A very large series was
taken, associated with a few S. ovali'i."
Subsequently, Pilsbry (1948:807) indicated
that "It occurred in great abundance. A few
typical S. ovali'i were found with them, but no in-
tergradation was seen." Hubricht (personal
rommunication) collected at Chittenango Falls on
May 31, 19.54, finding ovaliji and chittenangoenifi'i
about equally abundant, but again without in-
tergradation. Wayne Grimm, in 1964, 1965 and
1973 (personal communication) reported S. oralis
as fairly abundant, but found only a few chit-
tenangoensi% In June 1973, Glenn Goodfriend
found one live chittenangoensis, but no live
mmlis. On August 3 and 8, 1974, I found freshly
dead chittenangoensis in talus, fresh dead shells
of Oxyloma. live Oxyloma decampi gouldi Pilsbry,
1948, and one live juvenile oralis.

In 1905, chittenangoensis was common and
ovalis scarce: in 19.54 they were equally abun-
dant; in the mid-1960's ovalis was common and
chittenangoensis scarce; and in the early 1970's,
both morphs were scarce. The above anecdotal
statements of abundance are not sufficient to in-
dicate a trend. Natural fluctuations in numbers
seem more probable than a linear trend, but the
data do establish that ovalis and chittenangoensis
have been taken sympatrically on several occa-
sions. Whether the current low population
numbers are the result of habitat changes cannot
be established with certainty. Arthur Clarke (per-
sonal communication) has noted a drastic decline
in downstream unionid clam abundance during
the 1950's and 1960's. This change correlated with
increased upstream water pollution.

Specimens of chittenangoensis have been taken
from talus on both sides of the foot of the falls,
from talus halfway up the falls, and even from
rock surfaces behind the falls itself. The sightings
all involve actual spray zone or seepage areas of
the falls. No specimens have been found

elsewhere along Chittenango Creek, although
typical S. ovalis has, at times, been abundant
downstream. Despite intensive collecting efforts
in other areas of New York and adjacent states,
no additional colonies with the features of
chittenangoensis have been discovered. The col-
ony probably is unique. The shaded ravine
habitat, constant cool water flow, and spray zone
talus or rock face situation combine to produce a
very stable and cool habitat. Wayne Grimm (per-
.sonal communication) tried to transfer live
specimens to establish a refrigerated colony, but
even only four hours in an ice chest resulted in
their demise. The range of conditions in which
specimens of chittenangoensis live is far more
restricted and less variable than that encountered
by most succineids.

COMPARATIVE STRUCTURE

Since ovalis and chittenangoensis are s>tti-
patric and at least occasionally equally abundant,
their structures should show "species recognition
differences" if they were distinct species. The
shell difference (figs. 1, a-c) is larger size, which
frequently results from dwelling in more
fevorable conditions, and a more elongated spire.
Conceivably the spire change could result from a
single mutation. Pilsbry (1908, 1948) reported no
anatomical or color differences between ovalis
and chittenangoensis.

Dissection of several populations of Succinea
ovali.s from various parts of Eastern North
America and of the adult S o. chittenangoensis
(figs. 1, g-h) collected in June 1973 (FMNH
17.5425) revealed no significant anatomical dif-
ferences. Specimens of typical S. ovalis collected
August 31, 1965, from Dresden Id., Illinois River,
Grundy Co., Illinois (FMNH 169132) are il-
lustrated for comparison (fig. 1, /). A shell (fig. 1,
d) and genitalia (fig. 1, e) of Chittenango Falls
Oxyloma decampi gouldi (FMNH 175394) also are
figured for convenient identification by others.
Radular illustrations are given of all three taxa
(figs. 11-17). The much smaller sized shell with
flatter sided whorls and reduced callus in
Oxyloma (fig. 1, d) easily separate it from the
two Smcinea. The differences between S. ovalis
and form chittenangoensis (figs. 1, a-c) involve
only increase in whorl count and spire height.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 109

FIG. 1. Shells and anatomy, a-b, Succinea ovalis Say, 1817.
Dresden Islatid, Illiiwis River, Gumey Co., Illinois. FMNH
169132: c, Succinea ovalis form chittenangoensis Pilsbry.
1908. Chittenaiigo FaUs. Madison Co., New York. FMNH
175i25; d-e, Oxyloma decampi gouldi Pilsbry. 191,8. Chit-

tenango Falls, Madison Co., New York. FMNH 175391 d,
shell, e, genitalia; f, S. ovalis. genitalia: g-h, S. ovalis form
chittenangoensis. g, genitalia, h, interior of penit. Scale lines
equal 5 mm.

no THE NAUTILUS

July 21, 1976

Vol. 90 (3)

FIGS. 2-5. Radular teeth. Fig. 2. Central and early lateral
teeth of Succinea ovalis form chittenangoensis Pilshry.
FMNH I7r>U5. 905 X. Pig. 3, Central and first kUerd teeth
of Oxyloma decampi gouldi PUsbry. FMNH 175391 890 X.

Anatomically, specimens of Oxyloma (fig. 1, c)
are most easily separable from Succinea (figs. 1,
f-g) on the basis of penis structure. The
characteristic protruding epiphallic kxip (E) in
Siurinca is very different from the simple penis
(P), penis retractor (PR), and vas deferens (VD)
junction found in Oxyloma. More fundamental
internal penial differences exist, but this feature
is readily observable in early stages of dissection.
When the penial difference is combined with the
obvious shell size change, separating these taxa
presents no problems.

Species of SMvinra differ greatly in shell form,
pattern of the epiphallic loop protrusion, oviduct
and vaginal length, and also in the degree to
which the free oviduct and spermatheca are

Fiy.s. 4-5, Succinea ovalis Say. FMNH 1691S2. F\g. 4, Central
and first lateral teeth. 865 X. Fig. 5, hnr angle views of cen-
tral and early lateral teeth. 6i5 X.

coiled around each other (see Pilsbry, 1948). The
genitalia of S Dm.li'i (fig. 1, //) and form
(■hittcnamjoensis (fig. 1, y) have no significant dif-
ferences. The enlarged prostate (DG) and her-
maphroditic duct (GD) in chittrnangoen.vf: (;uid
in Oxyloma, fig. 1, e) relate to the June collecting
(noiTnally wet period) compared with the dry
August renditions in Illinois for the S oralis
sample. Tlie samples were in different reproduc-
tive phases when collected. In terms of penis (P)
and epiphallus (E). vagina (V) and free oviduct
(UV) length, aiiling of the .spermathecal shaft (S)
and free oviduct, length of uterus (UT), form of
albumen gland (GG), Uilon (GT) and ovotestis (G),
there are no differences between the two
Sriccinea. The slight difference in shape of the

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 111

spermathecal head is probably an artifact of
preservation. The basic similarities hold for all
populations compared.

The radular structure of the succineids has
been used for many years to distinguish species
and some higher taxa (see Quick, 1933, 1934;

FIGS. 6-11. Radular teeth, figs, b-7, Succinea ovalis /orm Central and lateral teeth. UO X. Fig. 9. Lateromwgmal

chittenanpiensis P\hbnj. FMNH I7.5J,^5. Fig. 6, Central and transitUm. 5iO X. Fig. 11. Unv angle rieiv of laiemmarginal

lateral teeth, i.35 X. Fig. 7, Latermnarginal transition. i35 transition. 875 X. Fig. 10, Part row of Oxyloma decampi

X. Figs. 8, 9, 11, Succinea ovalis Say. FMNH 169132. Fig. 8, gouldi Pilsbry. FMNH 1753%. ill X.

112 THE NAUTILUS

July 21, 197(i

Vol. 90 (3)

FIGS. 12-17 Radular teeth and jaws, /-yy.s 12, 13, 15, 16.

Succinea ovalis Say. tl4NH 1691;lt Fiy. 12, Oiitennost
margiruUx. 1,195 X. Fig. 13, Inner marginals. 805 X. Figa.
15-16, Jawx al 1,1.5 X showing variation in ridging. FHg. 14,

Midmiirginal teeth i>f Oxyloma decanipi gi>uldi Pilsbry.
FMNH l?.'>.m. I.H75 X. Fig. 17, Jaw o/ Succinea ovalis /onw
chittenangoensis Pilsbry. FMNH 175J,i5. 38.2 X.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 113

Pilsbry, 1948), but no report has been presented
on the functioning interrow teeth reactions. The
illustrations presented here thus serve a dual
purpose.

The central and early lateral teeth of S. ovcdis
(figs. 4, 5, 8) are identical in form, size and eleva-
tion angle to those of chittenangoensis (figs. 2, 6).
The observation angle of fig. 8 is more posterior
than that of fig. 6, which somewhat deemphasizes
the anterior flare on the individual teeth, but
also permits seeing the anterior basal support
ridge on the outer side of the plate. The presence
of two such ridges on the tricuspid rachidian
tooth and the functioning on the interrow sup)-
port can be seen clearly in the right portion of
fig. 5. The rachidian tooth also lacks the anterior
flare that is characteristic of the bicuspid laterals
(figs. 2, 4-6, 8). The central tooth of Oxyloma (fig.
3) has somewhat smaller ectocones and is a little
larger in relation to the laterals than in
Succinea.

The transition from laterals to marginals is
essentially identical in pattern for Succinea and
Oxyloma. The first ten or more laterals remain
constant in size and shape (figs. 6, 8), but then in
the course of perhaps three teeth (figs. 7. 9) make
a rather abrupt transition to the marginal pat-
tern. The ectocone enlarges and splits, the
mesocone becomes narrower, smaller in size, and
perhaps one tooth after the splitting of the ec-
tocone, a small endocone appears on the
mesocone. At the same time, the basal plate
shortens and the interrow support ridge is great-
ly reduced and then lost. Not visible from the top
view, but clearly seen in side view (fig. 11), is a
change in angle of cusp elevation. The laterals
(top third of fig. 11) point up at nearly a 60°
angle, while the marginals curve to point almost
directly backward into the mouth. The reduction
of the support ridge and the shortening of the
basal plate can be followed quite easily along the
row. The "cutting" nature of the laterals is evi-
dent and contrasts with the "catching" nature of
the marginals. The latter pull food into the
mouth that has been scraped or torn loose by the
laterals. The comparable view of Oxyloma (fig.
10) shows that the lateral teeth are not elevated
as much.lhat the marginal teeth basal plates are
longer and narrower, and that the cusps of the

marginal teeth seem to be different in pattern.

The variation in cusps on the marginal teeth is
very large both within and between radulae of
the same species, so that the large endocone seen
on the marginals of Oxyloma (fig. 14) may not be
a constant difference, although the elongated and
narrower basal plate does seem to be a species
level, if not generic level, difference (see Quick,
1933, 1934). The short, broad basal plate (figs. 12,
13) and multiple small cusps between the
mesocone and ectocone characterize the two
Succinea, but cusp splitting varies from tooth to
tooth (fig. 13).

Oxyloma has long and slender marginal basal
plates, compared with the short and broad basal
plates in Succinea, as was cited in Pilsbry (1948).
The different pattern of cusp elevation in the two
genera, and the shared pattern of interrow cen-
tral and lateral tooth supports have not been
reported previously. This same interrow support
system— a basic anterior flare interlocking with
a raised projection on the outer margin of the
basal plate in the laterals, and the two support
ridges on the basal plate of the central tooth— is
found in many families of the Stylommatophora
and may well prove to be the generalized pattern
of radular structure in the higher land mollusks.

Ribbing of the jaw in Succinea ovalis is highly
variable (figs. 15-17). The two specimens from
Dresden Island (figs. 15, 16) bracket the example
of chittenangoensis in terms of rib prominence.
There is thus no difference.

To summarize the above observations, in
radula, jaw, and genitalia, Succinea ovalis and
chittenangoensis show no differences that cannot
be regarded as seasonal (swollen hermaphroditic
duct and enlarged prostate) or individual varia-
tion (cusping on radular marginal teeth). The
only morphological difference is the longer spire
and slightly higher whorl count in the shell of
chittenangoensis.

DISCUSSION

Succinea ovalis chittenangoensis Pilsbry, 1908
differs from S. ovalis ovcdis only in spire height
of the shell, larger size, and in being restricted to
the very moist splash or seepage areas around
Chittenango Falls. At times this morph has oc-
curred abundantly with typical S. ovalis. In the

114 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

absence of any differences in radular (feeding
specialization) or genital (species recognition
phenomena) structure, despite the known sym-
patry, I cannot accept chittenangoensi.'i as being a
distinct species. The lack of intergradation in
shell form, the only known difference, rould be
the result of a simple dominant genetic change.
To what extent this shell difference is linked to
physiological and/or biochemical changes that aid
adaptation to the somewhat unusual environment
is unknown, but should be investigated. The
hyp(Ahesis of chittenangoensis representing a mu-
tant strain of S ovaliii raises far fewer problems
than attempts tx) call it a distinct species, in view
of its anatomical identity to typical S. ovalis.

The entire range of the mutant form lies
within Chittenango Falls State Park and, pro-
vided collecting is prevented, this variation has
every chance of continuing its normal span of ex-
istence. In time, fluctuations in abundance, caused
either by man's pollution or the unknown factors
that resulted in the great change in abundance of
both S. ovalis and chittenangoensis since 1905,

will lead to extinction by natural causes. Collect-
ing during periods of low abundance, such as the
1970's, could easily hasten this extinction, but the
protection provided by the Park rules plus the
cooperation of malacologists, can prevent our
hastening the departure of this interesting varia-
tion. Monitoring of changes in its population
level and biochemical comparisons between oco^i-s
and chittenangoensis are highly desirable future
activities.

LITERATURE CITED

Hubricht. Ijeslie. 1972. Endangered land snails of the Eastern

1 Inited States. .SV^rA-i'aHO 45: ^-M.
Pilsbry. H. A. 19(18. Notes on Sucnnea ovalis Say and i". obli-

<iua Sav. P»(/r. Amd. Nat. Sci. PhihuMiihia. 1908: 45-51, pi.

VII.
Pilsbry. H. A. 1948. Land Mollusca of North America (North

of Mexio)). Monograph Acad. Nat. Sci. Philadelphia S. 2(2):

i-.\lvii..521-111.3. figs. 282-585.
Quick. H. E. 19.33. The anatomy of Briti.sh Succineae. Proc.

Malac. Sw. London 20(6): 295-318, pis. 23-25.
Quick. H. E. 19:34. The development of radula and jaw, and

the specific differences in young Sucnnea pfeifferi Rossm.

and Succinea putris (L.). Proc. Malac. Soc. London 21(2):

96- 105, 6 figs.

GROWTH RATE OF FOUR SPECIES OF EUTHECOSOMATOUS
PTEROPODS OCCURRING OFF BARBADOS, WEST INDIES

Fred E. Wells

Curator of Molluscs

Western Australian Museum

Perth, Western Australia

Australia 6000

ABSTRACT

Gmwth rates of the four most common species of euthecosomatoits pteropods
occurting off Barbados were mean/red using the probability paper method.
Average gnnvth rates ivere: Limacina trochiformis 0.10 mm/month, L. inflata
0.12 mm/month, L. bulimoides 0.15 mm/month, and Creseis virgula conica 0.30
mm/month. The species reach metamorphosvi in I'/s to S months and sexual
matnnty in 7 to S'/t months. Tlir maximum life .spans <f nil four species are
estimated to he about one year.

INTRODUCTION
Euthecosomatoas pteropods are a small group
of holoplanktonic gastropod molluscs (x-curring

throughout the world oceans (van der Spoel,
1%7). Most are tropical though Limiwina
ivtroversa (Fleming) is a boreal species and L.

Vol. 90 (3)

July 21. 1976

THE NAUTILUS 115

TABLE 1. Growth rates of euthecosomatous pteropods off
Rfirhniids. Wc.ft Indies.

Species

Rate (mm /month)

Cre.ieis virgvta conifn

o.:30

Limacina hulimi/idex

0.15

Limcmnainflata

0.12

Limariiia trochifomm

0.10

helicina (Phipps) occurs in the Arctic and Antarc-
tic Oceans. Lifonnation on many of the basic
aspects of the biology of euthecosomes is lacking
because the animals, especially the tropical
species, survive for only a limited time in the
laboratory. Paranjape (1968) was able to main-
tain L. helicina hatched from ^gs for 30 days in
the laboratory, but no other species has been
cultured for even this long, and growth rates
from controlled studies are nonexistent. Ex-
amination of growth in field populations has
been done in only a few species. The present
paper reports the growth rates and life spans of
the foui' most common euthecosomes in the
tropical waters off Barbados, West Indies.

MATERIALS AND METHODS

Collections were made twice monthly at a sta-
tion 5 km west of the Bellairs Research Institute,
St. James, Barbados. West Indies (13°11'N;
59°41'W), from June 1971 to May 1973 using a 1
m diameter open plankton net equipped with a
flowmeter and No. 20 (76 tan) nylon mesh. On
each cruise 3 oblique tows were made from 300 m
to the surface. Samples were preserved in 10%
formalin buffered with hexamethylene tetramine.
Every month the maximum shell diameter of 300
Liynacina inflata (d'Orbigny) and the maximum
shell length of 200 Creseis virgula conim (Rang)
were measured with a dissecting microscope
equipped with an ocular micrometer. Maximum
shell length of all available individuals of L.
bulimoides (d'Orbigny) and L. trochiformis
(d'Orbigny) were also measured.

RESULTS

Nineteen species and subspecies of euthe-
cosomes were collected during the two years of
the study. Limacina inflata constituted 61.5% of
all individuals collected, Creseis virgula conica
23.0%, L. trochifotvnis 6.7%, and L. bulimoides
2.2%. Together the 4 species accounted for 93.4%

of all euthecosomes. All 4 reproduced continuous-
ly at high levels off Barbados (Wells, 1976), so
changes in the size-frequency curves could not be
used to estimate growth rates. Instead, the size-
frequency data was plotted on probability paper
■as described by Harding (1949) and Cassie (1954).
The method utilizes fluctuations in the numbers
of individuals in the various size classes to deter-
mine growth rates over short periods of time
such as 1 month. Cassie (1954) demonstrated a
technique to estimate mortality in species with
discrete reproductive periods, but the continuous
breeding of the 4 species off Barbados precluded
estimation of mortality.

