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Full text of "The Nautilus"

JANUARY 1974 



THE 



NAUTILUS 



Vol. 88 
No. 1 




A quarterly 

devoted to 

malacology and 

the interests of 

conchologists 



Founded 1 889 by Henry A. Pilsbry. Continued by H. Burrington Baker. 
Editors: R. Tucker Abbott and Charles B. Wurtz 



EDITORIAL COMMITTEE 



CONSULTING EDITORS 



Dr. Arthur H. Clarke, Jr. 
Department of Mollusks 
National Museum of Canada 
Ottawa, Ontario, Canada KIA-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 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 
1 Rickenbacker Causeway 
Miami, Florida 33149 



EDITORS 



Dr. R. Tucker Abbott 

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



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



Mrs. Horace B. Baker 

Business and Subscription Manager 

1 1 Chelten Road 

Havertown, Pennsylvania 19083 



OFFICE OF PUBLICATION 

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THE 
NAUTILUS 

Volume 88, number 1 — January 1974 

CONTENTS 

Kenneth D. Rose 

The Rehgious Use of Turbinella pyrum (Linnaeus), the Indian Chank 1 

Lowell L. Getz 

Species Diversity of Terrestrial Snails in the Great Smoky Mountains 6 

Hal Lewis 

A New Species of Hawaiian Gyrineum (Cymatiidae) 10 

Richard Houbrick 

Growth Studies on the Genus Cerithium (Gastropoda: Prosobranchia) 

with Notes on Ecology and Microhabitats 14 

Morris K. Jacobson and William E. Old, Jr. 

On a Sinistral Specimen oiLiguus virgineus (with Additional Remarks 

on the Genus Liguus) ^° 

Edward M. Stern 

The Chromosome Number of Euglandina rosea (Stylommatophora: Oleacinidae) 29 

Book Reviews 

(of) American Malacologists, 27; A. Gordon Melvin, 30; Publications Received ii 

INDEX TO THE NAUTILUS 

An index to The Nautilus, both author volume 90 in early 1977. It will cover 

and subject matter, will appear every five volumes 86 through 90 (1972-76). An 

years. The first index to cover the new format accumulative index is tentatively planned in 

will be issued separately at the completion of 1986 to cover volumes 61 through 100. 

i 



STATEMENT OF OWNERSHIP, MANAGEMENT AND 
CIRCULATION (Required by) Act of October 23, 1962: 
Section 4396. Title 39. United States Code, and postal 
regulation 132-622. 

1. Title of publication: THE NAUTILUS. 

2. Date of filing, September 25, 1973 

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 or General Business 
Offices of the Publishers: Delaware Museum of Natural 
History, Kennett Pike, Box 3937, Greenville, De. 19807. 

6. Names and addresses of publisher, editor, and managing 
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, 11 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. 
Extent and Nature of Circulation: 

Average 
12 Mos. 
Total No. Copies Printed (Net Press Run) 1,000 
Paid Circulation 

1. Sales through dealers and carriers, 
street vendors and counter sales 

2. Mail subscriptions 
Total Paid Circulation 

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by mail carrier or other means 

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back start subscription copies 

G. Total (Sum of E & F) - should equal net 
press run shown in A. 
I certify that the statements made by me above are correct 
and complete. 

(signed) R. Tucker Abbott, Editor 



C. 



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Issue 

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311 



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RECENT PUBLICATIONS 

Boss, K. J. and M. K. Jacobson. 1973. Monograph of 
Ceratodiscus (Archaeogastropoda; Helicinidae). 
Occasional Papers on Mollusks, Harvard Univ., vol. 
3, no. 45, pp. 253-279, 4 pis. Three species of this 
operculate land snail from tlie Greater Antilles are 
well treated. $1.40. 

Boss, K. J. and M. K. Jacobson. Sept. 1973. 
Monograph of the Genus Alcadia in Cuba 
(Mollusca: Prosobranchia: Helicinidae). Bull. Mus. 
Comp. Zool., Harvard, vol. 145, no. 7, pp. 
311-358, 6 pis. The genus is fully treated, with a 
new subgenus Glyptalcadia and a new subspecies, 
A. bermudezi jatibonica from Las VUlas, Cuba. 

Johnson, Richard I. 1973. Distribution of Hydro- 
biidae, A Family of Fresh and Brackish Water 
Gastropods, in Peninsular Florida. Occ. Papers on 
Moll., Harvard Univ., vol. 3, no. 46, pp. 281-303. 
The late Tertiary topographical history of Florida 
is interpreted from present-day hydrobiid 
mollusks, refuting some of F. G. Thompson's 1968 
interpretations. $1.20. 

Stem, Edward M. 1973. The Ashmunella rhyssa 
(Dall) Complex (Gastropoda: Polygyridae): Sierra 
Blanca — Sacramento Mountains, New Mexico. 
Science Series No. 5, Univ. of Texas at El Paso, VII 
& 57 pp., 18 text figs., 1 pi. $2.00. 

Ruhoff, Florence A. 1973. BibUography and 
Zoological Taxa of Paul Bartsch [1871-1960], 
with a Biographical Sketch by Harald A. Rehder. 
Smithsonian Contributions to Zoology, no. 143, 
pp. V + 166. Excellently done and extremely 
useful. $2.85 postpaid, Smitlisonian Institution 
Press, Wash. D. C. 



Kaicher, Sally D. Oct. 1973. Card Catalogue of 
World-wide Shells. MargineUidae, pack no. 1, 97 
cards. A useful and novel set of 3x5-inch cards, 
each bearing good black-and-white photographs, 
identification, marine province and short notes on 
colors and habitats. $3.00 per pack (postpaid), 
foreign $4.00 (airmail postpaid). Sally D. Kaicher, 
5633B 18th Way South, St. Petersburg, Ra. 
33712. 



indispensable ix 



TOR-IN-CHIEF 
cker Abbott 




american malacologists 

All the essential biographic facts about 
America's leading mollusk workers, 
shellfishery experts, paieoconcholo- 
gists and advanced shell collectors are 
now at your finger tips in this handy 
guide. 



ORDER 



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Vol. 88(1) 



THE NAUTILUS 



THE RELIGIOUS USE OF Ti RHINE LLA PYRUM (LINNAEUS), 
THE INDIAN CHANK 

Kenneth D. Rose 

Museum of Comparative Zoology, Harvard University 
Cambridge, Massachusetts 02138 



ABSTRACT 

The Indian chank, Turbinella pyrum (Linnaeus), has played an important role in 
Indian religion and art for centuries. Hundreds of years before the birth of Christ, 
chanks were in use in the Indus Valley civilizations. Chank sections and bangles 
served as ornaments and jewelry in many parts of India in the early Christian era. 
The earliest utilization of chanks as amulets and religious objects dates back nearly 
two millenia. Sinistral ("left-handed") specimens are very rare and have received the 
greatest veneration. Various Hindu gods have been associated with the chank; the 
most prominent of these is unquestionably Vishnu (or his incarnation Krishna), who 
is so often affdiated with the chank that it has become a reliable symbol of him. 
References to chanks, especially those modified as trumpets, are numerous in Hindu 
legends, and sacred wcitings such as the Bhagavad Gita. Some authors have suggested 
that Hindu influence may be responsible for similar reverence of large gastropod 
shells by the Aztecs. 



It is well-known that shellfish and seashells have 
long been significant items to the peoples of the 
Indian subcontinent. The early Hindus grouped 
crabs and mollusks under the name kambustha and 
used the cleaned shells as ornaments and amulets. 
Some shells, such as cowries, have served as 
money in parts of India (as well as throughout the 
Indo-Pacific region) for centuries in the past. Such 
uses as these have occurred in many cultures and 
have not necessarily been restricted to one or a 
few species. 

The Indian chank, Turbinella pyrum (Linnaeus) 
1758, is an example of an unusual instance in 
which one molluscan species has acquired a very 
special religious significance. The chank attained its 
prominence as a symbol of the Hindu god Vishnu, 
who is often portrayed holding a sinistral chank in 
one of his four hands. It is recognized particulariy 
as an emblem of Krishna, the most important 
avatar of Vishnu; but the chank is sometimes 
associated with other Hindu gods. The basis for 
the chank's religious significance can be traced to 
many Hindu legends, as will be shown below. 
Some preliminary remarks on the classification. 




FIG. 1. Map of the Indian subcontinent 



THE NAUTILUS 



January 29. 1974 



Vol. 88(1) 



natural history, and ornamental uses of the species 
will be discussed first. 

The controversy over the proper nomenciature 
for the Indian chank has been reviewed recently 




(Yokes, 1964) and is summarized here. Tiie chank 
was first named by Linnaeus (1758). who coined 
the binomial Valuta pynim for the species. 
Lightfoot (1786) listed the name Vohiia ponderosa 
for a sinistral ("left-handed") specimen of the 
Indian chank. but the name is unnecessary and 
invalid, for it refers to the same species described 
by Linnaeus. Later students discovered that this 
species had been incorrectly placed in the genus 
\'<>luia. Tiic genus name Xancus first appeared in 
reference to the Indian chank in Roding's Bolten 
Museum Catalogue (1798). but this reference was 
rather obscure until the eariy part of ihc twen- 
tieth century. TJierefore. Lamarck's (1799) name 
Turhinclla became widely known and was applied 
to the Indian chank by most authorities (e.g. 
Horneli. 1916) for more than a century. More 
recently, the name Xancus returned to use. due to 
a ruling on priority by the International Commis- 
sion on Zoological Nomenclature (Opinion 96, 
1926); but a later Opinion of the Commission 
(Opinion 489, 1957) reversed the 1926 ruling, 
formally suppressing the name Xancus and requir- 
ing use of the name Turbinella. Turbinclla pyrum 
is a member of the family Vasidae. 

Turbinclla pyntm occurs commonly in the Bay 
of Bengal off the Indian coast and in the vicinity 
t)f the Andaman Islands, and in the waters 
surrounding Ceylon, particularly the Gulf of Man- 
nar (Horneli. 1913, 1916. 1951). The Andaman 
islands form is often regarded as a distinct 
subspecies. Turbinclla pyrum fusus Sowerby 1825; 
it is characterized by its higli spire and angular 
shoulder. Other subspecies have been described 
(see, for example. Horneli. 1916) but most of 
these have not achieved universal acceptance. Like 
the majority of gastropods, the shell of Turbinella 



FIG. 2. A rare sinistral specimen (MCZ no. 
249020) of the Sacred Indian Chank, Turbinella 
pyrum (Linnaeus) (= "Voluta ponderosa" Light- 
foot, no. 402.-I in the Portland Catalogue). This 
prized specimen, once in the collection of the 
Duchess of Portland, is from the Trincomali Coast 
of India. It was purchased for the Museum of 
Comparative Zoology about fifteen years ago, as 
part of the collection of Mrs. Fiske Warren. (Scale 
is in centimeters.) 



Vol. 88(1) 



THE NAUTILUS 



pynim is typically dextral ("right-handed") but, as 
noted above, rare sinistral specimens have been 
recorded. It is the latter that have achieved the 
higliest veneration. 

The cleaned shell of the Indian chank is heavy 
and porcelainlike, a factor which contributes to its 
popularity and utility in jewelry and ornamental 
work. It is usually white or cream-colored, or 
rarely pnikish. in life, the shell is covered with a 
thick, light-brown periostracum, which may func- 
tion to some degree to protect the shell from 
boring sponges. Tlie animals are gregarious and are 
frequently found in large numbers on sand in 
relatively shallow water, up to ten fathoms deep. 
They feed chiefly on tube worms (Hornell, 1951). 
An interesting account of the breeding and larval 
development of Turbinella pynim is presented by 
Hornell (1951, pp. 24-25). 

Tlie use of the chank as an ornamental or 
religious object, although prevalent today, was 
perhaps more popular in the past. Bangles cut 
from the shell were widespread in India in ancient 
times, and have been the center of a small 
industry in more recent times. Chanks have been 
found in the excavations of the Indus Valley 
civilizations, which date back to centuries before 
the birth of Christ. They may have been collected 
from the Persian Gulf at that time. Chank sections 
were used in inlay patterns (e.g., petals, rosettes, 
crosses) in northwestern India over two thousand 
years ago, but examples are quite rare (Agrawala, 
1965). 

Important bangle workshops were located from 
Tinnevelly in the south to Kathiawar and Gujarat 
in the northwest, during the reign of the Pandyan 
kings in the early Christian era. "Maduraikkanchi", 
a Tamil poem of the second or third century A. 
D., describes the parawas, men who dived for 
pead oysters and chanks. In fact, the parawas are 
still active today (N. Hein, personal communica- 
tion). Another Tamil poem, attributed to the reign 
of the Pandyan King Nadunj Cheliyan II (second 
century A. D. ?), mentions sectioning chanks for 
use as bangles (Hornell, 1913). 

In north-central India, as eady as the first or 
second century A. D., there is evidence indicating 
that the religious significance of the chank was 
already established. Terracotta seals from Rajghat, 
near Benares, associate Vishnu with religious 
emblems including the wheel, spear and chank. 



The chank again appears in slightly later seals and 
seal impressions from the early Gupta Period 
(fourth century A. D.) at Basarh and Rajgliat. 
Inscriptions on some seals from Basarh and Bhita 
reveal associations of the chank with the god Siva 
and the goddess Laksmi, consort of Vishnu 
(Banerjea, 1941). Chanks also were "extensively 
used in wars by ancient Indians" (Bhattacharyya, 
1958, p. 438), supposedly to inspire warriors and 
to frigliten away the enemy. Indeed, the venera- 
tion of the chank by Hindus has evolved in large 
part from legends of its use as a war trumpet by 
the god Krishna. 

In more recent times, chank fisheries in India 
and Ceylon have gathered as many as two or three 
million chank shells per annum. Additional sub- 
recent shells are excavated from the silt beds of 
the Jaffna Lagoons in Ceylon. Chanks have been 
sent to Calcutta and Dacca to be sectioned for use 
as bangles by Hindu women of all castes. In this 
century, chank bangles have been most popular in 
Bengal and surrounding states (Hornell, 1913, 
1951). Not very long ago, the chank apparently 




FIG. 3. A normal (dextral) specimen of Turbinella 
pyrum (MCZ no. 235923). (Scale is in centi- 
meters. } 



THE NAUTILUS 



January 29. 1974 



Vol. 88 ( 1 ) 



achieved status as a good-luck charm in the Tamil 
districts of Madras. Whole shells and circular, 
hollowed sections worn as bracelets were used as 
amulets by some people, to (in the words of 
Homell, 1913, p. 410) "protect them against the 
baneful influence of the evil eye." Hornell (mi3) 
also reported their use as ornaments on the 
forehead of drauglit bulls in southern India. As 
religious objects chunks, which may be modified as 
trumpets, are often seen in Hindu temples; and 
they have been used in recent times in place of 
bells to initiate worship of the god Siva (N. 
Hein, personal communication). 

Chanks, especially sinistral specimens, have been 
of importance not only to Hindus, but also to 
Buddliists. According to Homell (1951), sinistral 
shells have been mounted in silver in some Tibetan 
lamaseries; and the value of "left-handed" chanks 
was once considered to be their weight in gold. 
Tlie chank has been associated with the Buddhist 
deities Sagaramati and Gandlialiasli (Bhattacharyya, 
1958). 

In the Hindu pantheon, Vishnu (or his incarna- 
tion Krishna) is the deity most often atfiliated 
with the chank - so often, in fact, that the chank 
has become a reliable symbol of Vishnu. Other 
Hindu gods, however, are occasionally shown in 
connection with a chank. For example, Siva is 
sometimes depicted with a chank in his hand 
(Jackson, 1916); Kubera, the corpulent god of 
wealth, may be portrayed with his foot resting on 
a chank (Rubel, 1968). 

The association of the chank with Krishna 
derives from the sacred Hindu poem Bhagavad 
Gita ("The Song of the Blessed One"), which 
forms a part of the great Hindu epic Mahabharata, 
Although the Bhagavad Gita was evidently not 
included in the original epic, and may have been 
written at a later date (Edgerton, 1964), it has for 
centuries been considered an integral part of the 
Mahabharata; it is unquestionably one of the most 
highly regarded of all Hindu sacred scriptures. The 
Bhagavad Gita itself is a dialogue (between Krishna 
and Arjuna, a warrior) in which major Hindu 
doctrines are expounded; while the main theme of 
the entire Mahabharata concerns a battle. Frequent 
references to the impending battle appear through- 
out the Bhagavad Gita, and it is in these that the 
chank is of paramount importance. The Sanskrit 
term sahkha, usually translated simply as "conch", 



is almost certainly a reference to the Indian 
chank. 

In Chapter 1 of the Bhagavad Gita, each warrior 
preparing for battle can be recognized by his 
personal conch, which is distinctive in color, size, 
and sound (Walker, 1968). In Chapter I, verse 12 
(Edgerton, 1964, 1:12), we read "The aged 
grandsire of the Kurus . . . blew his conch-shell, 
in full valor." Conch trumpets were sounded 
before the battle, and Arjuna and Krishna blew 
their conchs (Edgerton, 1:13-14). King Yudhisthira 
blew liis conch, named Anatavijaya: it was a long, 
slender yellow shell, with a mellow tone. Nakula's 
conch. Siighosa, was large, heavy, and gray, and it 
produced a neigliing sound. Sahadeva possessed a 
long, slender, pink chank called Manipuspaka 
("little jewel-flower"), which emitted a mooing 
sound (Edgerton, 1:16). Arjuna's chank was named 
Devadatta, "god-given" (Edgerton, 1:15). Tlie most 
important conch of all belonged to Krishna. It was 
a small, slender, sweet-sounding shell, called 
Panchajanya (Walker, 1968). 

According to legend, Krishna obtained his 
sacred shell in a confrontation with the demon 
Panchajana. In one version of the myth (Munshi, 
1963-1965) Panchajana, an evil member of a 
seagoing tribe, wore a beautiful pink conch over 
his shoulder. Krishna noticed the demon's shell 
and remarked " i will take this conch. I have 
never seen such a thing of beauty, nor heard such 
wonderful tones. I shall call it Panchajanya, the 
gift of Panchajana' " (Munshi. 2, p. 60). In another 
interpretation of the same legend (Walker, 1968), 
Panchajana lived in a shell at the bottom of the 
sea. Krishna pursued the demon and slew him, and 
used his shell for a trumpet. 

A different legend describes tlie chank as one 
of fourteen jewels (chaturdasa-ratnam) which e- 
merged Uom the "churning of the ocean", a major 
event in the epic confrontation between the gods 
and the demons. The chank was taken by Vishnu, 
but it was soon stolen from him by the shell 
demon, Sankasura. Vishnu slew the demon, how- 
ever, and recovered the conch, dedicating it to his 
own service. Thus chanks are blown in temple 
worship in modern time (Walker, 1968). 

Numerous other allusions to chanks in Hindu 
lore clearly associate them with Krishna. In the 
Krishnavatara, Krishna blew his chank trumpet to 
challenge the Rakshasa demons to battle; but the 



Vol. 88(1) 



THE NAUTILUS 



sound served to summon his friends, while scaring 
the demons to flight (Munshi, 3 pp. 189-200). 
Another tale relates Krishna's meeting with the 
King of Karavirapura. The deity arrived in a 
chariot, blowing his chank trumpet to greet the 
king (Munshi, 2, pp. 175-182). The Leelas of 
Krishna, stories adapted from the Bhagavata Para- 
na, tell of a wrestling match, between Krishna and 
a demon, which is initiated by trumpet blasts, 
perhaps chank trumpets, in a later episode, the 
arrival of Krishna at the court of his intended 
bride is accompanied by a flourish of trumpets 
(Sarma, 1948); this passage, too, probably refers 
to the chank. 

It may be significant that in the Aztec 
culture, similar reverence was centered around 
large snail shells, including Turbinella angulata 
(Lightfoot, 1786), a close relative of the Indian 
chank (Jackson, 1961; Yokes, 1963). Jackson 
emphasized similarities between Indian mythology 
involving the chank and Aztec moon worship 
involving large snail shells. Hindu influence on 
early Middle American civilizations is considered a 
distinct possibility by these authors. 

ACKNOWLEGDMENTS 

I am grateful to Dr. Norvin Hein, Department 
of ReUgjous Studies, Yale University, who read an 
earlier draft of this paper and offered helpful 
comments. I am indebted also to Dr. R. Tucker 
Abbott for providing suggestions regarding the 
text, and for calling my attention to several 
pertinent references. Dr. Kenneth Boss, Depart- 
ment of Mollusks, Museum of Comparative Zool- 
ogy, Harvard University, kindly permitted access to 
specimens of Turbinella pyrum under his care. The 
photographs were prepared by H. Jade Kimbell. 

LITERATURE CITED 

Agrawala, Vasudeva S. 1965. Studies in Indian 
Art. Vishwavidyalaya Prakashan, Varanasi, 1, 
288 pp. 



Banerjea, Jitendra Nath. 1941. The Development 

of Hindu Iconography. Univ. of Calcutta Press, 

Calcutta, 459 pp. 
Bhattacharyya, B. 1958. Tlie Indian Buddhist 

Iconography. K. L. Mukhopadhyay, Calcutta, 

478 pp. 
Edgerton, Franklin. 1964. (translator and inter- 
preter). The Bhagavad Gita. Harper and Row, 

New York, 202 pp. 
Hornell, James. 1913. The chank bangle industry; 

its antiquity and present condition. Mem. 

Asiatic Soc. Bengal 3: 407-448. 
Hornell, James. 1916. The Indian varieties and 

races of the genus Turbinella. Mem. Indian Mus. 

6: 109-122. 
Hornell, James. 1951. Indian Mollusks. Bombay 

Nat. Hist. Soc, Bombay, 96 pp. 
Jackson, J. W. 1916. The Aztec moon-cult and its 

relation to the chank-cult of India. Manchester 

Memoirs 60 (5): 1-5. 
Lamarck, J.-B. M. de. 1799. Prodrome d'une 

nouvelle classification des coquilles. Mem. Soc. 

d'Hist. Nat. de Paris, 
Lightfoot, John. 1786. A catalogue of the Port- 
land Museum. London, 194 pp. 
Linnaeus, C. 1758. Systema Naturae. Tenth edi- 
tion. Laurentii Salvii, Stockholm. 
Munshi, K. M. 1963-1965. Krishnavatara. Bharatiya 

Vidya, Bombay 2 and 3. 
Roding, Peter F. 1798. Museum Boltenianum. 

Hamburg, 199 pp. 
Rubel, Mary. 1968. The Gods of Nepal. Bhimratna 

Harsharatna, Kathmandu, 53 pp. 
Sarma, D. S. 1948. The Tales and Teachings of 

Hinduism. Hind Kitabs Ltd., Bombay, 180 pp. 
Yokes, Emily. 1963. A possible Hindu influence at 

Teotihuacan. Amer. Antiquity 29 (1): 94-95. 
Yokes, Emily. 1964. The genus Turbinella (Mol- 

lusca. Gastropoda) in tlie New Worid. Tulane 

Studies in Geol. 2 (2): 39-68. 
Walker, Benjamin. 1968. The Hindu Worid. George 

Allen and Unwin Ltd., London 1, 609 pp. 



THE NAUTILUS 



January 29, 1974 



Vol. 88(1) 



SPECIES DIVERSITY OF TERRESTRIAL SNAILS 
IN THE (;REAT smoky MOUNTAINS 

Lowell L. Getz 

Department of Zoology. University of Illinois 
Urbana, Illinois 61801 



ABSTRACT 

A comparison was made of species diversity (Shannon index and number of 
species) of larger terrestrial snails and gradients of moisture, temperature, and 
diversity of dominant tree, shrub and herbaceous plants in the Great Smoky 
Mountains. Estimates were also made of habitat breadth of the snails. There was a 
positive correlation between snail diversity and the moisture regime and diversity of 
dominant tree species. Tfiere was no correlation between snail diversity and 
temperature, or shrub and herbaceous vegetation diversity. Comments arc also made 
concerning the habitat breadths of the more common species. 



INTRODUCTION 

A series of terrestrial snail collections was made 
as a special class project by the University of 
Illinois Field Ecology Course to the Great Smoky 
Mountains, Tennessee and North Carolina, 28-31 
March, 1972, to compare species diversity in 
various communities of the region with selected 
environmental gradients. Although the data are not 
extensive, they do show indications as to the 
relationship between snail diversity and given 
environmental factors. They are presented here 
primarily to stimulate more intensive studies of 
species diversity of snails in the various com- 
munities within the Smoky Mountains. 

AREA OF STUDY 

Nine sites within eight of the community types 
defined by Wliittaker (1956) were sampled. Except 
where noted, special etTort was made to sample 
within a representative site in each community 
type. The following communities were sampled 
(see Whittaker, 1956, for detailed descriptions of 
the community types): 

Red spruce-Mt. LeConte. on Bullhead Trail, 
approximatel> 1,640 meters elevation. 

Grass bald -The upper half of Andrew's Bald, 
1,775 meters. 

Beech gap-Approximately 1.5 km. north of 
Indian Gap, 1,580 meters. 

High hemlock-On the south side of U. S. 
Route 411, at 1,200 meters. This site was typical 



of Whittaker's eastern hemlock type at its upper 
limits. Tlie tree canopy was composed almost 
entirely of hemlock; shrub stratrum was a com- 
plete cover of rhododendron. An herbaceous 
stratum was essentially absent. 

Low hemlock— Along the one-way road leading 
from Cherokee Orchard to Gatlinburg, at approxi- 
mately 745 meters. This site was characteristic of 
Wliittaker's description of the eastern hemlock 
type as it segregates from the Cove forest. The 
tree stratum was composed primarily of hemlock, 
but several deciduous species were also present. 

Rtch pine-table mountain pine heath-Mt. 
LeConte. along the Bullhead Trail at 1.100 meters. 
The site had essentially an equal mixture of pitch 
and table mountain pine. The rest of the vegeta- 
tion corresponded to that as described by Wliit- 
taker for the higher elevation pine heaths in the 
Smoky Mountains. 

Chestnut oak-chestnut-Mt. LeConte, a long 
Bullhead Trail at 850 meters. Tlie site sampled 
was in an area in which American chestnut 
originally made up the major portion of the tree 
canopy. The site is now occupied by a mixture of 
young oak and other deciduous trees. 

Virginia pine-Adjacent to the Cades Cove 
Campgrounds, 550 meters. 

Cove forest-Along the road in Greenbrier Cove, 
2 km. beyond the turnoff to the Trillum Gap 
Trail to Mt. LeConte. at 760 meters. 



Vol. 88(1) 



THE NAUTILUS 



METHODS 

A timed-interval search was used to sample all 
communities. The twelve individuals involved in 
the project each searched intensively for snails for 
ten minutes at each site, resulting in a total of 
two hours of searching. The search was conducted 
so as to cover as much total area as possible. All 
situations in which snails could be found were 
searched; these included under the leaf litter, 
under logs, fallen Umbs, and rocks, and in crevices 
at the base of trees. All live snails and dead shells 
were collected. The sampling of smaller species 
was not complete, so only larger species were 
included in the analyses; Retinella and other such 
small snails were excluded. 

Although there is bias in any collecting method, 
the one used eliminated some obvious sources. 
That the same twelve individuals sampled all nine 
sites reduced bias from different collecting idio- 
syncrasies; the same microhabitats received equal 
coverage in each community. The inclusion of 
dead snails in the analysis would tend to reduce 
the bias resulting from suppression of snail activity 
(and thus accessibility to collection) because of 
lower temperatures in the early spring in those 
communities at higher elevatons; there would be 
more adequate representation . of the species 
present in those communities. 

Spot checks by the author of most of the same 
community types on 12-13 April and 24-25 June, 
1972 indicated the original data were representa- 
tive of the abundance and diversity of species in 
the various communities. 

The species diversity of snails within each 
community was measured by the Shannon index, 
H' (Shannon and Weaver, 1963). The formula and 
tables of Lloyd, et aL (1968) were used in the 
calculations. Between-community species diversity 
indices were also calculated. The former are used 
to evaluate the influence of various environmental 
factors on the species diversity of snails; the latter 
are used to estimate relative habitat breadth of tlie 
species. 

RESULTS 

Within-community species diversity-Table 1 

summarizes the species diversity values witliin each 
community and the correlation with the various 
environmental gradients. The environmental gradi- 
ents have been summarized from Wliittaker (1956, 



1966). There was a positive correlation between 
species diversity of snails and the moisture regime 
in the nine communities (r^ = .87, P < .01; 
Spearman Rank Correlation, Siegel, 1956). Like- 
wise, there was a positive correlation between snail 
diversity and the number of dominant tree species 
present in each community (rg = .80, P =< .01). 
There was no correlation between snail diversity 
and temperature, shrub diversity, or herbaceous 
vegetation diversity. 

The major deviation from the correlation be- 
tween the amount of moisture in the community 
and snail diversity was in the Virginia pine 
community. This community was judged to be the 
third driest community studied, but ranked fourth 
highest in snaU species diversity. The Virginia pine 
community had one of the higher number of 
dominant tree species (third highest) which may 
be at least partly responsible for the greater snail 
diversity. 

The major deviation from the correlation be- 
tween number of dominant tree species and 
species diversity of snails is the high-elevation 
hemlock. This community ranked third lowest in 
the number of dominant tree species, but third 
highest in snail diversity. The high-elevation hem- 
lock, however, ranked as one of the more moist 
communities studied (third highest) which may be 
responsible for the greater snail diversity. 

Habitat breadth-Between-community diversity 
indices which have been used as an index of 
habitat breadth are summarized in Table 2. 

The immature Polygyridae had the widest range 
of habitats. This would be expected since several 
species were undoubtedly grouped into this cate- 
gory; we, therefore, are not dealing with one 
"habitat" but several and, thus, a wider apparent 
habitat. 

Pallifera sp. (probably only one species in- 
volved) also had a wide habitat range, but the 
numbers involved are rather low. The early 
seasonal aspect undoubtedly biased the results 
regarding this species. The observations made in 
May and June of 1972 did indicate, however, that 
the species was common in most of the habitats 
studied. 

Two or three species may have been involved in 
the Stenotrema sp. category. Thus, the comments 
concerning habitat breadth of the immature Poly- 
gyrids also apply to this grouping. 



8 



THE NAUTILUS 



January 29, 1974 



Vol. 88(1) 



TABLE 1. Correlation of species diversity of terrestrial land snails and environmental gradients in the Great 
Smoky Mountains National Park. 