Table 1 shows the growth rates of the 4
euthecosome species examined. They ranged from
0.10 mm per month for Limacina trochifonnis,
the smallest species, to 0.30 mm per month for
Creseis virgula conica, the largest. There are no
apparent stages in the life cycle during which
gi-owth is temporarily halted as occurs in some
other thecosomes. The animals begin enlarging
the embryonic shell immediately after hatching.
In euthecosomes metamorphosis is a gradual proc-
ess involving primarily the loss of the velum
and the development of parapodia, and in the
present species there is no substantial change in
shell morphology associated with the onset of the
juvenile state. One would expect juveniles to
grow rapidly and the grow^th rate to decline as
the animal ages. The data for each species was
divided into two groups at half of the maximum
shell size. A t-test showed there was no signifi-
cant difference between the growth rates of the
small and large groups of any species at the .05
level. It should be noted that most individuals of
a species were small, making the growth rates
calculated for larger individuals less reliable.

If the growth rate is assumed to be relatively
constant during the growth portion of the life of
an individual, an idea of the lifespan can be ob-
tained. Table 2 shows the sizes at which the
maturational stages were reached off Barbados
(Wells, 1976) and the time required to reach the
various stages. Limacina inflata releases veligers
67 ym in shell diameter (Lalli and Wells. 1973).
Tie other 3 species deposit freefloating egg
masses in the water column (Wells. 1976) but the
sizes at which veligers hatch are unknown. The

116 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

TABLE 2. Times required to reach maturatinrud stages ofeuthecosomatous pteropods nff Barbados, West iTidies.

Species

Stage

C mrgvia oonu-a
SiK (mmhMonthe

L

Size

(mm)- Months

Size (mm (-Months

L tmcktfarmts
Sze (mm (-Months

Minimum
Metamorphosis
Maturity
Maximum

0.15

0.6 - l'/2
30 - 9'/j
4.2 -13'/,

a 10

040-2

1.1 -7
1.4 -9

0.067
04 -3
1.0 -8

1.4 -8

0.10

0.25-lH
08 -7
1.0 -9

minimum size collected off Barbados is included
in Table 2. Veligers required from 1' 2 to 3
months to reach metamorphosis and a total of 7
to 9'/2 months to reach sexual maturity. Maximum
sizes of the various species would be attained in
9-13 months, indicating that all 4 can complete
their life cycles in 7-9 months off Barbados and
live a maximum of about a year.
DISCUSSION

Redfield (1939) studied the movement of a
population of Limacina retroversa in the Gulf of
Maine. An influx of juveniles into the Gulf in
December 1933 was traced for several months.
Growth rates calculated from the histograms
presented by Redfield averaged 0.21 mm per
month. Similarly growth rates of 0.18 mm per
month can be obtained from the data published
by Kobayashi (1974) for L. helicina in the Central
Arctic Ocean. Both figures are somewhat higher
than those of the tropical Limacina, but because
of the larger sizes involved the lifespan of L.
helicina in the Central Arctic was about 18-24
months and that of L. retroversa in boreal waters
was one year. The 3 tropical Limacina studied
here reproduced 7 to 8 months after hatching.
TTiis follows the pattern described by Dunbar
(1968) in which planktonic species in the Arctic
have a two year life cycle, related boreal species
live one year, and tropical forms less than a year.

All of the above species are members of the
Limacinidae, except Creseis virgula conica, which
is in the Cavoliniidae. This species also had a con-
tinuous growth pattern with a life span of up to
13 months off Barbados. The only other cavo-
liniids in which growth had been studied are Clio
pyramijdata Linne, Cuvierina columella (Rang),
Cavolinia gibbosa (Orbigny), and Diacria
trispinosa (Blainville). The growth pattern of
these species consists of a gradual enlargement of
the embryonic shell during the veliger and

juvenile stages followed by a period of rapid
growth during which the adult shells are laid
down. Little subsequent growth occurs after the
adult shell is complete. Van der Spoel (1973)
found all 4 species had a one year life cycle off
Bermuda, similar to that of Creseis virgula con-
ica off Barbados.

ACKNOWLEDGMENTS

I thank M. A. Paranjape for helpful discussions.
The research was supported by a National
Research Council of Canada Postdoctoral
Fellowship and a grant from the graduate faculty
of Dalhousie University.

LITERATURE CITED

Cassie. R. M. 1954. Some uses of probability paper in the

analysis of size frequency distributions. Attst. J. Mar.

Freshw. Res. 5: 513-522.
Dunbar, M. J. 1968. Ecological development in polar regions.

Prentice-Hall, Englewood Cliffs, N. J., 119 pp.
Harding, J. P. 1949. The use of probability paper for the

graphical analysis of polymodal frequency distributions. J.

Mar. Biol. Ass. U. K. 28: 141-153.
Kobayashi, H. A. 1974. Growth cycle and related vertical

distribution of the thecosomatous pteropod Spiratella

("Limacina") helicina in the Central Arctic Ocean. Mar.

Bwt. 26: 295-301.
Lalli. C. M. and F. E. Wells, Jr. 1973 Brood protection in an

epipelagic thecosomatous pteropod, Spiratella {"Limacina")

inflata (d'Orbigny). Rdl. Mar. Sci. 23: 933-941.
Paranjape, M. A. 1968. The egf^ mass and veligers of Limacina

helicina Phipps. Veliger 10: 322-326.
Redfield, A. C. 1939. The history of and population of

Limacina retroversa during its drift across the Gulf of

Maine. Biol. Bull. mar. biol. Lab., Woods Hole 76: 26-47.
Spoel, S. van der. 1967. Euthecosomata: a group with

remarkable developmental stages (Gastropoda, Pteropoda).

Gorinchem.J. Noorduijnen Zoon N. V.,375pp.
Spoel, S. van der. 1973. Growth reproduction and vertical

migration in Clio pyramidata Linne', 1767 forma lanceolata

(Lesueur, 181,3), with notes on some other Cavoliniidae

(Mollusca, Pteropoda). Beaiifortia 21(281): 117-134.
Wells, F. E. Jr. 1976. Seasonal patterns of abundance and

reproduction of euthecosomatous pteropods off Barbados.

West Indies. Veliger 18(3): 241-248.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 117

THE INVASION OF THE ASIATIC CLAM (CORBICULA MANILENSIS
PHILIPPI) IN THE ALTAMAHA RIVER, GEORGIA

J. A. Gardner, Jr.
W. R. Woodall, Jr.

A. A. Staats, Jr.

and J. F. Napoli

Georgia Power Company

Environmental Center

791 DeKalb Industrial Way

Decatur, Georgia 30030

ABSTRACT

The population of Corbicula mahilensis Philippi in the Altamaha River,
Georgia, increased considerably from October 1971 to November 1975. Density of
Corbicula generally reached a maximum in late summer or fall and was at a
minimum during winter and spring, a relation which was inversely related to
river discharge. Generally, densities of older age classes were greater in areas of
low current velocity, whereas densities of younger age classes were greater in
areas of high velocity. Average Corbicula densities increased from a minimum
of OAyf in 1971 to a maximum of 10,000/nf in 197U. The invasion f/ Corbicula
has been accompanied by a drastic decline in the populations of other bivalves.
Several species of Unionidae endemic to the Altamaha River may be affected
by Corbicula and are considered endangered.

INTRODUCTION

The Asiatic clam (Corbicula manilensis Phi-
lippi) has continued to spread in southeastern
rivers since their discovery in the Tennessee
River in 1959 (Sinclair and Ingram, 1961). Sickel
(1969) studied mussel populations in the
Altamaha River (Georgia) between river miles
113 and 118 and found nine species of unionids,
three of them in great abundance, but no
Corbicula. In 1971 Scott and Schindler, Universi-
ty of Georgia (personal communication) observed
Corbicula in the Altamaha River near river mile
116. Sickel (1973) proposed that Corbictda was in-
troduced into the Ocmulgee River, a tributary to
the Altamaha River, by overland transfer from
the Flint River (Apalachicola drainage) in 1968
or 1969.

Biologists at the Georgia Power Company have
been sampling the Altamaha River between river
miles 113 and 118 (Figure 1) since October 1971
as part of a comprehensive program to assess and
monitor the biota near E. I. Hatch Nuclear Plant
(Georgia Power Company, 1974). The purpose of FIG. l; Major nvers of Gecrgia. Arrow indicates study area.

118 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

this paper is to discuss changes in the popula-
tions of Grrbwula niamlensis and other bivalves
that have occurred from October 1971 throuj^
November 1975.

MATERIALS AND METHODS

Samples were collected at approximately six-
week intervals from several stations between
river miles 113 and 118 during the period of
study. A modified Petersen dredge which sampled
an area of .025 m^ was used. In October 1971 sta-
tions were established at RM 113.4 and 117.8.
Five to ten .samples were obtained at each sta-
tion. In May 1973 two new stations were added
to the sampling program at RM 115.9 and 116.6.
In 1974 the station at RM 113.4 was di.scontinued,
and a new station was added at RM 115.5. In
February 1975, the present method of sampling
was adopted in which six samples were taken in
a transect at each station (RM 117.8, 116.6, 115.9
and 115.5).

Samples were washed immediately in a field
screen having ten meshes/cm and preserved with

TEMPERATURE

3000

2500

'H 2000

o

<
X
U

1500

500-

10% formalin (4% formaldehyde). In the
laboratory, bivalves from each sample were
sorted and Corhicula , viere separated into size
classes by washing them through a series of five
U. S. standard soil sieves with openings of 2.00
mm. 4.75 mm, 9.50 mm, 12.50 mm and 19.00 mm.
The number of Corhicuin retained by each sieve
was recorded, empty shells were excluded.
Bivalves other than Curbinda were counted
together but not identified. These were mainly
Sphaeriidae, but included some Unionidae:
LampsilK dnlahraeformis Lea, Canthyria spinosa
Lea, and Elliptio hx)petonensis Lea (Sickel, 1969).

RESULTS AND DISCUSSION

Water temperature and discharge of the
Altamaha River reported from a United States
Geologic Survey station near Baxley are shown in
Figure 2 (U. S. Department of the Interior, 1972,
1973, 1974, 1975). Water temperature ranged from
6.5°C (winter minimum) to 30°C (summer max-
imum) during the period of study. Mean annual
water temperature for the Altamaha is about

30

10

o

III

a

I — I — I I I I I I — I — ■ I ■ I — T — r— 1 — ■ — I — I — I — I — I — I I I — ■ I I I — I — I — ■ ■ I I — ■ ■ ■ I I I I I I I ■

ond'jfmamjjasond'jfhamjjasondIjfmamjjasondIjfmahjj

1971 1972 1973 1974 1975

FIG. 2: Mean daily di'ichatye and teinperature uf Altamaha River near Baxley, Georgia (U. S. Geological Survey Data). Gaps in
data indicate equipment malfunction.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 119

10,000.3

1000

z

IK

z

100-

FIG. 3; Mean (± SE) density of first year, sexually immature Corbicula in Altamaha River, October 1971 through October
1975.

20°C. Mean annual discharge is 340 mVsec and
ranged during the period of study from 80
m^/sec (fall low) to a maximum of about 2.650
mVsec (spring 1975). Maximum discharges
decreased each spring during the period
1971-1974, but reached a maximum of 2,650
mVsec in 1975. Total discharge for spring flood
season was greater in 1973 and 1975 than in 1972
and 1974. The Corbicula spawning season begins
when the water temperature reaches approx-
imately 16-17°C (J. B. Sickel, personal o)m-
munication) and continues until temperature
falls below this, thus allowing a spawning season
in the Altamaha River usually from April
through November.

Shell lengths of Corbicuhi have been used to
approximate age (Sinclair and Isom, 1963; Keup,
Horning, and Ingram, 1963). The method used in
this study to determine size and age classes was
based on shell width and depth since these
parameters determined the maximum cross sec-
tional area that would pass through the sieve
openings. Joy and McCoy (1975) found a strong

correlation (r = 0.99) between Corbicula shell
length and width. Thus, the authors believe the
sieve system to be a fairly accurate method for
rapidly determining size and age classes, par-
ticularly when a large number of samples are in-
volved. Size classes and their approximate year
class (J. B. Sickel, personal communication) are
shown in Table 1.

The population of Corbicula in the Altamaha
River increased considerably during the period of

TABLE 1. Shell lengths retained by sieves and approximate
age classes (.J. B. Sickel, personal commumcation).

ShMt Leiiijlh

Si.r, .Si,-( Imml

Retmntd Imntl

Af/fjrunniiite Age

2.(»

<7..5

lyr.
(sexually immature)

4.7.5

7.5-13.5

lyr.
(sexually mature)

9..50

13.4-18.5

2yr.

12..T0

18.5-28.0

3yr.

19.00

>28.0

4 -1- yr.

120 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

10,000^

-I — I — I • 1 I I I I I — I— 1 — r— I — r— 1 — I I I I I I I I I III

ONDJFMAMJJASONDJFMAMJJAS ONDJFMAMJJAS ONDJFMAMJJ ASO
1971 I 1972 I 1973 I 1974 I 1975

FIG. 4: Mean (± SE) density of fi>f:t year, sexually mature Corbicula in Altamaha River. October 1971 thrmigh October
IDT.'-).

study. Mean densities of Corbicula for all year
classes are shown in Figures 3-6. Density of
Corhicula generally reached a maximum in late
summer or fall and was at a minimum during
winter and spring. In contrast, Villadolid and
Rosario (1930), Rickel (1966), Fast (1971), and
Taylor (1975) found Corbicula to be at maximum
in winter and minimum in summer. One explana-
tion for the high density in the Altamaha during
the late summer low water periods is that less
substrate is available at these times, thereby con-
centrating the organisms. The width of the river
ranges from 1(X)-2(M) m during the low water
period and is often greater than 2 km during
flood .stage. The available .substrate surface area
is about ten times greater at high water than at
low water. This could account, in part, for the
diffei"nces in ("(rrhirnld density, which is mughly
a change of the same magnitude. Maximum
discharge (Figure 2) occurred simultaneously
with low densities in CorbicuUt (Figures 3-6).
Seasonal variations in density diminished with
increasing size of the clams. Apparently the

smaller clams were probably picked up and swept
by the current during flood season more readily
than were the larger ones. Small Corbirnla shells
were found deposited in the flood plain and along
exposed sand bars indicating their presence dur-
ing high water.

Sexually immature Corbicula (Figure 3) usual-
ly were found in greatest density in summer.
Maximum density of this group increased by a
factor of 10 each year during the summers
1972-1974, reaching an average density of
9,257/m^ in July 1974. The largest sample col-
lected on this date contained 1,527 Corbicula or
61,080/m^ Winter and spring densities were
about lOO/m^ each year .since 1973. First year
.sexually mature clams (Figure 4) fluctuated
greatly since 1972, but generally reached max-
imum density in fall Recruitment into this size
class from se.xually immature Corbicula is evi-
dent in 1973 and 1974, occurring 4-6 months
after the maximum density of immature clams.
Average density of sexually mature first year
Corbicula was about 70/m' for 1974 and 1975.

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 121

Density of second year Corbicula (Figure 5) fluc-
tuated irregularly in 1971-1972, probably because
of s;impling bias and clumped distribution, but
rose steadily in 1973 and 1974. Density of this
size clam reached a maximum of 40/m^ in sum-
mer 1973, and a maximum of 100/m^ in summer
1974. Average density for second year Corbicula
was approximately 70/m' for 1974 and 1975.
Figure 6 shows average densities of third and
fourth year class Corbicula. Third year clams
were first collected in October 1972, but were not
ronsistently present until spring 1973. Maximum
density reached 100/m^ in fall 1974. Average
density for three year clams was about 70/m^ in
1974 and 1975. Corbicula in the fourth year class
were not collected until summer 1974. Veiy few
tour year clams were collected in dredge samples,
however larger clams were collected in
qualitative samples.

Corbicula have been reported occurring in a
wide variety of substrates. Sinclair and Isom
(1963) found Corbicula cominon in rock-gravel
substrates and black clay substrates in the Ten-

nessee River. Fast (1971) found a positive correla-
tion between Corbicula density and sediment
particle size in a Southern California reservoir.
Fuller and Powell (1973) reported C(n-bicula liv-
ing in a shifting sand bar in the Savannah River,
Georgia, and in a variety of substrates including
mud and fine gravel in the Delaware River.
Rhinne (1974) found greatest densities on rock and
rubble substrates in an Arizona reservoir. Diaz
(1974) found Corbicula in a variety of substrates
in the James River, Virginia, but mainly in silt-
clay sediment. Sickel and Burbank (1974) in a
substrate preference experiment, found that lar-
val Corbicula settled on fine sand, coarse sand,
and mud in decreasing order of preference. In the
present study, Altamaha River Corbicula were
found on a variety of substrates. A substrate
preference was not clearly determined by our
sampling. In general, more Corbicula were found
on substrates consisting of sand in combination
with mud or detritus than on substrates which
were predominantly mud or detritus.

Analysis of variance of 1974 and 1975 data was
used to compare densities of Corbicula from high

1000

4

IK

z

100-

1 — fill — T I > I I 1 I — f— I — I I I — I — I — I — I — I — r— I — I — I — I — I — I I I — I — I — I — I — 1 — I — I — I — I — I — I I I — I I I I I

ONDJFMAMJJASONDJFMAMJJASONDJFMAMJJASONDJFMAHJJASO
1971 I 1972 1 1973 I 1974 I 1975

FIG. 5: Mean (± SE) density of second year Corbicula in Altamaha River. October 1971 through October 1975.

122 THE NAUTILUS

July 21, 1976

Vol. 90 (3)

1000

IK

z

10-

I I I I I r— I I I T I I f I I < I I I ( I I ■! I

ONDJFMAMJJASONDJFMAMJJASONDJFMAMJJASONDJFMAMJJASO

1971 I 1972 I 1973 I 1974 I 1975

FIG. 6; Mean (± SE) density of third year (solid line) and fourth year (dashed line) Corbicula in Altamaka River, October
1971 through October 1975.

and low current velocity habitats. To meet
criteria for homogeneity of variances the densities
were transformed by log.n (X + 1). The results
indicated that first year Corbicula showed no
preference for either habitat, but older Corbicula
(two to three years) were found in greater
numbers in low velocity areas. Mean densities of
immature and mature first year Corbicula were
greater in high velocity areas than in low veloci-
ty areas, but the differences between the means
were not significant at the .05 level. Second year
clams were slightly more abundant in low veloci-
ty areas, but the difference between the means
was not significant at the .05 level. Mean den-
sities of third and fourth year Corbkula were
both significantly greater in low velocity habitats
at the .001 and .05 levels respectively.