Community- 


Number 


Number 


H'^ 


Moisture^ 


Environmental Gradients 




Type 


Species' 


Individuals 
























Temperature^ 


Vegetation Diversity^ 














Trees 


Shrubs 


Herbs 


Spruce 


10 


47 


2.9944 


9 


3 


8 


6 


6 


Cove Forest 


11 


44 


2.9715 


8 


8 


9 


7 


9 


Hemlock (High) 


9 


17 


2.8163 


7 


4 


3 


-) 


1 


Virginia Pine 


7 


18 


2.4806 


3 


9 


7 


9 


4 


Hemlock (Low) 


7 


75 


1.9724 


6 


6 


6 


3 


3 


Oak-Chestnut 


5 


35 


1.9039 


5 


7 


4 


8 


8 


Pitch-Table Mt. 


















Pine 


3 


3 


1.5849 


2 


5 


5 


5 


2 


Beech Gap 


3 


81 


0.3320 


4 


2 


2 


1 


5 


Grass Bald 


1 


8 





1 


1 


1 


4 


7 



' Includes two groupings (one genus and one family) considered as "species" 

^To log base 2 

^Ranked from low to liigh (1-9) 



Of the more abundant species, Ventridens 
elliotti, V. demissus, V. ligera, and Mesomphix 
andrewsae obviously have relatively wide habitat 
ranges while Vitrinizonites latissimus and Hap- 
lotrema concavum have more narrow habitats. The 
other species either had very low habitat breadths 
or were collected in too few numbers (i.e., 
Mesodon christyi) to place much significance on 
the relatively higli between-community diversity 
indices. 

Vitrinizonites latissimus was the most abundant 
species and occurred in five communities. The 
reason for the low H' appears to be related to its 
association with graminoid vegetation. Observations 
of the specific sites in wliich this species was 
found indicated that it occurred primarily where 
some type of grass or sedge was present. Gram- 
inoid vegetation was most abundant in the grass 
balds and the beech gap. V. latissimus is abundant 
in these two communities; the species is much less 
abundant and is spotty in its occurrence in the 
other communities studied. 

DISCUSSIONS AND CONCLUSIONS 

Tlie data obtained in this study indicate 
moisture and/or number of dominant species of 



trees are primary factors influencing species diver- 
sity of terrestrial snails within communities in the 
Smoky Mountains. Tliis differs somewhat from the 
trends in species diversity of insects in the Smoky 
Mountains observed by Wliittaker (1952). He 
found insect diversity to be greatest in the 
intermediate moisture conditions, with lesser diver- 
sity at both moist and dry extremes. 

Terrestrial snails (especially the families col- 
lected in this study) are relatively susceptible to 
desiccation. Tliose species with less tolerance to 
desiccation would tend to be restricted to the 
more moist communities. There would, therefore, 
be a gradual "filtering" process with the less 
tolerant species dropping out, as one progresses 
toward the drier communities. Tlie density of 
snails may not show such a relationsliip, however, 
since those species adapted to dry conditions 
could develop higli population densities in such 
sites. Except for the Virginia pine community 
these relationships are borne out by the data 
(Table 1). 

The beech gap community is of special interest 
in that more individuals were collected here than 
in any other community, but the diversity index 
was next to the lowest of the nine communities. 



Vol. 88(1) 



THE NAUTILUS 



TABLE 2. Habitat breadth of terrestrial snails in 
the Great Smoky Mountains National Park. 



Species 



Total Total 

Individuals Communities 



Polygyridae (immature) 


18 


6 


2.2109 


Pal'lifera 


6 


4 


1.9182 


Mesomphix andrewsae 


33 


5 


1.7712 


Stenolrcina sp. 


17 


4 


1.7575 


Ventridens ligera 


19 


4 


1.6164 


V. elliotti 


77 


4 


1.5040 


V. demisstis 


16 




1.4198 


Mesodon christyi 


5 




1.3710 


M. perigraptus 


2 




1.0000 


Vitrinizonites latissimus 


93 




0.9256 


Haplolrema concanim 


13 




0.7733 


Mesodon downieanus 


5 




0.7219 


Mesomphix subplanus 


1 







Triodopsis trideiUata 


1 







Mesodon andrewsae 


3 







Ventridens sp. (immature) 


2 







Mesodon ferrissi 


3 







M. clauses 


1 







Mesomphix sp. (immature) 


2 







Mesodon rugeli 


1 







Mesomphix sp. (adult) 


1 







M. vulgatus 


2 







Ventridens intertextus 


7 








To log base 2. 

Almost all the specimens from this community (77 
of the 81 collected) were Vitrinizonites latissimus. 
The beech gap has trees and a relatively deep leaf 
litter which moderate the physical environment 
(especially the surface soil moisture) in addition to 
the presence of a dense stand of grass. The only 
other community with significant grass is the grass 
bald. Trees and shrubs are very sparse in this site, 
however, so that there is not a cover of leaf litter 
to modify the surface soil moisture regime. A very 
low moisture availability in the grass bald may be 
responsible for the low populaton density of V. 
latissimus in this site. 

Since trees furnish most of the organic matter 
to forest soils (Lutz and Chandler, 1946), there 
would be a positive correlation between tree 
species diversity and diversity of nutritional and 
physical properties of the soU. This microhabitat 
diversity in turn would have a direct influence on 
the diversity of terrestrial snails (Burch, 1956) and 
may partially account for the correlation between 
tree diversity and snail diversity in the commu- 
nities studied. 

Much more data would be necessary to evaluate 
the habitat breadth of all the species of the 
region. The results of the present study do- 



indicate, however, that Mesophix andrewsae has 
broader habitat tolerances than most of the other 
species. Vitrinizonites latissimus displays more 
narrow habitat requirements. Tliis apparently re- 
sults from an association with graminoid vegeta- 
tion. Such vegetation occurs in abundance only in 
a few habitats. That these sites are also relatively 
xeric indicates that the primary factor influencing 
the distribution of this species is not moisture. 

Owing to the rather small amount of total 
collecting effort involved in the current study, 
more extensive analyses and extrapolations do not 
appear warranted. I think this preliminary study 
does indicate, however, the utility of making a 
more intensive study of this type. With compre- 
hensive sampling of these and other community 
types in the region, one should be able to arrive 
at more definitive conclusions regarding the factors 
influencing the diversity and habitat breadth of 
terrestrial snails. 

ACKNOWLEDGMENTS 

I wish to tliank the members of the Spring 
1972 Field Ecology Course from the University of 
Illinois for cooperating with the field collections 
from which the diversity indices were calculated. 

LITERATURE CITED 

Burch, J. B. 1956. Distribution of land snails in 

plant associations in eastern Virginia. Nautilus 

70: 60-64; 102-105. 
Lloyd, M., J. H. Zar, and J. R. Karr. 1968. On 

the calculation of information ~ Theoretical 

measures of diversity. Amer. Midi. Nat. 79: 

257-272. 
Lutz, H. J. and R. F. Chandler. 1946. Forest 

Soils. John Wiley and Sons, New York. 
Shannon, C. E. and W. Weaver. 1963. The 

Mathematical Theory of Communication. Univ. 

Illinois Press, Urbana. 
Siegel, S. 1956. Nonparametric statistics for the 

behavioral sciences. McGraw-Hill, New York. 
Whittaker, R. H. 1952. A study of summer foliage 

insect communities in the Great Smoky Moun- 
tains. Ecol. Monogr. 22: 1-44. 
Whittaker, R. H. 1956. Vegetation of the Great 

Smoky Mountains. Ecol. Monogr. 26: 1-80. 
Whittaker, R. H. 1966. Forest dimensions and 

production in the Great Smoky Mountains. 

Ecol. 47: 103-121. 



10 THE NAUTILUS January 29, 1974 Vol. 88(1) 

A NEW SPECIES OF HAWAIIAN GYRINEUM (CYMATIIDAE) 

Hal Lewis 

Research Associate, Department of Malacology 

Academy of Natural Sciences of Philadelphia 

Pliiladelphia, Pa. 19103 

ABSTRACT 

Gyrineum louisae is described as a new species from Hawaii The unusual sculp- 
ture of the protoconch is described and figured Tlie protoconchs of Gyrineum 
gyrinum (Linnej, Gyrineum nulator (RodingJ, Gyrineum bituberculare (Lamarck), 
and Gyrineum concinnum (Dunker) are figured for comparison. Various taxonomic 
characters of the genus are discussed. 



INTRODUCTION 

In the June 1963 issue of the Hawaiian Shell 
News, Dr. C. M. Burgess illustrated a species ta- 
ken during the Pele expedition and suggested 
that it was "similar to a Bursa. " The figured 
specimen is actually a new species of Gyrineum, 
Since that time no other specimens have been 
reported. Recently the figured specimen was 
brought to me for examination by Dr. Alison 
Kay of the University of Hawaii during her visit 
to the Academy of Natural Sciences of Philadel- 
phia. The morphology of tlie shell and the shape 
and proportion of the protoconch are typical of 
the genus (figs. 1-3 and 6). Microscopic examina- 
tion of the protoconch reveals a remarkable can- 
cellate sculpture wliich is unique to Gyrineum 
louisae. The regular, fine sculpture on the whorls 
of Gyrineum louisae are clearly distinct from any 
other species in the genus. 

HISTORICAL DISCUSSION OF 
THE GENUS GYRINEUM 

A great deal of confusion has existed con- 
cerning the proper use of Gyrineum Link, 1807. 
Many authors, including Wenz (1961, p. 1073), 
have considered this to be a name properly ap- 
plied to a bursid genus. This misuse still persists 
in recent Uterature, as well as in the systematic 
arrangement of various museum collections. 

Dall (1904, p. 115) discussed Link's genus and 
pointed out that there is a mixture of species 
included in the original description which "seems 
to have been based wholly on the presence of 
symmetrical lateral varices, and included species 



Uke M. gyrinus Linne, which have no posterior 
canal." He also stated that "Montfort 1810, saw 
more clearly and put the ranelliform tritons by 
themselves under the name of Apollon . . . with 
Murex gyrinus (Linne) Gmelin as type." Dall 
confirmed the validity of Gyrineum as a cymatiid 
genus, designating Murex gyrinus Linne, 1758, as 
the type, and listing Apollon as a synonym of 
Gyrineum. In spite of the wide-spread circulation 
of Dall's paper, many authors mistakenly contin- 
ued to use the name Gyrineum for a bursid 
genus and the name Apollon for the cymatiid 
genus which should properly be called Gyrineum, 

Cernohorsky (1967, p. 322) agreed with Dall 
and pointed out that the type for Apollon 
Montfort, 1810, is A. gyrinus (=Murex gyrinus 
Linne). Therefore Apollon is synonymous with 
Gyrineum Link, 1807. He also stated that 
Rovereto's designation (1899, p. 106) of 
Gyrineum spinosum (Dillwyn, 1817) as the type 
species for Gyrineum is invalid because spinosum 
was not originally included in Link's genus. 
Gyrineum spinosum { = G. echinatum Link, 
1807) belongs to the bursid genus Bufonaria 
Schumacher, 1817. Link's list included G. 
echinatum Link, G. rana (Linne) Link, G. 
bufonium, G. natator, M. gyrinus and G. 
verrucosum, a mixture of Bursa and Gyrineum, 

It does seem unfortunate that the rules of tax- 
onomy cause us to recognize Gyrineum and to 
synonymize Apollon simply because Link in- 
cluded a species which, in fact, is not typical of 
the genus he described. This is especially true 
when we realize the consequential confusion 
which has existed for almost 167 years concern- 



Vol. 88(1) 



THE NAUTILUS 



11 



ing the misuse of Gyrineum as a bursid genus. 
As recently as August 1973, Kilias (p. 13) per- 
sists in the use of Apollon for Gyrineum It is 
also unfortunate when we realize how much 
more clearly Montfort understood the relationsliip 
of the species he included in Apollon. 

Species of Bursa and Gyrineum are easy to 
confuse because of the similarity of shell mor- 
phology, especially since botli have more or less 
laterally aligned varices. However the presence of 
the open posterior anal canal in the Bursidae and 
the absence of it in the Cymatiidae as a distin- 
guishing characteristic is widely accepted and 
apphes very well in this instance. 

Genus Gyrineum Link, 1807 

Gyrineum Link, 1 807, Beschreibung der Naturalien 
Sammlung der Universitat zu Rostock, p. 123. Type 
species, Murex gyrinus Linne, 1758, subsequent 
designation W. H. Dall, 1904. 

Apollon Montfort, 1810, Conchyliologie 
Systematique, et Classification Methodique des 
Coquilles: p. 570-571. 

Description — Shells range in length from 20 
to 45 mm. The genus is typified by laterally 
aligned varices which on some species actually 
connect to form a smgle continuous varix on 
each side. This gives the whorls a distinct bilater- 
ally compressed appearance. Tliey are sculptured 
by spiral cords and axial ribs which form fine to 
coarse beads or nodules where they cross. The 
aperture is oval to round with dentition usually 
present on the inner edge of the outer lip. The 
anterior siphonal canal is short. The radula is ta- 
enioglossate and is differentiated from other 
Cymatiidae by the flat character of the base of 
the rachidian which contrasts with the arched 
base typical of the rachidian of most Cymatiidae. 
The opercula of all species examined are terminal 
in pattern, with the exception of occasional dam- 
aged specimens which have regenerated with a 
nucleus. This condition has been observed in 
other genera of the Cymatiidae. The protoconchs 
of the various species are very similar (figs. 6-10) 
with the exception of G. louisae which has a 
fine regular canceUate sculpture. Jaws were pre- 
sent in all species examined. 



Gyrineum louisae 
new species, Lewis 

Figs. 1-3 

Description - SheU white, 19 mm. in lengtli 
and 12 mm. in width at the periphery. There 
are 6 whoris producing a spire of 57 . The outer 
lip is thickened at the final varix. The 9 varices 
do not align but are slightly offset (fig. 3). 
There are 13 spiral cords crossed by 16 axial 
ribs between the varices which form a very fine 
beaded pattern. The axial ribs do not extend to 
the varices but the spiral cords cross the varices 
forming 13 distinct fine ridges on tire varix at 
the outer lip. Tlie siphonal canal is very short, 
measuring only \^A mm. from the base of the 
outer lip to the tip of the canal. There is a 
glossy raised peristome on the inner edge of the 
outer hp which continues to the upper edge of 
the glazed parietal waU. The protoconch is cover- 
ed by a fme network of axial ribs and spiral 
cords (fig. 6) but is similar in shape to other 
species in the genus (figs. 7-10). The operculum 
and animal are unknown. 

The distribution is unknown except for the 
type locahty where the holotype was taken on 
the Pele expedition at 180 fathoms, off Pokai 
Bay, Oahu, Hawaii. The holotype is deposited in 
the B. P. Bishop Museum, Honolulu. 

1 take great pleasure in naming this species 
after my wife Louise in small repayment for her 
continued patience during my work with the 
Cymatiidae. It is hoped that there will be no 
confusion with the little used name Bursa louisa 
M. Smith, 1948, wliich is a synonym for Bursa 
caelata (Broderip 1833) from the Panamic region. 

Differentiating features - Gyrineum louisae is 
most similar to Gyrineum natator but differs by 
being smaller, lacking pigmentafion by having 13 
spiral cords instead of 8. The protoconch of na- 
tator is smooth. 

Gyrineum louisae differs from Gyrineum 
gyrinum, the type of the genus, by being small- 
er, lacking pigmentation and the color bands of 
gyrinum, having finer sculpture with 13 spiral 
cords instead of 8. Tlie protoconch of gyrinum 
lacks the sculpture of louisae. 

Although most species of Gyrineum are pig- 
mented, Gyrineum pusillum (Broderip, 1832) is 
also white, and species such as hirasei Kuroda 



12 THE NAUTILUS 



January 29, 1974 



Vol. 88(1) 




FIGS. 1-1 l,t'xplanatioii on opposite page. 



Vol. 88(1) 



THE NAUTILUS 



13 



and Habe, 1964 and bituberculare Lamarck, 1816 
can be very pale. 

FOSSIL LITERATURE 

An investigation was made in order to deter- 
mine whether or not this species had been 
named in the fossil Uterature. Special attention 
was given to the various species from Java and 
Timor described and discussed by K. Martin. A 
partial list of tliese papers is included in the 
cited Uterature. No fossil species was discovered 
wliich can be considered to be this species. 

ACKNOWLEDGEMENTS 

I wish to thank Dr. AUson Kay, University of 
Hawaii, for bringing the specimen to Philadelplria 
so that I could examine and describe it; the Bish- 
op Museum of Hawaii for the loan of tlie spec- 
imen and Dr. R. T. Abbott, du Pont Chair of 
Malacology, Delaware Museum of Natural History 
for reviewing tliis manuscript. 



LITERATURE CITED 

Cernohorsky, Walter O. 1967. The Bursidae, Cyma- 
tiidae and Colubrariidae of Fiji. The VeUger 9 (3): 
310-329, pis. 42-46, 14 text figs. 



Dall, WiUiam H. 1904. An Historical and Systematic 
Review of tl;e Frog-Shells and Tritons, Smith- 
sonian Miscellaneous Collecrions 47 (1475) 
(Quarterly Issue) 1 14-144. 

Kilias, Rudolf Dr. 1973. Famiha Cymatiidae. Das 
Tierreich 92 (I-VIII) 1-235, 149 text figures. 

Link, H. F. 1807. Beschreibung der Naturalien- 
Sammlung der Universit'at zu Rostock. 

Martin, K. 1879. Die TertiarscWchten auf Java. pp. 
53-55, pi. 10. 

Martin, K. 1884. Beitrage zur Geologie Ost-Asiens 
und Australiens 3 Palaeontologjsche Ergebnisse von 
Tiefbohrungen auf Java, Nebst Allgemeineren 
Studien Ueber Das Tertiaer von Java, Timor and 
Einiger Anderer Inseln, pp. 129-139, pi. 7. 

Martin, K. 1916. Sammlung des Geologjschen 
Reichs-Museums in Leiden, (2): 242-243, pi. 3. 

Montfort, Denys De 1810. Conchyliologie System- 
atique, et Classification Methodique des Con- 
quiUes: 2: 570-571. 

Rovereto, Gaetano 1899. Prime Ricerche Sinoni- 
miche sui generi dei gasteropodi. Atti della Societa 
Ligustica di Scienze Naturali e Geografiche, 10: 
101-110. 

Smith, Maxwell 1948. Triton, Helmet and Harp 
SheUs, Winter Park, Florida, pp., V+57, 16 pis. 

Wenz, Wilhelm 1961. Handbuch der Palaozoologie 6 
(1) Gastropoda 1056-1076. 



FIG. 1-3. Gyrineum louisae new species. Lewis, 
Holor\'pe, 180 fathoms off Pokai Bay, Oahu, Hawaii 
19mni X 12 mm 

FIG. 4, Gyrineum gyrinum (Linne), North side of 
Kyangel Isl. Palau district. West Carolines 30 mm x 
20 mm 

FIG. 5, Gyrineum natator (Rbding), India 38.5 mm 
X 24 mm. 

FIG. 6, Protoconch of Gyrineum louisae Lewis, 
Holotype. 180 fathoms off Pokai Bay, Oahu, Hawaii 
X 17. 

FIG. 7, Protoconch of Gyrineum bituberculare 
(Lamarck), Tayabas Bay, Philippines, x 17. 



FIG. 8, Protoconch of Gyrineum natator (Rbding), 
Bay of Bengal, India, x 17. 

FIG. 9, Protoconch of Gyrineum gyrinum (Liim8), 
West Carolines, x 17. 

FIG. 10, Protoconch of Gyrineum concinnum 
(Dunker-, Obhur, Saudi Arabia, x 17. 

FIG. 1 1 , Larval shell of Gyrineum natator (Roding), 
Bay of Bengal, India, with periostracal formation 
showing spiral ridges somewhat similar to the spiral 
cords formed on the protoconch o/ Gyrineum louisae 
Lewis. (In the Cymatiidae, the shell sculpture of 
cords and ribs usually corresponds to periostracal 
formation.) 



14 



THE NAUTILUS 



January 29, 1974 



Vol. 88(1) 



GROWTH STUDIES ON THE GENUS C£"/?/r///fW (GASTROPODA: PROSOBRANCHIA) 
WITH NOTES ON ECOLOGY AND MICROHABITATS 

Richard (Joseph R.) Houbrick ' 

Department of Biology 

University of South Florida 

Tampa, Florida 33620 

ABSTRACT 

The growth rates and general ecology of four species o/ Cerithium were studied in 
Florida. Comparative ecological observations on worldwide species of the genus are made. 
All Cerithium species are shallow water subtidal or intertidal dwellers and most are 
associated with marine grasses and algae. Some species occur in large populations. They 
appear to be selective algal-detritus feeders and have style-bearingstomachs with complex 
ciliary sorting mechanisms. 

Species in Florida spawn from winter through spring, grow from juveniles to adult 
stages in a few months, and have life spans of about one year. Predation on Cerithium 
species occurs by carnivorous mollusks, crabs, starfish and bony fish. Smaller Cerithium 
species tend to be intertidal 



INTRODUCTION 

The genus Cerithium is common in a variety of 
shallow-water, tropical and subtropical habitats. 
There are few accounts of the ecology of this genus 
beyond some scattered remarks in various papers 
dealing with anatomy and systematics. Few studies 
have been made on the ecology of littoral gastropods 
in the tropics. The growfth rates of marine tropical 
and subtropical benthic mollusks are little known 
(Lewis et al, 1969) while those living in temperate 
and cold climates have been more thoroughly 
investigated. Literature concerning growth in inter- 
tidal marine organisms has been reviewed by Moore 
(1958), NeweU (1965, 1970), and WUbur and Owen 
(1964). Lewis et al. (1969) have surveyed the 
literature concerning the factors which are known to 
influence growth rates (gonadal maturation, age, 
temperature, food supply, and environmental fac- 
tors). The environmental factors have also been 
discussed by Vohra (1970). Houbrick (1970; 1974, in 
press) recently defined the mode of reproduction in 
Cerithium species from the Western Atlantic. 

The account which follows is primarily concerned 
with four species of Cerithium common in Florida, C 
muscarum Say, 1832 (Fig. 4, D), C lutosum Menke 
1828 (formerly C. variabile^ ) (Fig. 4, B) C. ebumeun. 



Present Address: Supervisoi for Invertebrates, Smithsonian 
Oceanographic Sorting Center, Smithsonian Institution, 
Washington, D.C. 20560. 



Bruguiere 1792 (Fig. 4, C) and C atratum (Bom, 
1778) {=€. floridanum Morch^]. A hterature survey 
and observations on other worldwide species of 
Cerithium and Rliinoclavis are also included. 

MATERIALS AND METHODS 

This study is based mainly upon material collected 
in Florida. Observations were made in the field and 
laboratory from September 1968, through May 1971. 
Supplementary field work was done at the Eniwetok 
Marine Biological Laboratory, Marshall Islands, in 
August 1970, and at Carrie Bow Cay, British 
Honduras, in May 1972. In Florida, monthly samples 
and observations, when possible, were made from a 
total of four field stations, while other areas in the 
state were visited less regulady. The sites selected for 
ecological and growth studies in Florida represent 
several environmentally different habitats and are 
located in different marine zoogeographical pro- 
vinces. The data collected on the populations of 
species studied at these sites does not necessarily 
apply to other populations of the same species in 
other parts of their ranges. 

The four main stations in Florida were located at 
Port Everglades (lat. 26°6'N, long. 80°4'W), Bear Cut 
(lat. 25°44'N, long. 80°8'W), Dunedin (lat. 28°2'N, 

C. varwbile C. B. Adams 1845 is a synonym of C. lutosum. 
This will be documented in a later paper. 

C. floridanum Mbrch, 1876 is a synonym of C. atratum. 



Vol. 88(1) 



THE NAUTILUS 



15 



long, 82°45' W), and Mullet Key (lat. 27°35'N, long. 
82°44'W). The first two stations are located on the 
lower east coast of Florida where the environment 
and fauna are largely tropical and Caribbean in 
nature, while tiie latter two are located along the 
central Gulf coast of the state, where the marine 
fauna and environment are subtropical and largely 
Carolinian in composition. More detailed descriptions 
of the four stations may be found in the body of this 
paper. 

Quantitative monthly data on temperature, sa- 
hnity, and tides were taken. Monthly measurements 
of the growth of populations of C. muscarum, C. 
lutosum, C. atratum, and C. ebumeum were made. 

For growth studies, samples from the four field 
stations were collected with a mesh push-net in grass 
beds, sand, and mud habitats. Material was passed 
through a screen of 0.25-cm mesh and the samples 
removed. Algae and marine grasses were washed in 
fresh water to collect any young snails in the 
populations. Collecting was limited to about one hour 
at each station. Measurements of the monthly 
samples were made in the laboratory. The length of 
the sheUs was determined to the nearest 0. 1 mm with 
vernier calipers. In most cases, 50 or more were 
measured. Snails with badly eroded apexes were not 
measured. Length was determined as tlie distance 
from the apex of the shell to the base of the aperture, 
and width by measuring the thickness of the last 
whori. Difficulty was encountered in width mea- 
surements because of the random presence or absence 
of varices on the body whorl. For this reason, length 
measurements were relied on in making size 
frequency plots. Size-frequency analysis was made on 
monthly measurements and the mean, mode, standard 
deviation, and range were computed. The addition of 
new whorls and increases in shell length were taken as 
indications of new growth. To determine population 
densities of species with obvious high densities, 
random samples were taken by dropping a lOcm 
square metal frame over the area to be sampled. All 
animals appearing within the frame were counted and 
Stein's two-stage samphng technique (Steel and 
Torrie, 1960) was used to compute average densities. 
Living animals were maintained at a temperature of 
25 C in aquaria of seawater with a salinity of 34°/oo. 
The snails were fed on local algae, marine grasses, and 
detritus from Tampa Bay. Observations and dis- 
sections of living animals were conducted to 
determine food preferences and stomach contents. 



Associations, kinds of predators, and behavior were 
also noted and are herein recorded. However, these 
observations were not of a quantitative nature and 
may not be significant. 

Various sites in Florida, the Caribbean and the 
Pacific, were also studied to collect comparative data 
on other species oi Cerithium. 

ECOLOGY OF CERITHIUM MUSCARUM 

Habitat 

Cerithium muscarum, throughout its range, is 
found associated with marine grasses such as Thalassia 
testudinum, Ruppia maritima, Halodule wrightii and 
Syringodium sp. 

Cerithium muscarum is a common inhabitant of 
bays and other estuarine areas, but is also found in 
the open sea in areas shallow enough to support 
extensive beds of grass such as occur on the Gulf 
coast of Florida. 

A population of C. muscarum was studied 




AMJ JA SONDJ FMAIMJ J ASONDJ 
MONTHS OF YEAR 

Fig. 1. Cerithium muscarum. Growth of population 
expressed as a measure of shell length. Vertical lines 
represent range, horizontal lines the mean, and bars, 
the standard deviation. Solid bars represent months 
of oviposition. 

intensively at the north end of Mullet Key in the 
entrance of Tampa Bay, Florida. This is a shallow 
estuarine habit with mangroves constituting the 
predominant shore line vegetation. The general 
ecology of Tampa Bay has been treated by Dragovich 
and Kelly (1964). There is httle wave action at Mullet 
Key and the mean fidal range is about 60 cm. Average 
water temperature at this station was 25.3 C, ranging 
from extremes of 14°C in January 1970, to 33°Cin 



16 



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January 29, 1974 



Vol. 88(1) 



June 1969. Mean salinity was 34.6°/oo with a range 
from 31°/oo in February 1969, to a high reading of 
37°/oo in August 1970. Salinity levels appear to be 
relatively stable, although heavy rains may lower 
them appreciable for short periods. Some wave action 
occurs when winds are strong causing considerable 
amounts of debris and detritus to be deposited in the 
intertidal zone and on the beaches. The water is 
generally clear during the winter and spring, but is 
turbid in summer and fall. 

Ccrithium muscanim is found living in the beds 
of Thalassia and Ruppia about 16m offshore, just at 
and below the low tide mark. Occasional minus tides 
expose the whole area. The substratum is sand but 
quantities of detritus and debris collect about the 
roots and in between the blades of the Thalassia and 
Ruppia. Cerithium muscarum is found browsing upon 
the epiphytic algae on Thalassia leaves and also 
partially burrowing in or crawUng on the detritus and 
sand. Its distribution is limited to the TJialassia and 
associated detritus. 

This species is also common in HiUsborougli Bay, 
Florida, a more brackish environment, where it is 
found in beds oi Ruppia near submerged oyster bars. 
I also observed it in beds of Thalassia in Biscayne 
Bay, Florida, and the Florida Keys. Tabb, Dubrow 
and Manning (1962) found it in the shallow brackish 
waters of Florida Bay. 

Behavior 

Cerithium muscanim is a continual browser with a 
monotaxic type of locomotion. Captive specimens 
exhibit shadow responses by quick withdrawal into 
their shells. When the water is stirred by wave action, 
C. muscanim buries itself in the sand at the bases of 
the Thalassia plants. During low tides, sliglit 
clustering of individuals occurs. 

Food and Feeding 

Cerithium muscarum feeds and deposits fecal 
pellets intermittently. In the aquarium it eats the 
sand and surface deposits on the bottom as well as 
epiphytic algae on Thalassia blades. Decaying 
Thalassia leaves are also consumed. Stomach contents 
consist of sand grains, detritus, and green algae such 
as Cladophora and ChaelDmorpha. Fecal pellets 
contain the same type of material as is found in the 
stomach, only many of the algal cells are evacuolated. 

Associations and Predators 

In some habitats, the potamidid snail, Batillaria 



minima, is associated with C muscanim but it 
occupies a higher tidal zone. No mi.ving between the 
two species occurs. Frequently, young Crepidula 
fornicata are found on the siphonal canal of the shell 
of C. muscarum Seventy-two per cent of the Mullet 
Key population harbor Crepidula fornicata on their 
shells. The digenetic trematode, Mesostephanus 
appendiculatoides, found in birds, uses C muscanim 
as its first intermediate host (Hutton and Sogandares- 
Bernal , 1960). In Tlialassia communities of the 
Florida Keys and Biscayne Bay, C muscarum is 
occasionally found with C ebumeum. 

Cerithium muscanim is attacked and eaten by 
crabs of the genera Callinectes, Menippe, and Libinia. 
Numbers of shells with broken aperatures indicate 
tliat predation by crabs is common. 1 also observed 
the carnivorous snails, Melungena corona, Busycon 
contrarium, Fasiolaria tulipa, and Pleuroploca gigan- 
tea preying upon C muscarum Shells with drilled 
holes indicate that naticid snails (Polinices, Natica, 
Sinumj as well as muricid snails (Murex, Eupleiira) 
may also be predators. Stingrays and horseshoe crab, 
Limulus, are abundant in the study area and are also 
suspected predators. 

Growth 

Size frequency analysis (Table 1 ) indicates that the 
monthly mean shell length of tiie Mullet Key 
population of C muscarum fluctuated between 23-16 
mm (Fig. 1). Oviposition takes place from January 
through July and development is direct with no 
pelagic stages (Houbrick, 1970). Althougli a few 
young snails were found in die population during the 
spring, young snails (5- 10mm) were most common in 
August and September. Growth rates were rapid. The 
mean shell length of the population, 16 mm in 
August, had reached 21 mm by Octt)ber. Thus, the 
new generation took only three montlis to reach an 
adult size. The largest individuals taken were 26 mm 
in length and were found in eariy spring. 

In addition to increase in shell length, another 
indication of growth is a thin-lipped shell aperture, 
formed during the addition of new whorls. Tliis was 
most evident during tlie fall and eariy winter 
(September-December). Monthly statistics on this 
population were maintained, and a summary is given 
in figure 1 . 

C. muscarum was most abundant during the winter 
when the density of the population averaged 25 
snails/m^. By late spring, the population size began to 



Vol. 88(1) 



THE NAUTILUS 



17 



decrease and during the summer was the lowest prior 
to the hatching of new snails. The new generation 
appeared in late August. In the fall, new adult 
individuals were easily differentiated from the 
previous generation on the basis of their shells, which 
were erosion-free, more colorful, and free of marine 
foulers. Snails over a year old had eroded shells, 
covered with oysters, barnacles, brozoans, etc. On the 
basis of the number of new individuals present in the 
population by November, and the lack of older snails, 
C. muscarum probably has a life span of about one 
year. 

ECOLOGY OF CERITHIUM LUTOSUM 

Habitat 

Cerithium lutusum exliibits great ecological diver- 
sity in terms of substratum preference. I collected it 
on substrata ranging from fine, muddy sand to 
limestone slabs and beachrock. Occasionally, it occurs 
in beds of Thalassia, but it is almost always associated 
with some type of algae. Cerithium hitosum 
(occurring in both estuarine and high-salinity 
environments) is euryhaline by comparison with most 
other species of Cerithium 

Detailed studies on this species were carried out at 
Port Everglades, Florida. This station is located in 
soutlieastern Florida between Ft. Lauderdale and 
Hollywood. It is a deep-water port on the Intracoastal 
Waterway, which opens to the ocean by a narrow 
inlet. In the vicinity of the port, tlie Intracoastal 
Waterway branches into several smaller canals, one of 
which is known locally as "Whiskey Creek". This was 
the site of the study and is a shallow, brackish tidal 
canal about 1 1 m wide extending for a length of 
about 2 mi. At its center it is about 2 m deep at high 
tide and slopes gradually upwards to the banks. Tidal 
fluctuations are about 1 m and generate a current 
between tides. The average bottom water tempera- 
ture, recorded monthly, throughout this study was 
28.4 C, ranging from 20°C in February 1969, to 
35 C in September 1969. Mean salinity was 27.5°/° o 
ranging from a low of 13°/oo in October 1969, to a 
high reading of 35°/°° in December 1969. Salinity is 
variable and may drop rapidly after periods of 
heavy raintali. Because there is no wave action, the 
bottom and intertidal zone are stable, but detritus is 
distributed and redeposited by tidal action. The canal 
bottom is sandy with occasional areas of muddy 
sediment. The sand is composed of broken shell and 



is coarse. The water, although darkly stained by 
tannic acid from the mangroves, is seldom turbid or 
muddy. The canal is bordered on one side with 
Rhizophora mangle, the red mangrove, and with open 
beach sand on the other side. Portions of the bottom 
are covered with algae, primarily Gracilaria folifera, 
Hypnea musciformis and Chaetomorpha gracilis. A 
vascular plant, Halophila balionis, is also present as 
well as Halodule wrightii. 

Cerithium lutosum occurs in great numbers 
(average density of 3,400/m^ ), occupying a zone 2 m 
wide along the shallow banks of the canal from the 
high-tide mark to just below the low-tide level. The 
highest concentration of snails (15,000/m^) is just 
above the low-water mark to inid-tide level. Much 
detritus is deposited in this area during tidal changes. 
Cerithium lutosum is closely associated with the 
green alga, Chaetomorpha gracilis. This alga covers 
the substratum and the shells of the snails. 1 also 



I rt 



I 15 
O 




-l_l_ 







I I ■ ■ ' 



T 



-L. 



MJ J ASONDJ FMAMJ J AS OND 
MONTHS OF YEAR 

Fig. 2. Cerithium lutosum. Growth of population 
expressed as a measure of shell length. Vertical lines 
represent range, horizontal lines the mean, and bars, 
the standard deviation. Solid bars represent months 
of oviposition. Asterisks represent months of 
oviposition when other measurements were not made. 

observed Cerithium lutosum on intertidal beach rock 
along Bear Cut, Key Biscayne, Florida, where it is 
likewise abundant (average density of 1,700/m^), 
clinging to the rocks or partially buried in mats of the 
filamentous green alga, Enteromorpha. The highest 
concentrations at Bear Cut were just above the 
low-tide mark (6,500/m^). This species was also 
abundant on intertidal coral rock at Pigeon Key, 
Florida. In the Laguna de Terminos, Campeche, 



18 



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January 29, 1974 



Vol. 88(1) 



Mexico 1 found it in the brackish lagoon, intertidally, 
on most algal-covered rocks. At Portcte, Costa Rica, 
and on Carrie Bow Cay, British Honduras, I observed 
it in shallow water Thalassia communities. Jackson 
(1972) found large populations of C variabile (now 
C. lutusum) in Thalassia in Jamaica. 

Behavior 

Cerithium lutosum moves frequently with tidal 
changes. It was found crawling on the substratum and 
also partially burrowing in the sand. Wlien tidal 
currents are strong the population orients itself with 
tlie anteriors of the shells facing the current and then 
buries itself almost completely. The snails emerge 
when conditions are more stable. Their mode of 
locomotion is monotaxic, direct. Cerithium lutosum 
is frequently exposed to the sun at low tide and is 
able to tolerate desiccation for this period. It is 
capable of surviving water temperatures in excess of 
41°C (Jackson, 1972). Light clustering of individuals 
occur during low tide, but not to the extent observed 
by Moulton (1962) in some Australian species. In the 
laboratory, the snails appear to be photopositive but 
are repelled by strong light and will also quickly 
withdraw into their shells in response to a shadow. 

Food and Feeding 

Observations in the laboratory indicate that C. 
lutosum is a relatively continuous feeder. It 
constantly rasps the substratum, engulfing algae and 
detritus, pausing occasionally, and intermittently 
deposits strings of fecal pellets. Stomach contents 
revealed a variety of material such as diatoms, 
Foraminifera, sand grains, blue-green and green algae, 
especially Euteromorpha and Chaetomorpha, and 
much detritus. It is difficult to determine what is 
selectively digested in the complex sorting system of 
the stomach. The above-mentioned stomach contents 
are also found in the fecal pellets. 

Associations and Predators 

In all habitats and locations studied, the potamidid 
snail, Batillaria minima, which closely resembles C 
lutosum, is found just above the tidal zone level 
occupied by C lutosum and upwards to the high tide 
mark. At the Port Everglades site there is a zone of 
mixing between the two species about 10 cm wide, 
but they generally tend to remain separate. They 
both feed on algae and detritus. 



Predators that eat C lutosum are the blue crab, 
Callinectes sapidus, hermit crabs of the genus 
Pagurus. and the snail Melongena corona. Raeihle 
(1968) observed the snail, Mitra floridana eating the 
young of C. lutosum. Jackson (1972) recorded 
predation of C. lutosum in Jamaica by the naticid 
snails Polinices and Natica. Predation by rays is 
suspected because they have been noticed frequently 
in the study areas. Other suspected predators are the 
horseshoe crab, Limulus, the spider crab, Libinia, 
bony fishes and wading birds. 

Growth 

C. lutosum has direct development (Houbrick, 
1970; 1973, in press), and size-frequency data (Fig. 
2) indicate tliat adult size is reached in about one 
year. Size-frequency analysis of the Port Everglades 
population shows that the monthly mean shell length 
varies between 7-11 mm througliout the year. The 
largest snails were 16 mm in length and were found in 
March. Frequent oviposition occurred from fall 
through early spring, with minor egg-laying, activity 
seen at other times of the year (Fig. 2). Most of the 
young snails were found from April tlirough 
September, indicating that development and growth 
of the new generation occurs during the summer 
months. The mean length of the snails during this 
period was 8 mm Average growth in length was most 
rapid in the fall (October-November). Size-frequency 
data indicate that young snails reach adult size in a 
few months. It was not possible to determine tlie life 
span of C. lutosum with accuracy because attempts to 
raise newly-hatched snails to adulthood were 
unsuccessful. However, it appears that snails in the 
Port Everglades population live about one year. 
Fluctuations in die size of the population (in 
numbers of individuals) occur during late summer and 
early fall when both generations are found together. 

ECOLOGY OF CERITHIUM EBURNEUM 
Habitat 

Cerithium ebumeum occurs in the shallow sandy 
areas associated with Thalassia. This species was 
studied at Bear Cut, Key Biscayne, Florida. Bear Cut 
is an inlet at the north shore of Key Biscayne leading 
into Biscayne Bay. Tlie general ecology of this region 
has been treated in detail by McNuity (1^62) and an 
ecological bibliography of the area has been compiled 
by Morrill and Olson (1955). In the shallow water 



Vol. 88(1) 



THE NAUTILUS 



19 



along the north shore of Key Biscayne, the plants 
Thalassia, Valonia and Padina are common. These 
shallow areas and their associated biota extend up to 
the sublittoral zone. Tidal fluctuations are about 1 m 
and flushing currents of considerable strength may be 
generated by changing tides. During the sampling 
periods the average bottom water temperature was 
26.7°C, ranging from 22°C in December 1970, to 
33 °C in August 1969. The average salinity was 
37°/ oo with a low of 34°/ oo in August 1970, and a 
high of 40°/ oo in December 1969. The water is 
usually clear, but can become turbid due to strong 
winds and rough seas. 

The population of C. ebumeum occurred sub- 
tidally, just beyond the low tide mark (MLT), but 
was never observed completely exposed. The snails 
were dispersed on a sandy substratum near beds of 
Thalassia at a density of about 4/m^. Populations 
observed in tlie Florida Keys and British Honduras 
occupy the same kind of habitat. 

Behavior 

Cerithium ebumeum is an active snail and crawls 
on the surface of algal-covered stones and shells 
between the grass beds as well as on the blades of 
Thalassia. The snails were normally on the surface of 
the substratum but some burrowing was occasionally 
observed. This snail Uved well in captivity. Its mode 
of locomotion is monotaxic, direct. 

Food and Feeding 

Cerithium ebumeum was fed in captivity on local 
algae and detritus. It was frequently observed eating 
complex algal mats, detritus, and the epiphytic algae 
on Thalassia leaves. Examination of stomach contents 
revealed detritus, fine sand grains, diatoms, blue-green 
algae such as Anacystis aeryginosa and Mirocoleus 
lyngbyaceus, and the green algae Enteromorpha and 
Chaetomorpha. Fecal pellets also contained tlie above 
material and were heavily invested with mucus. 

Associations and Predators 

Cerithium ebumeum is occasionally found with C 
muscarum In the Bear Cut population, the former 
often has its shell covered with filamentous green 
algae. The young of Crepidula fomicata are 
frequently attached to the siphonal canal of C. 
ebumeum (36% of the Bear Cut population). 

The prosobranch snails, Cymatium nicobaricum 
and Fascioloria tulipa were observed eating C. 



ebumeum Many drilled shells were found indicating 
predation by naticid or muricid snails. Crabs such as 
Callinectes sapidus and Calappa flammea were also 
observed eating C ebumeum Randall (1967) found 
C ebumeum in the stomachs of the blenny, 
Labrisomus nuchipinnis, the puffer, Diodon holo- 
canthus, and the porcupine fish, Diodon hystrix. 
Predation by rays is also suspected. 

Growth 

Cerithium ebumeum has an indirect development 
(Houbrick, 1970), but due to difficulties in raising 
the pelagic larvae, it is unknown how long the 
planktonic stage is maintained. Judging from the 
small larval sheUs, and the well-developed velum and 
cilia, the planktonic stage may be lengthy. Fretter 
and Graham (1962) have indicated that in species 
such as Cerithium, where the adult shell has a tall 
spire, there is a fairly long pelagic phase. 

20 



z 



15 



10 




I'll''' I'll 'III, 



JJASONDJ FMAMJJ ASON 
MONTHS OF YEAR 

Fig. 3. Cerithium ebumeura Growth of population 
expressed as a measure of shell length. Vertical lines 
represent range, horizontal lines the mean, and bars, 
the standard deviation. Solid bars represent months 
of oviposition. Asterisk represents months of ovi- 
position when other measurements were not made. 

Young snails 7-8 mm in length were first found in 
the population at midsummer and continued to 
appear through October. Although this was 4 months 
after oviposition, the young that had metamorphosed 
and settled out of the plankton to a benthic 
substratum may have been so small that they were 
overlooked until they attained a larger size. 
Therefore, the young snails that I collected may have 
settled several months earlier. This would indicate 



20 THE NAUTILUS 



January 29. 1974 



Vol. 88(1) 



TABLE 1. Environmental distribution of Centhium and Rliinoclavis species. 



Environments: 1. Sandy bottom 2. Rocky shore 3. Grass beds 4. Sand and rubble 5. Reef edges and fronts. 
Qualitive Abundance: R=rare, P=presenl, C=common, A=abundant. 



Species 



Predominant 

Plant 
Associations 



Intertidal Zone 
MHW MIL MI.W 



Sub tidal 
Zone 



Locale 



Author 



Chaetomorpha 
Gracilaria 
C. lutosum Hypnea 
Halophila 
Enteromorpha 
Tfialassia 



1,2,R 1,2,A 1,2,A 1,P 



Florida This study 



Jamaica Jackson, 1972 



Tlialassia 
C. muscarum Halodule 

Syringodium 



3,R 



3, A 


Florida 


Tliis study 
Jackson, 1972 




Puerto Rico 


Warmke & 


2,C;3,P; 




Almodovar, 


4,C 


Florida 


1963; 
Arnow et al., 
This study 



Hypnea 
C. litteratum Ceramium 
Dictyota 
Halmeda 



Laurencia 
C. eburneum Dictyota 
Padina 
Tlialassia 



C. nodulosum Porolithon 

Lithophyllum 
Polysiphonia 



3,P 



3,C 



5,P 



5,C 
5,P 



Warmke & 
Puerto Rico Almodovar, 

1963; 
Arnow ex^ ah 

1963; 
This study 



C. guinaicum 


- 


4,C 


Florida 


This study 


Enteromorpha 
C. atratum Gracilaria 


- 4,P 


4,A;1,C 


Florida 


This study 



Eniwetok Tliis study 
Seychelles Taylor, 1968 



Vol. 88(1) 



THE NAUTILUS 



21 



Species 



Predominant 

Plant 
Associations 



Intcrtidal Zone 
MHW MTL MLW 



Sub tidal 
Zone 



Local 



Author 



C. columna 



4,C 
3,P;4,P 



Eniwetok This study; 
Seychelles Taylor, 1968 



C. morum Gracilaria 
Thalassia 
Enteromorpha 



Enhalus 
Thalassia 
C. rostratum Syringodium 
Halophila 
Cymodocea 



2,A; 
3,P 

2,A 
2,A 



3,4 



Seychelles Taylor, 1968; 
Eniwetok This study 
Aldabra Taylor, 1971 



C. piperitum - 


. . . 


4,P 


Seychelles 


Taylor, 1968 


C. echinatum - 


. . . 


4,R 

4,A 


Hawaii 
Seychelles 


This study; 
Taylor, 1968 


C. sejunctum Jania 


2,A 2,P - 


- 


Eniwetok 


This study 


C. alveolus Jania 


- 2,A - 


- 


Eniwetok 


This study 


C. articulatum - 


- - - 


3,P;5,C 


Seychelles 


Taylor, 1968 



Aldabra Price, 1971 



Rhinoclavis 
asper 



1,C 
3,C;4,C 



Eniwetok This study; 
Seychelles Taylor, 1968 



R. fasciatus 



1,C 



Eniwetok This study 



R. pharos 



1^ 



Eniwetok This study 



R. sinensis 



4,C;5,P 



Eniwetok This study 
Hawaii 



22 



THE NAUTILUS 



January 29, 1974 



Vol. 88(1) 



that a possible pelagic period of 2-3 months. After 
the larvae settled, growth was rapid; the young snails 
observed in October had reached an adult size by the 
end of November. If one allows a month between 
settling and the first observation of young snails, it 
would take about 2 months for newly settled snails to 
reach a mature size. New growth, indicated by the 
presence of fresh whorls and thin apertural hps, 
occurred from July through November. Growth 
statistics for the entire sampling period are 
summarized in figure 3. Population size, in numbers, 
was lowest during the summer months, indicating 
that after the spawning period many of the adults 
died. The new generation showed up in late summer 
and by eariy winter the population size had 
considerably increased. It is thus probable that the 
Ufe span of this population of C. ebumeum is about 1 
year (Fig. 3). 

ECOLOGY OF CERITHIUM ATRATUM 

Habitat 

This species lives in habitats of considerable 
ecological diversity. It has been collected in shallow, 
sandy bottoms and dredged from deeper waters in the 
open sea. It may be found on limestone substratum, 
areas of rubble, sand, or in Thalassia. 

The collecting site at which C. atratum was studied 
is located at Dunedin, Florida, along St. Joseph 
Sound. The population was found on the north side 
of the causeway that runs to Honeymoon Island. 
Tides here range about 1 m and the causeway shore is 
subject to frequent wave action. Average water 
temperature was 26.7°C, ranging from 17°C in 
January 1969, to 42°C in June 1969. Mean salinity 
was 34.6°/oowith a low of 31"/°° in June 1969, and 
a higli of 38°/°° in July 1969. As in all shallow water 
environments, salinity is subject to sudden change by 
runoff from heavy rains. The bottom of the shallow 
portions of St. Joseph Sound is covered with 
Thalassia. Along the causeway, the bottom is 
irregular, consisting of rubble dredged up when the 
causeway was built. The rocks are covered with 
various filamentous algae and Gracilaria and Enter- 
omorpha-dxe common. Winds, waves and tidal action 
deposit considerable amounts of debris and detritus 
throughout the intertidal zone, and the waters are 
frequendy turbid. 

Cerithium atratum occurs subtidally in great 
numbers (150/m^) just below the low-tide mark in a 
band 2 m wide bordering the causeway. It is usually 



found buried in the calcareous sand around the bases 
of rocks and rubble. This species was rarely seen 
crawling on the substratum except during calm 
periods. It does not occur beyond the rubble area. 

■ lother population observed at Point of Rocks, 
Sarasota, Florida, was browsing upon the 
algal-covered rocks on a rocky subtidal shelf. In 
Sarasota Bay, I found C. atratum crawling subtidally 
on open sandy flats at low tide. 
Behavior 

Cerithium atratum is easy to maintain in the 
laboratory. In the lab, it is a relatively inactive 
animal, is usually burrowing, and moves mostly in the 
dark or when disturbed. Its mode of locomotion is 
monotaxic, direct. In the field, it burrowed and was 
rarely found at the surface of the substratum. 
Clustering on the surface was not observed, but many 
individuals were often found together in the sand at 
the bases of rocks. The animal exhibits a rapid 
shadow response by quickly withdrawing into its 
shell. Dr. Steiger (pers. commun.) claims that this 
species is migratory, but no migration was observed in 
the Dunedin population or at any other sites during 
the study period. 

Food and Feeding 

In tlie aquarium, Cerithium atratum feeds inter- 
mittently. After periods of starvation it is able to 
detect the presence of fresh algae and detritus placed 
in the aquarium and will immediately emerge from 
the sand and begin feeding. Feeding also occurs 
during the night. Stomach contents reveal many 
coarse sand grains, detritus, crustacean appendages, 
diatoms, blue-green algae and other debris. Enter- 
omorpha and unidentified evaculated algal cells were 
also found. In captivity, C atratum fed upon the 
detritus on the bottom of the aquarium, on decaying 
Thalassia and the alga, Enteromorpha. 

Associations and Predators 

The potamidid snail, Batillaria minima, is found 
just above the upper limits of the distribution of C 
atratum and extends upwards to the splash zone. No 
mixing between the two species was seen, (although 
they appear to play the same trophic role in tlieir 
respective zones). Cerithium atratum is frequently 
covered with Enteromorpha, bryozoans, barnacles, 
and young oysters. It is often parasitized by 
annulated rediae which give rise to fork-tailed 
strigeata-Uke cercariae. 



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23 



Predators include the carnivorous snails, 
Plcuroplnca gigantca, Fasciolaria himteria, Busycon 
contnirhini and Mclongena corDiia. The crab, 
Menippe, was also seen eating C. atratun Off-shore, 
C. atratum is frequently found in the stomach of the 
starfish Astropectcn articulatus (W. Lyons, pers. 
commun.). 

Growth 

Although samples of this population were collected 
monthly over a period of two and one half years, no 
significant changes in the mean length of individuals 
in the population occurred. Oviposition occurs from 
March througli July and development is indirect. A 
few young snails were found in November, December, 
and January of 1970, but despite thorough screening 
of the sediments, no other juveniles were en- 
countered. Consequently, it is not possible to 
estimate the growth rate of this population. 

ECOLOGY OF OTHER SPECIES 

Other, less detailed, observations were made on 
Cerithium species in Florida, the Caribbean, and in 
the Pacific. 

In Florida and the Caribbean, populations of 
Cerithium litteratum (Born) occur just at the low tide 
mark and subtidally. They are usually associated with 
algal-covered rocks and rubble found near the shore 
hne and in shallow water patch reefs. 1 observed a 
large subtidal population of C. litteratum on an 
algal-covered rocky bottom off of Boca Raton, 
Florida. Stomach contents of members of this 
population contained detritus and the algae Eiiter- 
omorpha and Cliaetomorpha. 

Dead snails with drilled shells were common at 
Boca Raton indicating predation of boring gastro- 
pods. Randall (1967) found C. litteratum in the 
stomach of the puffer fish, Diodon holacanthus. 

Cerithium guinaicum Philippi, 1849, /=C. 
auricoma Schwengel] ' occurs subtidally (1-3 m) in 
southern Florida and throughout the Caribbean under 
rocks and in the sandy pockets associated with reef 
flat rubble, 1 found large populations in reef habitats 
both at Sand Key, Florida and along the barrier reef 
off British Honduras. Captive specimens avoid briglit 
light. Stomach contents contain detritus, 
Foraminifera and carbonate sediments. Many drilled 
shells were seen. 



In the Pacific, at Eniwetok Atoll, Marsh:ill Islands I 
observed members of the genus Cerithium and the 
closely related genus Rhinoelavis in the shallow water 
on reef flats and lagoons. Wiens (1962) has discussed 
the general ecology of atolls and the Marshall Island 
group. At Eniwetok. different species of Cerithium 
are separated by microhabitat, bottom types and tidal 
zonation. Cerithium moms Lamarck occupies the 
higher tidal zones, where it is found under rocks and 
on beach rock. On the windward limestone benches, 
C. alveolus Hombron & Jaquinot is found associated 
with the alga, Jania at about the midtide mark, 
Cerithium columna Sowerby and Rhinoclavis sinensis 




C. auricoma Schwengel. 1940 is a synonym of C guinaicum. 



Fig. 4. A., Cerithium atratum (Born) [Jormerty C. 
floridanum Morchj B., Cerithium lutosum Menke 
(formerly C. variabile C. B. Adams): C, Cerithium 
eburneum Bruguiere; D., Cerithium muscarum Say. 



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Vol. 88(1) 



(Gmelin) are most common on the patch reefs and in 
the rubble at the edges of coral reefs. Cerithium 
nodulosum Bruguidre is found on rocky substratum 
just shoreward of the windward reef edges. 
Rhinoclavis fasciatus (Bruguiere) and R. asper 
(Linnaeus) are found in sandy bottoms of leeward 
lagoons. 

Taylor and Lewis (1970) found four species of 
Cerithium in the marine grass beds of Mahe, 
Seychelles. All were algal-detritus feeders. Cerithium 
rostratum Sowerby lives in grass beds in the leaves. 
Cerithium moms is present in large numbers in the 
sediment surface of the grass beds, in contrast to its 
habitat on Eniwetok. Riiinoclavis asper is found 
buried beneath the sediment on windward reefs. 

The stomach contents of these Indo-Pacific species 
consisted primarily of detritus, carbonate sediments 
and algae. Cladophora and Chaetomorpha were found 
in the stomach of C morus while the blue-green alga, 
Lyngbia and the red alga, Poiysiphonia, were 
common in the stomach of C nodulosum, Taylor and 
Lewis (1970) observed C rostratum engulfing the 
epiphytic alga, Enhahts on Seychelles. 

I observed the camiverous snail, Cymatium 
nicobaricum, eating Cerithium columna at Eniwetok. 
The same predator eats Rhinoclavis sinensis in Hawaii 
(Houbrick and Fretter, 1969). The snsA, Pleuroploca 
trapezium, preys upon C. echinatum (Lamarck) in 
Seychelles (Taylor and Lewis, 1968). Morula 
granulata, a muricid snail, reportedly eats Hawaiian 
species of Cerithium (Kohn, 1970). 

DISCUSSION 

The environmental distributions of members of the 
genus Cerithium are summarized in Table 1. Most 
species are tropical or subtropical, and temperature is 
undoubtedly the primary limiting factor in their 
distribution. It is difficult to derive any coherent 
ecological conclusions because only four species and 
their respective stations were examined in detail and 
the geographic ranges of these four species are 
extensive. Moreover, some species, such as C 
lutosum, occur in a variety of habitats and under 
differing environmental regimes. Substrate prefer- 
ences of cerithiids appear to vary between soft and 
hard bottom types. Most species occur on sandy 
bottoms or hard bottoms with algal mats. 

In terms of vertical distribution, the species most 
frequently exposed during low tides in the Western 
Adantic are Cerithium lutosum and C muscarum. 



Cerithium lutosum, the smallest member of the genus 
in the western Atlantic, occupies the highest tidal 
level, close to shore, while C. ebumeum, C. atratum 
and C litteratum occur subtidally. C. guinaicum lives 
in the deepest zones. C atratum, C. litteratum and C. 
guinaicum are the largest of the western Atlantic 
species. 

In the Pacific, C. morus, C. alveolus and C 
sejunctum, all small species, occupy the intertidal 
zone; C. morus lives in the highest tidal zone; C. 
columna and C. echinatum are found subtidally; the 
largest species, C. nodulosum, occurs in deeper, 
subtidal zones. Thus a pattern emerges in which 
species which are found intertidally are smaller than 
those occuring subtidally. Jackson (1972) noted the 
same phenomenon in Jamaica and suggested that 
epifaunal moUusks from high stress environments 
tend to be much smaller than their more stenotypic 
relatives. Atapattu (1972) found that Cerithium 
species in Ceylon were more abundant in sheltered 
places along the coast. 

In Florida C. muscarum and C lutosum are more 
euryhaline than other species although C atratum is 
in the brackish waters of the Intercoastal Waterway at 
St. Lucie, Florida. Parker (1959) found C lutosum in 
the hypersaline waters of the Laguna Madre, Texas. 

Many species of Cerithium are loosely associated 
with beds of marine grasses such as Tlialassia and 
Ruppia. A summary of the plant and algal 
associations with Cerithium species througliout the 
world is given in Table 4. 

All species of Cerithium that I examined are 
style-bearing algal-detritus feeders. In Florida, the 
Caribbean, and the Pacific, I observed several species 
occuring together in the same general habitat. Kohn 
(1971) has suggested that co-occurring congeners that 
feed selectively on detritus tend to specialize to 
different micro-habitats. This is probably true of 
Cerithium species because the stomach of all 
examined species are complex structures, higWy 
specialized for the sorting and transport of small 
particles and detrital material, indicating that partical 
selection is taking place. DriscoU (1972) found that 
the stomachs of the potamidids, Batillaria zonalis and 
Cerithidea califomica, were specialized to selectively 
transport and digest a continuous supply of detritus 
by means of complex ridges, grooves and ciliary 
currents. Batillaria and Cerithidea species are related 
style-bearing mesogastropods of the super-family 
Cerithicaeae. The role of detritus in the nutrition of 



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25 



marine detritus feeders has been discussed by Newell 
(1965) who suggested that animals living on detritus 
feed by abstracting proteins from the bodies of 
microorganisms, such as bacteria that coat the silt and 
organic debris, and reject the organic carbon 
compounds with the feces. Odum(1971) pointed out 
that detritus feeders obtain some of their energy 
directly from plant material, most of it secondarily 
from microorganisms, and some tertiarily through 
carnivores, such as protozoa and small invertebrates. I 
was unable to distinguish what the sympatric species 
of Cerithium selectively ate and consequendy their 
exact ecological niches in the trophic scheme remain 
unknown. It is probable that competition is avoided 
and ecological niches determined by particle selection 
in the complex sorting mechanisms of the stomach. 
But as Odum (1971) stated, apportioning the energy 
sources utilized by detritus feeders at the individual 
and species level presents a difficult technical 
problem which has not been solved. 

I observed many Cerithium species engulfing algae 
as well as detritus, especially the small epiphytic algae 
associated with blades of marine grasses. Feeding 
occurs continuously as in most mollusks possessing a 
style (Graham, 1939). A review of style-bearing 
gastropods and their feeding occurs in Driscoll 
(1972). The abundance of detritus and algae in 
shallow water habitats probably reduces competition 
for food among sympatric members of the genus 
Cerithium 

The reproductive biology of the genus Cerithium 
has already been discussed (Houbrick, 1970; 1971; 
1973, in press). 

Cerithium muscarum, C. lutosum, C. ebunieum, 
and C. atratum exhibit a definite seasonal repro- 
ductive activity. Oviposition occurs in these species 
from winter througli spring. Young snails appear in 
the populations during the summer and eady autumn. 