In October 1975 several shells from dead
Corbicula were found deposited on a sand bar at
river mile 113.4. Some of these were as large as
38 mm, and were probably six years old. It is
possible that the older clams prefer habitats
away from the main channel, such as sand bars

and sloughs. None of the sampling stations were
placed so that they were over sand bars or
sloughs on high water because these habitats
could not be sampled during low water. Another
possibility is that the larger clams were imported
from an older population upstream during the
unusually high water in spring 1975. If the clams
were established first upstream by overland
transport as Sickel (1973) speculates, one would
expect to find larger individuals upstream.

The invasion of Corbicula in the Altamaha River
since 1971 has been accompanied by a drastic
decline in populations of other bivalves (Figure
7). Corbicula density fluctuated greatly from late
1971 through summer 1972, indicating their ag-
gregated distribution. By late fall 1972 Corbicula
were collected consistently. Other bivalves
(Sphaeriidae and some Unionidae) maintained
average densities of approximately 200/m^ dur-
ing late 1971 and 1972. In October 1972 average
G)7-bicula density in areas sampled increased to
almost 200/m^ and the density of other bivalves
fell sharply. During winter and spring of 1973

Vol. 90 (3)

July 21, 1976

THE NAUTILUS 123

densities of Corbicuki fell to 60/m' and the den-
sity of other bivalves rose to 80-90/m^ Concur-
rently, much dead Corbicula tissue was collected
in drift samples (unpublished data), indicating a
large die-off. This phenomenon has been reported
by Sinclair and Isom (1963) and Bickel (1966). In
August 1973 Corbicula density rose above the
peak for the previous year reaching nearly
700/m', while the density of other bivalves
again fell sharply. In summer 1974 Corbicula
reached a density of almost 10,000, and other
bivalves disappeared from our samples. These in-
verse fluctuations in 1972 and 1973 may be due
to sampling bias as a result of clumped distribu-
tion of both Corbicula and other bivalves but
may also indicate some form of competition. In
the Flint River, Sickel (1973) observed that
"where Corbicula were most dense there were no
union ids, even though the habitat appeared
suitable." He further suggested that "this in-
dicated some form of competition, which was
unlikely to be simply spatial competition since
the size of Corbicula and its density did not ap-

pear to be great enough to exclude the much
larger unionids."

Canth/j/ria sjnnosa and L. dolabraefomiis were
collected commonly as late as October, 1974 but
have rarely been found since then by the authors
or by local fishermen who use the mussels for
bait. In November 1975 a survey was made of
sandbars and sloughs once described (Sickel, 1969)
as having an abundant population of L.
dolabraeformis, E. hopetonensis, and C. spinosa.
No L. dolabraeformis or C. spinosa were found.
A single E hopetonensis was found near an area
from which Sickel (1969) observed densities up to
16/m^ Corbicula was found in abundance in
these areas and in one slough the density was
710/m^ Scattered along the sandbars and in
shallow waters nearby were empty shells of E.
shepardianus, E. hopetonensis, L. dolabraeformis,
L. splendida, and C spinosa. Most of the shells
were found with both halves intact, and- some had
bits of dried mantle attached, indicating relative-
ly recent death. In December 1975 one of our co-
workers discovered a small bed of L. dolabraefor-

10, 000..

0 M D
1971

FIG. 7: Mean (± SE) density of total G)rbicula (solid line) <md other bivalves (dashed line) in Altamaha River, October
1971 through October 1975.

124 THE NAUTILUS

July 21, 1976

Vol. 9() (3)

viis on the north bank just above a sand bar (RM
114). Most of the shells examined were empty. A
few live L. dolabraeformis were found but were
observed to be extremely emaciated. It is in-
teresting to note that all of the above species ex-
cept L ifplendida are endemic to the Altamaha
River and are listed as endangered species by the
Georgia Department of Natural Resources (1974).
Additional endemic species listed as endangered
but not OTllected during this study include
Ala.'iiuidiinta nmtla Lea, Eliiptio dariensk Lea,
and A nodonta gibbosa Lea.

It is possible that Corhk-ula may have a higher
rate of filtration than mussels. Mattice and Dye
(1975) reported a filtration rate for Corbicula of 1
liter/hr. Stanczykowska, Lawacz, and Mattice
(1973) found that filtration rates ranged from
10-100 ml/hr for Dreissena polymorpha Pallas
and from 60-490 ml/hr for Unionidae. However,
Habel (1970) found a lower filtration rate of 11
ml/hr for Corbicula. Corbicula have been found
to be tolerant of a variety of adverse conditions.
Mattice and Dye (1975) found Corbicula tolerant
of high and low extremes in water temperature.
Sinclair and Isom (1963) reported Corbicula
tolerant of intense water level fluctuations in the
Tennessee River. Habel (1970) found Corbicula
strongly resistant to low DO. Diaz (1974) found a
high density of Corbicula in the James River
below an area receiving 90,000 lbs BOD/day.

Several features of the Corbicula reproductive
cycle (Sinclair and Isom, 1963) give them a
definite competitive advantage. Corbicula are
monoecious, incubatory and attain sexual maturi-
ty in less than one year. Unionidae, most of
which are dioecious, have a weakness in that lar-
val parasitism of fish is required for development
to maturity. Although many glochidia may be
produced, very few are able to find a suitable
host, and the period of development to sexual
maturity is often extended more than one season
(Storer and Usinger, 1957). Although sphaeriids,
like Corbicula. are monoecious and incubatory,
they may have a definite disadvantage of fragili-
ty. The authors have observed, especially in
young individuals, that the sphaeriid shells ap-
pear to \-)e tliinner and may not withstand scour-
ing caused by extreme river discharge as well as
Corbicula.

Density of sexually immature Corbicula

(Figure 3) did not reach a maximum in fall 1975
of the magnitude reached 'in 1973 and 1974. The
extreme river discharge in spring 1975 may have
exerted a flushing or diluting effect on the
Cirbicula. Another possibility is the attainment
of Corbicula carrying capacity in the river after
an initial overshoot. It is evident fi-om Figure 7
that the average density of Coi-bicula in 1974 and
U)75 was about the same as the density that
other bivalves were prior to fall 1972, which in-
dicates the replacement of other bivalves with
Cn-bicula.

A combination of factors probably was respon-
sible for the success of Corbicula and the decline
of other bivalves in the Altamaha River. Clearly,
more investigation is necessary to determine the
magnitude and extent of the invasion in the up-
per and lower reaches of the Altamaha drainage
system. Additional research, such as determina-
tions of relative filtration rates, food particle size
preference, and spatial interactions is needed to
elucidate the nature of competition between
Corbicula and other bivalves.

ACKNOWLEDGMENTS

The authoi-s wish to thank J. B. Sickel, Murray
State University and Drs. J. B. Wallace, D. C.
Scott and J. Schindler of the University of
Georgia for reviewing the manuscript. Many
employees of the Georgia Power Company En-
vironmental Affairs Division contributed support
in various ways. Special thanks go to Constance
G. Bell and George N. Guill for laboratory work,
Ismal Lingerfelt for illustrations, Deborah A.
Kirkus for typing, and J. H. Motz, Jr. and T. E.
Byerley for reviewing the manuscript.

LITERATURE CITED

Bickel. D. 1966. EcoUig>- of Carhirtda maiiili'ii.'^is Philippi in
the Ohio River at Louisville. Kentuck>-. Slcrkiann 23:
19-a}.

Diaz. R. J. 1974. Asiatic clam. Corbicula manilensis (Philippi)
in the tidal .James River, Virginia. Chesapeake Science
15(2): US- 120.

Fast, A. W. 1971. The invasion and distribution of the Asiatic
clam (Corbicula manilensis) in a Southern California reser-
voir. Bulletin Southern Califnrniii Academy of Science
70(2): 91-SH.

Fuller, S. L. H. and C. E. Powell. 1973. Range extensions of
Corbicula manilen.fi.'< (Philippi) in the Atlantic drainage of
the United States. The Nauhlun 87(2): .5,9.

Vol. fX) (;?)

Julv 2\. 1976

THE NAUTILUS 125

Georgia Department of Natural Resources. 1974. Endangered
apeciex of (ieorgia. proceedings of the 1974 Conference, May
3-4. 1974, Fernbank Science Center. Athmta, Georgia.

Georgia Power Company. 1974. Edwin I. Hatch Nuclear Plant
Unit No. 1. Preoperational surveillance report: Chapter 5.
biological monitoring. .58 pp.

Habel. M. L. 1970. Oxygen consumption, temperature
tolerancei filtration rate of the introduced Asiatic dam
Corbiada manUensis from the Tennessee River. M. S.
TTiesw. Auburn University. Auburn , Alabama. 6fi pp.

Joy, .1. E. and L. E. McCoy. 197-5. Comparisons of shell dimen-
sions and viscera mass weights in Corbicula numilensis
(Philippi, 1844). ne Nautiius 89(2): 51-.M.

Keup. L., W. B. Horning and W. M. Ingram. 19ft?. Elxtension
of range of Asiatic clam to Cincinnati reach of the Ohio
River. The Nautilus 77(1): 18-21.

Mattice, J. S. and L. L. Dye. 1975. Thermal tolerance of adult
Asiatic clam Corbicula manilensis (Mollusca: Bivalvia).
Presented at the Second Thermal Ecology Symposium.
Augusta, Georgia. 25 April. 197.5.

Rhinne, J. N. 1974. TYie introduced Asiatic clam Corbicula in
Central Arizona reservoirs. The Nautiht's 88(2): .56-61.

Sickel, J. B. 1969. A survey of the mussel populations
(Unionidae) and protozoa of the Altamaha River with
reference to their use in monitoring environmental
changes. M. S. Thesis. Einory University. Atlanta, Georgia.
133 pp.

Sickel. J. B. 1973. A new record of Corbicula mmiilensis
(Philippi) in the Southern Atlantic Slope region of Georgia.
ne Nautilus 87{\):n-l2.

Sickel, J. B., and W. D. Burbanck. 1974 Bottom substratum
preference of Corbiada manilensis (Pelecyixida ) in the
Altamaha River, Georgia. .4. 5. B. Bulletin 21 (2): »4.

Sinclair. R. M. and W. M. Ingram. 1961. A new record for the

Asiatic clam in the United States, the Tennessee River. The
NautdiL«7i(:i]: 114-118.

Sinclair. R. M. and B. G. Isom. 1963. Further .studies on the
introduced Asiatic clam {Corbiada) in Tennessee. Tennessee
Stream Pollution CVintrol Board, Tennessee Department of
Public Health. 75 pp.

Stanczykowska, A., W. I^awacz, and J. Mattice. 1973. Bivalves
as a factor affecting circulation of matter in the Lake.
Pages 53-58 in International sjTnposium on eutrophication
and water quality control. October 16-20. 1973. Reinhards-
brunn Castle. East Germany.

Storer, T. I., and R. L. Usinger. 19-57. (jeneral Zoology. 3rd ed.
McGraw Hill Book Company, Inc. New York. 664 pp.

Taylor, M. P. 1974. Biological monitoring in Wheeler Reser-
voir before operation of Browns Ferry Nuclear Plant. Pages
399-413 in -J. W. Gibbons and R. R. Sharitz. eds. Thermal
ecology. Technical Information Services, United States
Atomic Energy Commission, 670 pp.

United States Department of Interior. 1972. Water resources
data for Georgia. Water Resources Division, U. S.
Geological Survey. 239 pp.

United States Department of Interior. 1973. Water resources
data for Georgia. Water Resources Division, U. S.
Geological Survey. 231 pp.

United States Department of Interior. 1974. Water resources
data for Georgia. Water Resources Division, U. S.
Geological Survey. 327 pp.

United States Department of Interior. 1975. Water resources
data for Georgia. U. S. Geological Survey Water-data Re-
port GA -7.5-1. 368 pp.

Villadolid, D. V. and F. G. Del Rosario. 19-30. Some studies on
the biologj' of TuUa (Corbiada mandensis Philippi). a com-
mon food clam of Laguna De Bay and its tributaries. The
Philippine AgrituLtwrisl. 19: 355-382.

SUCCINEA RAOI NEW NAME FOR SUCCINEA ARBORICOLA RAO, 1925
(STYLOMMATOPHORA : SUCCINEIDAE)

N. V. Subba Rao and S. C. Mitra

Zoological Survey of India
8 Lindsay Street
Calcutta-700016, India

Mousson (1887) described a new species,
Succinea arborea from Kalaruri { = Kalahari),
Southeast Africa. As the name was preoccupied
by Succinea arborea Adams and Angas (1863)
from South Australia, Connolly (1912) proposed
the new name, Succinea arboricola for the South
.\frican species.

During the course of our studies on molluscs
from Poena District, Maharashtra, we have come
across a species of succineid, Succinea arboricola
Rao, the tj'pe specimens of which were collected
by Dr. S. L. Hora. during August, 1924, on. the
bark of mango trees in the compound of
Hamilton Hotel at Lonavla, Poona District. Signi-
fying its peculiar habitat, Rao (1925) named the
new species as Succinea arboricola which.

however, is distinct from the South African and
South Australian succineids. Since Succinea ar-
boricola Rao is a junior homonym of Succinea ar-
boricola Connolly, it is necessary to propose a
new name for the Indian species. We take this
opportunity to propose the new name Succinea
raoi. for Succinea arboricola Rao, in honour
of late Dr. H. S. Rao, who made significant
contributions to Indian malacologj'.

LITERATURE CITED

Mousson, A. 1887. Jimr. de Cmchl. Paris. 35: 297, pi. 12, fig. 1.
Adams, A. & Angas, G. F. 1863. Proc. Zool. Soc.. Lord.. 52a
Connolly, M. 1912. Ann. Smdh Afriean Mus. 11: 220.
Ran. H. S. 19^5. Records Indian Mus. 27: 401-403.

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THE

NAUTILUS

Vol. 90
No. 4

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Museum of Zoology
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THE

NAUTILUS

Volume 90, number 4 — October 29, 1976

CONTENTS

Harry S. Ladd

New Pleistocene Neogastropoda from the New Hebrides 127

Clifford M. Nelson

The Type-Species of Neptunea Rbding, 1798

(Gastropoda : Buccinacea) 139

Mary G. Curry and Malcolm F. Vidrine

New Fresh-Water Mussel Host Records for the Leech Placobdella Mmtifera,

with Distributional Notes 141

Brian R. Rivest and Larry G. Harris

Eubmnchus Tricolor Forbes in the Western Atlantic 145

Helen M. Garlinghouse

William Seward Teator (1860-1930) 148

Douglas G. Smith

Abnormal Shells of Gyraulus Parvus (Planorbidae) 150

Lyle D. and Sarah C. Campbell.

Sinistral Specimens of Olivella, Prunum. and Granulina from the Pliocene of

Virginia and North Carolina 151

Fred G. Thompson

Land Snails from Monito Island, West Indies 152

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 127

NEW PLEISTOCENE NEOGASTROPODA FROM THE NEW HEBRIDES

Harry S. Ladd

Department of Paleobiology

National Museum of Natural History

Smithsonian Institution

Washington, D. C. 20560

ABSTRACT

One new genus and eleven new species, representing six families of neogastro-
pod molbisks, are described from the highly fossiliferous beds of the Navaka
sands on the island of Santo. Also included is a highly decorated cone, possibly
identical with a living species. The fossiliferous sediments were deposited at
moderate depths in an off-reef environment.

INTRODUCTION

Several recent publications have cited the oc-
currence on the island of Santo, New Hebrides, of
richly fossiliferous Pleistocene sediments
(Mallick, 1971, 1973, 1974, 1975; Mallick and
Greenbaum, 1975; Greenbaum, 1974, 1975). Collec-
tions of fossils made by Messrs. Mallick and
Greenbaum of the New Hebrides Condominium
Geological Survey were sent to the U.S. National
Museum for identification starting in 1970. They
proved of such interest that Thomas Waller of
that institution and Warren Blow of the U.S.
Geological Survey visited the island in 1974 to
collect bulk samples. As work on all of these col-
lections proceeds, it becomes apparent that the
Santo sediments contain perhaps the richest and
most diversified and certainly the best preserved
fauna of fossil mollusks yet discovered in the
islands of the Pacific, possibly in all of the Indo-
Pacific region. Recently I described two new
volutes from the area (Ladd, 1975). Since that
time eleven other new species of mollusks have
appeared, a surprisingly large number in view of
the demonstrated Pleistocene age of the beds. The
entire moUuscan assemblage is being studied, but
it will necessarily be years before a comprehen-
sive report is published. The purpose of the pres-
ent paper is to describe the additional new forms
that have appeared.

LOCATION

Localities where fossils were collected are
shown on Fig. 1. SM242 on the Kere River is 166°

55.74' E, 15°34'S at an altitude of 70 meters. U.S.
Geological Survey Cenozoic locality numbers
25715 and 25718 cover the same spot. SM43 on
the Navaka River is 166°51.04'E, 15°36.08'S at an
altitude of 50 meters. U.S. Geological Survey
Cenozoic locality numbers 25731, 25736 and 25742
are in the same outcrop area. All are on the
island of Santo, New Hebrides.

A collecting locality SG79 is mentioned in the
text but does not appear on the map. It includes
float from a tributary to the Sarakata River 20
km. northeast of SM242.

N

\

k

V*--SM242
\ 25715

n 2,7,

I

, 25736

\) 25742

^ — ^f'^/^ ^

\/^SM4S
^-^ 25751

(

^

Tongoa It.

/*

^ ^

)

/X'^\^

Z'^---

^**te««*^

' — -- 1 ^Aroilll

C )

"-'OOm,.

--'

"•■,,^0^ ;.

n

L_

. . . ?