1 was unsuccessful in attempts to rear newly 
hatched snails to adulthood, but size frequency data 
along with qualitative observations indicate that it 
takes about one year to attain maturity. Raeihle 
(1968) was successful in rearing larvae of C hitosum 
from the Florida Keys to adulthood. She found that 
the larval shells were less than 1 mm in length 5 
weeks after hatching; at 1 2 weeks they had reached 
1.3 mm and by 13 months they were 8-11 mm in 
length and were reproductively mature, having 
spawned 13 months after the time of hatching. These 
findings are compatible with my size-frequency data 



which indicate a life-span of one year. 

It is more difficult to determine the growth rates 
of Cerithium species with pelagic life histories than 
those with direct life histories because the time spent 
in the plankton before settling is unknown, and one is 
never sure if the juveniles found in a population are 
products of the spawn of that particular population. 
The results of this study indicate that the Florida 
populations of C. lutosum, C. muscarum and possibly 
C ebunieum grow from juvenile stages to adult stages 
in a few months, and that their life spans last 
approximately one year; however, spawning and 
growth may vary in other populations of Cerithium 
species depending upon their geographic distribution. 
Lewis et al. (1969) found different rates of growth 
for the same species of mollusks, depending upon 
their latitudinal distribution in the Caribbean. They 
also mentioned that microclimatic differences are 
equally as important as latitudinal ones. The annual 
cycles of the species studied indicate that the 
majority of the adult populations die after spawning. 
Vohra (1970) observed the same phenomenon in 
Cerithidea cingulata. 

Horizontal movement, migration and seasonal 
recruitment from other areas were not observed in 
the populations of C. lutosum and C. muscarum; 
despite the fact that these species have a direct 
development, it is possible that eggs on marine grasses 
may drift from one locality to another. In species 
with indirect development, recruitment from other 
populations is probable. More detailed studies may 
reveal subde tidal or season migrations in Cerithium 
species. Mark and recapture experiments with 
Cerithium stercusmuscanim indicate a migratory 
pattern due to positive phototaxis to the rising sun 
(Burch and Burch, 1970). Vohra (1965, 1970) found 
that the potamidids, Pyrazus ebenitjus and Cerithidea 
cingulata, migrated with tides and seasons, respec- 
tively. Horizontal and vertical migrations may be 
correlated with drainage and presence of detrital food 
as well as with spawning behavior. A discussion of 
these factors may be found in Vohra (1970). 

1 observed segregation between older (larger) and 
younger (smaller) individuals of C lutosum Older 
specimens were found further upshore while the 
younger ones occurred just subtidally. A similar 
segregation pattern was also noticed by Vohra (1970) 
in Pyrazus ebeninus. 

Some clustering of Cerithium lutosum, C. morum, 
C. alveolus and C sejunctum occurs at low tides. 



26 



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January 29. 1974 



Vol. 88(1) 



Moulton (1962) believed that this phenomenon is an 
adaptation of Ceriihium to drying conditions and 
higli temperatures on tropical beaches and postulated 
that clustering is a homeostalic mechanism. He 
suggested that Ccrithhim possesses a hydrostatic 
mechanism which helps to determine whether the 
animals shall be clustered or dispersed. Fischer (1966) 
added the idea that adhesion to a preferable 
substratum may also be a factor in aggregation. 

The potamidid snail, Batillaria minima was found 
closely associated with most of the Ccrithiiim species 
in Florida. Batillaria appears to fulfill the same 
trophic function as Cerithium only at a higlier level in 
the tidal /one. Its close association and resemblance 
to Cerithium lutosum has led to confusion between 
the two species (Abbott, 1954), and to erroneous 
reports of egg laying, etc. At Port Everglades, Bear 
Cut, and Pigeon Key, Florida, 1 observed the two 
species overlapping in a minor degree in their vertical 
distribution. During periods of high seas they are 
frequently mixed together. 

Considering the great numbers of snails observed in 
the study areas, it is surprising that more predators of 
Cerithium were not seen. Most of the predators listed 
in this study were observed infrequently and only 
account for minimal mortality. Fish may prove to be 
the main predators of the species with very large 
populations. A more quantitative study of predation 
is needed in order to elucidate the exact position of 
Cerithium species in the trophic structure of the 
shallow-water communities they inhabit. 



ACKNOWLEDGEMENTS 

This paper forms part of a series dealing with the 
biology of the genus Cerithium Much of the work 
was done as part of a PhD program at the University 
of South Florida at Tampa under the direction of Dr. 
Joseph L. Simon. I am indebted to him for his help, 
guidance and criticism during tlie project. My thanks 
are also due to the members of my committee and 
the faculty of the Department of Biology. My 
appreciation is extended to Cathy Lamb who kindly 
assisted in the proof-reading of the manuscript. My 
thanks are also extended to Sally Kaicher who kindly 
took the photographs. Support for the work at 
Eniwetok was provided by the U.S. Atomic Energy 
Commission througli the University of Hawaii and the 
Eniwetok Marine Biological Laboratory. 



LITERATURE CITED 

Atapattu, D. H. 1972. Littoral moUusks of Ceylon. 
Mar. Biol. 16: 1. SO- 164. 

Burch, T. A. and B. L. Burch 1970. Dispersion of 
Cerithium stercusmuscarum on a tidal sand flat. 
The Echo, 1970: 18. 

Dragovich, A. and J. Kelly 1964. Ecological 
observations of macro-invertebrates in Tampa Bay, 
Florida. Bull. Mar. Sci. 14(4): 74-102. 

DriscoUe, A. L. 1972. Structure and function of the 
alimentary tract of Batillaria zonalis and 
Ceriihidea califoniica, stylebearing mesogas- 
tropods. The Veliger 14(4): 375-385. 

Fischer, P. 1966. Disposition gr^gaire chez un 
Cerithium Indo-Pacifique. Jour. Conchyl. Paris. 
105:49-52. 

Fretter, V. and A. Graliam 1962. British Prosobranch 
MoUusks. Ray Society, London. 755 p. 

Graham, A. 1939. On the Structure of the 
Alimentary Canal of style-bearing Prosobranchs. 
Proc. Zool. Soc. London (Ser B.) 109: 75-1 1 2. 

Graham, A. 1955. MoUuscan diets. Proc. Mai. Soc. 
London 31: 144-1.59. 

Houbrick, J. R. 1970. Reproduction and develop- 
ment in Florida Cerithium Amer. Mai. Union Inc., 
Ann. Rep. 1970:74. 

Houbrick, J. R. 1971. Some aspects of the anatomy, 
reproduction, and eady development of Cerithium 
nodulosum Brugui^re (Gastropoda, Prosobranchia). 
Pacific Sci. 25(4): 560-565. 

Houbrick, J. R. 1974. Studies on the reproductive 
biology of the genus Cerithium in the Western 
Atlantic. BuU. Mar. Sci. (in press). 

Houbrick, J. R. and V. Fretter 1969. Some aspects of 
the functional morphology and biology of 
Cymatium and Bursa. Proc. Mai. Soc. London. 38: 
415-429. 

Hutton, R. F. and F. Sogandares-Bemal I960. Studies 
on helminth parasites from the coast of Florida, II. 
Digenetic trematodes from shore birds of the west 
coast of Florida. Bull. Mar. Sci. Gulf and Carib. 
10(1): 40- .54. 

Jackson. J. 1972. The ecology of the mollusks of 
Thalassia communities in Jamaica, West Indies. II. 
Molluscan population variability along an environ- 
mental stress gradient. Mai. Biol. 14(4): 304-337. 



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27 



Kohn, A. J. 1970. Food habits of the gastropod A/;7ra 

Uttcrata Lamarck: Relation to trophic structure of 

the intertidal marine bench community in Hawaii. 

Pacific Sci. 24(4): 483-486. 
Lewis. J. B., F. Axelsen. L Goodbody, C. Page. G. 

Chislett, and M. Choudhoury 1969. Latitudinal 

differences in growth rates of some intertidal 

mollusks in the Caribbean. Mar. Sci. Manuscript. 

Rep. 1 2, McGiU Univ., Toronto. 89 p. 
McNulty, J. K. 1962. Level sea bottom communities 

in Biscayne Bay and neighboring areas. Bull. Mar. 

Sci. Gulf and Carib. 12(2): 204-233. 
Moore, H. B. 1958. Marine Ecology, Wiley and Sons, 

New York. 493 p. 
Mornll, J. B. and F. G. W. Olson 1955. Literature 

survey of the Biscayne Bay area. Fla. State Univ. 

Oceanogr. Inst. Mimeo. Rpt. to U.S. Navy Hydro. 

Office. 1 34 p. 
Moulton, J. M. 1962. Intertidal clustering of an 

Australian gastropod. BioL Bull. 123(1): 170-178. 
Newell, R. 1965. The role of detritus in the nutrition 

of the marine deposit feeders, the prosobranch 

HydnMa itlvae and the bivalve, Macoma halthica. 

Zool. Soc. (London), Proc. 144: 25-45. 
Odum, E. P. 1971. Fundamentals of Ecology, 3rd 

Ed., W. B. Saunders Co., Philadelphia. 574 p. 
Parker, R. H. 1959. Macro-invertebrate assemblages of 

central Texas coastal bays and Laguna Madre. Bull. 

BOOK 

AMERICAN MALACOLOGISTS. (editor) R. Tucker 
Abbott. First Edition, iv + 494 pages. American 
Malacologists, 6314 Waterway Drive, Falls Church, 
Virginia 22044. Hardbound, $12.50. 



This is the first attempt to bring together the 
biographical sketches of all American malacologists, 
both past and present. Its scope is wide, as it covers 
both the professional and amateur students interested 
in any phase of the mollusca. 

These personal sketches cover a wide spectrum of 
facts, not only the vital statistics, but in addition, the 
interests, travels, publications and other data of much 
historical value. Many of the deceased persons 
covered in the book built up important shell 
collections. A large number of these collections have 
been given or sold to museums. Their present location 
is of considerable value to historians and research 
workers as a source of much informative data. 



Amer. Assoc. Petrol. Geologists. 43(9): 2100-2166. 
Raeihle. D. 1968. Notes on captive Ccrithium 
variabilc and Mitra floridana. Amer. Mai. Union, 
Inc. Ann. Rep. 1968: 35-36. 

Steel, R. and J. Torrie I960. Principles and 
procedures of statistics. McGraw-Hill, New York. 
481 p. 

Tabb, D. C, D. L. Dubrow, and B. Manning 1962. 
The ecology of northern Florida Bay and adjacent 
estuaries. State of Fla. Board of Conserv. Tech. 
Ser. 39: 81 p. 

Taylor, J. 1968. Coral reef and associated inver- 
tebrate communities (mainly molluscan) around 
Mahe, Seychelles. Phil. Trans. Roy. Soc. London 
254B: 129-206. 5 pis. 

Taylor, J. and M. S. Lewis 1970. The flora, fauna and 
sediments of the marine grass beds of Mahe, 
Seychelles. Journal. Nat. Hist. 4: 199-220. 

Vohra, F. C. 1965. Ecology of intertidal Zostera flats 
of Moreton Bay. Ph.D. Thesis, University of 
Queensland. 

Vohra, F. C. 1970. Some studies on Cerithidea 
cingidata (Gmelin 1790) on a Singapore sandy 
shore. Proc. Mai. Soc. London, 39(2/3): 187-201. 

Wilbur. K. M. and G. Owen 1964. Growth, pp. 
211-242, In K. M. Wilbur and C. M. Yonge, 
Physiology of Mollusca. Academic Press, N.Y. 

REVIEW 

A feature of considerable importance, in addition 
to the biographies of 539 past workers, is a list of 420 
persons about whom little is known other than their 
names. These people have had a particular interest in 
mollusks, and most of them at one time or another 
reached die printed page either as authors or 
collectors. Dr. Abbott hopes that interested persons 
may be able to add new data or give references where 
such information may be found. Completion of this 
section will be a major contribution to the history of 
our science. 

Analyses have been made of all living malacologists 
as to their geographic location, their individual fields 
of research and endeavor, and their main occupation 
if they are not professional malacologists. Among our 
reference books, this will be one of the most 
frequently consulted. 

William J. Clench 

26 Rowena Street 

Dorchester, Mass. 02124 



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Vol. 88(1) 



ON A SINISTRAL SPECIMEN OF LIGVUS VIRGINEUS 
(WITH ADDITIONAL REMARKS ON THE GENUS LIGLVS) 

Morris K. Jacobson and William E. Old, Jr. 

American Museum of N;itural History 
New York, New York 10024 



Sinistral specimens of Ligitus virgineus 
(Linnaeus) from Hispaniola are exceedingly rare. 
Pilsbry (1899: 163-164) listed five records known 
up to that time, citing illustrations for three of 
lliem. However, the figures published by Klister & 
Pfeiffer (pi. 14, fig. 9, 10) are copies of those of 
Chemnitz (1788, pi. 173, figs. 1682-1683) so that 
up to the present, sinistral specimens have been 
figured only by Favanne (1780, pi. 65, fig. G4) 
and Qiemnitz (1788). 

The specimen here illustrated, therefore, is of 
interest. Tire shell was presented to The Ainerican 
Museum by Mr. Burton Anderson of Dania, 
Rorida, who found it, together with another such 
specimen, in a shipment of L. virgineus from 
Haiti. No other data are available. 

The present specimen measures 33 mm in 
height, 18.5 mm in width, aperture height 12 mm. 
The color bands are as follows: a yellow band 
below the suture, a purplish-black band, a slate 
blue one, and a rose one at the periphery. There 
is a faint yellow band encircling the base. 

A word might be added here about the rarity 
of this type of teratology in the genus Ligitus. 
Pilsbry (1946: 39) guessed that it occurs among L. 
fasciatus (Miiller) in Rorida in the order of one in 
10,000 and cited the testimony of Mr. R. F. 
Deckert who knew of only 9 sinistral shells. W. J. 
Clench (personal communication) stated that he 
has examined perhaps 60,000 specimens of Liguus 
without having encountered a single sinistral spec- 
imen. 

Dautzenberg (1914; 51) commented on the 
relative abundance of reported sinistral shells 
among Helix pomatia Linnaeus and H. aspersa 
Miiller as compared to other pulmonale species. 
He concluded that this is probably due to the fact 
that the former were collected - even bred - in 
vast numbers for culinary purposes and thus many 
more shells came to the attention of collectors. 
This would also partly explain the scarcity of 
similar shells in the genus Liguus. 



Two other mmor comments can be made. 
Dautzenberg (1914) presented a list of all species 
in which dextral and sinistral teratological speci- 
mens were reported, but strangely included Liguus 
poeyanus (Pfeiffer) (=vittatus Swainson) of Cuba, a 
species which like Amphidwmus from southeastern 
Asia, appears ambidextrously in most populations. 
Zilch (1960: 518) erroneously included Cozumel 
Island as lying within the range of Liguus 
(Oxystwmbusj. This subgenus is limited to south- 
ern Florida, Cuba, and the Isle of Pines - which 
Zilch transcribes in the Portuguese fashion as 'Isla 
dos Pinhos.' 

LITERATURE CITED 

Chemnitz, J. H. 1788. Neues Systematisches 

Conchylien-Cabinet, Nurnberg, 10: 1-376, pis. 

137-173. 
Dautzenberg, P. 1914. [Sinistrosites et dextrosites 

teratologiques chez les moUusques gasteropods] . 

Bull. Soc. Zool. de la France 39: 50-59. 




FIGS. 1 and 2. Liguus virgineus from Haiti Lej.. 
a specimen of the dextral or normal form, 32 mm. 
in height. Right. Sinistral specimen, 33 mm, in 
height. (Photos courtesy of The American Museum 
of Natural History). 



Vol. 88(1) THE NAUTILUS 29 

ftvanne de Montcervelle. 1780. 3rd Edition of Land Mollusca of North America (North of 

Desallier D'Argenville's La Conchyliologie. Paris, Mexico). Acad. Nat. Sci. Philadelphia, Mono- 

2 vols, and atlas. graph 3, 2 (1): 37-102, figs. 20-50 + colored 

Kiister, H. C. and L Pfeiffer [1840] -1857- [1865]. frontispiece (genus Liguus) 

Systematisches Conchylien-Cabinet, (1) 13: Smith, E. A. & H. W. England. 1937. Jour. Soc. 

281-304 [pi. 14 appeared in 1843, fide Smith Bibliog. Nat. Hist. 1: 89-99. 

and England, 1937.] Zilch, A. 1960. Gastropoda, pt. 2, Euthyneura 

Pilsbry, H. A. 1899. Manual of Conchology (2) [in] Handbuch der Paliiozoologie, Berlin (6) 3: 

12: 160-175, pis. 55-60 (genus Liguus). 1946. 517-518, figs. 1803-1805 (genus /./gw«x). 



THE CHROMOSOME NUMBER OF EUGLANDINA ROSEA 
(STYLOMMATOPHORA: OLEACINIDAE) 

Edward M. Stem 

Department of Zoology and Physiology 
Louisiana State University 
Baton Rouge, La. 70803 

ABSTRACT 

No chromosome numbers have been reported for members of the Stylom- 
matophoran family Oleacinidae. Examination of chromosome spreads for Euglandina 
rosea (Fentssacj revealed a haploid number of n=29. It has been suggested that 
higher chromosome numbers may be correlated with phylogenetically more advanced 
or morphologically specialized Euthyneuran snails. The high chromosome number 
obtained here substantiates this, even in the light of the extremely conservative 
nature of chromosome numbers. 



^-# • •^ 



Chromosome numbers are known for less than 
0.5% of the species of recent mollusks, and none 
has been reported for members of the Stylom- 
matophoran family Oleacinidae. Several individuals 
of Euglandina rosea (Ferussac) were collected in 
January, 1973, from under moist debris along the 
Mississippi River levee. Port Allen, West Baton 
Rouge Parish, Louisiana. The snails were injected 
directly through the shell near the apical whorl 
with .15cc of Velban (Img/ml concentration) and 
returned to their container. They were sacrificed 
approximately 16 hours later and the ovotestis 
removed. Meiotic chromosome squashes were pre- 
pared using an acetic-orcein squash technique as 
described by McPhail and Jones (1966). 

Six spreads of E. rosea were examined and 
revealed a haploid number of n=29 (Fig. 1). 1^ •■ 

Morphologically, with regard to the modified 

radular teeth, and ecologically, as evident by its FIG. 1. Meiotic chromosomes of Eu^andim rosea, 

carnivorous diet, E. rosea might be considered a Scale line = 5 micra. 






30 



January 29, 1974 



Vol. 88 (1) 



specialized species. Burch (1965), Patterson (1969 
and 1971) and others have suggested that higlier 
chromosome numbers may be correlated with 
phylogenetically more advanced or morphologically 
specialized Euthyneuran snails. Conversely, lower 
chromosome numbers are found in the more 
"primitive" groups. Tiie infraordcr Hoiopoda con- 
tains some relatively morphologically specialized 
groups of land snails, including the active, rapa- 
cious members of the family Oleacinidae. Haploid 
chromosome numbers for the Hoiopoda range 
from n=21 to n=3l. The high hapkiid chromosome 
number (n=29) of E. rosea seems to substantiate 
the above contention. 

The chromosome number for E. rosea is similar 
to those found for other species in the suborder 
Signiurcthra, which is ihouglit to be the most 
advanced Stylommatophoran group with a mean 
chromosome number of 28.6 and a mode of 29 
(Patterson, 1971). Ranier (1967) stated that, in 
general, relationships suggested by cytologjcal 
studies have correlated well with the modern 
classification of the Stylommatophora. However, 
because of (1) the extremely conservative nature 
of chromosome numbers, even at the subordinal 
level as noted above, and (2) the number of 
exceptions, as pointed out by Ranier (1967) in 
the Helicidae, a broad statement may not yet be 



justified. Nevertheless, when used in conjunction 
with other techniques, cylolaxonomy represents a 
valuable tool that may be used by the systematist 
in an attempt to confirm or question phylogenetic 
relationships previously based solely upon morph- 
ological and/or anatomical features. 

ACKNOWLEDGMENT 

Special thanks are given Dr. J. B. Burch for his 
comments concerning this paper. 

LITERATURE CITED 

Burch, J. B. 1965. Chromosome numbers and 

systematics in euthyneuran snails. Proc. First 

Europ. malacol. Congr., 1962, p. 215-241. 
McPhail, J. D. and R. L. Jones. A simple 

technique for obtaining chromosomes from 

teleost fishes. J. Fish Res. Bd. Canada 23: 

767-769. 
Patterson, C. M. 1969. Chromosomes of molluscs. 

Proc. Symp. Moll., Mar. Biol. Assoc. India 

1969: 635-686. 
Patterson, C, M, 1971. Taxonomic studies of the 

land snail family Succineidae. Malacol. Rev. 4: 

131-202. 
Ranier. M. 1967. Chromosomenuntersuchungen an 

Gastropoden (Stylommatophora). Malacologia 5: 

341-373. 



BOOK REVIEW 



SEASHELL PARADE. By A. Gordon Melvin. 369 
pp., 74 ph., 1 in color. Charles E. Tut tie, Co., 
Rutland, Vt. 0570 L Hardback, $11.50. 



For shell collectors who enjoy reading about shells 
and learning more about their usefulness and interest 
to man, this book will supply many pleasant hours. 
The 76 short chapters consist of illustrated vignettes, 
many of which had been published in Hobbies 
Magazine. A novel chapter at the end covers the 
biographies of some malacologjsts. The author 
requests readers to send in data on living malacolo- 



gists, but this project is now superseded by the rather 
extensive biographies recently pubhshed in the 
national register. "American Malacologists. " 

An excellent chapter gives a panoramic treatment 
of some of the shell books likely to be of most 
interest to shellers. Curiously, however, the author 
has evidently forgotten that the writer of the famous 
children's book. Captain January, was Mrs. Laura E. 
Howe Richards, and not California's Julia Ellen 
Rogers, author of The Shell Book. 

R. Tucker Abbott 

du Pont Chair of Malacology 

Delaware Museum of Natural History 



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APRIL, 1974 



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THE 
NAUTILUS 

Volume 88, number 2 — April 1974 

CONTENTS 

Harald A. Rehder and Clifton S. Weaver 

A New Species of Volutocorbis from South Africa 31 

Harald A. Rehder 

On the Genus Volutocorbis with Descriptions of Two New Species from 

South Africa 33 

Don Mauer, Les Watling and Glenn Aprill 

The Distribution and Ecology of Common Marine and Estuarine Pelecypods 

in the Delaware Bay Area 38 

Glenn A. Long 

Frog Motifs on Archaeological Mollusks of Hohokam and Mogollon Indian 

Cultures 47 

Donald W. Kaufman 

Additional Record tor Mesodon leatherwoodi (Pulmonata: Polygyridae) 51 

Alice Denison Barlow 

New Florida Records tor Hypselodoris edenticulata (Nudibranchia: 

Dorididae) 52 

M. Ellen Crovo 

Further Notes and Corrections Concerning the Spawn of Florida 

Cyphoma (Ovulidae) 53 

Dominique A. Bucci 

Viviparus malleatus in Montreal, Canada 55 

John N. Rinne 

The Introduced Asiatic Clam, Corbicula, in Central Arizona Reservoirs 56 

Stanley V. Margolis and Robert E. Carver 

Microstructure of Chalky Deposits Found in Shells of the Oyster, 

Crassostrea uirginica 62 

Fred B. Blood and Marceile B. Riddick 

Unionidae of the Pamunkey River System, Virginia 65 

Lowell L. Getz 

Arion subfuscus in the Vicinity of Washington, D.C 66 

Allyn G. Smith 

Galapagos Bulimulids: A Taxonomic Correction 67 

Joan Antill 

Another Fossil Ovoviviparous Turritella 67 

News and Errata 68 

Book Reviews 

(of) Louie Marincovich, 37; Arthur H. Clarke 45 



III 




Marine MoUuscan Genera 
of Western North America 

An Illustrated Key 

A. Myra Keen & Eugene Coan 

Second Edition. First published in 1963, this 
Key has become the standard reference work 
and handbook in its field. This second edition 
has been completely revised and reset, the page 
size has been reduced to make the book more 
portable, and the illustrations have been pro- 
vided with additional information to aid the 
novice in making easy identification. The text of 
the Keys takes account of the most recent 
nomenclatural changes and introductions of 
genera to the region, and an entirely new section 
has been added to identify the species used for 
each illustration in the Keys. The Systematic 
Lists, Notes on Ranges and Habitats, Glossary, 
and Bibliography have been greatly expanded 
and revised; and the Systematic Lists now in- 
clude the many non-shelled genera to be found 
on the Pacific Coast. $8.75 



Stanford University Press 



Vol. 88 (2) 



THE NAUTILUS 



31 



ANEW SPECIES OF VOLUTOCORBIS FROM SOUTH AFRICA 

Harald A. Rehder 

National Museum of Natural History 

Smithsonian Institution, Washington, D. C. 20560 

and 

Clifton S. Weaver 

1038 Mokulua Drive 

Kailua, Hawaii 96734 



Some years ago Mrs. Helen Boswell, of 
Valhalla, Transvaal, South Africa, sent speci- 
mens of an apparently new species of 
Volutocorbis to the junior author, who 
prepared a preliminary description. Somewhat 
later Mrs. Boswell sent further specimens of 
the same species to the senior author. In view 
of this we have decided to prepare this paper 
jointly. 

In addition to expressing our appreciation 
to Mrs. Boswell for her continuing coopera- 
tion, we also wish to thank Mr. Michael 
Meyer, of Durban North, Natal, and Mr. 
Kenneth J. Fuller, of Lambton, Germiston, 
Transvaal, both of whom have sent us 
material of the new species. A fine specimen, 
which has been made the holotype, was sent 
us recently by Mr. Richard N. Kilburn, of the 
Natal Museum, Pietermaritzburg, to whom we 
express our thanks. 

After this paper was completed two further 
specimens were loaned to us by Mr. William 
E. Old, Jr. of the American Museum of 
Natural History. These specimens, found 
attached to Xenophora pallidula Reeve, were 



received from Mr. C. P. Fernandes of 
Lourengo Marques, Mozambique. They repre- 
sent an extension of range, and so have been 
included in this paper. Our grateful thanks to 
Mr. Old for allowing us to examine this 
material. 

Volutocorbis semirugata 

Rehder and Weaver, new species 

Figs. 1-8 

Diagnosis — Shell of medium size, 33.0 to 
55.3 mm (VA to 2V4 inches) in length, rather 
shiny, axial ribs absent on body whorl or if 
present found only below angulate shoulder 
as low broad, rather obscure folds, especially 
in early portion of whorl. Outer lip very much 
thickened and reflected, posteriorly ascendant 
on penultimate whorl, sometimes obscurely 
denticulate, especially in gerontic specimens. 
Resembles V. gilchristi (Sowerby, 1902) but 
is larger, with weaker sculpture on last whorl, 
and with sloping shoulder, not canaliculate 
subsuturally. 

Range — From off central Natal, South 
Africa, between Durban and the mouth of the 




FIGS. 1-8. Volutocorbis semirugata Rehder 
and Weaver, new species: Figs. 1, 5, holotype. 
Natal Museum Moll. 9939, 45.1 mm. in 
length. FIGS. 2, 6, paratype #1, USNM 



709349, 54.3 mm. in length. FIGS. 3, 7, 
paratype #3, Boswell Colin., 47.9 mm. in 
length. FIGS. 4, 8, paratype #7, Boswell 
Colin., 38 mm. in length. 



32 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



Tugela River, to off Louren90 Marques, 
Mozambique, in 100 to 280 fathoms. 

Description — Shell of medium size, 33.0 
to 55.3 mm (I'/i to 2'/^ inches) in length, 
elongately ovate. Ground color pale yellow to 
straw color or light grayish yellowish brown, 
sometimes bluish gray on the body whorl; 
fresh specimens vnth interrupted (occasion- 
ally continuous) axial streaks of reddish 
browTi or with spiral bands of interrupted 
blotches of reddish brown. Protoconch 
mammillate, with 2V4 smooth, rounded, pale 
straw-color whorls, initial whorl slightly 
tilted. Early postnuclear whorls with low, 
rather distant axial ribs that show a small 
node below the suture, and a somewhat 
larger one on the shoulder, with an obscure 
one below, or rarely above. The subsutural 
series may increase in strength for one or 
more whorls and then decrease, or the series 
may rapidly become obscure, ridgelike, and in 
the last whorl disappear; the shoulder knobs 
are strongest on the antepenultimate and 
penultimate whorls but become weaker on 
the last whorl, being present either as one or 
two unequal low ridges or a series of low 
nodes. The lower half of the body whorl is 
strongly marked by spiral grooves, which 
towards the base form angulate ridges. 
Aperture long, narrow, slightly arcuate, the 
anterior canal rather narrow and at a slight 
angle to the axis of the aperture. Outer lip 
broad, posteriorly ascending halfway up on 
the penultimate whorl, generally thickened 
internally and externally, where it forms a 
stout varix; noticeably denticulate at inner 
edge. Parietal lip meeting in a broad angle 
with the columellar lip which is usually made 
slightly arcuate by reason of the columellar 
pad bearing the numerous plaits; plaits on 
columellar pad normally 9 to 11 of varying 
strength, separated from basal fold by a 
pronounced groove. A rather broad, white 



callus, thick on the columellar area, extends 
from the inner lip over half of the ventral 
surface of the body whorl. 

Material - Holotype: SE of the Bluff, 
Durban, in 120 fathoms; collected by G. 
Scott, August 1872. Natal Museum, Mollusca 
No. 9939. 

Paratypes (see table of measurements 
below): Nos. 1, 6, 10, 13: 10-20 miles off 
mouth of Tugela River, in 120-150 fathoms; 
Nos. 3, 4, 7: 15-20 miles off Durban, in 280 
fathoms; Nos. 2, 5, 8, 9: off southern 
Zululand, in deep water; Nos. 11, 12: 10 
miles NE of Inhaca Island, Lourengo Marques, 
Mozambique, in 100 fathoms. 

Measurements (mm) 

length width no whorls 





Holotype 








(Natal Museum 










Moll. 9939) 


45.1 


19.5 


6 '4 




Paratypes 








#1 


(USNM 709349) 


54.3 


23.6 


6'/2 


#2 


(Fuller Colin.) 


49.6 


25.3 


(apex worn) 


ii3 


(Boswell Colin.) 


47.9 


21.6 


6'/! 


#4 


(USNM 709350) 


43.7 


19.2 


6'/4 


#5 


(Visagie Colin.) 