Kllomtlfn

FIG. 1 Pari of south Santo, New Hebrides, showing the

Incaticm of fossil sites on the Navaka and Kere Rivers (after
Mallick and Greenbaum. 1975). Numbers without prefix are
USGS Cenozoic locality numbers.

128 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

STRATIGRAPHY

WTien Mawson studied the geology of the New-
Hebrides some seventy years ago he collected a
large number of fossil mollusks from beds out-
cropping near Tasiriki on the southwest coast of
Santo. He referred to these beds as the Tasiriki
foundation-beds (1905, p. 448. 451). Mallick and
Greenbaum (197.5, p. 8) identify them with the
Navaka Sands. Mawson pointed out that the beds
at Tasiriki were intermediate in character be-
tween the soft "soapstone" (calcareous clay) and
fossiliferous cinder beds. Mallick noted that the
typical beds were soft unlithified sands and silts
with some gravel. Mallick and Greenbaum
mapped the geology of a part of south Santo, the
area covered including the fossiliferous beds on
the Navaka and Kere Rivers. Ladd (1975) re-
ferred to the fossiliferous sediments as marls, us-
ing the term rather loosely. In their 1975 discus-
sion, Mallick and Greenbaum refer to the SM242
outcrops on the Kere River as the Kere Shell
Bed— a sediment composed of 50-70% calcareous
skeletons and fragments in a gray silt. The unit
had an observed thickness of at least 1 meter and
its base appeared to dip SSE at about 5 degrees.

PALEOECOLOGY

A brief summary on this subject was included
in a paper describing two new fossil volutes from
Santo (Ladd, 1975). At present there is little to be
added to that account. I still favor the view that
the fossiliferous beds were accumulated on an
off-shore shelf at depths in excess of 50 meters. In
this connection it may be noted that Hedley, who
examined the numerous fossil mollusks collected
by Mawson from Tasiriki on Santo, was reminded
of an assemblage collected elsewhere in 15
fathoms (27 meters) (Hedley, 1905, p. 477).

The high percentage of new species of mollusks
contained in the beds may reflect present lack of
knowledge of the existing fauna rather than great
age. Very little dredging has been done in the
New Hebrides at depths comparable to those
postulated for the Navaka Sands. Some of the
fossil species here described as new may even-
tually be found living in the existing seas. The
cone, Knn/<inin. here described, may be identical
with a species that lives today at depths of
150-190 meters in Japanese waters.

AGE

In 1970 Miss Ruth Todd of the U.S. Geological
Survey reported on the rich and beautifully
preserved Foraminifera contained in the sands
found on the Navaka River at SM43. She noted at
least 150 species of benthonics and about 18
species of planktonics. Among the latter was
Gldborotalia tnuicatulindideiy (d'Orbigny), in-
dicating an age no older than Pleistocene. (R.
Todd, written communication August 10, 1970).

As noted in 1975 (Ladd, p. 136) a Uranium-
Thorium age determination on well-preserved
coral from SM242 by Barney Szabo of the U.S.
Geological Survey gave a figure of 14,000 years, a
date at approximately the Pleistocene- Holocene
boundary. This figure seemed small in view of
the field relations and the occurrence of
undescribed species of mollusks and, at Mr.
Szabo's suggestion, a carbon 14 test of the same
coral was made. This determination, by Dr.
Robert Stukenrath of the Radiation Biology
Laboratory of the Smithsonian Institution, gave a
figure of 25,280 ± 460 years— a place clearly in
the Pleistocene.

SYSTEM ATICS

Order Neogastropoda

Family Coralliophilidae

Genus Coralliophila H. and A. Adams

Adams, H. and A. 1853, Genera of Recent

mollusca, vol. 1, p. 135.

Tv'pe (by subsequent designation. Iredale. 1912, Mai. Soc.
London, Proc. Vol. 10, p. SI): Miirei iieritoideus Chemnitz
= Purpura violacea Kiener. Holocene, Pacific.

Coralliophila mallicki new species

Figs. 5-7

Shell small and thin with a low, flattened spire
and widely expanded body whorl. Non-umbilicate,
aperture broadly triangular, outer lip thin, inner
lip wide with a concave columellar callus that ex-
tends the full length of the aperture. Sculpture
consisting of about 30 shallow spiral grooves that
produce low-flat-topped spiral ribs. Measurements
of the holotype, USNM 214348, SM242-444A:
height 11.9 mm, diameter 10.0 mm.

The single small New Hebrides fossil may be
immature. It resembles the variable living type
species, CA^mlliophila inolacea Kiener, but has a

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 129

flatter spire, a thinner and more expanded outer
lip. In overall shape and sculpture ('. tnallirki
resembles some of the fossil species assigned to
Gnwholepas (Beu, 1970; Yokes, 1972), but the ex-

cavated columellar area of the New Hebrides shell
seems to place it clearly in Coralluiphila.

The species is named for Dr. D. I. J. Mallick,
formerly Senior Geologist of the New Hebrides

.••-v

^^'

\

m

-liilfc^

^' '^5%

^c:

-^^

.J 6

FIGS. 2-4. Latiaxis (Tolema) blowi new species. Holotxfpe, USNM 2U250. X 2. 5-7 Coralliophila
mallicki new species. Hol/itype. X 6. 8-9 Phos bakeri new species. Holotype. USNM 2HS07. X 3.
10 Metula kerensis new species. Holotype, USNM 2U288. X 3. 11 Metula santoensis new species.
Holotype. X 2.

130 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

Geological Survey, who discovered the fossil beds
on the Kere River, and collected this and many
other unique shells.

Occurrence: A single specimen from SM242 on
the Kere River.

Genus Latiaxis Swainson
Swainson, 1840, Treatise on malacology, p. 306.

TN'pe (b\' subsequent designation, Gray, 1847, Proc. Zool. Soc.
London, pt. 15, p. 135): Pj/ruia mawae Gray. Holocene.
Indo-Pacific.

Subgenus Tolema Iredale

Iredale, 1929, Records Australian Mus., v. 17, no.

4, p. 186.

Type aCZN Op. 911, 1970): Purpura sertala Iredale ( = Tolema
austndis Laseron). Holocene, Australia.

Latiaxis (Tolema) blowi new species

Figs. 2-4

Shell biconic, strongly turreted. Protoconch
consisting of about two whorls, coiled at a slight
angle to the axis of the spire, followed by six
sculptured whorls. Surface of shell covered by
close-set scaly spiral cords; shoulder sharply
elevated with triangular open scales that are
more prominent on early whorls than on the
body whorl; axial ribs, about 9 on penultimate
whorl, are broadly rounded. Body whorl con-
stricted anteriorly; aperture, triangular outer lip
thin, made Urate within by the exterior spirals;
inner lip thinly callused; umbilicus a shallow
chink.

Measurements of the holotype (only specimen),
USNM 214250: height 28.0 mm, diameter 18.3
mm.

L. bloun seems most closely related to L.
filaregis. a Holocene species described by
Kurohara (1959), but that species is more slender,
more coarsely sculptured and less constricted
anteriorly.

This species is named for Warren Blow of the
U.S. Geological Survey who collected the only
specimen from USGS locality 25715 on the Kere
River outcrops, Santo, New Hebrides.

Occurrence: U.S. Geological Survey station
25715 on the Kere River. L. fUnregia Kurohara,
the related form mentioned above, occurs at
depths of -50-100 meters off Shikoku, Japan
(Habe, 1964, p. 86).

Family Buccinidae
Genus Phos Montfort

Montfort, 1810, Conchyl. Syst. p. 495.

Type (by original designation): Murex aenticosus Linnaeus.

Holocene, southwest Pacific.

Phos bakeri new species
Figs. 8, 9

Medium in size, biconic. Protoconch consisting of
four whorls, each of the lowest three with two fine
spiral ribs on its lower half. Aperture broadly len-
ticular with a short and slightly twisted canal
anteriorly; outer lip with a thin edge, thickened
within and bearing short denticles; columella with
two plaits, the anterior one larger. Sculpture con-
sisting of strong smooth axial ribs, fourteen on the
penultimate whorl, and many fine spirals that
become coarse near the base. Measurements of the
holotype, USNM 214307: height 18.4 mm, diameter
9.0 mm.

P. bakeri seems most closely related to P. dingsi
described by MacNeil (1960, p. 74, pi. 3, fig. 21) from
the Miocene Yonobara Clay, Shimajiri Formation,
of Okinawa. That species, however, has more
numerous axial ribs, some of which are clearly
formed varices. P. bakeri is also related to a
Japanese Holocene species, P. hirasei Sowerby (see
Habe, 1964, p. 95, pi. 31, fig. 7) but that species is
much larger, has well developed spiral cords and
occasional varices.

This species is named for Mr. F. E. Baker, British
District Agent on Santo, who assisted Thomas
Waller and Warren Blow in many ways during
their visit to the area in 1974.

Occurrence: Three shells from the Kere River
outcrops at USGS locality 25715.

(jenus Metula H. and A. Adams
H. and A. Adams, 1853, (Senera of Recent Mollusca,
V. 1, p.84.
Type (by hidden tautonymy): Buccinum hindsii H. and A,

Adams { = Buccinum metula Hinds). Holocene, Pacific coast

of Panama.

Metula kerensis mw species

Fig. 10

Shell small and slender; protoconch consisting

of 2' 2 glassy convex whorls, followed by 5''2

sculptured whorls. Sculpture consisting of fine,

irregularly-spaced axials and close-set flattened

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 131

spirals. Sculpture on some specimens uniform
over entire shell, on others the spiral immediate-
ly below the suture is more prominent than the
others; there are occasional low varices. Aperture
elongate, truncated anteriorly; outer lip
thickened both anteriorly and posteriorly, smooth
within save for a broad node posteriorly; col-
umella aincave, inner lip heavily callused.

Measurements of the holotype, USNM 214288:
height 24.3 mm, diameter 7.3 mm.

M. kerensis differs from described species of
Metula by the subdued nature of its sculpture.
TTie pattern of axials and spirals are clearly seen
only with the aid of a lens.

Occurrence: Represented by eight shells from
the uses localities 52715 and 52718 Kere River,
Santo.

Metula santoensis new species
Fig. 11

Small to medium in size, slender, whorls gently
convex, suture lightly impressed; protoconch not
preserved. Sculpture consisting of close-set,
slightly curved axial ribs that are stronger than
the over-riding spirals, especially on the whorls of
the spire; immediately below the suture and on
the base the spirals are more widely spaced than
elsewhere. Aperture elongate, outer lip thickened,
crenulate within; inner lip smooth, heavily
callused. Measurements of the holotype, BM (NH)
GG19763: height 30 mm, diameter 9.8 mm.

M. santoensis closely resembles M. elongata
Dall dredged off Japan in 57 fathoms of water
(Dall, 1957, p. 166) but that species is longer and
more slender.

Occurrence: Represented by two specimens, the
holotype from station SM242 on the Kere River,
and a smaller shell from river debris on the
Sarakata River (SG79), Santo.

Family Nassariidae
Genus Nassarius Dumeril

Dumeril, 1806, Zoologie analytique, p. 167 (genus

without species).

Type (by monotypy) Froriep, 1806, C. Dumeril's Zoologie
analytique, p. 167: fide Iredale, 1916, Proc. Mai. Soc
London, v. 12, p. 83): Buccinum amdaris Linnaeus.
Holocene, western Pacific.

Subgenus Alectrion Montfort

Montfort, 1810, Conch. Syst. v. 2, p. 566.
Type (by original designation): Buccinum papillomm Lin-
naeus. Holocene, Indo-Pacific.

Nassarius (Alectrion) barsdelli new species
Figs. 12-15

Medium in size, thin, body whorl greatly in-
flated. Early whorls with rounded axial ribs
crossed by fine spiral grooves: subsequent whorls
may be slightly crenulated at the deeply chan-
neled suture and may have a faint subsutural
spiral groove; late whorls mostly smooth except
for spiral grooves over the base of the body
whorl. On some shells weak spirals can be seen
over the entire body whorl (Figure 15). Aperture
broadly lenticular, outer lip thin, columella
smooth except for obscure corrugations near its
base.

Measurements of the types: Holotype, USNM
214274 (Figs. 12-14) height 23.8 mm, diameter
14.0 mm; paratype, USNM 214278 (Fig. 15 height)
23.8 mm, diameter 15.0 mm.

The new species is smaller than N. glans
(Linnaeus) and is proportionately shorter and
more inflated. None of the nearly 40 fossils has a
denticle on the parietal wall and none shows a
trace of color pattern. I first considered the fossil
form as a new subspecies of N. glans (Linnaeus)
but the later recovery of two incomplete but
typically banded shells of A^. glans from the out-
crop on the Kere that yielded the fossils indicates
that the two are distinct.

This species is named for Mark Barsdell, for-
merly of the New Hebrides Geological "Survey,
who, in 1974, aided Messrs. Waller and Blow in
collecting on the rivers and in dredging.

Occurrence: Abundant in the Kere River out-
crops, USGS locality 25715. N. glans (Linnaeus)
lives today in many parts of the tropical Pacific
(Cernohorsky, 1972, p. 180).

Bathynassa Ladd, new genus

Type: Bathynassa bolangoi Ladd. new species. Pleistocene.

Santo. New Hebrides.

Small, slender. Protoconch of three convex
whorls, the middle one feintly keeled, the last
more strongly keeled. Early whorls of teleoconch
with sharply elevated axial ribs that are over-

132 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

ridden by weaker spirals; on later whorls axials
and spirals become subequal; uppermost spirals
on each whorl forming a rim that bounds a
deeply excavated subsutural furrow. Aperture

broadly lenticular; inner lip callused, with a low
denticle posteriorly; outer lip faintly lirate
within, backed by a strong varix.
The genus is characterized particularly by its

FIGS. 12-15 Nassariu-s (Alectrion) barsdelli new species. 12, 13 Hohtype. USNM 2U27i. X 25.
14 Apex of holotype. X ,5. 15 Parati/pe. USNM 2U278. X 25. 16-20 Fasciolaria (Pleuroploca)
walleri new xppcies 16, 17 Hohtype. USNM 2Ui!tS0. X /. (uncoated to show ariginal rnlor pattern)
18-20 Paratypc, USNM21J,26L X 1. 21-22 Kenyonia cf. diiangi (Azuma) USNM 211,291. X 6.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 133

deeply excavated, nearly flat -bottomed subsutural
furrow.

Bathynassa bolangoi nevj species

Figs. 34-40

Shell small, slender. Protoconch consisting of
three gently convex glassy whorls; middle whorl
with a trace of a median keel, the lowest whorl
with a stronger keel. Teleoconch of six whorls; on
early whorls strong axial ribs are overridden by
weak spirals but on later whorls the axials and
spirals are subequal in strength; on the base the
spirals are sharply elevated and more widely
spaced. A deep subsutural furrow has a gently
concave floor that is crossed by the axial ribs.
Under low magnification the furrow appears
deeper than in Figs. 38 and 39 which are SEM
photographs. Aperture broadly lenticular, inner
lip thinly callused, the callus edge slightly
elevated; columella smooth except for a low den-
ticle posteriorly; outer lip weakly lirate within,
backed by a strong varix. Siphonal canal short
and broad.

Measurements of the types:

Holotype USNM 214343 length 13.9 mm. diameter .5.2 mm.

Paratype A 214344 12.8 5.2

B 214345 13.6 .5.2

C 214346 (incomplete) about 5

The fossils are more slender than the average
nassarid but the proto(»nch of the fossil seems
typically nassarid, likewise its aperture and outer
lip varix. Its excavated, nearly flat -bottomed sub-
sutural furrow separates it from other members
of the family. I have not found a living or fossil
species with a furrow of this type. Superficially,
the new species resembles Nassarius caelatus A.
Adams from Southeast Asia, but the latter is
much larger, more obese and with weaker spiral
threads.

This species is named for John Bolango of the
New Hebrides Condominium Geological Survey
who collected with Thomas Waller and Warren
Blow when they visited Santo in 1974.

Occurrence: Seven shells from the Navaka
River beds, all from the northern end of the out-
crop area, stations 25736 and 25742. It may be
that the beds in this area accumulated at
somewhat greater depth than those farther south

on the Navaka or the beds on the Kere River to
the east.

Family Fasciolariidae
Genus Fasciolaria Lamarck

Lamarck, 1799, Prodrome d'une nouvelle
classification des coquilles. . . Mem. Soc. Hist,
nat, Paris 1, p. 73.

Type (by monotypy): Murex tulipa Linnaeus. Holocene,
Caribbean.

Subgenus Pleuroploca P. Fischer

Fischer, P., 1884, Jour, de Conchy!, vol. 32, p. 169.

Type (by monotypy): Murex trapezium Linnaeus. Holocene,
Indo-Pacific.

Fasciolaria (Pleuroploca) walleri new species
Figs. 16-20

Shell small, slender, fusiform. Protoconch con-
sisting of 2V2 smooth, convex whorls, followed by
8 sculptured whorls. Sutures appressed; aperture
broadly lenticular, extended anteriorly into a
long and strongly recurved siphonal canal; outer
lip lirate within; columella callused with a low
broad fold, the callus with a detached outer edge.
Sculpture consisting of broad, rounded axial
folds, 8-10 on the penultimate whorl; folds
becoming less well developed on the latter half of
the body whorl; all whorls covered by close-set
weak spirals that are a little stronger on the
folds than in the intervening valleys; spirals
much stronger at the base of the body whorl.
Crest of each axial fold with a band of reddish-
brown color, the color deeper between the fine
spirals than on their crests.

Measurements of the types: Holotype, USNM
214260: length 66.6 mm, diameter 22.6 mm.
Paratype, USNM 214261: length .58.7 mm,
diameter 21.3 mm. A specimen in the Mallick col-
lection (SM242-63A) is 71.4 mm in length.

F. wallen resembles F. filamentosa (Roding), a
common and widely distributed species in ex-
isting Indo-Pacific seas, but is smaller, has finer
spiral sculpture and a much longer and more
strongly recurved siphonal canal .

This species is named for Dr. Thomas R.
Waller of the Smithsonian Institution who
organized a collecting trip to Santo, during the
course of which the types of this species and
many other fossils were collected.

134 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

Occurrence: Four specimens from the Kere
River, (USGS locality 2.57115 and SM242).

Family Turridae

Genas Epidirona Iredale

Iredale, 1931, Records Australian Mus., v. 18, no.
4, p. 22.5.

Type (by original designation): Epidirona hedlevi Iredale.
Holocene, Australia.

Epidirona greenbaumi new species

Figs. 23-26

Shell medium in size, stout, biconic. Protoconch
of two glassy convex whorls followed by eight and
one-half sculptured whorls. Aperture lenticular,
outer lip thin, lirate within; inner lip callused;
sinus moderately deep; anterior canal short,
wide, slightly flaring. Sculpture consisting of
strong primary spirals that alternate with
weaker secondaries; primary ribs beaded by ax-
ials (about 25 on penultimate whorl); upper two
spirals set off by a groove to form a distinct sub-
sutural band; on the whorls of the spire the ax-
ials are nearly straight but become slightly
sinuous on the body whorl.

Measurements of the holotype, USNM 214306
from USGS locality 25715: length 20.8 mm,
diameter 8.3 mm. Paratype, BM(NH)GG 19762
from SM242: length 20.0 mm, diameter 8.1 mm.

E greenbaumi is closely related to E perksi
(Verco), a species that lives off South Australia
(Verco, 1896, p. 224, pi. 17, figs. 3, 3a-c). I have
not seen shells of E. perksi but, judging by
Verco 's detailed account, it appears that the New
Hebrides fossil has coarser sculpture, particularly
on the body whorl, a more prominent collar and
straighter axials on the whorls of the spire.

This species is named for Dr. David Greenbaum
of the New Hebrides Condominium Geological
Survey who mapped the geology of parts of Santo
and made large collections of fossils from out-
crops on the Kere River and on other streams.

Occurrence: Two shells from USGS locality
25715 and three from SM242 on the Kere River.
Verco 's closely related species, E. jx'rks'i, was
dredged alive in 15 fathoms (27 meters) off South
Australia.

Genus Euclathurella Woodring

Woodring, 1928, Carnegie Inst. Washington, Pub.
385, p. 187.

T^pe (by original designation): Oalhurella vendryesianus
Dall. Miocene. Jamaica.

Euclathurella santoensis new species
Figs. 27-30

Small, slender, fusiform, high spired. Pro-
toconch consisting of about four convex whorls,
the first three smooth, the last bearing curved,
close-set axials; teleoconch of 6 whorls with thin,
widely spaced axials, about a dozen on
penultimate whorl. Axials extend from suture to
suture and are slightly sigmoid with a sharp
peripheral angulation more than one-third of the
distance below the suture; below the angulation
the rib is convex in profile, above it is flat; sur-
fece of whorl between axials is smooth; a few
spiral threads are discernible on the base under
magnification. Aperture long and narrow, its
length exceeding that of the spire; sinus deep and
broadly rounded; outer lip with a thin edge but
callused posteriorly and backed throughout its
length by a prominent varix; ailumellar area
thinly callused except for a pad below the anal
sinus; anterior canal long, wide and rather
abruptly truncated. Measurements of the
holotype, USNM 214337: height 14.0 mm,
diameter 4.9 mm.

I could find no close relative of E santoemis.
Its axial ribs are more widely spaced than those
of the Caribbean type species, E. vendryesianus,
and the spiral sculpture of the new species is
mostly absent. The protoconchs of the two are
similar but that of the New Hebrides shell has
more whorls. Our new species superficially
resembles Eucythara funiculata (Reeve), but lacks
the small teeth in the columellar wall and outer
lip. We are provisionally placing santoensis in
Eurlathurella.

Occurrence: Four shells from USGS locality
25718 on the Kere River.

Family Conidae

Genus Kenyonia Brazier

Brazier, 1896, Linnean Soc. New South Wales, vol.
21, p. 346.

Type (by monotypy): Kenyonia pulcherrium Brazier,
Holocene, New Hebrides.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 135

Kenyonia cf. chiangi (Aznmn)
Figs. 21-22

Shell, small, conical, with a low spire
culminating in a protoconch of at least two
slightly convex glassy whorls. Shoulder sharply
angled, bearing a series of elevated triangular
plates that form cup-like structures opening in-
ward and forward; fifteen cups on body whorl;
cups give shell a stellate appearance when viewed
apically. Whorls of spire with close-set spiral
grooves that are overridden by finer, curved, ax-
ial threads. Body whorl with shallow wavy
grooves and finer irregularly spaced axial lines.

Aperture elongate; columella slightly concave
near base; outer lip thin, straight. Much of the
lower third of the body whorl is faintly tinged
with brown color.

Measurements of the figured specimen, USNM
214291: length 10.4 mm, diameter 5.9 mm.

The fossil may be conspecific with the species
described by Azuma as Tarantecomis chiangi (1972,
p. 59, figs. 5, 6) and recently figured by Okutani
(1975. p. 194. pi. 10, fig. 27) but the fossil is more
slender anteriorly and may have stronger spiral
sculpture.

The fossil has many of the unusual features
described for the type species, K. jmlcherrima, but

FIGS. 23-26 Epidirona greenbaumi neiv species 23 Hohtype. USNM 2U306. X 3. 24 Apex of
holott/pe. X,5. 25, 26 Parnti/pc. X j. 27-30 Euclathurella santoensis new species 27 Apex of kolti-
typf- (slightly retmifhed). X 11 28-29 Hohtxfpe. USNM 2US3?- X i. 31-.33 Terebra (Microtrypetes)
kerensis new species 31, 32 Hahitifpe. USNM 2U3JtO. X 6. 33 Apex of tuilotype. (slightly re-
touched). X 10.

136 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

_^

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 137

the fossil is smaller by one-third, is proportionately
wider, has a lower spire, fewer peripheral plates
and a straight outer lip. These two New Hebrides
shells differ greatly fn:)m other cones and from
most turrids. The fossil here described may be an-
cestral to the Holocene shell described by Brazier
(1896, p. 346); unfortunately. Brazier's single shell
has apparently been lost.

Occurrence: A single specimen from USGS
locality 25731 on the Navaka River. Azuma's
type was collected on the South China Sea at a
depth of 200 fathoms (365 meters) Okutani found
living specimens feirly common on banks at
depth of 150-190 meters in Japanese waters.

Family Terebridae
Genus Terebra Bruguiere

Bruguiere, 1789, Ency. methodique, Histoire

naturelle des Vers, vol. 1, p. 15 (genus without

species).
Type (by monotypy): Lamarck, 1799, Soc. Histoire Nat. Paris,

Mem. p. 79: Buccinum subulatum Linnaeus. Holocene,

western Pacific.

Subgenus Microtrypetes Pilsbry and Lowe

Pilsbry and Lowe, 1932, Proc. Acad. Nat. Sci.

Phil., vol. 84, p. 43.
TVpe (by original designation): Terebra tola Pilsbry and
Lowe. Holocene, west coast of America.

Terebra (Microtrypetes) kerensis new species
Figs. 31-33

Small, very slender; a protoconch of about
three smooth whorls is followed by eleven
sculptured whorls that are flat-sided but slightly
shouldered. Sculpture consisting of sharp, straight
axial ribs, sixteen present on penultimate whorl,
and narrow spiral grooves, 4-5 on each whorl;
one groove close to the suture is larger than the
others, suggesting the boundary of a subsutural
band. Aperture lenticular, drawn out to form the
anterior canal ; columella wdth a single low fold.

Measurements of the holotype, USNM 214340:
height 10.0 mm, diameter 2.0 mm.

This little species resembles T. spei described
by Brown and Pilsbry (1913, p. 497, fig. 1) from
the Pleistocene of Panama but is more slender,
has less curvature in its axials and its whorls are
slightly shouldered; also, the subsutural groove
on the species here described is less developed
than on the shells of the Panama species. T.
kei'erms is more slender than T. iola. type of the
subgenus and has fewer spiral grooves than that
species.

Occurrence: Many specimens from USGS
locality 25715 on the Kere River.

ACKNOWLEDGMENTS

I am deeply indebted to Dr. D. I. J. Mallick
and Dr. David Greenbaum of the New Hebrides
Condominium Geological Survey and Dr. Thomas
Waller and Warren Blow of the Smithsonian In-
stitution. All four of these geologists studied the
fossiliferous deposits in the field and made exten-
sive collections of mollusks. Warren Blow
skillfully prepared the material collected by him
and by the others mentioned; this included the
specimens of Bathynassa photographed by Dr.
Waller with the Scanning Electron Microscope.
Druid Wilson of the U. S. Geological Survey, Dr.
Harald A. Rehder of the Smithsonian Institution
and Dr. R. Tucker Abbott of the Delaware
Museum of Natural History gave helpful sugges-
tions during the course of my study.

LITERATURE CITED

A2uma, Masao. 1972. Descriptions of four new gastropods

from South China Sea, Venus, 31, no. 2: 55-60, 10 figs.
Beu, A. G. 1970 Review of the species of Concholepas

(Gastropoda, Muricidae), Jour. Malacol. Soc. Amtrdwi 2(1):

39-46.
Brazier, John. 1896. A new genus and three new species of

MoUusca from New South Wales, New Hebrides, and

Western Australia. Proc. lAnnaen Soc. New South Wdes.

21: S15-347.
Brown, Amos P. and Henry A. Pilsbry. 1913. Two collections

of Pleistocene fossils from the Isthmus of Panama. Proc.

Acad. Nat. Sci.. Philadelphia, p. 493-500.
Cernohorsky, W. 0. 1972. Indo-Pacific Nassariidae (Mollusca:

Gastropoda). Records Auckland Irist. and Mus. 9: 125-194.
Ball, William Healey. 1907. Descriptions of new species of

FIGS. 34-40 Bathynassa bolangoi new genus and new species. Figures S8-i0 taken by Scanning Electron Microscope. 34, 35
Holotype. USNM m343. X 6. 36, 37 Paratype A. USNM 2USU. X 6. 38 Paratype R USNM 2im5. X 21. 39 Paratype R
USNM2UM5. X 26. 40 Paratype C. USNM 2im6. X 72.

138 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

shells, chiefly Buecinidae, frtim the dredginie; of Ihe U.SS.

"Albatross" during 1906, in the northwestern Pacific, Ber-
ing, Okhotsk and Japanese Seas. Smithsonian Misc. CoUec-

lions. 50-. i:»-173.
Greenbaum, D. 1974. Central Santo. Annual Report. New

Hilindea Oimiominium OeoL Sun: for year 197J. fipp.
Greenbaum, D. 197.5. Eastern Santo. Annual Rept. New

Hebrides Omdom inium Geol. Surv. for year 197S. p. ."j-d
Habe, Tadashige. 1964. Shells of the western Pacific in color.

2:2£3pp.,66pls.
Hedley, C. 190.5. In Mawson, Pmc. Linnean Soc. New South

Walea. 30: 477-478.
Hinds, R. B. 1844. Zoology of the voyage of HMS. Sulphur. 2,

,V/()//».sra, 72p..21pls.
Kurohara, Kazuo. 19.59. On Latiaxis filaregis n. sp. Veniis

20(4): :M2-»14.
Ladd. Harr>' S. 1975. Two Pleistocene Volutes from the New

Hebrides (Mollusca: Gastropoda). Veligrr. 18(2), pp. 1.34-1:38.
MacNeil, F. S. 1960. Tertiar>' and Quaternary Gastropoda of

Okinawa. U.S. Geological Survey Professional Paper 339,

148 pp.
Mallick. D. I. J. 1971. Santo. Annual Rept, New Hebrides

Condominium Geol. Surv. for year 1970, pp. 16-20.
1973. Santo. Annual Rept., New Hebrides Con-

dumunum Geol.Surv. for year 1971. pp. 11-12.

1974. South-west Santo. Annual Rept.. New Hebrides

Condominium Geol. Surv. for year 197J, pp.4-.5.

1975. Western and st)Uthern Santo. Annual Rept.. New

Hebrides Cimdominiutn Geol. Surv. fur year 197S. pp. 6-8.
Mallick, D. I. .J. and D. Greenbaum. 197.5 The Navaka

fossiliferous Sands and the Kere Shell Bed. Annual Rept.

New Hebrides Condominium Geol. Sun: for year 197,1. pp.

H-ll
Mawson, I). 1905. Tlie geology of the New Hebrides. Pruc. Lin-
nean Soc. New S(ruth Wales. 30: 400-485.
Okutani, Takashi. 197.5. Glimpse of benthic molluscan

fauna . . . submarine . . . bank . . . Japan, Venas, 33: 18.5-204, 3

figs., 3 pis.
Powell, A. W. B. 1966. The molluscan families Speightiidae

and Turridae. Bidl. Auckland In.ft. and Mus. 5: 184 pp., 23

pis.
Verco, J. C. 18%. Descriptions of new species of marine Mollusca

of South Australia. Trans. Royal Soc. Soidh Australia,

20(2): 217-232, 3 pis.
Yokes, Emily H. 1972. On the occurrence of the genus C<m-

cholepas (Gastropods: Thaididae), with the description of a

new species, Tulane Studies in Geology and PtUeontoiogy.

19(1): 31-40.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 139

THE TYPE-SPECIES OF NEPTUNEA RODING, 1798
(GASTROPODA: BUCCINACEA)

Clifford M. Nelson'

Museum of Natural History
Smithsonian Institution
Washington, D.C. 20560'

ABSTRACT

Fridolin Sandberger's subsequent designation in 1861 of Fusus antiquus (Lin-
naeus) as the type-species of Neptunea Riiding, 1798, ex Bolten MS, replaces the
often-cited, althnujh unavailable., selections by Monterosato (1872) and Kobelt
(1876).

Peter Friedrich Roding (1798, 115-116), in his
sale catalogue^ of the Bolten Museum collections,
established, without diagnosis or type-species
designation, genus Neptunea for a melange of
caenogastropods centered on Murex antiquus Lin-
naeus, 1758. M. despectus L., 1758, M. antiquus
L, 1758 and M. contrarius L., 1771, the first,
fourth and fifth, respectively, of 17 species-group
taxa listed therein, presently remain valid Nep-
tunea. Two of the remaining species included by
Roding may tentatively be synonomized with M.
antiquus L. Bxw^inum liratum Martyn, 1784 and
B. saturum M., 1784, both Murex sensu Gmelin
(1791, 3498, 3531) and now valid Neptunea, are
not among species assigned by Roding to Nep-
tunea, Buccinum, Colus, Fusus, Murex or Tti-
tonium.

Present neptuneids were subsequently so often
included in Fusus, Tritonium or Trvphon, that
Swainson (1840, 90, 308), in describing F. anti-
quus (L.) and the other North Atlantic species,
established Chrysodomus for them. C.
argyrostoma, Swainson 's type-species, is a species
inquirenda. Later designations of type-species by
Hermannsen (1847, /, 234: "Typus: Fusus despec-
tus Linn." of Chrysodomus) and Gray (1847, 137:
'Type of Chrysodomus Swainson, 1840: Murex an-
tiquus") remain unavailable. Jeffreys' (1867, 328)
selection "Bolten founded his genus Neptunea,

' Present address: Museum of Paleontology. University of
California, Berkeley, California 94720.

' Approved as nomenclatorially available by ICZN Opinion
96, dated 8 October 1926; Roding designated author in Direc-
tion 48, dated 21 November 1956.

and Swainson his genus Chrysodomus on the pres-
ent species." Fusus antiquus, [discussion pp.
323-328] is invalid under provisions of Article
67(c) of the International Code of Zoological
Nomenclature. Subsequent to Bernardi's (1858,
183) equation of Roding s and Swainson 's names,
Gabb (1869, 3, 71) also synonomized Chrysodomus
with Neptunea and emphasized the priority of
the Bolten Catalogue names over those of La-
marck (1799).

Heinrich Link and Fridolin Sandberger were
the only European investigators to employ con-
sistently Roding 's names prior to the publications
of Wilhelm Kobelt. Sandberger (1861, 216), in
describing species of "Fusus Bruguiere 1791"
[1789] in his conchology of the Mainz Tertiary
basin, selected ". . . , fiir das Pliocan und den Crag
des Erscheinen der jiingsten aller Fusus-Gruppen,
Neptunea Bolt. (Typus F antiquus) ... ." No
previous discussion of type-species selections for
Neptunea Roding has cited Sandberger's subse-
quent designation.^

Tommaso, Marquis di Monterosato's (1872, 17)
designation of " . . . il genere Fusus solanto pel F.
antiquus monstr. contrarius, ch'e il tipo dei
generi Neptunea Bolten e Chrysodomus Swain-
son.", Jeffreys' sinistral morph of F. anti-
quus (L.), is confused by Monterosato's (1872, 33)
subsequent equation of "Fusus antiquus, (Murex)
L. Monstr. contrarius =M. contrarius L.". This
identification and the dedication of the work to

' I am indebted to Druid Wilson of the Branch of Paleon-
tology and Stratigraphy, U. S. Geological Survey. Washington.
D. C. for this reference.

140 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

Jeffreys likely reflects the profound influence of
Monterosato's correspondence with Jeffreys and
his visit to England in 1871, where Monterosato
would have observed the sinistral specimen of A'.
(Nf'ptunea) antiqua (L.), now U. S. National
Museum of Natural History (USNM) 192193, and
the two iV; {SulcDitipho) contraria cantraria (L.),
now USNM 192195, then in Jeffreys' personal col-
lection. Jeffreys clearly distinguished F. antiqium
"Monstr. /. contrarium. Spire reversed, [and]
(Murex Cdntrariua. Linn.=F. sinisfrdrs/is.
Desh.)". The latter species-group taxon is a junior
subjective synon.vTn of the nominate subspecies of
A'. (Snlainiphd) amtraria (L.). Thas Monterosato's
equation of sinistral A^. (Neptunea) antiqua (L.)
with A'. (S) amtraria contraria (L.) is invalid, as
is Habe and Sato's (1972, 2) "Neptunea antiqua
(L\nne)= Neptunea contraria Roeding" [non L.].