38.5 


17.1 


6^8 


#6 


(Boswell Colin.) 


36.8 


17.3 


6'/4 


#7 


(Boswell Colin.) 


38.0 


17.4 


eVg 


#8 


(Meyer Colin.) 


35.3 


16.5 




#9 


(Meyer Colin.) 


33.0 


15.5 




#10 


(Boswell Colin.) 


55.9 


22.3 


7 


#11 


(AMNH 177285) 


41.6 


19.8 


61/4 


#12 


(Fernandes Colin 


)41.1 


18.1 




#13 


(Boswell Colin.) 


on Xenophora 


pallidula 




Reeve 









Remarks — Volutocorbis semirugata is 
distinguished from all previously described 
species by the axial sculpture of the early 
postnuclear whorls disappearing on the last 
half of the body whorl leaving it smooth 
except on the angulate shoulder, and on the 
base where it is marked by spiral sculpture 

One specimen, paratype No. 10, is a rather 
thin shell, very pale yellow without spots, and 
is a typically elongate with the outer lip only 
moderately thickened. 



Vol. 88 (2) 



THE NAUTILUS 



33 



ON THE GENUS VOLUTOCORBIS WITH DESCRIPTIONS 

OF TWO NEW SPECIES FROM SOUTH AFRICA 

Harald A. Rehder 

National Museum of Natural History 
Smithsonian Institution, Washington, D. C. 20560 



In the last few years I have received new 
material of the genus Volutocorbis from Mrs. 
Helen Boswell of Valhalla, Transvaal, South 
Africa, and from Mr. Kenneth J. Fuller of 
Lambton, Germiston, Transvaal. Among them 
are specimens of three new species, two 
described in this paper, and one described in a 
previous paper in this issue of The Nautilus 
(vol. 88, no. 2). In a loan of several interesting 
species of marine mollusks from the Natal 
coast, sent to me by Richard N. Kilburn of 
the Natal Museum, Pietermaritzburg, were 
specimens of two of the new species described 
in these papers. To all these correspondents I 
give my grateful thanks. 

Darragh (1971) has questioned the 
propriety of regarding this genus as distinct 
from Athleta Conrad, 1853, and Volutospina 
Newton, 1906. In this respect he follows the 
conclusions reached by Cossmann (1909, p. 
210), who suggests that Volutocorbis, Voluto- 
spina and Neoathleta Bellardi, 1890, should 
be considered junior synonyms of Athleta 
Conrad, 1853, because he felt that in 
sculptural characters and general shape there 
were species that represented transitional 
stages between these groups that he had at 
one time considered of sectional rank. In 
support of this viewpoint he cited the work of 



Burnett Smith (1906) on the races of 
Volutilithes petrosus Conrad, 1853. 

Both Cossmann and Darragh with justice 
depreciate the importance of the size and 
number of whorls of the protoconch as a 
basic character in classifying the Volutidae. 
Cossmann complained that Dall 
overemphasized the generic significance of the 
nuclear whorls while ignoring the characters 
of the columellar folds (Cossmann, 1907, p. 
191). Earlier, Cossmann (1899, p. 101) in 
discussing his classification of the Volutidae 
had stressed the necessity of utilizing all 
characters found in the shells. 

In the process of reviewing the problem of 
the proper allocation of the group Voluto- 
corbis I decided to use this occasion to 
reorganize and arrange the Cenozoic members 
of the family Volutidae present in the 
National Museum of Natural History. I had, 
therefore, the opportunity of examining 
hundreds of specimens from both Europe and 
the United States, which I attempted to 
arrange according to what I considered a 
logical classification. Particular attention was 
paid to the representatives of the subfamily 
Athletinae. Needless to say, the conclusions 
arrived at, and which I outline in the 
following paragraphs, are in a sense prelim- 




FIGS. 1-4 Volutocorbis nana Rehder, new 
species: FIGS. 1, 3, holotype, USNM 709351, 



23.5 mm. in length. FIGS. 2, 4, paratype. 
Fuller Colin., 20.6 mm. in length. 



34 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



inary, and should be considered as suggested 
guideposts in future, more detailed phylo- 
genetic studies similar to the excellent one 
published by Fischer, Rodda, and Dietrich 
(1964). It is to be hoped, however, that these 
studies will involve related species and genera 
from other faunal areas, on both sides of the 
Atlantic. 

Darragh in his study makes only occasional 
references to the columellar plaits found in 
members of the groups under discussion, 
emphasizing primarily the characters of the 
protoconch and external sculpture. I believe 
that the folds on the columellar can be 
utilized in arriving at a satisfactory classifica- 
tion provided one considers their basic 
characters and is not led astray by minor 
details. 

I consider Athleta Conrad, 1853, whose 
type-species is Valuta rarispina Lamarck, 
1811, of the Miocene of France, to be distinct 
from the Volutospina — Volutocorbis 
complex. The columellar folds are stouter, 
with two lowermost ones equal or subequal in 
strength, the upper one of the two frequently 
the stronger. On opening the shell behind the 
aperture three ascendant plaits are seen on the 
columella, the upper one usually less promi- 
nent than the other two. The early post- 
nuclear whorls may be cancellate or with axial 
ribs crossed by spiral grooves. The protoconch 
is turbinate or mammillate with several 
smooth whorls. Synonyms are Eoathleta 
Gardner, 1945, and Volutovetus Pilsbry and 
Olsson, 1954. Based on the figure and 
description Bendeluta Fames, 1957, may also 
for the time being be placed in the synonymy 
oi Athleta. 

The genera Volutocorbis Dall, 1890 (type- 
species V. limopsis (Conrad)) and Voluto- 
spina Newton, 1906 (type-species V. spinosa 
(Linne)) are very closely related. Both groups 
have the columellar folds rather steeply 
ascending with the most anterior one the 
strongest and the posterior varying greatly in 
number and sometimes on a more or less 
prominent columellar pad. In sculpture and 
shape one can find among the European 
Eocene species an almost complete gradation 
from V. spinosa (Linne, 1767) through 



luctator Solander in Brander, 1766 — scalaris 
Sowerby, 1843 — ambigua Solander in 
Brander, 1766 - suturalis Nyst, 1836 - 
crenulifer Bayan, 1870, to digitalina Lamarck, 
1811, a species close to the type species of 
Volutocorbis. It is therefore difficult to 
determine the limits of these groups, and 
therefore for the present I consider Voluto- 
corbis Dall as the generic name to be used, 
with Volutospina Newton as a junior 
synonym. As Dai-ragh points out some of the 
recent South African species I have described 
resemble closely the Miocene species V. 
suturalis Nyst, 1836. 

Notoplejona Marwick, 1926, seems to be a 
genus rather variable in sculpture, judging 
from the literature and the two specimens I 
have been able to examine in the collection 
here. The nature of the columellar folds and 
the characters of the sculpture lead me to 
place it near Volutocorbis but as a distinct 
subgenus because of the strong parietal callus 
and broad anterior siphonal notch. 

I have been unable to examine a specimen 
of Voluta affinis Brocchi, 1814, the type- 
species of N eoathleta Bellardi, 1890, but the 
figure given by Brocchi shows a species that 
seems to belong in Volutospina (i.e. Voluto- 
corbis). Cossmann states that affinis is 
congeneric with Voluta cithara Lamarck, 
1811, the type-species of Volutopupa Dall, 
1890, which, judging from the figure of 
affinis, seems unlikely. Until the protoconch 
of V. affinis can be examined and described, I 
am inclined to add Neoathleta to the 
synonyms of Volutocorbis Dall, 1890. Unfor- 
tunately, the date of publication of Neoath- 
leta Bellardi is 6 April 1890, while that of 
Volutocorbis Dall is August 1890, so that 
Neoathleta would replace Volutocorbis as a 
generic name, if my surmise on the allocation 
of affinis is correct. However, because of the 
present uncertainty as to the nature of the 
protoconch of the species, I am continuing to 
use Volutocorbis, and consider Neoathleta to 
be a genus inquirendus for the present. 

DeiII, in 1890, proposed the name Voluto- 
pupa as a section of Volutilithes for a group 
of species with a high, many-whorled, 
relatively large protoconch, citing as type 



Vol. 88(2) 



THE NAUTILUS 



35 



Voliita cithara Lamarck. This name, as stated 
above, Cossmann placed in the synonymy of 
Neoathleta Bellardi, and included in the group 
a number of Paris Basin species, some of 
which undoubtedly do not belong here. The 
only one that is definitely congeneric with V. 
cithara is lyra Lamarck, and V. lineolata 
Deshayes also is probably a Volutopupa. I 
have examined the protoconch of V. biilbula 
Lamarck, 1803, and find that it possesses a 
small, conical protoconch with few whorls, 
and thus should be placed in Volutocorbis. 
Volutopupa can be retained as a subgenus of 
Volutocorbis for those species with a 
relatively large, elevated-conical, multispiral 
protoconch, and a rather thin shell with a 
more less inflated last whorl. 

The Australian species, that Darragh places 
in Athleta (Ternivoluta), and of which I have 
been able to examine several lots of 
antiscalaris levior (McCoy, 1866) and anticin- 
gulata McCoy form indivisa McCoy, 1866, I 
would place in the "Volutospina section" of 
Volutocorbis. 

Ternivoluta Martens, 1897, is definitely 
worthy of subgeneric rank under Voluto- 
corbis because of its large, paucispiral, 
deviated protoconch. The Australian Eocene 
to Miocene species that Darragh placed in 
Ternivoluta belong in Volutocorbis since they 
possess a protoconch typical of this group and 
the posterior columellar folds are not placea 
on a columellar pad that is generally found in 
Ternivoluta. 



Volutocorbis nana Rehder, new species 
Figs. 1-4 

Diagnosis — Shell small, with strong axial 
ribs and obscure spiral sculpture, a thick outer 
lip, and four to five folds on the columellar 
wall. Closest to V. gilchristi (Sowerby, 1902), 
which is strongly subsuturally channeled, with 
stronger spiral sculpture, and more pro- 
nounced columellar folds. 

Range — Off southern Zululand, Natal, 
South Africa, in 160-180 fathoms. 

Description — Shell small, 20.6 to 23.5 mm 
(3/4 to 7/8 inches) in length, ovate, rather 
stout, color of dead shells dull ivory white. 



Protoconch depressed-mammillate, of about 
I'/q smooth whorls, early postnuclear whorls 
marked by rather sharp axial riblets, 20 in 
second postnuclear whorl, marked by two 
increasingly prominent nodes, one subsutural 
and the other stronger; the narrow platform- 
like subsutural ramp and the strong nodes at 
the shoulder give the early postnuclear whorls 
a stepped appearance; in the penultimate and 
ultimate whorls the subsutural ramp becomes 
gradually more inclined and the subsutural 
row of nodes less angulate. The last whorl 
with 16 and 18 axial ribs in the two 
specimens seen, showing obscure minor nodes 
below the shoulder, marking the presence of 
obscure spiral ridges, which continue anter- 
iorly to the neck where they become rather 
strong cords; in the mid-portion of the last 
whorl they are visible only as very faint nodes 
on the ribs. Aperture narrow; outer lip gently 
arcuate, broad, thickened internally, and 
varicose, possibly obscurely denticulate in 
fresh specimens; inner lip weakly angled at 
juncture of parietal and columellar portions, 
the latter with 7 or 8 low rounded folds of 
varying strength, the anteriormost one the 
largest. Parietal callus thin, obscure. 

Material — Holotype: off coast of southern 
Zululand, Natal, in 160-180 fathoms, 
attached to Xenophora pallidula Reeve, 
USNM 709351. Paratype: same locality as 
holotype; also attached to Xenophora palli- 
dula Reeve; Fuller Collection. 

Measurements (mm)— 

length width no. whorls 

Holotype 23.5 12.5 6V<i 

Paratype 20.6 11.0 6 

Remarks — This species is distinct because 
of its small size (the holotype has the same 
number of whorls as the holotype of V. 
semirugata Rehder and Weaver, 1974, 
measuring 45.1 mm, almost twice as long), 
relatively strong axial riblets, without obvious 
spiral sculpture on the upper parts of the 
whorls, and the thickened, varicose outer lip. 

Volutocorbis mozambicana Rehder, 1972 

1972. Volutocorbis mozambicana Rehder. 
The Veliger, vol. 15, p. 12, figs. 3-5, 7-9. 



36 THE NAUTILUS 



April 30, 1974 



Vol. 88 (2) 



I have recently received a specimen of this 
species trawled off Durban, which extends the 
previously known range of this species 
southward for 650 miles. 

Through the kindness of Mr. Richard N. 
Kilburn I have been able to examine the 
holotype of Volutocorbis glabrata Kilburn, 
1971. This species is somewhat larger, with a 
relatively shorter spire, and a last whorl which 
is smooth rather than strongly sculptured as 
in mozambicana; the whorls lack the sub- 
sutural shelf seen in the latter species. 

Volutocorbis kilbumi Rehder, new species 
Figs. 5-8 

Diagnosis — Shell smooth except for very 
faint, obscure, irregular spiral threads, and 
with a pronounced and narrowly canaliculate 
suture. Outer lip moderately thickened and 
recurved, narrowly varicose externally. 

Range — From off Ilha Bazaruto, Inham- 
bane, Mozambique, to off Durban, Natal, 
South Africa in 180 to 280 fathoms. 

Description — Shell of medium size, 33 to 
39.2 mm (IVa to 1'/: inches) in length, ovately 
obconical with evenly convex whorls 
separated by a deeply impressed suture. Color 
dark grayish yellow (Kelly and Judd, 1965; 
color No. 91), the body whorl with distant 
reddish brown spots below the suture, 
occasionally prolonged into streaks, and with 
obscure pale maculations over the whole 
whorl, these becoming darker and more or 
less arranged in spiral bands towards the 
apertural outer lip; the bands mark the varix 
of the outer lip with rectangular maculations. 
Protoconch conical-mammillate, consisting of 



2'/4 smooth convex whorls with impressed 
suture. Early postnuclear whorls with flat- 
tened subsutural shelf which gradually 
becomes convex as the suture deepens and 
becomes canaliculate. Postnuclear whorls 
rather high and weakly convex, resulting in a 
rather narrowly conical spire; whorls smooth, 
without sculpture, except for very weak, 
obscure spiral ridges and irregular growth 
ridges. Aperture narrowly elongate, outer lip 
gently arcuate, thickened and reflected, 
smooth; inner lip rather straight, only slightly 
angled at juncture of parietal and columellar 
portions; columellar lip with a thickened 
callus on which are situated 9 to 12 folds, the 
7 to 10 upper or posterior ones separated 
from the two anterior ones by a more 
pronounced gap; of the latter two the 
posterior one is large, the anterior one low 
and broad. Siphonal canal rather broad and 
open. Parietal callus very thin. 

Material — Holotype: 15 miles off Durban, 
Natal, in 280 fathoms; USNM 709352. 
Paratype No. 1: 10-15 miles off Durban, 
Natal, in 280 fathoms; Boswell Collection. 
Paratype No. 2: off Ilha Bazaruto, Inham- 
bane, Mozambique, in 180 fathoms; ex A. 
Visage; Natal Museum Moll. No. 9769. 



Measurements ( 


mm) — 








length 


width 


no. whorls 


Holotype 








(USNM 709352) 


39.2 


18.3 


ev* 


Paratype #1 








(Boswell Colin.) 


38.1 


18.5 


6'/4 


Paratype #2 








(Natal Museum 








Moll. 9769) 


33.0 


15.1 


6'/fe 




FIGS. 5-8. Volutocorbis kilbumi Rehder, new 
species: FIGS. 5, 7, holotype, USNM 709352, 



39.2 mm. in length. FIGS. 6, 8, paratype, 
Boswell Colin., 38.1 mm. in length. 



Vol. 88(2) 



THE NAUTILUS 



37 



Remarks — This distinctive species is not 
close to any known forms of Volutocorbis. 
Paratype No. 2, from off Mozambique, is an 
immature specimen with a thin, not fully 
formed outer lip. 

This species is named for Mr. Richard N. 
Kilburn of the Natal Museum, 
Pietermaritzburg, Natal, in appreciation of his 
important contributions to our knowledge of 
the molluscan fauna of this part of the South 
African coast. 

LITERATURE CITED 

Cossmann, M. 1899. Essais de Paleocon- 
chologie Comparee. Livr. 3: 201 pp., 8 pis. 



Cossmann, M. 1907. [Review of] A Review 

of the American Volutidae, by W. H. Dall. 

Revue Crit. Paleozoologie 11: 191. 
Cossmann, M. 1909. Essais de Paleocon- 

chologie Comparee. Livr. 8: 248 pp., 4 pis. 
Darragh, T. A. 1971. Revision of the 

Australian Tertiary Volutidae (Mollusca; 

Gastropoda). 1. The subfamily Athletinae. 

Jour. Malac. Soc. Australia 2 (2): 163-185, 

pis. 14-16, text figs. A-C. 
Fischer, W. L., P. U. Rodda, and J. W. 

Dietrich. 1964. Evolution of Athleta 

petrosa stock (Eocene, Gastropoda) of 

Texas. Bur. Econ. Geol., Univ. Texas Publ. 

No. 6413: VI+ 117 pp., 11 pis., 33 

text-figs. 



BOOK REVIEW 



INTERTIDAL MOLLUSKS OF IQUIQUE, 
CHILE. By Marincovich, Louie. Los 
Angeles County Natural History Museum, 
Science Bull. 16, 49 pp., 102 figs. Feb. 20, 
1973. Available from Los Angeles County 
Museum Bookshop, $2.35 (postpaid, in- 
cluding tax). 

Although the west coast of South America 
was early explored and the first mollusks 
from there were described as long ago as 
1782, the fauna has remained rather sketchily 
represented in most collections. Literature is 
scanty and scattered. The present work results 
from two collecting trips, comprising a total 
of six months of intertidal collecting. Some 
87 molluscan species and one brachiopod are 



discussed, all being well illustrated by 
photographs and by line drawings of radulae 
(except for five forms that are specifically 
unidentified). One new genus, Salitra, is 
proposed in the family Columbellidae. The 
type species, S. radwini, also is new. Ten 
other new species are described, in the genera 
Nucula, Lyonsia, Tricolia, Eatoniella, 
Eatonina, Fartulum, Aesopus, and Iselica. 

The systematic account is well docu- 
mented, and the utility of the paper is 
increased by discussion of biogeography and 
by a review of pertinent literature. The author 
is to be commended for this useful work. 

Myra Keen, Department of Geology, 
Stanford University, California 



38 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



THE DISTRIBUTION and ECOLOGY of 
COMMON MARINE and ESTUARINE PELECYPODS 
in the DELAWARE BAY AREA' 
Don Maurer' , Les Watling' , Glenn Aprill^ 

Field Station' ^ Dept. Environmental Sciences 

College of Marine Studies University of Virginia 

University of Delaware Charlottesville, Va., 22903 

Lewes, Delaware 

ABSTRACT 

Samplings from 1967 to 1973 of the marine-estuarine pelecypods of the 
Delaware Bay region indicates that about half of the 44 common species are 
true estuarine while the other half are evenly distributed between euryhaline 
and stenohaline marines, with only a single oligohaline species, Rangia 
cuneata. The latter case is a northern range extension for this southern 
species. 



INTRODUCTION 

This research was undertaken to determine 
the distribution and ecology of common 
marine and estuarine pelecypods in the 
Delaware Bay area. Increased attention to 
pollution problems has renewed interest in 
benthic ecology. As a result, a series of local 
surveys have been conducted dealing with 
different taxonomic groups (Watling and 
Maurer 1972 a, b, Watling et al, 1973). This 
paper represents a part of those surveys. 

Lowden (1965) provided an annotated 
checklist of marine molluscs which covered 
Delaware Bay and New Jersey ocean beaches 
and enclosed bays. Watling and Maurer (1974) 
prepared a guidebook for the Delaware Bay 
region fauna which included a taxonomic key 
for the marine and estuarine molluscs. 
Moreover, some studies on pelecypods col- 
lected among oyster beds were also reported 
(Maurer and Watling 1973 a, b). 

METHODS 

This report is based on samples collected 
from 1967 to 1973 with a wide variety of 
sampling gear; epibenthic dredge, oyster 
dredge, hard clam dredge, hydraulic surf clam 
dredge. Van Veen bottom grab (0.1 m' ), 
Petersen bottom grabs (0.1 m^ 1/15 m" ). 
Several areas on Coast and Geodetic Survey 



^Contribution No. 84, College of Marine Studies. 



Maps 1218 and 411 which received intensive 
sampling are: 1) quantitative samples off Cape 
Henlopen, 13 transects from the capes to 
Woodland Beach, Cape Henlopen flat, Reho- 
both, Indian River, and Little Assawoman 
Bays, eight miles east of Rehoboth, 2) 
qualitative samples include the above si.es 
together with heavy sampling in Delaware's 
oyster beds. All quantitative samples were 
sieved through a 1.0 mm mesh screen and the 
residual on the screen was preserved in 10% 
buffered formalin. Selected organisms from 
the qualitative (dredge) samples were pre- 
served in a similar manner. 

Standard hydrographic data (temperature, 
salinity, dissolved oxygen) were collected for 
many of the samples together with samples of 
the sediment. The sediment samples were 
dried and sieved through a graded sieve series 
to determine sediment particle size. 

RESULTS AND DISCUSSION 

A list of the species discussed in this paper 
together with a summeiry of their ecology is 
presented in telescopic form. Salinity values, 
spawning and substrate data are derived from 
our data in the Delaware Bay region and from 
other sources (Chanley 1958, Loosanoff ef al. 
1966, Chanley and Andrews 1971). Notations 
for burrowing behavior are drawn from 
Stanley (1970). Carriker (1967) developed a 
scheme of geographic divisions, salinity 



Vol. 88(2) 



THE NAUTILUS 



39 



ranges, types and distribution of organisms in 
estuaries. His scheme is adopted to facilitate 
comparison with other estuaries. 

Among 44 species, 20 species are desig- 
nated as true estuarine, 11 as euryhaline 
marine, 12 as stenohaline marine, and one as 
oligohaline. These designations represent the 
maximum distribution of these species rather 
than exceptional or marginal occurrences. 

OLIGOHALINE 

Rangia cuneata is the only local oligohaline 
species. It was reported from upper Chesa- 
peake Bay and Elk River, Maryland (Pfitzen- 
meyer and Drobeck 1964). Subsequently, 
Gallagher and Wells (1969) indicated that it 
should be expected in upper Delaware Bay. 
Dead shells were collected near the eastern 
end of the Chesapeake-Delaware Canal by the 
Field Station. Recently several specimens 
were sampled from Delaware waters (J. 
Lindsay and Ron Smith, personal communi- 
cation). This represents a northern range 
extension for this species. One specimen (29 
mm in length) was collected August 20, 1971 
in 1.0 m of water from sand bottom off 
Oakwood Beach, New Jersey. A second 
specimen was collected August 15, 1972 in 
1.8 m of water from a mud and detritus 
bottom 200 m north of Appoquinimink 
Creek. Although not normally considered as 
oligohaline species, Mya arenaria and Macoma 
balthica have been reported from salinities as 
low as 5 %o in European and American 
estuaries (Segerstrale 1957, Bird 1970). These 
species must occur in the bay in great 
abundance between the St. Jones River and 
Woodland Beach because the volume of their 
shell debris is large. Other local species 
(Modiolus demissus and Brachiodontes recur- 
vus) also extend their range into areas where 
salinity becomes lower than 5 -L , but they 
more properly belong to true estuarine 
species. 

TRUE ESTUARINE 

Amygdalum papyria, Mysella planulata, 
and Modiolus demissus are found attached by 
byssal threads to oysters. In the rivers, M. 
demissus and A. papyria are most commonly 
attached to marsh vegetation or partly buried 



in soft sediment. The ribbed mussel, M. 
demissus, is more common intertidally on 
roots of Spartina alterniflora than subtidally 
(Lent 1967), while A. papyria is always far 
less abundant than M. demissus and occurs 
subtidally. The ribbed mussel is uncommon in 
the bay except at Woodland Beach. Here the 
proximity of the marshes as a source of brood 
stock favors heavy setting on any firm 
substrate. Kunkel (personal communication) 
informs us that the hooked mussel, Brach- 
iodontes recuruus was at one time frequently 
collected above the Cohansey River, but is 
now very rare. The reason for its decline is 
unknown, but it was coincident with the 
mid-1960's drought. 

Two bivalves show an affinity for a specific 
substrate. Petricola pholadiformis and Barnea 
truncata are characteristic of sections of the 
Murderkill, St. Jones, and Leipsic rivers with 
substrates of hard clay and packed marsh 
debris. 

Infaunal species such as Macoma balthica, 
M. tenia, Mya arenaria, Ensis directus, Solen 
viridis, Tagelus plebeius, and T. divisus mainly 
occur in mud, fine sand, and shelly-mud 
bottoms. High density (200/0.1 m' ) popula- 
tions of juvenile razor clams, Ensis directus, 
were found in sandy shoal areas bordering the 
ship channel, particularly from the mouth of 
the bay to the Miah Maul shoal. The above 
species together with Solemya velum (50 
individuals per 1/15 m^ ) is also very abundant 
in the fine sands of Rehoboth and Indian 
River Bays. The soft clam, Mya arenaria, 
occurs in mud (> 50% silt-clay) bottoms of 
the smaller bays. 

The oyster, Crassostrea virginica, is a 
dominant member of the estuarine com- 
munity and locally ranges from the Cape May 
Flat to north of Arnolds Point. Maximum 
development of natural seed beds extends 
from Woodland Beach to Port Mahon on the 
Delaware side of the Bay and from Egg Island 
Point to north of Arnolds Point on the New 
Jersey side. In addition to its commercial 
significance, the oyster forms the nucleus of a 
community that contains many species 
(Maurer and Watling 1973 a, b). 

Anomia simplex was formerly reported in 



40 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



abundance in New Jersey oyster beds where 
the salinity is above 20 %» (Kunkel, personal 
communication). Our experience with A. 
simplex is primarily restricted to Rehoboth 
and Indian River Bays where it is found 
attached to algae, rocks, and shells. 

Two small (< 2 cm) bivalves. Gemma 
gemma and Mulinia lateralis, are locally very 
common, but their maximum distributions 
are dissimilar. Mulinia lateralis is found in 
muddy and sandy substrates and is one of the 
most abundant pelecypods in Delaware Bay. 
Great numbers (8-10,000/0. Im^ ) of M. 
lateralis shells in channels and troughs near 
the mouth of the bay attest to its abundance. 
Gemma gemma inhabit a silty (20% silt-clay) 
or muddy-sand substrate and occur in the bay 
in relatively small numbers. It is, however, 
extremely abundant in Rehoboth and Indian 
River Bays, where counts of subtidal popula- 
tions were as high as 280,000/m' . Both 
species are ecologically significant, because a 
number of fish, invertebrates, and birds feed 
on these bivalves (Sellmer 1967, Calabrese 
1969). 

The hard clam, Mercenaria mercenaria, is 
commonly collected in fine sand with some 
clay. In Delaware Bay it ranges from 
Woodland Beach to the ocean, although it is 
most abundant in the lower Bay from south 
of Port Mahon to Broadkill Beach (Keck et al. 
1972). Further, the hard clam occurs in 
commercial numbers in Rehoboth and Indian 
River Bays. Coincident with the occurrence of 
the hard clam in the smaller bays is that of 
Pilar morrhuana, which is commonly col- 
lected but in considerably lower numbers. 
Both species are on the borderline between 
true estuarine species and euryhaline marine 
species because they frequently occur near 
high salinity inlets or in the ocean. 

EURYHALINE MARINE 

Two species which occur in oceanic salinity 
but also extend into the estuary are the wood 
borers, Bankia gouldi and Teredo navalis. 
Evidence of their work can be found in 
wooden pilings along Delmarva and Delaware 
Bay beaches. Teredo navalis has a wide 
tolerance to salinity and B. gouldi occurs in 



Chesapeake Bay in water with a mean salinity 
of 9.3 %o and a range of 3.3 °oo— 15.6 
%„ (Scheltema and Truitt 1954, Nair and 
Saraswathy 1971 ). Among other euryhaline 
marine species Siliqua costata and Tellina 
agilis are considered rapid burrowers and 
Corbula contracta, Lyonsia hyalina, Anadara 
ovalis, A. transversa, and Noetia ponderosa 
are considered slow burrowers (Stanley 
1970). Tellina agilis is a dominant species in 
fine sand (0.25 mm median sediment size) 
near the mouth of the Bay. A codominant 
species occurring with T. agilis is Nucula 
proximo which is common in sediments with 
high (> 50%) silt-clay content (Maurer et al. 
1973). Tellina agilis is also common on the 
Cape Henlopen flats. This tellinid may also 
occur with L. hyalina, which is most common 
in sediment with 20-40% silt-clay. The ark 
shells, Anadara transversa and .4. ovalis, occur 
in the ocean but are more frequently 
collected in algae beds of the smaller bays. In 
contrast, Noetia ponderosa is more common 
in the ocean. 

STENOHALINE MARINE 

Tellina versicolor, Donax fossor, and 
Spisula solidissima occur very near open shore 
beaches. In fact, Donax fossor may be 
considered an intertidal species. These species 
are primarily restricted to clean sand with 
shell and gravel. The surf clam, Spisula 
solidissima, is an important offshore com- 
mercial species (Yancey and Welch 1968). 
Laboratory observations showed that S. 
solidissima was unable to survive the diurnal 
tidal fluctuation in the Broadkill River 
(14-28 %o ). 

Species such as Pandora gouldiana, Astarte 
undata, Venericardia borealis, Cerastoderma 
pinnulatum, Abra aequalis, and Arctica 
islandica occur in deeper water (> 12 m) in 
coarse sand. However, P. gouldiana is 
collected from the Cape Henlopen flat. 
Fragments of Cyrtopleura costata shells com- 
monly wash ashore on Delaware's Atlantic 
coast but we have not collected any alive. 
None of these species is abundant with the 
exception of A. islandica. It probably occurs 
in commercial numbers, but has not been 
vigorously marketed. 



Vol. 88(2) 



THE NAUTILUS 



41 



Yoldia Umatilla also is common in the 
ocean, but it has the same affinity for 
sediment with high silt-clay content as N. 
proxima. Both species occur together locally. 
Nucida proxima is more dominant in shallow 
and semi-enclosed water than Yoldia Umatilla. 
Mytilus edulis is found attached to rocks, 
wrecks, and jetties near the mouths of bays 
and in the ocean. It occasionally occurs in 
such numbers to form small lenticular reefs in 
rivers (e.g. Broadkill) along the lower Bay. 