Kobelt's (1876, 63) "...Die Neptuneen der
borealen und arctischen Regionen umfassen zwei
ziemlich scharf geschiedeneGruppen, deren Typen
einerseits Neptunea antiqua, andererseits islan-
dica Chemnitz sind. Man hat aus ihnen zwei Gat-
tungen, Neptunea und Sipho, ..." is not rigidly
construed as required by the provisions of ICZN
Article 67(c).

Dall (1902, 520-521) and in subsequent publica-
tions (1906, 291-292; 1918, 213-215; 1919, 336; and
1922, 36) believed Neptunea had priority for and
should be restricted to muricids principally
a.ssigned to Boreotrophon Fischer, 1884 and then
t.vpified by Tivphon clathratus L. This concept,
although used by Oldroyd (1925, 13), was never
widely adopted and was subject to a lengthy
literature debate in articles by Dall, Iredale
(1921, 1922) and Winckworth (19k). Rehder and
Bartsch (1911), Rehder (1942, 1945), Winckworth
(1945) and Dodge (1957) subsequently discussed
prior designations of the type-species of
Nept tinea.

Cx)ssmann (1901, f)8) designated F(«».s despec-
(M.S (L.) as the type-species of Chrysodomus
[.sensu stricto]. His, Monterosato's, and Kobelt's
selections are those most often quoted in the
twentieth -century literature treating the type-
species of Neptunea. Of subsequent designations
noted in papers from that of Dall (1902) to
Nelson (1974), including Golikov (1963), Strauch
(1972) and Habe and Sato (1972), nine authors

cite N antiqua (L.), two ase N. despecta (L.) and
four employ A^. contraria (L.). All of the last cite
Monterosato as the subsequent designator. None
refer to Sandberger's selection, the only un-
eciuivocal subsequent designation of a type-species
of Neptunea Roding in the nineteenth-century
literature.

LITERATURE CITED

Bernardi. Felix Edouard. 18.58. Description d'especes

nciuvelles../ Om-httlwl. 7: 182-184. pi. V'll.
Cossmann, Alexandre Edouard Maurice. 1901. Es-^is de

paleoc()iwhol(jyie aimparec. 4: 1-293, pi. I-X.
Dall, William Healey. 1902. lllu.strations and descriptions of

new. unfigured or imperfectly known shells, chiefly

American, in the United States National Museum. Proc. I'.

S. Natl. A/!(.s-, 24: 499-.t66, pi. XXVII-XL.
Dall. William Healy. UHXi. Early history of the generic name

F».sHi-. ,/. Com-h. 11: 2<9-297.
Dall, William Healy. 1918. Notes on Chrysudomug and other

mollusks from the North Pacific Ocean. Proc. U. S. Natl.

.V/».s- 54: m-iM.
Dall. William Healy. 1919. Descriptions of new species of

Mollusca from the North Pacific Ocean in the collection of

the United States National Museum, [bid. 56: 293-:?71.
Dall, William Healy. 1922. Note on the genera Neptunea

and Stfncem. Proc. Malacal. Sue. London 15: 36.
Dodge, Henry. 19.57. A historical review of the mollusks of

Linnaeus. Part .5. The gen as Murex of the Class Gastropoda.

Bull. Anier Mm. Nat. Hint. 113: 77-2i4.
(labb. William More. 1869. Tertiary invertebrate fossils. Part

II Description of new species (c«ntinued). In Palaeontology

of Caltfonua. Geol. Surv. Calif. [Whitney] //.■ 39-63, pi.

14-18.
Gmelin, Johann Friedrich [ed.]. 1791. Vermes Testacea. In

Caroli a Linne Systema naturae per regna tria naturae...

Editio decima tertia. aucta, reformata. Lipsiae:

Rudolphipoli.Litteris Bergmanniaiiius./[V1]: S)21-3910.
Golikov. Alexandr Nikolaevich. 1963. Bryukhonogie molUiLtki

nida Neptimea Bilten. Fauna SSSR. Molliuski. V (1) [nov.

s?r..(85)]: 1-217. pi. I-XXVIII.
Gray. .John Edward. 1847. A list of the genera of Recent

Mollusca. their synonyma and types. Proc. Zool. Soc. London

h%7[lb\: 129-219.
Habe, Tadashige and Junko Sato. 1972. A classification of the

family Buceinidae from the North Pacific. Pitie Jap.

Soc.Syst.ZmiiS): 1-8, pi. 1-2
Hermann.sen. August Niciilaus. 1846-1847. Indicis generum

nialacoz<K)runi primordia. Nomina subgenerum. generum,

familiarum, tribuum. ordinum, dassium: adjectis auc-

toribus, temporibus, locis .systematicus atque literariis,

etymis, synonymis. Cassellis. Theodori Fischeri. /; xxvii -I-

l-fOT |pp. 2;«-360. 1 March 1847).
Iredale, Tom. 1921. Molluscan nomenclatorial problems and

solutions. No. II. Proc. Malacol. Soc. Loiulon 14: 198-208.
Iredale, Tom. 1922. A reply to the genera Neptunea and

Sifncera Ibid. 15: 37.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 141

Jeifreys. John Gwi,-!!, 1867. British conchnlogy, or an acrount
of the Mollusca which now inhabit the British Isle; and
the surrounding seas. Volume IV. Marine shells, in con-
tinuation of the Gastropoda as fer as the Bulla family, bin-
don. John Van Vorst: 1-486, pi. I-VIII.

Kobelt, Wilhelm. 1876. Beitrage zur Arctischen fauna. Jahrb.
Deutsch. Malakozool. Ges. 3: 61-76. 16.5-180, 371 -.37.3. pi. 2.

Lamard\. .Jean Baptiste Pierre Antoine de Monet de. 1799.
Prixlrome d'une nouvelle cIas.sification des coquilles cnmpre-
nant une redaction appropriee des caracteres generiques et
I'establissement d'un grand nombre des genres nouveaax,
. . . Mem. Soc. Hi':!. Nat. Pariit 1: 63-91.

Marty-n, Thomas. 1784. The universal conchologist. exhibiting
the figure of every known shell, accurately drawn, and
painted after nature: with a new systematic arrangement
by the author. . . [Half title: Figures of non descript shells,
collected in the different voyages to the South Seas since
the year 1764...] London 2: e.xplanatory table, fig. [pi.]
41-80.

Monterosato, Tommaso di Maria Aller>', Marchese di. 1872
Notizie intorno alle conchiglie fossili de Monte Pellegrino e
Ficarazzi. Palermo. Michele Amenta: 1-44.

Nelson, Clifford Melvin. 1974. Evolution of the late Cenozoic
gastropod Neptunea (Gastropoda: Buccinacea). Unpubl. doc-
toral dissert. Univ. California. Berkeley: 1-802, pi. 1-66.

Oldroyd, Thomas Shaw. 1925. The fossils of the lower San
Pedro fauna of the Nob Hill cut. San Pedro. California,
Prof. U. S. Nntl. Mux. 65: l-:39, pi. 1-2.

Rehder, Harald Alfred. 1942. TTie genotype of Neptunea. The
Nautitm 56: 69.

Rehder, Harald Alfred. 1945. A note on the Bolten Catalogue.
im. 59: 50-52.

Rehder, Harald Alfred and Paul Bartsch. 1941. The type of
Neptunea ■'Bolten" Rikiing. Ibid. 54: 125-12(;.

Rliding, Peter Friedrich. 1798. Museum Boltenianum sive
catalogus cimeliorum e tribas regtiis naturae quae olim col-
legerat. Pars secunda cuntieas conchylia sive testacea
univalvia, bivalvia et multivalvia. Hamburgi. Johan Christi
Trappii:vii -I- 1-199.

Sandberger, Carl Ludwig Fridolin. 1863 [1858-1863]. Die con-
chylien des Mainzer Tertiarbeckens. Wiesbaden. C. W.
Kreidel: 1-258 [+8], pi. l-a5 [Heft ,5-6, pp. 15.3-232, pi.
21-30, 1861, ./T* SchSndorf. 1907. 1,50].

Schbndorf, Friedrich. 1907. Verzeichnis der im Natur-
historisehen Museum zu Wiesbaden aufbewahrten
originale. Abteilung fur geologie und palaontologie. 1.
Originale zu Frid. Sandberger, Die konchylien des
Mainzer Tertiarbeckens. Jahrb. Nassau. Ver. Naturk. 60:
148-169.

Strauch. Friedrich. 1972. Phylogenese, adaptation und
migration einiger nordischer mariner molluskengenera
{Neptunea. Panomya. Cyrtodaria und Mya). Abhandl.
Senckenberg. Naturforsch. Ge.i. 531: 1-211, pi. 1-11.

Swainson. William. 1840. A treatise on malacology, or
shells and shellfish. London. Longman, Orme, Brown,
Green, and Longmans ... and John Taylor: viii -I-
1-419.

Winckworth, Ronald. 1934. Names of British Mollusca. II.
J. Com-h. 20: 9-15.

Winckworth, Ronald. 1945. The types of the Boltenian genera.

P)-nr. Mdijcol Soc. London).. 1.36-148.

NEW FRESH-WATER MUSSEL HOST RECORDS FOR THE LEECH
PLACOBDELLA MONTIFERA. WITH DISTRIBUTIONAL NOTES

IWary G. Curry

VTN Louisiana, Inc.

Engineers, Planners, Environmental Scientists

2701 Independence Street

Metairie, Louisiana 70002

and

Malcolm F. Vidrine

Gulf South Research Institute

P.O. Box 1177
New Iberia, Louisiana 70560

ABSTRACT

The leech Placobdella montifera Moiyre (Annelida: Hinuiinea: Gbssiphoniidae)
is reported for the first time fixmi the mantle cavities of eight species of fresh-
water mussels (Bivalvia: Ummidae): Anodonta grandis Say. Fusconaia undata
(Barnes). Glebula rotundata Lamarck. Lampsilis teres (Rafinesque), L. ovata
(Say). Obliquaria reflexa Rafinesque. Proptera purpurata (Lamarck) and
Quadrula pustulosa (Lea) Other specified molluscan hosts are unknoum for P.
montifera. Mussels and leeches were collected fi-om twelve localities in eight
parishes in the western half of Louisiana.

INTRODUCTION
Placobdella montifera Moore is an uncommon
species of leech about which very little is known

(Sawyer, 1972). Published distributional records
of P. montifera in the United States include
Georgia (Patrick et al.. 1966), Illinois (Moore,

142 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

1901 and 1906; Paloumpis and Starrett, IWO).
Indiana (Mfx)re, 1920), Iowa (Mathers, 191X:
Carlson, 1968), Kansas (Harms, 1959 and 1960),
Michijjan (V'errill, 1874; Miller, 1987), Minnesota
(Moore, 1912), Missouri (Meyer, 1937), Ohio
(Miller, 1929; Bangham, 1933) and Wisconsin
(Pearse, 1924; Bere, 1931; Sapkarev, 1968). In
Louisiana, the species was only recently reported,
from fresh-water habitats west of the At-
chafalaya River, where it was commonly en-
countered in leaf litter and on the undersurfaces
of cans, bottles, sticks, boards, and other
moderately smooth substrates (Curry, 1975).

Knowledge of relationships between fresh-
water leeches and fresh-water mussels is so
meager that any additional information giving
specific identifications and/or ecological and
distributional notes, is of considerable importance.
Relationships involving Flncuhdella rmmtifem and
various, unspecified mollusks were first observed
by Kelly (1902), who considered the relationship
unimportant. Clark and Wilson (1912) and Coker
et at. (1921) commonly encountered leeches in
mussels and suggested that the leeches were
eating the mucus secreted by the clams. Moore
(1912) observed that P. montifera habitually
entered the shells of mussels (unspecified), but
reported no feeding activities. Waffle (1963) sug-
gested that invertebrates are probably not the
usual food of P. numtifera. Fuller (1974) regular-
ly encountered P. montifera in the mantle
cavities of living mussels and suggested that
there is no host specificity and that there are no
clear advantages secured by the leech other than
"clandestine shelter."

According to Moore (1912), Miller (1929),
Sawyer (1972), and Fuller (1974),. Placohdella
montifera is known to attack aquatic worms,
snails, insect larvae, frogs, toads, turtles, fishes,
and mammals, in addition to mussels. Klemm
(1972) erroneously reported that Harms (1959 and
1960) took P. montifera from frogs, mussels, and
snails, however. Harms (1959 and 1960) rep<irted
the leech only from a single species of fish. The
only specified hosts recorded for Placobdella mon-
tifera are the fishes Lepi.sosteu.'t osseiia (Linnaeus)
(Ryerson, 1915; Hoffman, 1967), Acipenser
brevirostrum Lesueur (Hoffman, 1967; Pearse,
1924), Perca flavescens (Mitchell) (Bere, 1931),

Lepomis gitihoiiuii (Linnaeus) (Ryerson, 1915; Hoff-
man, 1967), Micriiptems salmoidea (Lacepede)
(Bangham, 193:3; Bangham and Hunter, 1939;
Hoffman, 1967), M. (iolamieui Lacepede (Pearse,
1924; Bangham, 1933; Bere, 1931; Hoffman, 1967),
Ictalunis melas (Rafinesque) (Hoffman, 1967;
Harms, 1959 and 1960), Scaphii-hi/nchu.'i jiatoryn-
chua (Rafinesque) (Pearse, 1924), Moxoatoma
anisunim (Rafinesque) (Hoffman, • 1967), and
Cuprinnf! rarpii) Linnaeus (Hoffman, 1967;
Pearse, 1924) and the turtle Strmothents
idnratun (Latreille) (Curry and Kennedy, 1975).

RESULTS AND DISCUSSION

Between May, 1973, and November, 1974, 28
adult and several young specimens of Placotxiella
montifera were recovered from the mantle
cavities of eight species of fresh-water clams
representing three subfamilies of unionids (tax-
onomy according to Ortmann 1910, 1911 and
1912): Anodontinae, Anodonta grandis Say;
Unioninae, Fusconaia undata (Barnes) and
Quadnda pustulosa (Lea); and Lampsilinae,
Glebula rotundata Lamarck, Lampsilis teres
(Rafinesque), L. ovata (Say), Obliquaria reflexa
Rafinesque and Proptera purpurata (Lamarck).
The host clams were collected from a lake in
southwestern Louisiana and /or from one or more
of 11 sluggish streams (bayous) from north cen-
tral to southwestern Louisiana. Approximately
2,300 clams were examined during this study.

The morphology of the leeches is identical to that
of free-living Placobdella montifera collected
from other southern Louisiana bayous. The mor-
phology is, also, consistent with that described by
Sawyer (1972) for the species. Relaxed leeches
ranged in length from 1.0 mm to 20.0 mm and
from less than 1.0 mm to 6.0 mm in width.

No leeches were observed feeding, and there
appeared to be no morphological specialization
for feeding. However, there may be a physi-
ological specialization which would indicate a
trophic rather than the presently suggested pro-
tective relationship. As in the cases of other sym-
biotic associations not fully understood, final ex-
planations must be preceded by careful feeding
observations and/or detailed digestive tract
analyses.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 143

No more than five adult leeches were found
within the mantle cavity of a single clam (Lamp-
sUis teres), although as many as 11 juveniles
(1.0-2.0 mm long) and one adult (9.0 mm long)
were ena)untered in a single clam (Glehula
mtundata). Fuller (1974) indicated that "although
leech populations can reach epidemic proportions,
these animals seem to pose no threat to mussels."

One specimen of Placobdella montifera oc-
curred with 12 water mites {Umonkola spp.,
Acarina: Trombidiformes: Unionicolidae) in Aru)-
donta grandis. P. montifera occurred with two
species of Unionicola. and the aspidogastrid
trematodes (Platyhelminthes: Trematoda: Aspido-
gastridae). Aspidogaster conchicola Baer and
Cotylaspis insignis Leidy, also, in two specimens
of Lampsilis teres. In one specimen of Proptera
piuimmta. 229 specimens of A. conchicola and 57
unionicolids (Unionicola spp.) occurred with P.
montifera. Unionicolids and aspidogastrid
trematodes are frequently encountered parasitiz-
ing freshwater clams in central and southwestern
Louisiana (Vidrine, 1973 and 1974).

Host records and collection data are as follow:
Lampsilis feres— Evangeline Parish: Bayou Mar-
ron at Louisiana Highway 95, 2 miles northwest
of Chataignier, southeast of Mamou (18 May
1973): Bayou des Cannes at La. Hwy. 10 (19 May
1973). Acadia Parish: Mamou Irrigation Canal at
La. Hwys. 97 and 368 junction (1 September
1973).

Lanip'iilis omta— Allen Parish: Calcasieu River,
10 mi. north of Oberlin (4 June 1973).
Glebula rotundata-St. Landry Parish: Bayou
Wauksha at La. Hwy. 10 (17 November 1973). St.
Martin Parish: Lake Palourde near Grassy Lake
(2.5 August 1973).

Anodonta grandis— AvoyeWes and Rapides
Parishes: parish line, Big Creek at La. Hwy. 115
(7 October 1973). Iberville Parish: Bayou Mar-
ingouin, 2 mi. south of Ramah (23 November
1974). Evangeline Parish: Bayou Grand Louis, La.
Hwys. 13 and 104 junction at Mamou (19 May
1973). Natchitoches Parish: Cane River at La.
Hwy. 1 near Derry (22 August 1974).
Qiuuirula pustidosa— Evangeline and St. Landry
Parishes: parish line. Bayou Grand Louis at U. S.
Hwy. 167 (4 July 1973).

Fmconaia undata—St. Landry Parish: Bayou
Carron at La. Hwy. 182 (17 November 1973).
Proptera purpurata— Evangeline Parish: Bayou
Marron at I^. Hwy. 95 (18 May 1973).
Obliijnaria /-e/Zexa— Natchitoches and Red River
Parishes: parish line, Bayou Pierre at La. Hwy.
174 (22 August 1974).

This study confirms the claim of Fuller (1974)
that there is no host specificity exhibited by
Placobdella montifera for clams. Although Fuller
(1974) indicated that the leech-clam relationship
is "more common in lentic situations", this in-
vestigation indicates that the leech (P.
m()ntifera)<\am relationship in Louisiana is more
frequently encountered in bayous (than in lakes),
which often maintain a steady, but slow, current
which increases significantly following periods of
intense rainfall, which are common in southern
Louisiana.