The Bay scallop, Argopecten irradians is 
occasionally obtained in Rehoboth and Indian 
River Bay. This species is not abundant, but 
when it occurs it is associated with algae in 
the smaller bays. We have found it only 
occasionally in the ocean, but it may be more 
common there. 

COMMUNITY STUDIES 

In an earlier study, the habitat zone, 
substrate, form, and feeding type of mollus- 
can communities of Beaufort, North Carolina, 
were described (Bird 1970). With the caveats 
of different sampling design, methods, and 
treatment of pelecypod molluscs alone, 
comparison of Bird's data with ours show the 
following similarities and differences. From 
estuary mouth to the head he named three 
communities: Tellina, Mulinia — Syndosmya 
[Abra] , Retiisa; Syndosmya [Abra] — Ali- 
gena; and Macoma balthica. Only the Macoma 
community was sharply delineated. The 
association of the estuary mouth graded into 
the shallow open-ocean community of the 
area, the Tellina — Spisula community. 

There was no attempt here to define 
pelecypod communities per se. Instead, 
particular suites of species were recognized 
based on salinity distribution. Following 
Carriker's (1967) outline for biota and 
salinity divisions, pelecypods (Spisula, Donax, 
Astarte, Venericardia) occurring in local 
stenohaline marine conditions would proba- 
bly agree with Bird's (1970) open ocean 
community (Spisula — Tellina). Pelecypods 
(Tellina, Lyonsia, Anadara, Corbula) locally 
recognized as euryhaline marine species may 
be equated with Bird's Tellina, Mulinia — 
Syndosmya [Abra] Retusa community. 



Those species (Macoma, Modiolus, Mulinia, 
Brachiodontes ) which are true estuarine forms 
may fit Bird's Macoma community. 

Two other comparisons can be made. The 
range of salinity of species distribution 
reported by Bird (1970) is narrower than 
salinity ranges for similar species in this study. 
This tends to telescope molluscan assemblages 
towards the mouth of the estuary. As a result, 
differences between his results and ours are 
more superficial than significant. The impor- 
tant fact remains that the relative sequence of 
pelecypod assemblages is very similar in both 
areas. He commented that community bound- 
aries were gradational even between open 
ocean and estuary-mouth communities. 
Gradual shifting of relative abundance of the 
most abundant species rather than wholesale 
change in species composition characterized 
community flux. We agree with Bird's (1970) 
findings in that in some cases it was difficult 
to distinguish among true estuarine, eury- 
haline marine, and stenohaline marine species. 
Controlling mechanisms to explain these 
differences remain to be studied. 

In summary, there are approximately 44 
common species of marine-estuarine pelecy- 
pods in the Delaware Bay region. As might be 
expected about 50% are true estuarine 
species. The other 50% are evenly distributed 
between euryhaline and stenohaline marine 
species with a single bonafide oligohaline 
species (Rangia cuneata). The latter is a 
northern range extension. The designation of 
stenohaline marine and oligohaline species is 
easier to determine than euryhaline marine or 
true estuarine forms. 

SUMMARY OF ECOLOG\ 

Salinities in parentheses represent values 
from published literature, while those not in 
parentheses represent our data. The substrate 
is classified by median sediment size, in mm: 
fine sand, 0.063-0.25; medium sand, 
0.25-0.50; coarse sand, 0.50-2.00. 

Rangia cuneata (Gray): Salinity, 0-10 %^ , 
(0-20 °oo ), oligohahne; spawning months, 
April through June; substrate, silt-clay and 
fine sand; mode, infaunal suspension feeder, 
slow burrower. 



42 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



Brachiodontes recurvus (Rafincsque): 
Salinity, 8-15 °o'. , (0-20 °o. ), true estuarine; 
spawning months, April through December; 
substrate, rocks and oysters; mode, epifaunal 
suspension feeder with strong hyssus. 

Modiolus demissus (Dillwyn): Salinity, 
5-25 %o, (2-30 °oo ), true estuarine; spawning 
months. May through October; substrate, 
marsh grass and algae, occasionally rocks; 
mode, semi-buried suspension feeder, weak 
byssus. 

Barnea truncate (Say): Salinity, 13-25 %» , 
(10-30 ?oo ), true estuarine; spawning months, 
April through November; substrate, hard clay; 
mode, infaunal suspension feeder, moderately 
rapid burrower. 

Cyrtopleura costata (Linne): Salinity, 
13-25 %o , (10-30 %o ), true estuarine; sub- 
strate, hard clay; mode, infaunal suspension 
feeder, moderately rapid burrower [not found 
living] . 

Amygdalum papyria Conrad: Salinity, 
8-25 °oo , (5-25 °oo ), true estuarine; substrate, 
marsh grass, algae and oysters; mode, 
epifaunal suspension feeder with byssus. 

Mya arenaria (Linne): Salinity, 5-20 %<, , 
(5-25 %o ), true estuarine; spawning months, 
March through May and September through 
December; substrate, silt-clay through 
medium sand; mode, infaunal suspension 
feeder, slow burrower. 

Macoma balthica (Linne): Salinity, 
10-25 %o , (5-25 %o ), true estuarine; spawning 
months, March through May and August 
through November; substrate, silt-clay 
through medium sand; mode, infaunal deposit 
feeder, moderately rapid burrower. 

Bankia gouldi Bartsch: Salinity, 15-35 %= , 
(10-35 %o ), euryhaline marine; substrate, 
wood; infaunal suspension feeder, slow 
burrower. 

Teredo navalis Linne: Salinity, 15-35 %» , 
(10-35 °oo ), euryhaline marine; spawning 
months, June through October; substrate, 
wood; mode, infaunal suspension feeder, slow 
burrower. 

Macoma tenia (Say): Salinity, 15-25 %o , 
(10-30 %o ), true estuarine; substrate, silt-clay 
through medium sand; mode, infaunal deposit 
feeder, moderately rapid burrower. 



Solen viridis Say: Salinity, 13-28 °=o , 
(7-28 V ), true estuarine; substrate, fine sand 
and medium sand; mode, infaunal suspension 
feeder, rapid burrower. 

Ensw directus Conrad: Salinity, 13-28 °.'o , 
(7-32 °.. ), true estuarine; spawning months, 
January through April; substrate, fine sand 
and medium sand; mode, infaunal suspension 
feeder, rapid burrower. 

Siliqua costata (Say): Salinity, 15-25 V 
(15-28 °oo ), euryhaline marine; substrate 
silt-clay through medium sand; mode 
infaunal suspension feeder, rapid burrower. 

Tagelus plebeius (Lightfoot): Salinity 
13-30 °oo , (13-28 "oo ), true estuarine: sub 
strate, silt-clay through medium sand; mode 
infaunal deposit feeder, slow burrower. 

Mulinia lateralis (Say): Salinity, 13-28 /.<. 
(10-35 ' ), true estuarine: spawning months 
March through November; substrate, silt-clay 
through medium sand; mode, infaunal suspen- 
sion feeder, moderately rapid burrower. 

Corbula contractu Say: Salinity, 20-30 °U , 
(15-35 °»c ), euryhaline marine; substrate, 
silt-clay and fine sand; mode, infaunal 
suspension feeder, slow burrower. 

Crassostrea virginica (Gmelin): Salinity, 
13-30 °oo , (0-35 °ic ), true estuarine; spawning 
months, June through September; substrate, 
rocks and shells; mode, epifaunal suspension 
feeder, in clusters. 

Solemya velum Say: Salinity, 17-25 ?C, , 
(15-28 °^o ), true estuarine; substrate, silt-clay 
and fine sand; mode, infaunal suspension 
feeder, rapid burrower. 

My sella planulata Stimpson: Salinity, 
15-25 °L , (13-28 ".o ), true estuarine; sub- 
strate, algae, hard shell, rocks; mode, 
epifaunal suspension feeder, weak byssus. 

Anomia simplex Orbigny: Salinity, 
15-30 °oo , (10-30 °oo ), true estuarine; 
spawning months, April through October; 
substrate, algae, hard shells, rocks; mode, 
epifaunal suspension feeder, calcified byssus. 

Pitar morrhuana (Linsley): Salinity, 
17-30 %o, (15-35 °oo ), true estuarine; 
spawning months. May through August; 
substrate, silt-clay through medium sand; 
mode, infaunal suspension feeder, moderately 
rapid burrower (?) 



Vol. 88(2) 



THE NAUTILUS 



43 



Mercenaria mercenaria (Linne): Salinity, 
15-30 °oo (10-35 %o ), true estuarine; spawn- 
ing months, May through October; substrate, 
silt-clay through medium sand, some shell; 
mode, infaunal suspension feeder, moderately 
rapid burrower. 

Tagelus divisus (Spengler): Salinity, 
15-25/00, (15-29 %o ), true estuarine; sub- 
strate, silt-clay through medium sand; mode, 
infaunal deposit feeder, rapid burrower. 

Lyonsia hyalina (Conrad); Salinity, 
18-30 %o , (15-28 °^ ), euryhaline marine; 
spawning months, February through May; 
substrate, silt-clay and fine sand; mode, 
infaunal suspension feeder, slow burrower. 

Tellina agilis Stimpson: Salinity, 13-35 %o , 
(12-35 %c ), euryhaline marine; spawning 
months, March through July; substrate, 
silt-clay through medium sand; mode, 
infaunal deposit and suspension feeder, rapid 
burrower. 

Tellina versicolor DeKay: Salinity, 
20-35 %o , (15-35 %o ), stenohaline marine; 
substrate, fine sand through coarse sand; 
mode, infaunal deposit and suspension feeder, 
rapid burrower. 

Anadara ovalis (Bruguiere): Salinity, 
15-30 %o, (15-35 %o ), euryhaline marine; 
spawning months. May through October; 
substrate, fine sand through coarse sand; 
mode, infaunal suspension feeder, weak 
byssus, slow burrower. 

Argopecten irradians (Lamarck): Salinity, 
20-35 %o , (17-35 %o ), stenohaline marine; 
spawning months, April through August; 
substrate, algae; mode, vagile suspension 
feeder, weak byssus. 

Gemma gemma (Totten): Salinity, 
18-30 %o , (13-32 fo'o ), true estuarine; sub- 
strate, silt-clay and fine sand; mode, infaunal 
suspension feeder, moderately rapid bur- 
rower. 

Anadara transversa (Say): Salinity, 
18-30 %o, (15-32 "o'o ), euryhaline marine; 
spawning months. May through September; 
substrate, algae, silt-clay through medium 
sand; mode, infaunal suspension feeder, weak 
byssus, slower burrower. 

Noetia ponderosa (Say): Salinity, 17-30 %» , 
(15-35 %o ), euryhaline marine; spawning 



months, June through November; substrate, 
algae, silt-clay through medium sand; mode, 
infaunal suspension feeder, weak byssus, slow 
burrower. 

Mytilus edulis Linne: Salinity, 20-35 %» , 
(15-35 %o), stenohaline marine; spawning 
months, January through December; sub- 
strate, rock, shell; mode, epifaunal suspension 
feeder, strong byssus in clusters. 

Petricola pholadiformis Lamarck: Salinity, 
15-29 %o , (10-32 %o ), euryhaline marine; 
spawning months, March through November, 
substrate, hard clay; mode, infaunal suspen- 
sion feeder, moderately rapid burrower. 

Pandora gouldiana Dall: Salinity, 23-35 %„ , 
(20-35 %o ), stenohaline marine; substrate, fine 
sand through coarse sand; mode, infaunal 
suspension feeder, slow burrower. 

Astarte undata Gould; Salinity, 25-35 %» , 
(22-35 %o ), stenohaline marine; substrate, 
medium sand and coarse sand, shell; mode, 
infaunal suspension feeder, slow burrower. 

Nucula proxima Say: Salinity, 25-35 %» , 
(20-35 %o ), euryhaline marine; substrate, 
silt-clay and fine sand, organic mud; mode, 
infaunal deposit feeder, moderately rapid 
burrower. 

Venericardia borealis (Conrad): Salinity, 
25-35 %o , (22-35 %» ), stenohaline marine; 
substrate, medium sand and coarse sand, shell; 
mode, infaunal suspension feeder, slow 
burrower. 

Cerastoderma pinnulatum (Conrad): Salin- 
ity, 25-35 %o , (22-35 %» ), stenohaline marine; 
substrate, medium sand and coarse sand, shell; 
mode, infaunal suspension feeder, moderately 
rapid burrower. 

Donax fossor Say: Salinity, 29-35 %o , 
(25-35 %o), stenohaline marine; spawning 
months, June through October; substrate, 
medium sand and coarse sand, shell; mode, 
infaunal suspension feeder, rapid burrower. 

Abra aequalis (Say): Salinity, 29-35 %» , 
(25-35 %o ), stenohaline marine; substrate, 
medium sand and coarse sand, shell; mode, 
infaunal deposit feeder (?), moderately rapid 
burrower (?) 

Yolida limatula (Say): Salinity, 25-35 %o , 
(22-35 %„ ), stenohaline marine; substrate, 
silt-clay and fine sand, organic mud; mode. 



44 THE NAUTILUS 



April 30, 1974 



Vol. 88 (2) 



infaunal deposit feeder, rapid burrower. 

Spisula solidissima (Dillwyn): Salinity, 
27-35 %o , (10-35 %o ), stenohaline marine; 
spawning months, March through May and 
September through November; substrate, 
clean, coarse sand, shell, medium sand; mode, 
infaunal suspension feeder, rapid burrower. 

Arctica islandica (Linne): Salinity, 
30-35 %o , (28-35 %. ), stenohaline marine; 
spawning months, June through October; 
substrate, clean, medium sand and coarse 
sand, shell; mode, infauna. 

ACKNOWLEDGMENTS 

Our associates, Wayne Leathem and Peter 
Kinner, provided much of the raw data for 
this paper. Because of their efforts we were 
able to expand the species list. Mr. John 
Lindsay and Mr. Ron Smith, Ichthyological 
Associates, generously shared their collecting 
data on Rangia cuneata. Since the latter is a 
northern range extension, Mr. Lindsay and 
Mr. Smith deserve recognition for their 
contribution. Finally, Dr. R. Tucker Abbott 
kindly checked several identifications and 
encouraged us to develop this account. 

LITERATURE CITED 

Bird, S. O. 1970. Shallow marine and 
estuarine benthic moUuscan communities 
from area of Beaufort, North Carolina, 
Amer. Assoc. Pet. Geol, Bull. 54 (9): 
1651-1676. 

Calabrese, A. 1969. Reproductive cycle of the 
coot clam, Mulinia lateralis (Say), in Long 
Island Sound. Veliger 12 (3): 265-269. 

Carriker, M. R. 1967. Ecology of estuarine 
benthic invertebrates: a perspective. In: 
Estuaries (ed. Lauff, G. H.) Amer. Assoc. 
Adv. Sci. Publ. 83: 442-487. 

Chanley, P. E. 1958. Survival of some juvenile 
bivalves in water of low salinity. Proc. Nat. 
Shell. Assoc. 48: 52-65. 

Chanley, P. E. and J. D. Andrews. 1971. Aids 
for identification of bivalve larvae of 
Virginia. Malacologia 11 (1): 45-119. 

Gallagher, J. S. and H. W. Wells. 1969. 
Northern range extension and winter 
mortality of Rangia cuneata. Nautilus 83 
(1): 22-25. 



Lent, C. 1967. Effect of habitat on growth 
indices in the ribbed mussel, Modiolus 
(Arcuatula) demissus. Chesapeake Sci. 8 
(4): 221-227. 

Loosanoff, V. L., H. C. Davis and P. E. 
Chanley. 1966. Dimensions and shapes of 
larvae of some marine bivalve mollusks. 
Malacologia 4 (2): 351-435. 

Lowden, R. D. 1965. The marine Mollusca of 
New Jersey and Delaware Bay, an anno- 
tated checklist. Proc. Phila. Shell Club. 1 
(8-9): 5-61. 

Maurer, D. and L. Watling. 1973 a. Studies on 
the oyster community in Delaware: The 
effects of the estuarine environment on the 
associated fauna. Inter, ges. Revue der 
Hydrobiologie 58 (2): 161-201. 

Maurer, D. and L. Watling. 1973 b. The 
biology of the oyster community and its 
associated fauna in Delaware Bay. Delaware 
Bay Report Series, Volume 6 (D. F. Polls, 
ed.). College of Marine Studies, University 
of Delaware, pp. 1-97. 

Nair, N. B. and M. Saraswathy. 1971. The 
biology of woodboring teredinid molluscs, 
p. 336-509. In: Advances in Marine 
Biology, Vol. 9 (ed. F. S. Russel and M. 
Younge), Academic Press. 

Pfitzenmeyer, H. T. and K. G. Drobeck. 1964. 
The occurrence of the brackish water clam, 
Rangia cuneata, in the Potomac River, 
Maryland. Chesapeake Sci. 5 (4): 209-212. 

Scheltema, R. S. and R. V. Truitt. 1956. The 
shipworm Teredo navalis in Marylemd 
coastal waters. Ecol. 37 (4): 841-843. 

Segerstrale, S. G. 1957. Baltic Sea. In: 
Treatise on Marine Ecology and Paleo- 
ecology Vol. 1 (ed. J. W. Hedgpeth) Geol. 
Soc. Amer. Mem. 67, 751-802. 

Sellmer, G. P. 1967. Functional morphology 
and ecological life history of the gem clam, 
Gemma gemma, (Eulamellibranchia: Vener- 
idae). Malacologia 5 (2): 137-223. 

Stanley, S. M. 1970. Relations of shell form 
to life habits of the Bivalvia (Mollusca). 
Geol. Soc. Amer. Mem. 125: 1-296. 

Watling, L. and D. Maurer. 1972 a. Marine 
shallow water amphipods of the Delaware 
Bay area, U.S.A. Crustaceana. Studies on 
Peracarida, Supplement 3: 251-266. 



Vol. 88(2) 



THE NAUTILUS 



45 



Watling, L. and D. Maurer. 1972 b. Shallow 
water hydroids of the Delaware Bay region. 
Jour. Nat. Hist. 6: 643-649. 

Watling, L. and D. Maurer. 1973. Guide to the 
macroscopic estuarine and marine inverte- 
brates of the Delaware Bay region. 
Delaware Bay Report Series, Volume 5 (D. 
F. Polls, ed.) College of Marine Studies, 
University of Delaware, pp. 1-178. 



Watling, L., J. Lindsay, R. Smith and D. 
Maurer. 1974. The Distribution of Iso- 
poda in the Delaware Bay Region. Int. 
Revue ges. Hydrobiol. (in press). 

Yancey, R. M. and W. R. Welch. 1968. The 
Atlantic Coast surf clam with a partial 
bibliography. U. S. Fish & Wild. Serv. Cir. 
288: 1-14. 



BOOK REVIEW 



THE FRESHWATER MOLLUSCS OF THE 
CANADIAN INTERIOR BASIN. By 
Clarke, Arthur H. 1973. Malacologia, 
13(1-2): 1-509, 9 text figures, 9 tables, 87 
maps, 28 plates (1-14 in color, 15-28 in 
black and white), 35 charts. 

Of monographic proportions, this regional 
study provides an immense amount of data on 
the biology of 103 species and subspecies in 
37 genera and subgenera of an area 
encompassing more than 1/3 of North 
America. Ten families (2 bivalve, 3 proso- 
branch and 5 pulmontate) are reviewed with 
the sphaeriids, lymnaeids and planorbids 
being among the more speciose. For certain 
taxonomic groups this study constitutes the 
first modern systematic treatment, and many 
of the taxa have never been critically 
reviewed, properly described or adequately 
illustrated. 

Geographically, the Canadian Interior Basin 
comprises both the Hudson Bay Basin and 
the Canadian portion of the Arctic Basin, 
including such extensive river systems as the 
Mackenzie, Churchill, and Saskatchewan. The 
front endpapers provide a colored map of the 
principal drainage basins and the rear covers 



detail, in color, phytogeographic and geo- 
morphic features. Dominating the geologic 
scene is the Precambrian Shield, a poor source 
of limestone and therefore not particularly 
hospitable for shelled animals. A more 
suitable substrate, the Hudson Bay Lowland 
provides a more calcium rich environment and 
is characterized by low species diversity and 
by large population sizes typical of highly 
variable environments. 

Approximately 10 years of field work 
during which nearly 600 stations were 
sampled and over 3000 lots collected, form a 

basis for this study Including material from 
various sources, ultimately over 100,000 
specimens were examined. In conjunction 
with fossil evidence, temperature preferences, 
and distributional data, the probable faunal 
origins are analyzed for each species. In an 
enlightening introduction, previous research 
and the geologic history of the area are 
surveyed. 

The major portion of the text consists of 
the systematic section. Although each species 
is provided vdth a synonymy, the treatment is 
irregular and incomplete. As the author 
himself points out, not all synonyms are listed 



46 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



and few citations of type specimens are 
included. For example, rather than attempt to 
assess the validity of all North American 
nominal Gyraulus, an effort is made to 
evaluate the status of all taxa recorded from 
the study area. Following a short diagnosis, a 
longer, more detailed description is given for 
each species. An illustration, a list of 
specimens examined and a map of the species' 
distribution in the study area are augmented 
with comments on overall distribution, a 
discussion of biology and ecology, and 
remarks on closely related species and 
probable synonyms. Clear, dichotomous keys, 
with references to page numbers and illus- 
trations, aid in identification of each family, 
genus, species, and subspecies. 

The taxonomy of freshwater mollusks has 
always constituted a considerable problem. 
Dr. Clarke employed some biometric methods 
to describe the variation in these species. He 
utilized these data to detect subspecies, to 
discover the meaning or implication of 
geographically correlated morphometric char- 
acteristics, and to describe more fully the 
variability exhibited by some species. Adduc- 
ing that evidence of gene exchange between 
otherwise distinguishable groups of popula- 
tions is indicative of the existence of 
subspecies whereas no gene exchange means 
that two or more distinct species are involved. 
Dr. Clarke recognized a dozen polytypic 
species, some with as many as 3 subspecies in 
the study area. An examination of the 
distribution of one of these polytypic species, 
for example Valvata sincera with its 3 
polytopic subspecies, V.s. sincera, V.s. ontari- 
ensis, and V.s. helicoidea shows that all three 
may live in the same river system (Albany and 
Severn drainages) and even near or in the 
same body of water (Lake Nipigon). To me, 
such a pattern casts doubt on the interpreta- 
tion of these populations as subspecies since 
subspecies are, by definition, geographical 
isolates. 

Certain complex nomenclatorial problems 
are resolved. To insure stability and allow the 
continued widespread usage of such im- 
portant hydrobiid generic names as Amnicola 
and Pomatiopsis, a neotype is designated for 



Paludina lustrica Say, 1821, the type species 
of Amnicola. An attendant oddity is that this 
specific name, though having priority, is 
considered a nomen oblitum and A. walkeri 
Pilsbry, 1898, a subjective synonym, utilized. 

Among the outstanding contributions in 
this volume are the extremely useful distinc- 
tions between easily confused species, the 
thorough accounts of previously very poorly 
known species, and the comprehensive 
analyses of certain species. Lymnaea colum- 
ella and Succinea ovalis are very similar and 
frequently misidentified, but here they are 
clearly differentiated conchologically and 
anatomically (p. 293). 

Many intrinsically intriguing biological 
facts are brought to light. Documenting the 
tenacity and perseverance of some mollusks 
are the extreme northern occurrences of 
certain species: the cosmopolitan sphaeriid 
Pisidium casertanum on Baffin and Victoria 
Islands, the panboreal physid Aplexa hypno- 
rum also on Victoria Island, £ind the Beringian 
Lymnaea atkaensis at home on the Arctic 
Coastal Plain. Additional specific results 
include the synonymization of Lymnaea 
emarginata with L. catascopium (p. 328) and 
the recognition of the European Gyraulus 
albus as distinct from the Nearactic G. 
deflectus (p. 396). 

In summary, this work is truly a magnum 
opus, constituting the most comprehensive 
treatment of the mollusks of a faunal area in 
North America and the most thorough 
analysis of many intriguing taxa. Setting a 
high standard of excellence, it forms the 
foundation for any future work on the 
freshwater mollusks of Canada and, indeed, 
the United States. An invaluable treatise and 
exemplary source book for the limnologist 
and aquatic biologist, it is a must for the 
library of any malacologist and a fitting 
memorial to the author's late wife, Louise, to 
whom the work is dedicated. 



Kenneth J. Boss 

Museum of Comparative Zoology 

Harvard University 

Cambridge, Mass. 02138 



Vol. 88 (2) 



THE NAUTILUS 



47 



FROG MOTIFS ON ARCHAEOLOGICAL MOLLUSKS OF 

HOHOKAM AND MOGOLLON INDIAN CULTURES 

Glenn A. Long 

The Baltimore Museum of Art 

Baltimore, Maryland 21218 

ABSTRACT 

Thirty-seven pendants and eight bracelets carved with frog motifs, or 
overlaid with turquoise mosaic, comprise this initial checklist. Of the carved 
pendants without overlay, several motific groups can be identified. Pendants 
and bracelets were made from whole valves of various species, such as 
Glycymeris gigantea (Reeve) and G. maculatus (Broderip). Other shells were 
used but less frequently. Carved frog pendants are found throughout the 
Hohokam and Mogollon culture areas and were frequently excavated in 
connection with burials. 



This is a preliminary report on carved shell 
ornaments from archaeological remains of 
prehistoric Indian cultures in the Southwest. 
In the current phase of study, a checklist of 
frog images is being compiled and motific 
groups are being catalogued. For reasons 
which go beyond this assembly and subdivi- 
sion of objects and data, records are being 



made of archaeological contexts in which frog 
images were found in the hope that significant 
frequency patterns will emerge from the data. 
We assume that discovery of carved shell 
ornaments in archaeological remains means 
that these objects had intrinsic value to 
certain prehistoric people. We also assume 
that by studying these objects we might 




FIG. 1 Overlaid Shell Pendants. Photograph by Helga Teiwes, Arizona State 
Museum, catalogue nos. GP39336, GP9895, GP10768 and GP5765. 



48 THE NAUTILUS 



April 30, 1974 



Vol. 88 (2) 



contribute to a more thorough understanding 
of the cultures which left them behind. 

The carved shell ornaments come from the 
Southwest, which is one of nine archaeo- 
logical culture areas in North America. This 
area centers on the states of Arizona and New 
Mexico, spreading northward into Utah and 
Colorado, and southward to encompass nearly 
all of the Mexican states of Sonora and 
Chihualiua (Willey: 1966, pp. 178-181; see 
also Haury: 1962; Jennings and Reed: 1956). 
The southeast quadrant of this area is named 
after the Mogollon Mountains which lie east 
of the Rio Grande, running diagonally from 
Arizona into Southwestern New Mexico. To 
the west of the Mogollon subarea, the Verde, 
Salt and San Pedro Rivers flow into the Gila 
River. The Hohokam ancestral Itmds consist 
of this Lower Gila River drainage area and the 
desert country to the south. North of the 
Hohokam and Mogollon subareas lies Pueblo 
Indian country. This third subareal division is 
called by the anthropological designation 
"Anasazi." There is cultural overlapping 
among all three cultural subdivisions with a 
pre-Historic to Historic cultural continuum 
from Paleo-Indian times (ca. 14,000 B. C.)to 
the present (see Rouse: 1962; Wheat: 1955; 
BuUard: 1962; Martin and others: 1952). 

The time period of greatest importance to 
us is from about A. D. 600 to 1400 which 
includes the last three phases of both the 
Hohokam and Mogollon cultural traditions, 
the transition from Basketmaker to Pueblo 
cultural tradition in the Anasazi subarea and 
the florescence of cultural habitation at Casas 
Grandes in Chihuahua. Evidence from Snake- 
town Ruin (Gladwan, et al.: 1937, pp. 
135-153), situated north of Tucson on the 
Gila River, indicates that carved shell industry 
among the Hohokam during the Santa Cruz 
Phase (ca. A. D. 700-900) was well in advance 
of the Georgetown and San Francisco Phases 
of Mogollon culture, and Pueblo I stage of 
Anasazi culture. Yet, it was not until the 
succeeding Sacaton Phase at Snaketown that 
the carved shell industry reached a high point 
at that site. The Sacaton Phase (ca. A. D. 
900-1100) was the last period of Hohokam 
habitation at Snaketown (see Gladwin, et al.. 



1937, p. 247). During the Classic stage of 
Hohokam culture (ca. A. D. 1100-1400, see 
Rouse: 1962, Fig. 3; Haury: 1962, Fig. 2, 
gives the time period ca. A D. 1200-1500 for 
the Classic stage), ornamental shell work 
began to decline both in quality of work- 
manship and numbers of objects. 

Thirty-seven pendants and eight bracelets 
carved with frog motifs comprise the initial 
checklist. All the pendant specimens are 
bivalve shells with the umbo pierced for 
suspension. Bracelets are also bivalve shells 
with frogs carved on the umbonal region and 
the body of the shell ground off to form a 
circular band. Six shells overlaid with 
turquoise mosaic have been included with the 
pendants. Three of the specimens (Fig. la and 
b) are carved as well as overlaid. One is carved 
with a notch on both the posterior and 
anterior margins, as well as on the ventral 
margin of the shell to indicate the retracted 
legs and feet of a squatting frog. This 
specimen is painted blue on both the 
posterior and anterior sides of the convex 
portion of the shell with twelve rows of 
turquoise tesserae overlaid on the center 
portion. In the center of the overlay, there is 
a large red tessera. 

The posterior and anterior margins of a 
second overlaid pendant are flattened and 
there is a V-shaped notch cut into the ventral 
margin opposite the umbo. The turquoise 
overlay covers all but the edges of the convex 
portion of the shell, with four tesserae set on 
either side of the notch in a manner to suggest 
hind legs. A large red tessera is set in the 
center of the overlay on this specimen also. 
The third overlaid pendant is notched on the 
posterior and anterior margins of the shell. 
The overlay is in a fragmentary state, but 
probably covered the entire convex portion of 
the shell except for the tips of the four 
flanges on the margin of the shell, which were 
carved to represent frog legs and feet. There is 
no CEirving on three of the mosaic ornaments. 
Nevertheless, they are pendants and are 
suggestive of the compact form of frogs. 

Of the carved pendants without overlay, 
several motif ic groups can be identified. One 
motific form represents the frog with nearly 



Vol. 88(2) 



THE NAUTILUS 



49 



straight sides and the front and hind legs 
widely separated (Fig, 2). Of the most 
complete specimen, collected in the Flagstaff 
area, the upper and lower portions of the legs 
are well-defined and separated from the body 
of the animal. Incised lines suggest the 
webbed toes of the frog. A second motific 
form includes specimens with more bulbous 
sides. In this type, the legs are more 
anatomically articulated as well as separated 
from the body of the animal (Fig. 3). All four 
specimens of this type at the Arizona State 
Museum show that their makers were careful 
in articulating the eyes. Wear, caused by 
continuous handling of these ornaments, 
often makes it difficult to distinguish minute 
features on the pendants. In the case of these 
specimens, fine quality workmanship is 
evident even though they are worn down. 
There is a third straight-sided type. Specimens 
in this group are rather crudely carved and 
lack any indication of a dorsal ridge. Two 
specimens from the Arizona State Museum 
are polished from cultural use, but when 
compared to other well-used specimens with 
carved dorsal ridges still visible, it seems that, 
for this type, the dorsal ridge was never 
carved. Two specimens of this type show a 
distinctly flattened umbo. 

One specimen is recorded with a ground-off 
umbo similar to the preceding type. The 
specimen is bulbous and crudely carved, and 
has been assigned to a group of miscellaneous 
specimens for the time being. 

A group of specimens with very curved 
bulbous sides is a fifth type. The legs of these 
specimens are compressed to the body and 
clearly incised, not carved in a rounded, more 
three-dimensional manner (Fig. 4 and 5). The 
toes in this type are treated as incised, 
serrated projections from the legs. On one 
specimen, an incised line separates the body 
of the animal from the head, and the eyes are 
also incised. 

Five specimens are included in a sixth type. 
These specimens are drilled or perforated with 
holes which seem to represent eyes. Some of 
the specimens are perforated at the umbo for 
suspension and some are not. Some are 
incised wdth geometric patterns, and some are 



cut or ground off to make a lEurge perforation 
in the center of the shell. One specimen 
incorporates all of these motifs. 

A seventh type includes specimens which 
are not carved in distinct frog form. These 
shells are only partially modified by grinding 
along the ventral margin, and are perforated 
with a large circular hole generally in the 
center of the shell. They differ from type six 
in that they lack drilled or perforated eye 
treatment. 

A triangular shell pendant was found at 
Broken K Pueblo (Fig. 6) with a relief image 
of a frog-like animal carved on it. The front 
and hind legs are extended. The body, head 
and eyes of the animal are not clearly 
indicated, but the dorsal ridge is clearly 
defined. Unlike the other specimens, this 
pendant was made from a shell blank, a piece 
cut from a larger shell. The pendants. 



/ * 





^Sz^S^ 



FIGS. 2-6 Shell Pendants (2) photograph by 
Marc Gaede, Museum of Northern Arizona 
catalogue no. 1545L/A5838 (3) photographs 
by the author (4) Arizona State Museum (5) 
catalogue nos. GP9870, GP49130 and 
A25300 (6) photograph by Division of Photo- 
graphy Field Museum of Natural History 
catalogue no. 283703. 



50 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



previously described, were made from an 
entire valve of Glycymeris gigantea (Reeve) or 
G. maculatus (Broderip) (see Gladwin, et al.: 
1937, pp. 135-142; Di Peso: 1956, pp. 
83-116; personal correspondence with Di 
Peso: 1973; Van Stone: 1973; Dobrinski and 
Hitchcock: 1973; Chaffee: 1973). 

Finally, all specimens which are too worn 
or fragmentary or poorly carved to be placed 
in separate groups are included in a group of 
miscellaneous specimens. 

At the Arizona State Museum there are two 
fragmentary specimens of open-work carving. 
One specimen might represent a horned lizard 
and not a frog because of its elongated form, 
a head which is separated from the body by a 
rudimentary neck, and a short tail. The other 
specimen might represent a frog. Both 
specimens have been carved so that the animal 
motif is enclosed within the circular band of 
the ventral margin. Only the hind section of 
the second specimen remains so that exami- 
nation of head and fore-leg features is 
impossible. The hind legs are partially 
extended, a feature unlike other frog 
pendants from Hohokam and Mogollon 
culture areas, but similiar to the triangular 
pendant from Broken K Pueblo, the Anasazi 
site in Northern Arizona. No tail is indicated. 

The bracelets with frog images carved on 
the umbonal region of the shells are less 
varied in form than are the pendants. All 
specimens included in the preliminary check- 
list have been placed in one group. The 
animals are rectangular in shape and are quite 
thick (nearly as thick as they are wide). The 
frog's nose is the umbo of the shell. The body 
of the frog is carved from the thick umbonal 
region with the front legs of the frog 
compressed to the body and the feet placed 
next to the head, as if the frog were grasping 
the circular band of the bracelet. The hind 
legs are carved as if they were overlapping the 
lower portion of the body, with the heels of 
the feet touching the posterior end of the frog 
and the toes spread perpendicularly to the 
dorsal axis. The hind leg motif takes the form 
of a capital M. The remainder of the shell was 
cut away except for a thick circular band, 



which was the marginal circumference of the 
living shell. 

Frog motifs are not restricted to worked 
shell. During an Arizona University expedi- 
tion in 1965, a cache of carved stone and clay 
objects was excavated (Ariz. U:31:l, 10-G, 
Cache 1) which included two bowls. One, 
carved from stone, depicts a snake devouring 
a frog and one is made of clay with frog 
images clinging to the outer walls of the vessel 
in much the same manner as the frog images 
appear to cling to the bracelets. A corrugated 
clay jar from Chihuahua in the collections of 
The Amerind Foundation, Inc. also incor- 
porates this "clinging frog" motif. 

One recurrent archaeological context for 
frog pendants is evident in the initial data. Of 
the forty-three carved and overlaid pendants, 
twenty-eight have a known provenance. Of 
these twenty-eight, ten are known to have 
been associated with inhumation or cremation 
burials. The age of the deceased is known in 
eight of these ten burial contexts. In each of 
five contexts, the pendants were buried with 
the remains of children. The remaining three 
were associated with young adults and are all 
of the seventh motific type, i.e., pendants of 
indistinct frog form (see Fig. 6). All three 
specimens came from Canyon Creek Ruin, a 
Salado/Hohokam transitionjil site. 

Research is in progress to find and assemble 
accounts of frog symbolism in American 
Indian ethnology. A few legends and practices 
are known which associate shells and frogs 
with children and childbirth (for example, see 
La Flesche: 1925, pp. 251-257). No specu- 
lations regarding associations of frog pen- 
dants, life and death, burial, children and 
childbirth or any other extra-ornamental use 
are made here due to lack of data. 

Conclusions which can be drawn to date 
are: one, incidence of carved shell frog 
pendants is rather frequent in archaeological 
contexts throughout the Hohokam and 
Mogollon culture areas in the Southwest. 
Two, carved shell frog bracelets are found in 
the same contexts as the pendants, but with 
less frequency. Three, the pendants can be 
divided into several motific groups, and four, 



Vol. 88 (2) 



THE NAUTILUS 



51 



that when not found in association with 
architectural fill and floor debris, the 
pendants have been excavated most fre- 
quently in connection with burials. 

LITERATURE CITED 

Bullard, W. J., Jr. 1962. The Cerro Colorado 
Site and Pithouse Architecture in the 
Southwestern United States Prior to A. D. 
900. Cambridge, Harvard Univ., Peabody 
Museum Papers 44(2): xii+205 pp. 

Di Peso, Charles C. 1956. The Upper Pima of 
San Cayetano del Tumacacori. Dragoon, 
Arizona, The Amerind Foundation, Inc. 
no. 7: xxiv+589 pp. 

Gladwin, Harold S. et. al. 1937. Excavations 
at Snaketown: Material Culture. Globe, 
Arizona, Medallion Papers no. 25: 
xviii+305 pp. 

Haury, Emil W. 1962. The Greater American 
Southwest, in Courses Toward Urban Life. 
New York, Wenner-Gren Foundation for 
Anthropological Research, Inc., Viking 
Fund Pubhcation in Anthropology no. 32: 
106-131. 

Jennings, J. D. and E. K. Reed. 1956. The 
Americcin Southwest: A Problem in Cul- 



tural Isolation, in Seminar in Archaeology: 
1955. Salt Lake City, Society for American 
Archaeology Memoir no. 11: 59-127. 

La Flesche, Francis. 1925. The Osage Tribe: 
Rite of Vigil, in Thirty-Ninth Annual 
Report of the Bureau of American 
Ethnology, 1917-1918. Washington, D. C, 
Smithsonian Institution: 31-630. 

Martin, Paul S. et al. 1952. Mogollon Cultural 
Continuity and Change: The Stratigraphic 
Analysis of Tularosa and Cordova Caves. 
Chicago, Chicago Nat. Hist. Museum, 
Fieldiana: Anthropology 40: 507 pp. 

Rouse, Irving. 1962. Southwest Archaeology 
Today, in An Introduction to the Study of 
Southwest Archaeology with a Preliminary 
Account of the Excavations at Pecos, by A. 
V. Kidder, rev. ed. New Haven, Yale Univ.: 
1-53. 

Wheat, Joe B. 1955. Mogollon Culture Prior 
to A. D. 1000. Menasha, Wisconsin, 
American Anthropological Association 
Memoir no. 82: xiii-(-242 pp. 

Willey, Gordon R. 1966. An Introduction to 
American Archaeology. Englewood Cliffs, 
New Jersey, Prentice-Hall, Inc. 1:178-245. 



ADDITIONAL RECORD FOR MESODON 
LEATHERWOODI (PULMONATA: POLYGYRIDAE) 

Donald W. Kaufman 

Department of Zoology, University of Texas, 
Austin, Texas 78712 



Mesodon leatherwoodi Pratt was recently 
described from specimens collected at a single 
locality in western Travis County, Texas 
(Pratt, 1971). It is of interest to report the 
occurrence of M. leatherwoodi in the 
Pedernales Falls State Park, Blanco County, 
Texas, which is approximately 13 miles 
upstream from the type locality. Four 
specimens were found near the Pedernales 
Falls within 1 meter of each other at the base 
of a large rock on August 6, 1972. The 
collection site was above flood debris along 
the river suggesting that the snails were from 
the general area of the Falls, although, the 



shells may have been washed down from the 
oak-juniper community higher on the river 
bank. 

The specimens have been deposited in the 
collection of the Fort Worth Museum of 
Science and History (catalog number 
94V-3103). W. L. Piatt verified the identifi- 
cation of the specimens. 



LITERATURE CITED 

Pratt, W. Lloyd, 1971. Mesodon leather- 
woodi, a new land snail from central Texas. 
The Vehger 13(4): 342-343; 1 pit. 



52 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



NEW FLORIDA RECORDS FOR 

HYPSELODORIS EDENTICULA TA 

(NUDIBRANCHIA: DORIDIDAE) 

Alice Denison Barlow 

5 Downey Drive 

Tenafly, New Jersey 07670 

The large and conspicuous chromodorid, 
Hypselodoris edenticulata (White, 1952) was 
originally recorded only from Dry Tortugas, 
Florida. Marcus and Marcus (1967, p. 56) 
gave four other records in the vicinity of Palm 
Beach, Miami, Alligator Reef, and Lake 
Worth, all southeast Florida, at depths from 8 
to 102 feet. 

On March 2, 1971, Ralph Woodring 
collected a specimen in 35 to 40 feet of 
water, 20 miles southwest of the Sanibel 
Island Lighthouse. I maintained this specimen 
for four weeks in an aquarium and made 
several photographs of it. The animal was 64 
mm. in length and 17 mm. in width. The 
color was blue-black with brilliant 
chrome-yellow markings of uneven circles and 
lines with one line running unevenly com- 
pletely around the outer edge of the upper 
part of the body. The sole was a lavender 
blue. The eleven (Marcus reports 10, and 
White 9), branchial plumes were outlined in 
chrome-yellow, with a yellow line running 
down the center of each plume, with diverse 
yellow spots on either side. The secondary 
pinnules on the plumes were lavender; the 
rhinophores blue-black. White (1952, p. 114) 
records that the vermilion spawn is laid on the 
alga, Caulerpa prolifera. 

In the Spring of 1971, Mr. Russell Jensen 
of the Delaware Museum of Natural History 
sent my photographs to Mr. Gale Sphon of 
the Los Angeles County Museum of Natural 
History who kindly identified them as 
Hypselodoris edenticulata (White), with the 
suggestion that this gives a further range for 
the animal that should be noted in the 
literature. 

In October, 1973, I wrote Mr. WiUiam G. 
Lyons of the Bureau of Mzirine Science and 
Technology Florida, for any information he 
might have on the species. He very kindly 
gave much additional information: 



"Hypselodoris edenticulata (White) is 
perhaps the most common large nudibranch 
offshore along the Florida west coast. In any 
event, it was the most frequently collected 
during Project Hourglass, our 28-month study 
of the fauna on the central west Florida shelf. 
In addition, I have seen many specimens 
brought in by divers from as far north as 
Tarpon Springs. Like your specimen, all I 
have seen from the Gulf coast are from 30-40 
ft. depths out to some as great as 180 ft. 
Specimens are occasionally taken along the 
lower east coast of Florida in estuaries where 
tropical conditions prevail. 1 have taken them 
for several years in the Indian River near the 
St. Lucie Inlet, Martin County, but only when 
conditions allow intrusion of many other 
tropical species." 

LITERATURE CITED 

Marcus, Eveline and Ernst Marcus. 1967. 

American Opisthobranch Mollusks. Univ. 

Miami, Florida. 256 pp. 
White, Kathleen M. 1952. On a Collection of 

Molluscs from Dry Tortugas. Proc. Mai. 

Soc. London 29(2-3):106-120. 





FIG. 1. Hypselodoris edenticulata (White, 
1952) from Sanibel Island, Florida, in 35-40 
feet of water. Length: 64 mm. Lower view 
shows details of gills (photos by A. D. 
Barlow). 



Vol. 88 (2) 



THE NAUTILUS 



53 



FURTHER NOTES AND CORRECTIONS CONCERNING THE 

SPAWN OF FLORIDA CYPHOMA (OVULIDAE) 

M. Ellen Crovo 

2915 S.W. 102 Avenue 

Miami, Florida 33165 

ABSTRACT 

The oothecae, manner of capsule deposition, and the operculate veligers 
of Cyphoma gibbosum (Linne) from Florida are described. Observations 
made by Harding B. Owre on the spawn of C. macgintyi are published. The 
egg capsule illustrated by Gather and Crovo (1972, The Nautilus 85(4): 113) 
is now believed to have been that of an Anachis (Columbellidae). 



Conflicting accounts of the nature of the 
oothecae of Cyphoma gibbosum have recently 
been published (Gather and Crovo, 1972; 
Bandel, 1973; Ghiselin and Wilson, 1966). It 
now appears that the ootheca illustrated in 
The Nautilus (85(4): 113, fig. 1) by Gather 
and Crovo is not that of Cyphoma, but rather 
an egg capsule of a columbellid snail, most 
closely resembling that of Anachis avara 
(illustrated by Scheltema, 1968, p. 5, text fig. 
2) and Anachis sp. [catenata?] (illustrated by 
Raeihle 1969, p. 26, fig. 2). Cather (in litt.) 
believes his error may be due to the 
undetected presence in his aquarium of a 
columbellid near the base of the sea fan. 

Further recent observations by the author 
substantially confirm the accounts of Cypho- 
ma oothecae by Bandel (1973) and by 
Ghiselin and Wilson (1966). 

On November 9th, 1969, four living 
specimens of Cyphoma gibbosum (Linne) 




FIG. 1. Egg capsule of an Anachis from 
Bermuda, erroneously identified as Cyphoma 
gibbosum in The Nautilus, vol. 85, p. 113, 
1972. 



were placed in a five gallon saltwater 
aquarium. Eleven days later, on November 19, 
one snail was observed working over a 
three-inch-square area of glass an inch below 
the surface of the water. On the morning of 
November 20 a network of 23 flexible, 
translucent capsules containing minute white 
eggs was formed. These capsules were 
approximately 2.0 x 2.1 mm., 
irregularly-placed rather than in even rows. 
Each capsule had a very short, indistinct, 
slotlike hatch at one end. 

Each morning the mollusk returned to her 
laying area, adding to it until the last of 73 
capsules was laid by late evening of November 
24. The mother remained close to the mass of 
capsules, returning each morning, carefully 




FIG. 2. Egg capsules of Cyphoma gibbosum 
(Linne), both empty and full, laid on a 
denuded section of a seafan from Florida. 
Photo courtesy of R. T. Abbott (greatly 
magnified). 



54 THE NAUTILUS 



April 30, 1974 



working over the area for a period of three to 
four hours. 

Five days after formation of the capsules 
active embryos were observed within the 
capsule walls. Ten days later, the capsules 
became a light flesh-pink color, gradually 
darkening to a deep-rose as the veligers grew 
to full size. On the fifteenth day the 
free-svnmming veligers began to escape 
through a newly-formed slit on the top of 
each capsule. Without proper food and 
environment the veligers died after a few 
days. By carefully opening one capsule wath a 
sharp needle, it was found to contain about 
1270 veligers. 

Similar observations v«th other egg-laying 
Cyphoma gibbosum were made in August, 
1972. One small male and four larger female 
Cyphoma were collected from one Gorgonia 
ventalina Linne 1758. Each female laid her 
eggs in a separate area on the same Gorgonia, 
and all produced their capsules within five 
days. It was noted that warmer room and 
water temperatures reduced incubation time 
by 36 to 72 hours. We were also successful in 
obtaining photographs and measurements of 
capsules and veligers. The average size of the 
latter was 0.153 mm. The number of capsules 
and veligers varies according to the size of the 
producing adult Cyphoma. The veliger count 
of one full capsule in this series was 780. 
Adults were several millimeters smaller than 
those observed in November. Veligers from 
one capsule lived in a petri-dish of seawater 
for nine days with no attention other than 
daily checks on their activity. A tiny 
operculum is clearly visible on the Cyphoma 
gibbosum veligers, but this organ evidently is 
lost during metamorphosis. 

The following account of the spawn of 
Cyphoma macgintyi Pilsbry and the accom- 
panying drawings were kindly supplied by Dr. 
Harding B. Owre of Miami, Florida, and were 
taken from her unpublished Master's thesis 
(1949, pp. 24-25): 

Cyphoma macgintyi "is generally found on 
an alcyonarian, where it feeds by sucking up 
polyps as it crawls along a branch. It deposits 
its spawn on a portion of a branch which has 
been cleared of polyps. Although it is 






Vol. 88 (2) 



d 



FIG. 3. Veliger of Cyphoma gibbosum 
(Linne) showing shell, soft parts and oper- 
culum (greatly magnified). 





,-\^7i^'^^^''^^^^X^0(k'^'^^. 




Sd^'J^uj^K^'t^ - -'^^-i? 



FIGS. 4-6. Cyphoma macgintyi Pilsbry from 
Soldier Key, Florida. 4 and 5, preveligers. 6, 
oothecae on a stem of alcyonarian. (drawings 
by Harding B. Owre). 

probable that the adults lay eggs at other 
seasons, spawn has not been found except in 
the spring. 

"Two egg masses were collected on April 
10, 1948, in the alcyonarian bed on the ocean 
side of Soldier Key. In both cases, the spawn 
was laid on Eunicea multicavda, which was 
growing in water about four feet deep. An 
adult, presumably the parent, was found on 
each branch with the spawn. The maintenance 
of the spawn in the laboratory was difficult, 
for it could not, with safety, be separated 
from the cut branch of Eunicea, and the latter 
survived only two days. 

"The spawn is laid out in an area which is 



Vol. 88(2) 



THE NAUTILUS 



55 



roughly rectangular, about 12 cm long and 1 
cm wide. The mass is composed of numerous 
variously-shaped cases, which are gelatinous, 
thin, and flat or faintly convex on the upper 
side. In one mass, there were 111 cases, each 
one measuring approximately 4.5 x 4.0 x 1.0 
mm. There are about fifty minute embryos in 
each case. The color of the spawn varies from 
white to pale pink, becoming a darker pink as 
the young mature. 

"When collected, the young were late 
trochophore larvae. By April 13, 1948, the 
Eunicea had disintegrated to such an extent 
that the larvae in some of the cases were dead 
and it was necessary to release the rest. The 
"hatching" was premature, for the veliger 
stage had not quite been reached, and the 
larvae did not survive. 

"The pre-veliger had a colorless translucent 
shell of one whorl. The diameter was about 
0.12 mm. The heavily ciliated velum was still 
a single lobe with an extension on either side 
and one in the middle. There was a tuft of 
especially long cUia, remaining from the 
prototroch, on each projection. The foot was 
ciliated. The eyes and tentacles had not yet 
appeared." 

ACKNOWLEDGEMENTS 

I wish to thank Dr. Harding B. Owre for 
her interest and advice on photographing the 
Cyphoma gibbosum veligers and the use of 
her equipment. I am also indebted to her for 
the additional information which she gener- 



ously shared with me on Cyphoma macgintyi 
from her studies for her Master's thesis. I 
would also like to thank R. Tucker Abbott 
for his editorial assistance and for the 
photograph of the oothecae of Cyphoma 
gibbosum. 

LITERATURE CITED 

Cather, J. N. and M. E. Crovo. 1972. The 
Spawn, Early Development and Larvae of 
Cyphoma gibbosum (Cypraeacea). The 
NautUus85(4):lll-114. 

Bandel, Klaus. 1973. Notes on Cypraea 
cinerea Gmelin and Cyphoma gibbosum 
(Linnaeus) from the Caribbean Sea and 
Description of their Spawn. The Veliger 
15(4):335-337. 

Ghiselin, Michael T. and Barry R. Wilson. 
1966. On the Anatomy, Natural History, 
and Reproduction of Cyphoma, a Marine 
Prosobranch Gastropod. Bull. Marine 
Science 16(1):132-141. 

Owre, Harding B. 1949. Larval Stages of 
Some South Florida Marine Gastropods. 
Master's Thesis, Univ. Miami, Florida; pp. 
24-25. 

Raeihle, Dorothy. 1969. Egg Cases of 
Nitidella ocellata Gmelin and an Anachis. 
Annual Report for 1969, Amer. Mai. 
Union, pp. 25-26. 

Scheltema, Amelie H. 1968. Redescriptions of 
Anachis avara (Say) and Anachis translirata 
(Ravenel) with Notes on Some Related 
Species (Prosobranchia, Columbellidae), 
Breviora, no. 304, pp. 1-19. 



VIVIPARUS MALLEATUS IN MONTREAL, CANADA 

Dominique A. Bucci 

320 91st Street, Chomedy, 
Laval, Quebec, Canada 



Heretofore, the most northerly record for 
the freshwater gastropod, Viviparus malleatus 
(Reeve), has been New Hampshire (Perron 
and Probert, 1973, The Nautilus 87(3):90). In 
the summer of 1973 I found this species 
abundant in one to two feet of water in a 



small lagoon in the public park at Cartierville, 
Montreal Island, Quebec. During the fall and 
wdnter, adults move to deeper water. Speci- 
mens have been deposited in the Delaware 
Museum of Natural History. 



56 THE NAUTILUS 



April 30, 1974 



Vol. 88 (2) 



THE INTRODUCED ASIATIC CLAM, CORBICULA, 

IN CENTRAL ARIZONA RESERVOIRS 

John N. Rinne' 

Research Associate 

Department of Zoology and Lower Colorado River 

Basin Research Laboratory 

Arizona State University 

Tempe, Arizona 85281 

ABSTRACT 

Horizontal and vertical densities and biomasses of Corbicula in two central 
Arizona reservoirs were estimated employing meter square quadrats and 
Ekman dredge sampling. Concentrations of clams increased with depth of 
water and down-lake from inflow areas characterized by greater turbidity 
(suspended sediment). Densities were highest on rock-rubble slopes and 
increased directly with complexity (number of components) of substrate. 
Data suggest food supply, substrate, turbidity and perhaps fish predation as 
important factors in determining densities and biomasses of clams in the two 
reservoirs examined. 



INTRODUCTION 

Corbicula was first recorded in Arizona in 
1956 from the Phoenix CEinal system (Dundee 
and Dundee, 1958). Introduction into 
Arizona, possibly from CEilifornia, most likely 
occurred by man in the role of tourist, 
fisherman, or aquarium hobbyist. It was first 
recorded in abundance in the Southwest from 
the Coachella Valley, California, in 1953 
(Ingram, 1959). In 1963, Corbicula had 
re-invaded irrigation systems of the Colorado 
River Indian Reservation eifter its eradication 
a year earlier (Ingremi, et al., 1964). Since that 
time it has spread throughout the entire lower 
Colorado River basin. The rapid spread of this 
animal upon introduction at various localities 
in the United States led Sinclair (1971) to 
describe Corbicula manilensis as " . . . 
currently the most costly liability of all exotic 
molluscs in North America . . ." This "pest" 
currently inhabits the Salt River reservoir 
system, central Arizona, where it occurs most 
abundantly in Roosevelt and Apache lakes 
(Fig. 1) Corbicula are scarce in the lower two 
reservoirs. Canyon and Saguaro lakes, for 
which I have no explanation since they are 



abundant upstream, and downstream in the 
Salt River between Stewart Mountain and 
Granite Reef dams and in the Phoenix canal 
systems. Locally, they comprise a major 
component of the benthic fauna of the upper 
two reservoirs. 

METHODS AND MATERIALS 
Corbicula were collected sporadicEilly from 

TOKTO CRCEK r^FLOH 



Y^"-* (WOSEVELT UK£ 





'Current Address: EAFFRO, P. O. Box 1881, 
Kisumu, Kenya 



FIG. 1. The two most upstream lakes, 
Roosevelt and Apache, of the Salt River 
system of reservoirs showing transect loca- 
tions and place names used in text. 



Vol. 88 (2) 



THE NAUTILUS 



57 



Roosevelt and Apache lakes (Fig. 1) in 
November 1970, 1971 and February 1972. 
Almost all specimens were collected in a 
moribund state, or dead, on exposed lake 
shore during low-water conditions. Several 
meter-square {m2) quadrats were randomly 
thrown at a given site. All clams within this 
area with hinges yet attached were collected, 
and retained for later examination. In some 
cases intact valves would break upon 
handling, or were parted when later examined 
and measured. In either instance, these were 
counted. No specific information concerning 
time required to sufficiently decompose 
hinges and promote separation of valves was 
available to me. This undoubtedly varies with 
conditions following death. Most collections 
were made after a drop in reservoir level and 
consisted predominantly of individuals which 
had died of desiccation. Time-lapse between 
collection and exposure to drying varied in all 
cases, and could, indeed, affect density 
estimates. Autumn 1970 collections in Roose- 
velt and Apache were both within a month 
after the substrate was exposed by receding 
water. The November 1971 sampling in 
Roosevelt at R-1 was performed near water 
line and specimens were most likely exposed 
for only 2 to 3 months. By contrast, 
November 1971 and February 1972 collec- 
tions in Apache were subject to approxi- 
mately 7- to 10-month exposures, respec- 
tively, and sampling across from Frazier's 
Landing (equidistant between R-2 and R-3, 
see Table 2, Fig. 1) was undertaken on 
bottom that had been dry for more than a 
year. Other shortcomings of such collecting 
techniques were alteration of information by 
predatory mammals and birds, and activities 
of man. The last was circumvented to a large 
extent by selecting sites away from human 
activities. 

Clams were measured (widths) and counted 
in the laboratory. Live clams were processed 
to determine dry and ash-free dry weights of 
animals excluding the valves. Regression 
analysis of size and weight indicated a power 
function giving the highest r-value (+0.98; 
equation: y = [0.0110608] x X 3.0129). 
Mean size of all Corbicula within a quadrat 



was employed to estimate approximate 
biomass per unit area using the plotted 
regression line. 

RESULTS 

Two, shallow-to-deep-water transects at 
arbitrarily selected locations in Roosevelt and 
Apache lakes were sampled to determine the 
possible effect of depth of water on densities, 
sizes, and biomasses of Corbicula. Both 
transects generally indicated an increase in 
numbers and biomasses of clams with 
progression to deeper water (Table 1; Fig. 1), 
depending somewhat on substrate. Sampling 
in approximately 3.4 meters (m) of water on 
the north shore of Roosevelt Lake yielded no 
clams on rubble bottom. At deeper, down- 
slope sites, the animal became progressively 
more dense. Substrate along this transect was 
generally rocky. However, diversity of the 
habitat, increased directly with increasing 
depth. Shallower sites were far more uniform 
in sizes of substrate components, whereas at 
deeper levels, sand, rubble, gravel and 
boulders were interspersed. Average sizes of 
clams neither consistently, nor significantly, 
changed with depth. 

The transect near A-2 (Burnt Corral, see 
Figs. 1 and 2) was located on an extremely 
steep, rock-covered slope, with the exception 
of several m" quadrats sampled on mud-sand 
flats. Numbers of clams were low at a depth 
of 2.2 m on sand-silt substrate (Table 1). 
Quadrats at 3.4 m were located near the crest 
of a rock slope (approximately 26% grade). 
Numbers and biomasses of clams then 
increased dramatically, remaining high to a 
depth of 18 m, where a drastic decrease in 
density occurred. The last site (BC-1-5) was 
located at the base of the rocky slope and was 
composed of sand-gravel substrate. Four 
quadrats were sampled on sand-gravel sub- 
strate, lying upon the old river terrace 
immediately below the rocky slope. Numbers 
cdso were extremely low in this area (BC-4-1). 
Several more quadrats were sampled at 20 and 
22 m below full lake level (BC-2-1 and 
BC-3-1), on a second rocky slope, which 
dropped toward the old river channel. 
Densities of clams increased over those on the 



58 THE NAUTILUS 



April 30, 1974 



Vol. 88 (2) 



lABlE I. AVERAGE SIZES, DENSITIES, A«) BIOHASSES OF COBBICULA AT SHALLOH-TO-OEEP-WATER TRANSECTS IN ROOSEVELT A«) 



APACHE 


LAKES. HArCES ARE 


StOKN IN 


( ). 










TRANSECT 




jEPTM 


BELOW r. 


., 


..uhSTRAIf. 