We suggest that, because leeches seek relative-
ly sm(X)th substrates, such as the exterior of a
clam shell, they are likely to haphazardly move
inside the shell while it is agape. This suggestion
seems to be supported by the infrequency (21 of
some 2,300 clams contained leeches) of the leech
(Placobdella montifera)-clam relationship in
Louisiana.

Voucher specimens of each species of clam
mentioned in this manuscript are on deposit in
the Delaware Museum of Natural History, Green-
ville, Delaware. The leeches are in the private col-
lection of the senior author in Metairie, Loui-
siana. The junior author collected and identified
the clams.

ACKNOWLEDGMENTS

We sincerely thank Dr. Nell Causey and Miss
Betty Everitt (Louisiana State University,
Department of Zoology and Physiology, Baton
Rouge) and Mr. Samuel Fuller (Academy of
Natural Sciences of Philadelphia, Department of
Limnology) for critically reviewing this
manuscript.

LITERATURE CITED

Bangham, R. V. 1933. Parasites on the spotted bass,
Micmptenis pseudaplite.'s Hubbs. and summary of parasites
of smallmouth. and largemouth black bass from Ohio
streams. Trans. Amer. Fish. S(x:.. 63: 220-228.

144 THE NAUTILUS

October 29. 1976

Vol. 90 (4)

Bangham, R. V. and C. W. Hunter, III. 19.39. Studies on fish

para.sites of Lake Erie. Distribution Studies. Zaolugica

{Ne7v Y,n-k). 24(27): 385-448.
Bere, R. 1931. Leeches from the laltes of northeastern Wiscon-
sin. Trans. Wisc.Acwl &-i.. 26: 437-440.
Carlson, C. A. 1968. Summer bottom fauna of the Mississippi

River above Dam 19. Keokuk. Iowa. Eadi^y. 49(1): 162-169.
Clark. H. W. and C. B. Wilson. 1912. The mussel fauna of the

Maumee River. Rep. U. S. Commercial Fish, for 1911 and

Spec. Papers pp. 1-72. Separately issued as U. S. Biir. Fish

Document No. 757.
Coker. R. E., A. F. Shira. H. W. Clark, and A. D. Howarf.

1921. Natural history and propagation of freshwater

mussels. Bull. U. S. Bureau Fisheries. 37: 77-181. Separate-
ly issued as Bur. Fvth. Document No. 893.
Curry, M. G. 197.5. A new leedi (Hirudinea: Glossiphoniidae)

for Louisiana with ecological notes. The ASB (Association

of Southeastern Biologists) A;//.. 22(2): 49.
Curry. M. (i. and W. G. Kennedy. -Jr. 197.5. Louisiana turtle

leeches with new host record. A-oc. La. Acatl. Sci.. 38: 124.
Fuller, S. L. H. 1974 Clams and mussels (Mollusca: Bivalvia).

h C. W. Hart. .Jr. and S. L. H. Fuller (editors). Pollution

KciiliHjy nf Frc.ih water Invertebrates. Academic Press. New

York and London.
Harms, C. E. 1959. Checklist of parasites from catfishes of

northeastern Kansas. TYaiK. Kan. Acad. Sci.. 62(4): 262.
Harms. C. E. 1960. Some parasites of catfishes from Kansas. ./.

Paranil . 46: 69.5-701
Hoffman, G L, 1967. Parasites of North American Fresh -

Water Fishes. University of California Press. Berkeley.

California.
Kelly. H. M. 1902. A statistical study of para.sites of the

Unionidae. Bull. UHnois State Lab. Natural History. 5:

399-418.
Klemm. D. .1. 197^ The leeches (Annelida: Hirudinea) of

Michigan. Mich. Academician. 4(4): 405-444.
Mathers. C. K. 1948. The leeches of the Okoboji region. Proc.

Iowa Acad. Sci. 55: 397-425.
Meyer. M. C. 1937. I<eeches of Southeastern Missouri. Ohio

J. Sa. 37: 248-^51.
Miller. J. A. 1929. The leeches of Ohio. Contrib. Franz

Theodore Stone Ub.. No. 2: 1-.38.
Miller, J. A. 1937. A study of the leeches of Michigan with key

to orders, sub-orders and specie. Ohio ,/. Sci.. 37(2): 85-i)0.
Moore, J. P. 1901. T^ie Hirudinea of Illinois. BuU. Rlinais

Stale Lab. Natural History. 5: 479-.517.
Moore, J. P. 1906. Hirudinea and Oligochaeta collected in the

Great Lakes region. Bdl U. S Bureau Fish.. 25(598):

1.53-172.
Moore, J. P. 1912 Classification of the Leeches of Minnesota.

In H. F. Nachtrieb (editor). The Leeches of Minnesota.

GeoUigical and Natural History Survey of Minn.. Zool.

Series. No. V. Pt. III. pp. 63-150.
Moore. J. P. 1920 The Leeches. Lake Maxinkuckee, a physical

and biological sun'ey . Indiana Dept. Conserv.. 2: 87-96.
Ortmann. A E. 1910. The discharge of the glochidia in the

Unionidae. Nautihijt. 24: 94-95
Ortmann. A. E 1911. A monograph of the najades of-

Pennsylvania. Mem. Carnegie Mus., 4: 279-347.
Ortmann, A. E. 1912. Notes upon the families and genera of

the najades. ^nri. Carnegie Mus.. 8: 222-365.
Paloumpis, A. A. and W. C. Starrett. 1960. An ecological

study of benthic organisms in three Illinois River

Floodplain lakes. Am. Midi Nat. 64(2): 406-435.
Patrick. R.. .1. Cairns. Jr.. and S. S. Roback. 1966. An

ecosystematic study of the fauna and flora of the Savannah

River. Pi-oc Acad. Nat. Sci. Pi.. 118(5): 109-407.
Pearse, A. S. 1924. The parasites of lake fishes TVan.s. Wi<<c.

Aaid. Sci.. Arts and Letters. 24: 161-194.
Ryerson, C. G. S. 1915. Notes on the Hirudinea of (Georgian

Bay. Contrib. Canadian Biol.. 2: 165-175.

Sapkarev, J. A. 1968. The taxonomy and ecology of leeches
(Hirudinea) of Lake Mendota. Wisconsin. Tratis. Wife.
Acad. Sci.. A rts and Letters. 56: 225-2.5.3.

Sawyer. R. T. 1972 North American Freshwater Leeches. Ex-
clusive of the Piscioolidae. with a Key to All Species.
Illinois Biol. Monogr. 46.

Verrill. A. E. 1874. Synopsis of the North American
Fresh-water leeches. i?pp. U. S. CMnmercial Fish.. 73: 666-
689.

Vidrine. M. F. 1973. Freshwater mussels (Bivalvia: Union-
idae) from Evangeline Parish. Louisiana, parasitized by
water mites (Acarina: Trombidiformes. Unionicolidae)
and aspidogastrid trematodes (Trematoda: Aspidogaster-
idae). Proc. La. Acad. Sci.. 36: .53.

Vidrine. M. F. 1974 Aspidogastrid Trematodes and Acarine
Para.sites of Freshwater Qams in South Central and
Southwestern Louisiana. M. S. Thesis. Ijouisiana State
University. Baton Rouge. La.

Waffle. E. L. 196.3 An Ecological Study of the Iowa
Glossiphoniidae (Annelida: Hirudinea) with Emphasis on
Feeding and Reproductive Habits. M. S Thesis. Iowa State
University. Ames. Iowa.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 145

EUBRANCHIJS TRICOLOR FORBES IN THE WESTERN ATLANTIC

Brian R. Rivest and Larry G. Harris

Department of Zoology

University of New Hampshire

Durham, New Hampshire 03824

ABSTRACT

The aeolid muiibranch Eubranchus tricolor Forbes, 1838. is reported for the
first time in the western Atlantic. Specimens have been collected from the
northern Gvlf of Maine. The morphology and ecology of E. tricolor are dis-
cussed and related to information available on several other Eubranchus species.

INTRODUCTION

Eubranchus tricolor was originally described
by Forbes (1838) from a specimen dredged from
20 fathoms off Ballough, England, and has been
reported a number of times from around Great
Britain (Adler and Hancock, 1945; Jeffries, 1869;
Garstang, 1890; Colgan, 1914; Miller, 1961;
Edmunds and Kress, 1969). It has also been col-
lected from the North Sea (Walton, 1908), the
western coast of Norway (Friele and Hansen,
1876; Sars, 1878), the White Sea (Roginskaya,
1962) and the northern coast of France
(Vayssiere, 1913). Edmunds and Kress (1969)
listed the reported occurrences of Eubranchiis
tricolor and its synonyms in their paper on the
European species of Eubranchus. They discussed
the problems earlier workers had in clarifying
the taxonomic status of closely related species.
Their careful description of E. tricolor clearly
distinguishes it from two similar species, E.
pallidus (Alder and Hancock, 1842) and E. farrani
(Alder and Hancock, 1844).

The ecology of Eubmnchus tricolor is poorly
known. In European waters E. tricolor has been
collected in the shallow subtidal (Garstang, 1890)
and to a depth of 50 to 100 fathoms (Walton,
1908). In summarizing depth distribution records,
Edmunds and Kress (1969) stated that E. tricolor
is most commonly found offshore from depths of
16 to 60 m on shell gravel and stony deposits.
Garstang (1890) reported finding E. tricolor on
the hydroid Obelia genicidata (Linnaeus, 1758),
although as Edmunds and Kress (1969) pointed
out, Garstang did not distinguish E. farrani from
E. tricolor. Miller (1961) concluded that E.

tricolor feeds on hydroids because it was found in
dredge hauls along with Tubulaiia indii'isa
Linnaeus, 1767, Abietinaria abietina (Linnaeus,
1758), Hydrallmania falcata (Linnaeus, 1758), and
Nemertesia antennina (Linnaeus, 1767).

Gosner (1971) listed Eubranchus tricolor as oc-
curring along the eastern coast of the United
States. He was actually referring to the E.
pallidus reported in New England waters by
Gould and Binney (1870), Johnson (1915, 1934)
and Moore (1964), but based his classification of
E. tricolor on the systematic scheme used by
Pruvot-Fol (1954) who listed E. pallidus as being
a variety of E. tricolor (Gosner, 1974, personal
communication). Edmunds and Kress (1969),
however, considered E. pallidus to be a separate
species. Four specimens of E. tricolor recently
have been collected intertidally and subtidally in
the vicinity of Eastport, Maine, and the purpose
of this note is to report information obtained
from these specimens.

MORPHOLOGICAL OBSERVATIONS

The morphology of the four specimens collected
was consistent with that described tor Eubranchus
tricolor by Edmunds and Kress (1969). The body
was translucent white to greyish white in color.
The relatively numerous cerata were arranged in
indistinct clusters, and were of the same color as
the body. There were 52 cerata in a 6 mm
specimen and 86 cerata in a 19 mm specimen.
The larger cerata were inflated and anterior-
posteriorly compressed. A band of white pigmen-
tation surrounded the region of the cnidosacs.
Ti\e liver diverticula were smooth and cylindrical

146 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

FIG. 1. Chmera lucuia drawings of a jaw and its masticatory
margin of Eubranchus tricolor. Scale equals 0.1 mm.

and appeared reddish-brown in color, Tlie
acleioproctic anus was in the interhepatic space
to the right and just posterior to the heart.

The large jaws possessed a single row of
distinct denticles on the projecting masticatory
border (Figure 1). The triseriate radulae con-
tained 49 rows in a 7 mm specimen and 64 rows
in a 17 mm animal. The rachidian tooth had a
prominent central cusp and 3 to 4 denticles along
each side (Figure 2). The broad lateral teeth had
a sharply pointed cusp, and a width to height
ratio of almost 2.5:1.

The gonopore was found on the right side ven-
tral to the middle of the first cluster of cerata.
The reproductive systems of two specimens were
dissected, and neither contained a penial stylet.
Euhrnnchn.^ farrnni and E. pallidus possess a
penial stylet whereas the penis of E tyicohr is
unarmed (Edmunds and Kress, 1969). A single
egg ribbon was deposited in the laboratory in a
counterclockwise coil. It was a tall collar very
similar to that pictured for E. farrani by Alder
and Hancock (1845).

ECOLOGICAL OBSERVATIONS

On May 5, 1973 a specimen of Eubranchus
trwolor 19 mm in length was collected using
SCUBA at 15 m about 20() m south of the
breakwater in Eastport, Maine (44° 54' N 66° 59'
W). The bottom in this area consisted of small
rock and cobble with occasional protruding rock
ledges. The area was heavily grazed by the sea
urchin Strongylocenirotus droebachiensi^ (Miiller,
1776) and was relatively devoid of algae except
for a)nspicuous clumps of red algae on the larger
rocks and ledges. These clumps contained several

hydroid species, the most obvious being Tubularia
spectabilis (Agassiz, 1862). This specimen of E
tricolor was collected near the base of one of
these clumps. The nudibranch was maintained in
a recirculating sea water system at the Univer-
sity of New Hampshire where it was observed
feeding on T. spectabiiis. No other hydroids were
offered to the nudibranch.

Two other specimens of E tricolor have subse-
quently been collected from the same area in
Eastport. A nudibranch 17 mm long was collected
on June 2, 1973 at a depth of 12 m. This in-
dividual was crawling over the cobble bottom
apart from any large clumps of hydroids. On
November 1, 1974 a third individual 7 mm long
was found at about 15 m near a clump of
Abietinariasp.

A single individual 6 mm in length was col-
lected at Wilbur's Neck in Dennys Bay, Maine
(44° 53' N 67° 9' W) from a large deep tidepool
near the low tide mark on a blade of the brown
alga Laminaria saccharina (Linnaeus)
Lamouroux. The dominant hydroid in this tide
pool was Lh/namena (Sertularia) pumila (Lin-
naeus, 1758) growing on Ascophyllum nodosum
(Linnaeus) LeJolis.

The two smaller individuals were collected in
the fall and the others in the spring and early
summer, suggesting that Eubranchus tricolor
may have an annual life cycle. Miller (1962),
however, felt that E. tricolor had two or more
generations per year but with a life span of 8-12
months.

Eubranchus tricolor has not been observed
along the New Hampshire-southern Maine
coastline despite extensive observations in these
areas. Two other species of Eubranchus are found
in New England waters, E pallidus and E
eriguus (Alder and Hancock, 1848) (Moore, 1964;
and personal observations). Meyer (1971) reported
finding Eubranchus olivaceus (O'Donoghue, 1922)

FIG. 2. Camera lurida drawings of a rachidian and lateral
tooth o/ Eubranchus trirolor. Scale eqiwls 0.05 mm.

Vol. 90 (4)

October 29. 1976

THE NAUTILUS 147

in Maine waters, a nudibranch previously
reported only from the West Cbast of North
America. Her description of K olivaceus fits that
of E. exiyuKS given by Edmunds and Kress (1969).
It is likely that she had found E exigmis and not
E olivaceus.

A specimen cf E. tricolor has been deposited at
the Museum of Comparative Zoology, Harvard
University, Cambridge, Massichusetts.

ACKNOWLEDGEMENTS

We would like to express our appreciation to
Terrence M. Gosliner, Frank Perron and Alan M.
Kuzirian for their assistance in searching for
Eubranchus tf'icolor, and to Mary -Jane Rivest
and Claudia Foret for their assistance in the
preparation of the manuscript.

LITERATURE CITED

Alder. J. and A. Hancock. 1845-1855. A monograph of the

British nudibranchiate Mollusca, with figures of all the

species. London. Ray See. parts, 1-7: 438 pp.
Q)lgan. N. 1914. The opisthobranch fauna of the shores and

shallow waters of County Dublin. Irish Nat. Jmim. 23:

161 -2(M.
Edmunds. M. and A. Kress. 1969. On the European species of

Eubranchus (Mollusca Opisthobranchia). Jour. Mar. Biol.

Ass. U.K. 49: 879-912.
Forbes. E. 1838. Malacologia Monensis, a catalogue of the

Mollusca inhabiting the Isle of Maine and the neighboring

sea. 63 pp.
Friele, H. and G. A. Hansen. 1876 for 1875. Bidrag til

Kundskaben om de Norske nudibranchier. Vidensk. Selsk,

Forhamtl..p.e9-90.
Garstang, W. 1890. A complete list of the opisthobranchiate

Mollusca found at Plymouth; with further observations on

their morphology, colours and natural history. Jour. Mar.
Bud. Ass. N.S. 1: 399-457.

Gosner, K. L, 1971. Guide to Identification of Marine and
Estuarine Invertebrates, Cape Hatteras to the Bay of
Fundy. Wiley -Inter-Science, New York. 693 pp.

Gould, A. A., and W. G. Binney. 1870. Report on the In-
vertebrates of Massachusetts. Second ed. Wright and Potter,
Boston.. 524 pp.

Jeffries, J. G. 1869. British Conchology or an account of the
Mollusca which now inhabit the British Isles and the .sur-
rounding seas. 5: 1-258.

Johnson, C. W. 1915 Fauna of New England. 13 List of the
Mollusca. Occ. Fhp. Boston Soc. Nat. Hist. 1: 1-231.

Johnson, C. W. 1934 List of marine Mollusca of the Atlantic
roast from Labrador to Texas. Proc. Boston Soc. Nat. Hi'it.
40(1): 1-204.

Meyer, K. B. 1971. Distribution and zoogeography of fourteen
species of nudibranchs of northern New England and Nova
Scotia. Veliger 14(2): 137-152.

Miller. M. C. 1961. Distribution and food of the nudibranch-
iate Mollusca of the south of the Isle of Man. Jour. Arum.
&o/. 30(1): 95-116.

Miller, M. C. 1962 Annual cycles of some Manx nudibranchs,
with a discussion of the problems of migration. Jour. Anim.
&0/. 31(3): 54.5-569.

Moore, G. M. 1964. Phyllum Mollusca, shell-less Opisthobran-
chia. (in) Keys to marine invertebrates of the Woods Hole
R^ion. Mar. Bio. Lab. Woods Hole. p. 153-164.

Pruvot-Fol, A. 19.54 Mollusques Opisthobranches. Faune de
Prance. Paris. 58: 1-460.

Roginskaya, I. S. 1962. The nudibranchiate mollusks of the
White Sea in the region of the Biological station of M.G.U.
(in) Biology of the White Sea. Moscow U., Belam. Biol.
Slant. MGU. Biol. Belogo Maria I: 88-108.

Sars, G. 0. 1878. Bidrag til Kundskaben om Norges Arktiske
faune. I. Mollusca Regionis Arcticae Norvegiae. 466 pp.

Vayssiere, A. 1913. Mollusques de la France et des regions
voisines. Octave Doins et i51s. 420 pp.

Walton, C. L. 1908. Nudibranchiata collected in the North Sea
by the S.S. "Huxley" during July and August, 1907. Jour.
Mar Biol. Ass. U.K. 8: 227-240.

148 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

WILLIAM SEWARD TEA TOR (1860-1930)

Helen M. Garlinghouse

Red Hook, New York

It was through our Red Hook Bicentennial
Committee that I heard of William S. Teator.
Many of the land and freshwater snails that he
collected locally had been stored in one of the
Red Hook schools. They were turned over to the
Gjmmittee as being of possible interest because
he was a native. Since there was no one with any
interest in shells but myself, I have had the ex-
citing privilege of examining them, reading his
fascinating collecting notes made during 1890,
perusing letters he received and speaking with
folks who knew him.

William Seward Teator was bom in Upper Red
Hook, New York on April 28, 1860. He was
named for William H. Seward because of his
family's strong Republican leanings. He grew up
on a farm and must have, at an early age,
become aware of all the various manifestations of
life about him. He knew the names of the trees,
wild flowers, birds, the kinds of soil and rocks
with which he came in rontact. He was full of
wonder with the ways of nature. In his notes of
June 5, 1890, he says, "In Almont Woods myriads
of snails in all stages of development— two or
three very sultry and rainy days have sent them
all out doors—and on each log are 15 to 50
perfect specimens— wonderful where they all
come from!" On June 20, 1890 he writes, "I
planted 28 specimens of Helix clansa [Mesodon
clausus (Say)] in Almont Woods sent me from
Connersville, Indiana by Thos. F. Curry— they
were young, vigorous snails. I placed them
alongside of some old rails of a decaying fence-
some old logs near by and a thick growth of
weeds— Solomon's seal, sassafras and blood root
and sweet cicely." On July 26, 1890 he visited a
region north of Elizaville on the Roeliff Jansen
Kill. He puts in his notes, ". . . discovered a colony
of Helix fuliginosus fMesomphix cupreus Raf-
inesque/ the most flourishing I have ever met
with— obtained 40 perfect and very pretty ex-
amples alive— did not take immature shells. The
locality is a steep wooded hillside with gravel,

debris of the glacial era, well covered with small
stones and years accumulations of litter from
trees, oak, elm, ash, hemlock etc. The place where
the snails are most abundant is a small section of
a terraced slope that a little further along forms
the bank of the river, also found some palliata
[Triodopsis notata Deshayes/ and concava
[Haplotrema concavum Say/ and alternata
[Anguispira alternata Say7 and tridentata
fTtiodopsit tridentata Say/"

In his early manhood he became private to
General J. Watts de Peyster of Tivoli, New York.
General de Peyster (1821-1884) was an Honorary
Fellow of the Society of Science, Letters and
Arts of London, 1893, and a well-known author
on Swedish -American history. He was awarded
their Gold Medal of 1894 "for Scientific and
Literary Attainments." The general took a keen
interest in Teator. In 1889 he wrote to Major

FIG. 1. William Svwani Tratnr (\m) i;«()). a formal por-
trait taken about 189t).

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 149

**■■

^#*-'

View of the Catskiu. Mountains from the Heights East of Upper Red Hook, Drawn bv William S. Teator.

EXECUTtO BT n. 1 ENQDAVIhO CO. ron GENEftltL J WATTS DE PETITER.

General John H. Ketcham and in 1890 to M.
Saunders, United States Senator from Montana,
to ask their help and influence in obtaining a
position for Teator "in the Government employ
to do work in connection with explorations which
requires drawing and Commitment to paper. He
is a fine looking fellow, healthy, strong, active,
enured to toil. He would repay the Government
by service far beyond any meager salary that the
Government pays its servants ..." I have found
no evidence that these efforts ever succeeded.

We do know that Mr. Teator's own efforts did
succeed. When he took over the old homestead he,
through painstaking cultivation, became a very
respected farmer. He shared his knowledge with
others by describing his methods. He became an
apple orchardist who won many blue ribbons
here and abroad. The Rural New Yorker of Oc-
tober 18, 1930, says in part, "To him the tree was
more than a stock of wood with branches and
leaves— a means to an end. It was a living.

breathing, sensitive thing that could appreciate
a kindness and feel a hurt." This statement of
Burton Coon's can be expanded to encompass all
the living things with which Teator came in con-
tact. Like the true naturalist he was, he respected
all life and admired and was aware of even the
most minute of the biota.

Teator published three articles on land and
freshwater shells of New York in The Nautilus
(all in volume 3, 1889-1890). He was an ac-
complished artist and the accompanying sketch
by him shows the areas where he collected (about
1890.) His main collection of mollusks will be
housed in the Delaware Museum of Natural
History.

He passed away on August 17, 1930. In the
70 years of a life of active and time-consuming
farming, he found time to stop, look and listen.
He left us a legacy consisting of a very carefully
labeled collection of all the land and freshwater
mollusks to be found in his collecting vicinity.

150 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

ABNORMAL SHELLS OF GYRAULUS PARVUS (PLANORBIDAE)

Douglas G. Smith

Museum of Zoology, University of Massachusetts
Amherst, Massachusetts 01002

ABSTRACT

7\('o similar, malformed shells of Gyraulus parvus (Say) are reported from the
Connecticut River system in Massachusetts. Each has a prolonged body whorl that
is extended obliquely downward, terminating beneath itself. A species described by
F. C. Baker (1932) approaches the above but a paratope examined by Clarke (1973)
was determined to be a repaired specimen. Present specimens do not show repair,
suggesting mutational or pathogenetic growth.

Shell abnormality in gastropods is a rarely
observed phenomenon as indicated by the scarcity
of literature citations. Instances mentioned
usually involve regeneration or the occurrence of
oppositely coiled specimens.

Recent intensive surveying of the aquatic
mollusks in the central Connecticut River water-
shed has yielded two malformed but similar
specimens of Gyraulus paribus. Both were col-
lected in Massachusetts, the first on 18 June 1973

FIG. 1. Two deformed Gyraulus parvus (Say) from Hamp-
shire County, Massachusells.

in the Mill River, Hampshire Co., Williamsburg
(Fig. la), and the second on 19 May 1975 in the
Connecticut River Oxbow, Hampshire Co.,
Northampton (Fig. lb). Each specimen is
characterized by a continuation of the body whorl
downward and beneath itself. TTie subsequent
prolongation of the body whorl presents a stacked
appearance when viewed frontally (Fig. 1).

F. C. Baker (1932:9) based his description of G.
latistomus on the abrupt downward deflection of
the apertural region, suggestive of the condition
occurring in present specimens. However Clarke
(1973:403), after examining a paratype of Baker's
species, considered the deflected aperture to be
the result of repaired damage. The Connecticut
River shells show no evidence of repair indicating
a pathogenetic or mutational growth. The
specimens are deposited in the Museum of
Zoology, University of Massachusetts at Amherst.

LITERATURE CITED

Baker. F. C. 1932. New species and varieties of Helisoma and
Gyraulus from Canada. The Nautihis. 46: 6-9.

Clarke, A. 1973. The freshwater Mollusca of the Canadian In-
terior Basin. Afo/acofojia, 12(1-2): 1-509.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 151

SINISTRAL SPECIMENS OF OLIVELLA. PRUNUM. AND GRANULINA
FROM THE PLIOCENE OF VIRGINIA AND NORTH CAROLINA

Lyle D. and Sarah C. Campbell

University of South Carolina
Columbia, South Carolina 29208

In the course of the 1974 summer field season
we discovered sinistral specimens of Olii-ella
mutica (Say, 1822), Prunum helium (Conrad,
1868), (one specimen each), and Granulina amian-
tuln (Dall, 1890) (two specimens), from Pliocene
deposits in North Carolina and Virginia. We
believe this is the first such record for each
species and the first report of sinistral ab-
normalities in the American Tertiary.

Our specimen of Olivella mutica measures 7.0
mm in height, 3.2 mm in width, and has an aper-
ture height of 4.2 mm. The specimen is unbroken,
retains a hi^i gloss, and has a faint spiral color
band on the body whorl. The specimen was
discovered on spoil piles from the marina under
construction by Carolina Shores, Incorporated,
near Calabash, North Carolina. Age of the
specimen is upper Pliocene (Waccamaw Forma-
tion).

Our specimen of Prunum helium measures 6.1
mm in height, 2.9 mm in width, and has an aper-
ture height of 4.8 mm. It is juvenile and the lip is
somewhat chipped, but otherwise preservation is
quite good. The specimen was discovered in place

in the lowest bed exposed at Carolina Shores, In-
corporated (see above).

Our figured specimen of Granulina amiantula
measures 2.8 mm in height, 1.8 mm in width, and
has an aperture height of 2.5 mm. The second
specimen measures slightly larger. Both were
found in place in the Lone Star Cement Company
pits north of Chuckatuck, Virginia, (uppermost
bed, west wall). Age of the specimens is Middle
Pliocene (upper Yorktown Formation).

Dautzenberg (1914: 58) reported one recent and
two fossil Olivella species, all European, for
which sinistral specimens had been discovered.
However, we have been able to discover no subse-
quent sinistral records for the genus.

FIG. 1. Olivella mutica from Calabash, North Carolitia. Left.
Dextral .specimen, 6.5 mm in height. Right. Sinistral speci-
men. 7.0 mm in height.

FIG. 2. Granulina amiantula from Oiuckatuck, Virginia.
Left. Sinistral specimen, 2.8 mm in height. Right. Dextral
specimen, 3.1 mm in height.

Dautzenberg (1914: 58) cited fourteen recent
and three fossil species of Marginella for which
sinistral individuals had been discovered. Many
of these species have subsequently been assigned
to other genera within the Marginellidae. The
specimens described here thus become the second
species of Prunum and Granulina to be reported
sinistral, the first being P. apicina (Menke, 1828)
from the recent of North Carolina to the Carib-
bean, and G. dandestina (Brocchi, 1814) from the

152 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

FIG. 3. Prunum bellum /n;Hi ColatKLth. Naiili Canil ma. Left.
Dextral (utult. S.i mw in height. Middle. Sini.<<lral juvenile,
ti.l mm in heiijht. Riijhl. Dextnd juvenile. K..i mm in height.

Mediterranean (Dautzenberg, op. cit.). Consider-
ing the propensity of margineliids to generate
sinistral individuals, our new records are not sur-
prising. Sinistral specimens of P. apirinn are not
una)mmon, and sinistral Gmmilina, though ex-
ceedingly rare, are undoubtedly overlooked due to
their small size. The figured specimens are in the
author's collection.

LITERATURE CITED

Dautzenberg, P. 1914 . Sinistrosities et dextrosities terato-
logiques chez les moUusques gasteropods. Hidl. Sue. Z<Hd. de
la France 39: .50-59.

LAND SNAILS FROM MONITO ISLAND, WEST INDIES

Fred G. Thompson

Florida State Museum

University of Florida

Gainesville, Florida 32611

Monito Island is a small limestone island ap-
proximately a half square kilometer in area
and adjacent to Mona Island in the Mona
Passage between Hispaniola and Puerto Rico.
Monito lies about 5 km northwest of Mona and
the two islands are separated by a depth of
only about 240 m. Monito is bordered on all
sides by precipitous cliffs which rise 35 m or
more above the surrounding sea and is virtually
accessible only by helicopter. The ground sur-
fece is rugged and pitted and is covered with
xeric scrub vegetation that seldom exceeds 2 m
in height. Because of the proximity of Monito
to Mona I anticipated prior to my visit that the
land snail fauna of the two islands would be
similar (for a report on the land snails of Mona
Island see W. J. Clench, 1951, Journal de Con-
chyliologie, 90: 269-276).

On May 20, 1974, through the courtesy of the
United States Coast Guard, I had the op-
portunity to visit Monito for 24 hours, during

which time I devoted nearly all of my attention
to collecting mollusks, reptiles and amphibians.
The following land snails were collected, and
are deposited in the Florida State Museum.

Lucidella umbonata (Shuttleworth )
Gastrocopta pellucida (Pfeiffer)
Hojeda inaguensis (Shuttleworth)

It is particularly noteworthy that larger
species of land snails were not found. Six other
genera, Cerion, Drymaeus. Brnchypodella,
Hrniifnirhits. Plaijioptychn and (''h<ni(idn)p(ima,
were anticipated but there was no evidence of
these on the island, not even dead shells or
fragments. The six genera not enaiuntered are
entities that would be expected on the island for
biogeographic reasons. They occur on other small
islands in the area. The island is ecologically
suitable for them. The island is close to other
islands which could serve as founder sources, and
the island is in the center of a hurricane tract.

Vol. 90 (4)

October 29, 1976

THE NAUTILUS 153

which almost guarantees adventitious dispersal of
some land snails.

Members of these six genera are non-secretive.
They are active on exposed surfaces and they
aestivate on exposed plants and rocks. I postulate
that their absence is due to predation by in-
troduced rats. The island is infested with Rattus

mtfus. which readily devours land snails in other
places where this rodent occurs. (Most of the
specimens of L. umhwmta found were gnawed
shells.) I suspect that the absence of the larger
land snails on Monito Island is a consequence of
rat predation and is not a reflection of an
originally prehuman depauperate fauna.

NOTICES

1977 Amsterdam Meeting

The Sixth European Malacological Congress of
the UNITAS MALACOLOGICA EUROPAEA
will be held in the week 15-20 August, 1977, in
the Fi-ee University, Amsterdam. Under the
auspices of Dr. Vera Fretter (U.K.), Dr. A. Riedel
(Poland), Dr. K. M. Wilbur (U.S.A.), Dr. J. Lever
and Dr. C. P. Raven (both from the Netherlands).
All malacologists, whether in a professional
capacity or not, are invited to attend the Am-
sterdam congress. For further information write
to Sixth European Malacological Congress, '^/o
Congresbureau van de Vrije Universiteit, De
Ifeelelaan 1105, Amsterdam, Holland.

W.S.M. 1977 Meeting

The tenth annual meeting of the Western
Society of Malacologists will be held June 15 to
June 18, 1977, at Kellogg West, Center For Con-
tinuing Education, California State Polytechnic
University, Pomona, California. Inquiries about
the meeting should be directed to Mrs. Jo Ram-
saran, Secretaiy, 807 North Road, San Ber-
nardino, Ca. 92404.

PUBUCATIONS RECEIVED

Paraense, W. Lobato. 1975. &tado Atual da Sistematica dos
Planorbideos Brasileiros. Arg. Mus. Nac. RJ, vol. 55. pp.
10.5-128, 69 figs. Anatxjmy and shells well-illustrated.

Abbott. R. Tucker (Editor). April 1976. The Best of The Nau-
tilus. A Bicentennial Anthology of American Conchology.
viii + 280 pp., 1 color pi., text figs. American Malacolo-
gists. Publishers, Box 4208, Greenville, De. 19807. Hardback,
$1.3.95 Presentation copy with slip box, $38.00.

Hastings, Louise B. 1976. Index to the Taxonomic Names in
EMwin A. Joyce, Jr., 1972. A partial Bibliography of Oys-
ters, with Annotations. Florida Dept. Natural Resjurces.
St. Petersburg. Pamphlet. 40 pp. Available from Delaware
Museum of Natural History, Box 3937, Greenville, De.
19807, by sending 3 13-cent postage stamps.

Quayle. D. B 1975. Tropical (3yster Culture- A Selected Bib-
liography. 40 pp. (267 entries). International Development
Research Cents', Box 8500, Ottawa, Canada KIG 3H9.
$2.50.

Gasull. Luis and Juan Cuerda. 1974. Malaoologia del Conten-
ido Gastrico de las Grandes Estrellas de Mar. Bol. Soc. Hist.

Nat. Baleares, vol. 19, pp. 1.55-173. 3 pis.

FVanchini. Dario A. (Editor). 1976. Simposio sui molluschi
terrestri e dulcicoli dell' Italia Settentrionale. Mantova.
102 pp., 9 pis., text figs. 11 articles on such mollusks as
Cinijidifera. Ancyliis. iMtietia. Palmiilhiitpsis andDreis-
seiui.

Tchang. Si, et al. 1975. A Checklist of Prosobranchiate Gastro-
pods from the Xisha Islands. Guangdong Province, China.
Studia Marina Sinica. no. 10 pp. 105-1.32. 7 pis. (7 Nan-Hai
Rd., Tsingtao. People's Republic of China).

Bandel Klaus. 1976. Morphologie der Gelege und Okologische
Beobachtungen an Buccinaceen (Gastropoda) aus der Siid-
lichen Karibischen See. Bonn. Zool. Beitr., vol. 27, pp. 98-
133. Also treats with fasciolariid and turbinellid egg cap-
sules.

Hubendick. B. and A. Waren. 1976. Framgalade Srackor fran
Svenska Vastkusten. Collection of 7 articles on the marine
prosobranchs of Sweden. Excellent illustrations in this
useful handbook originally published 1969-1976. Box 11049,
Naturhist, Mus.. Goteborg. Sweden 40030. 25 kronors.

154 THE NAUTILUS

October 29, 1976

Vol. 90 (4)

We regret to announce the death of Allyn G.
Smith. August 18, 1976, at the age of 83, in
California. An obituary will appear in a later
issue. He is survived by his wife, Isabel. 722
Santa Barbara Rd., Berkeley, Ca. 94707. to whom
sympathies are extended.

SUBSCRIPTION RATES

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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.

The Delaware Museum of Natural History

has extensive modern facilities and equipment
for the housing and curating of voucher
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the identification, locality data and its
bibliographic reference. There is no charge for
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1881

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