A.tiWii 


NUMBER /M^ 


BIOMASS 




DESCRIPTION 




POOL WATER MARK 


(M) 




SIZE (mm) 




KE/HA 




apacme lake 


(BURNI CORRAL) 
















BC-I-I 






2.2 




Sand-Si IT 


19.6(7-38) 


7.0(5-9) 


6.0 




BC-l-2 






3.4 




Rubble 


19.7(5-57) 


208.0(27-367) 


181.0 




EC- 1-3 






9.0 




Rubble 


22.5(5-38) 


383.0(221-589) 


482.6 




ec-i-4 






13. 4 




Rubble 


19.8(3-38) 


380.0(240-499) 


338.2 




BC-l-5 






18.0 




Gravel-sanO, 
stnal 1 rubble 


22.5(10-38) 


25.0(20-29) 


31.5 




BC-4-1 






17.0 




Sand-gravel 


25.0(19-28) 


3.0(5-9) 


5.4 




ac-3-i 






22.0 




Rubble 


14.5(6-28) 


32.0(0-64) 


9.9 




EC-2-1 






20.0 




Sand-rubble 


18.4(7-28) 


17.0(0-34) 


12.2 





ROOSEVELT LAKE (NORTH SHORE EQCJ IDI STANT BETWEEN R-2 Mt> R-3) 
F-50 3.4 

F-lOO 7.0 

F-150 10.4 



F-200 



14.0 



Rubble 


0.0 


0.0 


Rubble 


13.8(5-25) 


22.0(12.3) 


Sand-gravel 


20.2(8-36) 


124.0(86-166) 


Sand, gravel , 


19.2(8-32) 


176.0(121-163) 


rubble, boulder 







higher terrace, however, they were far lower 
than those on the shallower, rocky slope. Mud 
flats near this locality, despite excavation to 
depths of 0.5 m yielded no indications of 
clams. 

Another shallow-to-deep transect similar to 
those discussed above was sampled in the 
vicinity of R-4 (Fig. 1) on a predominantly 
silt slope containing little rock or sand. Eleven 
m^ quadrats were examined — seven con- 
tained no clams, three had 2, and one had 3 
clams. Two quadrats at approximately 15 m 
below high waterline contained only 2 
clams/m' . Two samples from about 17 m of 
water contained only 2 and 3 clams/m^ . 
These data also support the evidence for 
greater densities in deeper water and on 
rock-rubble slopes. 



Variation in average sizes, numbers, and 
weights per unit area of all Corbicula 
collected in areas as near to established 
transects as possible in Roosevelt and Apache 
lakes are in Table 2. No consistent trends in 
average sizes of clams were detectable among 
localities in Roosevelt Lake. Greater biomass, 
however, was present at down-lake transects 
(e.g. R-2). Densities of clams at about a 
kilometer (km) east of R-2 and on the north 
shore of Roosevelt roughly equidistant 
between R-2 and R-3, were 2 to 6 times the 
mean densities, and 4 to 10 times the 
biomasses recorded nearer inflow areas. 
Evident harvesting of clams by humans at 
Frazier's landing, a major boat launching area, 
was reflected in drastically lower densities 
(Table 2). Considering all quadrats sampled in 



Vol. 88 (2) 



THE NAUTILUS 



59 



T*BLt 2. AVERAGE SIZES, NUMBERS, UNO BIOHASStS OF CORBICULA AT SELECTED LOCALITIES IN ROOSEVELT AND APACHE LAKES. 
RANGES ARE SHOWN IN ( J. 



LAKE 

LOCALITY 



AVERAGE SIZE 

Cmm) 



BI0MA5S 
< KG/HA 



ROOSEVELT 

R-l 11.4(10.1-13.7) 

I km. E. R-2 14.7(10.0-18.5) 



Frazier's Landing 



21.8(18.8-27.8) 



N, shore of Roosevelt 

equidistant from R-2 and R-3 18.6(14.2-20.9) 



53.0(12.0-103.0) 

I 19.0(42.0-243.0) 

19.0(52.0-243.0) 

I 10.0(32.0-243.0) 



10.0(1.4-14.0) 



45.0(10.7-87.5) 



I 10.0(10.6-137.8) 



110.0(10.6-137.6) 



0.5 Wn. N. A-2 



25.9(23.5-29.0) 



20.6(10.5-27.9) 



20. 8( 17.2-25.9) 



19.4(11.5-23.8) 



26.0(11.0-59.0) 
177.4(5.0-589.0) 
73.0(14.0-166.0) 
65.0(30.0-152.0 



49.9(35.9-105.6) 
194.1(0.65-1,060.0) 
68.9(18.2-164.3) 
56.2(11.4-214.0) 



Roosevelt Lake, numbers of clams ranged 
from 12 to 243 /m^ , and biomasses from 1.4 
to 137.8 kilogram per hectare (kg/ha). 

Average size, density, and biomass of clams 
generally decreased downlake in Apache 
(Table 2). Great variation in these parameters 
at two sites, one at A-2 and another less than 
a km north, reflects the influence of bottom 
type on clam populations (Table 2). At A-2, 
the substrate consisted of compacted gravel, 
and clams were scarce; however, in 
boulder-strewn slopes, up-lake Corbicula were 
almost eight times as numerous per unit area 
(Table 2). Furthermore, three sets of adjacent 
samples taken in February 1972 on 
rock-boulder (in contrast to the sand-gravel 
substrate at A-3 in Apache Lake— (Fig. 3) 
yielded significantly greater densities in all 
cases in the former, ranging from 2.5 to 9.0 
times higher (66-25, 121-14, 38-8) than in 
A-3's sand-gravel substrate type. 

Over-all, densities of Corbicula in Apache 
Lake ranged from 5.0 to almost 600/m^ , and 
standing crops from 0.65 to 1,060 kg/ha, 
excluding weights of shell. Analysis of 



variance showed non-significant differences 
between numbers, sizes, and biomasses 
relative to depth at all transects and in 
comparison of samples from the two localities 
at A-2. 

Meager data on Corbicula were obtained 
from Ekman dredge samples (Table 3). Few 
clams occupied the soft, fine-grained sedi- 
ments that the Ekman dredge sampled most 
efficiently. Numbers of live clams taken in 
Ekman dredge samplings were comparable to 
those collected in meter square quadrats. For 
example, 5 of 20 Ekman samples taken at 
A-2, in Apache Lake indicated clam densities 
of 43 to 86/m^ (Table 3), compared to 
26/m^ estimated by the quadrat method 
(Table 2). Densities of clams at A-5 estimated 
by these same two sampling methods, also 
were comparable (Tables 2 and 3). 

DISCUSSION 

Data from Roosevelt and Apache Lakes 
were not significantly different at the 0.05 
level in either biomasses or numbers of clams 
between lakes or in most cases, among 



VAUTI] 


.US 




April 30, 1974 








Vol. 88 (2) 


TUBLE 5. 


5U»«ARY QF 


COfiBlCULA COLLECTED krl 


TH AN EtWAr. DREDGE IN APACHE 


LAKE, 


1971. 






TRAHSECT, 


STATION 


DATE 


NUMBER COMTAINING 




NUMBER/DREDEING 


ESTIMATED 








CORSICULA 








MUMBER/M^ 


»P»CME 
















»-2-l 




3-30-7 1 


3 o* 8 dredgings 






1 


43.0 


A-2-5 




3-29-7 1 


1 0* 10 dredgings 






2 


ae.o 


A-2-3 




3-30-71 


I of 2 dredgings 






2 


86.0 


*-5-l 




3-23-71 


1 of 8 dredgings 






4 


172.0 


A-4-3 




3-22-71 


2 of 10 dredgings 






1 
2 


43.0 

86.0 


A-5-1 




3-22-71 


3 of 15 dredgings 






2 

1 


86.0 

43. C 



transects, but actual values of each of these 
seemed to vary inversely up- to down-lake, 
when the two reservoirs were compared. 
Inflow areas of Roosevelt Lake were more 
turbid, and normally had more phyto- 
plankton as indicated by chlorophyll-a data 
(Portz, 1973; Rinne, 1973). As given above, 
clams were far more dense down-lake from 
inflow areas in Roosevelt Lake. The effect of 
greater inorganic suspended solids at the Salt 
River inflow of Roosevelt may well have 
suppressed the population of clams, despite 
an adequate food supply. 

By comparison, densities and biomasses of 
Corbicula decreased down-lake in Apache 
Lake in presence of both sparser food and less 
turbidity relative to that recorded in up-lake 
sectors. These data indicate that food supply 
may be more limiting to Corbicula than 
turbidity. Prokopovich (1969) recorded de- 
creases in densities of clams downstream in 
the Delta-Mendota Canal, California, and 
attributed this to decreasing food supply. 
However, turbidity as a factor in affecting 
dispersion of clams can not be eliminated as 
indicated by my data and that of others. A 
high mortality of Corbicula in the Ohio River 
in spring was attributed to increased tur- 
bidities (more than 400mg/l) by Bickel 
(1966). 



Vertically, densities of Corbicula seemed to 
increase with depth, modified somewhat by 
bottom type and location within the reservoir 
system. This may be an indication of the 
influence of food supply (phytoplankton) as 
effected by photic conditions (Portz, 1973; 
Rinne, 1973). In addition, rocks and boulders 
upon slopes vnthin these two reservoirs 
provide protection for juvenile clams from 
predators. Several species of fishes; carp 
(Cyprinus carpio Linnaeus), smallmouth (Icti- 
obus bubalus [Rafinesque] ) and black ('/c^i- 
obus niger [Rafinesque]) buffalofishes 
consume large numbers of Corbicula 
(Minckley, et al., 1970; Rinne, 1973). 
Increase in densities of clams with depth may 
therefore be a reflection of greater fish 
predation in shallower areas of the lake. 

Corbicula is knovra to remove suspended 
orgEinic and inorganic particles from water 
and deposit them as pseudofeces (Proko- 
povich, 1969). Heinsohn (1958) reported two 
to three small Corbicula were capable of 
clearing 500 milliters of "very turbid water" 
in less than 2 minutes. Precipitation of 
plankton from aquatic media by Corbicula 
was reported by Greer (1971), and laboratory 
studies at Arizona State University suggested 
filtration rates are directly related to concen- 
tration of algal cells in solution (Richard 



Vol. 88(2) 



THE NAUTILUS 



61 



Stephenson, pers. comm.). Above certain 
critical concentrations of algal cells, clams 
began indiscriminantly to precipitate food 
and inorganic particles, presumably to clear 
their gUls and thereby prevent asphyxiation. 
Ideal conditions for Corbicula seemingly 
would include both clear waters and adequate 
food supply. Large concentrations of this 












FIG. 2. Photograph of a rock-rubble slope 
typical of central Arizona reservoirs (A) and 
closeups (B and C) showing complexity of 
these habitats and interstices providing 
protection for clams from fish predation. 



clam downstream from hydro-electric dams 
has been attributed to clear, plankton-rich 
waters (Heard, 1964), 1 noted the greatest 
concentrations of clams (1,500/m^ ), in the 
canal below Granite Reef Dam where both 
clear water and adequate food were present. 
LITERATURE CITED 

Bickel, D. 1966. Ecology of Corbicula 
manilensis Philippi in the Ohio River at 
Louisville, Kentucky, Sterkiana 23: 19-24. 

Dundee, D. S., and H. A. Dundee. 1958. 
Extensions of known ranges of 4 mollusks. 
The NautUus 72: 51-53. 

Greer, D. E. 1971. Biological removal of 
phosphates from aquatic media. Unpub- 
lished M. S. Thesis, Univ. of Arizona, 
Tucson, 29 p. 

Heard, W. H. 1964. Corbicula fluminea in 
Florida. The Nautilus 77: 105-107, 

Heinshohn, G. E. 1958. Life history and 
ecology of the freshwater clam, Corbicula 
fluminea. Unpublished M. S. Thesis, Univ. 
of California, Santa Barbara. 64 p. 

Ingram, W. M. 1959. Asiatic clams as 
potential pests in California water supplies. 
Jour. Amer. Water Works Assoc. 51: 
363-370. 

Ingram, W. M., L. Keup, and C. Henderson. 
1964. Asiatic clams in Parker, Arizona. The 
Nautilus 77: 121-124. 

Minckley, W. L., J. E. Johnson, J. N. Rinne, 
and S. E. Willoughby. 1970. Foods of 
buffalofishes, genus Ictiobus, in central 
Arizona reservoirs. Trans. Amer. Fish. Soc. 
99: 333-342. 

Portz, D. E. 1973. Plankton pigment hetero- 
geneity in seven reservoirs of the lower 
Colorado basin. Unpublished M. S. Thesis, 
Arizona State Univ., Tempe. 168 p. 

Prokopovich, N. P. 1969. Desposition of 
clastic sediments by clams. Jour. Sedi- 
mentary Petrology 39: 891-901. 

Rinne, J. N. 1973. A limnological study of 
central Arizona reservoirs with reference to 
horizontal fish distribution. Unpublished 
Ph.D. Thesis, Arizona State Un.v., Tempe. 
350 p. 

Sinclair, R. M. 1971. Annotated bibliography 
on the exotic bivalve Corbicula in North 
America. Sterkiana 43: 11-18. 



62 THE NAUTILUS 



April 30, 1974 



Vol. 88 (2) 



MICROSTRUCTURE OF CHALKY DEPOSITS FOUND IN SHELLS 
OF THE OYSTER CRASSOSTREA VIRGINICA' 



Stanley V. Margolis 

Department of Oceanography, 

University of Hawaii 

Honolulu, Hawaii 96822 



and Robert E. Carver 

Department of Geology 

University of Georgia 

Athens, Georgia 30602 



ABSTRACT 

Scanning electron microscopy has revealed that chalky deposits in shells 
of Crassostrea virginica consist of blade-shaped crystals of calcite oriented 
perpendicular to the inner surface of the shell. From a structural standpoint, 
these chalky deposits appear to represent a layer of calcite which is a 
morphologically distinct entity, and not merely a porous and disoriented 
variant of the calcite ostracum. Chalky deposits are common at all stages of 
growth and are irregularly distributed across the inner surfaces of the valves. 
It is suggested that deposition of calcite in the form of chalky deposits 
occurs as a specific physiological response to environmental stimuli, possibly 
during periods of maximum respiration. 



The shell of Crassostrea virginica, the 
common commercial oyster of the Atlantic 
coast of North America, has been described as 
consisting of two layers of crystalline calcite 
with a thin, to absent, outer organic 
periostracum (Galtsoff, 1964). Our exami- 
nation of various portions of fresh C. virginica 
valves by scanning electron microscopy has 



'Contribution number 594, Hawaii Institute of 
Geophysics 



revealed that the outer crystalline layer is 
composed of elongate, prismatic calcite 
crystals oriented perpendicular to the shell 
wall and enmeshed in a reticulum of 
conchiolin which separates and defines the 
individual calcite prisms (Fig. lA). The 
electron micrographs shown here represent 
specimens which first were cleaned of 
adhering organic material with a 5% sodium 
hypochlorite solution, and then etched 
briefly in a 10% solution of acetic acid in 
order to bring the crystal structure out in 



FIG. 1 (opposite page) 



A. Cross-section of outer crystalline layer of 
C. virginica showdng elongate calcite crystals 
oriented perpendicular to outer shell surface. 
Conchiohn has been partially removed by 
sodium hypochlorite. 

B. Cross-section of inner calcite ostracum 
layers consisting of thin sheets oriented 
parallel to inner surface of shell. 

C. Fractured portion of inner calcite ostracum 
illustrated in B showing structure of calcite 
sheets. 

D. Etched cross-section of hinge area of C. 
virginica shovnng thick inner calcite ostracum 



(O) and thinner interbedded discontinuous 
chalky layers (C). 

E. Interface between chalky layer (upper 
portion of photo) and calcite ostracum (lower 
portion) showing different orientation and 
morphology of crystals. 

F. High resolution photo of chalky layer 
showing aggregates of blade-shaped crystals. 
Clumpy material adhering to crystals are 
remnants of conchiolin which had been 
incompletely removed by sodium hypo- 
chlorite. 



Vol. 88 (2) 



THE NAUTILUS 



63 





7*'<k'>vV>>^.lOii 



FIG. 1. Microstructure of Oyster Shell, Crassostrea virginica 
(explanation on opposite page) 



64 THE NAUTILUS 



April 30, 1974 



Vol. 88(2) 



relief. The inner layer of calcite is much 
thicker than the prismatic layer and consists 
of thin blocks, or sheets, of calcite oriented 
with the long axes parallel to the inner surface 
of the shell (Figs. IB, C). In the inner layer, 
or calcite ostracum, as in the prismatic layer, 
each calcite crystallite is completely sur- 
rounded by a thin membrance of conchiolin 
(Watabe et al., 1958). Stenzel (1963) found 
that the hypostracum, the crystalline material 
of the areas of attachment of the adductor 
muscle imprint of Quenstedt's muscle, con- 
sists of aragonite, rather than calcite. We also 
noted slender aragonite crystals in our 
examination of the hypostracum. 

The most intriguing aspect of the shell 
structure of C. virginica and other species of 
Crassostrea is the almost universal occurrence 
of patches of dead-white, porous material 
called "chalky deposits" on the interior 
surface of the shell. Chalky deposits also 
occur within the body of the shell, inter- 
layered with calcite ostracum (Figs. ID, E), 
indicating that they represent temporary 
phenomena, deposited at some time, when 
overgrown by the more abundant calcite 
ostracum. Galtsoff (1964) studied the mor- 
phology and distribution of chalky deposits in 
C. virginica and found that they are randomly 
distributed over the inner surface of the shell 
and do not appear to be related to either 
injury or senility. Medcof (1944) and 
Korringa (1951) had previously suggested that 
chalky deposits serve to correct the internal 
volume and curvature of the shell to conform 
to body size and shape, but Galtsoff found no 
evidence to support this view. 

We report that examination of the "chalky 
deposits" show them to consist of 
blade-shaped crystals of calcite oriented 
perpendicular to the inner surface of the shell. 
The structure is not porous nor a disoriented 
phase of the normal calcite-ostracum struc- 
ture, as has been previously thought, but an 
entirely different, perhaps physiologically 
unique, structure. "Chalky deposits" consist 
of aggregates of blade-shaped calcite crystals 
(Figs. IE, F) oriented with long axes 
perpendicular to the inner surface of the shell. 
Intermediate axes of neighboring crystals tend 



to be oriented subparallel to the plane of the 
shell surface, establishing crystal domains 
consisting of 5 to 20 similarly oriented calcite 
crystals. "Spurs" extending from the long 
axes of calcite crystals at approximately 60° 
(Fig. IF) suggest that the long axes are 
parallel to the c crystallographic axis of 
calcite, the intermediate axes parallel to a. 
The etching treatment was desirable in 
revealing the internal structure of the chalky 
deposits, although it somewhat blunted and 
pitted individual crystallites. Further exami- 
nation of specimens etched to a lesser degree, 
revealed that the crystallites and spurs are 
smooth-walled and sharp-edged, and that 
spaces between crystals are filled with 
conchiolin. 

The contrast in orientation and mor- 
phology between the crystals of the calcite 
ostracum and the "chalky deposits" (Figs. 
lA, B) suggests that the "chalky deposits" 
perhaps represent selective growth by the 
oyster of these discontinuous layers as a 
physiological response to one or several 
environmental stimuli. Furthermore, the irreg- 
ular distribution of "chalky deposits" 
throughout the body of the shell and across 
the inner surface of the shell described by 
Galtsoff (1964) indicates that the process of 
formation of chalky deposits is highly 
irregular vnth respect to growth stages of the 
organism, and with respect to time. Although 
unknown, the environmental stimuli involved 
are probably factors which experience episo- 
dic fluctuations, and we can draw on the 
experience of Dugal (1939) for a possible 
analogy. 

Dugal (1939) found that C. virginica and 
Mercenaria mercenaria (Veneridae) resorb ma- 
terial during anerobic metabolism resulting 
from long periods of shell closure, smd that 
the resorption buffers a potential decrease in 
pH of body fluids basically attributable to 
accumulation of CO^ in fluids of the body 
cavity. The Dugal effect, resorption of shell 
material to buffer a low body-fluid pH, may 
be the exact opposite of the physiological 
process leading to the accumulation of chalky 
deposits. It may be possible that during 
periods of maximum ventilation, the CO^ 



Vol. 88(2) 



THE NAUTILUS 



65 



content of the body fluids decreases, with a 
consequent increase in pH. Elimination of 
calcium from the body fluids at this stage by 
decreasing the CaCOa saturation would tend 
to reduce pH and buffer the effect of excess 
ventilation. We suggest that this type of 
calcite deposition is physiologically different 
from that of normal shell growth, and might 
explain the morphologic difference between 
the chalky deposits and the calcite ostracum 
layers. 

ACKNOWLEDGEMENTS 

The authors would like to thank Richard 
Young for helpful suggestions. This research 
was supported by N.S.F. grant GD-34270 for 
the establishment of the Scanning Electron 
Microscope Laboratory at the University of 
Hawaii. 

LITERATURE CITED 
Dugal, L. P. 1939. The use of calcareous shell 



to buffer the production of anaerobic 
glucosis in Venus mercenaria. Jour. Cell. 
Comp. Physiol. 13 (2): 235-251. 

Gaitsoff, P. S. 1964. The American Oyster. 
Fish. Bull. Fish Wildlife Serv., 64: 1-167. 

Korringa, P. 1951. On the nature and 
function of chalky deposits in the shell of 
Ostrea edulis Linnaeus. Proc. Calif. Acad. 
Sci., Ser. 4, 27: 133-159. 

Medcof, J. C. and Needier, A. W. H. 1944. 
The influence of temperature and salinity 
on the condition of oysters (Ostrea 
virginica). Jour. Fish. Res. Bd. Canada 6 
(3): 253-257. 

Stenzel, H. B. 1963. Aragonite and calcite as 
constituents of adult oyster shells. Science 
142: 232-234. 

Watabe, N., Sharp, D. G. and Wilbur, K. M., 
1958, Electron microscopy of crystal 
growth of the nacreous layer of the oyster 
Crassostrea virginica. Jour. Biophys. Bio- 
chem. Cyt. 4: 281-291. 



UNIONIDAE OF THE PAMUNKEY 

RIVER SYSTEM, VIRGINIA 
Fred B. Blood and Marceile B. Riddick 

Biology Department 

Virginia Commonwealth University 

Richmond, Virginia 23220 

During the Fall and Winter of 1972 and 
Spring of 1973, the investigators collected 
over 1200 unionid specimens on the Pamun- 
key River System (York River Drainage). The 
following is a listing of species collected: 
Elliptio complanata (Lightfoot) 
*E. angustata (Lea) 
E. lanceolata (Lea) 
*Lampsilis radiata radiata (Gmelin) 
L. cariosa {Say) 
*Ligumia nasuta (Say) 
Alasmidonta undulata (Say) 



*A. heterodon (Lea) 
Lasmigonia subviridis (Conrad) 
*Anodonta cataracta cataracta (Say) 
Elliptio complanata comprised approxi- 
mately 85% of the specimens. By the most 
recent records available (Johnson, 1970), the 
indicated species (*) are drainage records for 
the river system. A specimen of Anodonta 
implicata (Say), also a drainage record, was 
collected on the James River below Rich- 
mond, Va. 

The authors are indebted to Dr. J. P. E. 
Morrison for his assistance in identification. 

LITERATURE CITED 

Johnson, R. I. 1970. The Systematics and 
Zoogeography of the Unionidae (Mollusca: 
Bivalvia) of the Southern Atlantic Slope 
Region Bull. Mus. Comp. Zool. 140:6. 



66 THE NAUTILUS 



April 30, 1974 



Vol. 88 (2) 



ARION SUBFUSCUS IN THE VICINITY OF WASHINGTON, D.C. 

Lowell L. Getz 

Provisional Department of Ecology, Ethology and Evolution, 
University of Illinois, Urbana, Illinois, 61801 



The previously recorded distribution of the 
introduced European slug, Arion subfuscus 
(Draparnaud, 1805), in eastern North 
America extended on the west from Green- 
wich, Connecticut, northward through the 
Catskill and Adirondack mountains to the St. 
Lawrence River and eastward to the coast 
(and onto Newfoundland); there is also a 
population recorded from the Kipawa Reserve 
in Eastern Ontario. In addition, there are 
scattered records from Pennsylvania and one 
from East Aurora, New York (Chichester and 
Getz, 1969; Getz and Chichester, 1970). 

Spot checks made in the vicinity of 
Washington, D.C. during July 1973, indicated 
Arion subfuscus to be very abundant in this 
region. Collections were made in Falls 
Church, Virginia and Bethesda, Maryland. A. 
subfuscus, along with another introduced 
slug, Umax maximus, was found in high 
densities in flower beds and lawns at both of 
these sites. Discussions with individuals living 
in various places within the District of 
Columbia and surrounding communities indi- 
cated both species to be common throughout 
the metropolitan region. The only previous 
record oi Arion from the District of Columbia 
is A. fasciatus (Nilsson) (as circumscriptus 
Johnston, by Pilsbry, 1948). The abundance 
of A. subfuscus indicates the species has been 
present in this region for a considerable 
period of time, however. 

Examination of the individuals from the 
two populations revealed a much more 
heterogeneous assemblage of color forms than 
was observed in any of the local populations 
in New England. Individuals resembling three 
of the four color forms (Forms 1, 2, and 4; 
Chichester and Getz, 1969) identified in New 
England occurred at both sample sites; only 
the unhanded, yellow-orange form (Form 3) 



was not observed. In addition there was 
greater intergradation between color forms 
than was observed in most other local 
populations. There was a continuous range of 
color from an almost completely black 
dorsum above the lateral bands (as in Form 1) 
to a very light yellowish-brown form with 
light lateral bands (Form 4). This intergrada- 
tion of color forms indicates a possible long 
existence of the species in the region. 

The presence of such an abundant, 
unreported population of A. subfuscus 
existing in this region emphasizes an earlier 
comment concerning the need for more 
detailed information concerning distribution 
of introduced European slugs (Chichester and 
Getz, 1968). 

ACKNOWLEDGEMENTS 

I wish to thank Mrs. Margaret Gray Towne 
for pointing out existence of the slugs in Falls 
Church and Miss Barbara Buckingham for 
assistance in obtaining the collection from 
Bethesda. 

LITERATURE CITED 

Chichester, L. F. and L. L. Getz. 1969. The 
zoogeography £md ecology of arionid and 
limacid slugs introduced into Northeastern 
North America. Malacologia 7: 313-346. 

Chichester, L. F. and L. L. Getz. 1968. 

Terrestrial Slugs. The Biologist 50: 

148-166. 
Getz, L. L. and L. F. Chichester. 1971. 

Introduced Slugs. The Biologist 53: 

118-127. 
Pilsbry, H. A. 1948. Land Mollusca of North 

America (North of Mexico). Monogr. 3, 

Acad. Nat. Sci. Philadelphia 2 (2): 

521-1113. 



Vol. 88 (2) 



THE NAUTILUS 



67 



GALAPAGOS BULIMULIDS: 

A TAXONOMIC CORRECTION 

Allyn G. Smith 

Research Associate, Dept. of Geology 

California Academy of Sciences 

San Francisco, California 94118 

Dr. Abraham S. H. Bruere, Division of 
Systematic Zoology, University of Leiden, 
Leiden, The Netherlands, who is studying the 
Bulimulidae, has kindly and quite properly 
called my attention to a taxonomic situation 
that needs correction. Last year I described 
three new land snails from Isla Santa Cruz 
(Indefatigable Island), Galapagos, that were 
presumed to be new species (Smith, 1972). 
These were Naesiotus cavagnaroi, N. deroyi, 
and N. scalesiana. At the time this report was 
being prepared I was totally unaware of the 
important contribution by the distinguished 
Swedish malacologist. Dr. Nils H. Odhner, in 
which two new Galapagos land snail species 
were described, also from Isla Santa Cruz, as 
Bulimulus blombergi and B. eos, respectively 
(Odhner, 1951). Careful reading of Odhner's 
descriptions along with a review of his 
excellent illustrations leave no doubts that 
Naesiotus deroyi A. G. Smith, 1972, is 
exactly the same species as N. blombergi 
(Odhner, 1951), and that N. scalesiana A. G. 
Smith, 1972, is completely equivalent to N. 
eos (Odhner, 1951). My new names, there- 
fore, should be placed into the synonymies of 
Odhner's species names. Apologies are in 
order for the inadvertent creation of two 
synonyms in the Mollusca: Stylommatophora, 
family Bulimulidae, and for unnessarily 
complicating the taxonomy of the 
family-group to this extent. 

LITERATURE CITED 

Odhner, Nils Hjalmar. 1951. Studies on 
Galapagos Bulimulids. Journal de Conch- 
yliologie, 90(4):253-268, 2 pis. (figs. 1-13). 
Paris. 25 January. [In English] . 

Smith, Allyn Goodwin. 1972. Three new land 
snails from Isla Santa Cruz (Indefatigable 
Island), Galapagos. Proc. California Acad. 
Sci., (4), 39(2): 7-24, figs. 1-25. San 
Francisco. January 21. 



ANOTHER FOSSIL OVO VIVIPAROUS 
TURRITELLA 

Joan Antill 

4201 Cathedral Avenue, N. W. 
Washington, D. C. 20016 

At the Kenneth E. Rice Fossil Pit of 
Miocene age at Hampton, Virginia, in 
September 1973, the writer found a 37-mm 
specimen of Turritella alticostata Conrad that 
contained 41 preserved immature shells. This 
is the fifth species of Turritella from the 
Chesapeake and Floridian Miocene which is 
known to have ovoviviparous reproduction. 
The species was kindly identified by Druid 
Wilson, Geologist of the U. S. Geological 
Survey at the Smithsonian Institution. The 
specimens are in the collection of the writer 
at present, but vnll be given to the Kenneth E. 
Rice Memorial Museum shortly. 

Palmer, Katherine V. W. 1961. Additional 
Note on Ovoviviparous Turritella Jour. 
Paleont. 35(3): 633. 

Sutton, A. H. 1935. Ovoviviparous Repro- 
duction of Miocene Turritellidae. Amer. 
Midland Nat. 16(1):107-109. 



indispensable ^Tre-fH,EF 




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NEWS 

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Pont (1970, 375 pp., 79 colored plates), has 
had its retail price drastically reduced from 
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readily available to malacologists. Send check 
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ERRATUM 

In the article on "Growth Studies on the 
Genus Cerithium . . ." by R. Houbrick, 
appearing in the last issue of The Nautilus, 
vol. 88, no. 1, p. 17, the captions to Figs. 2 
and 3 were inadvertently interchanged. In Fig. 
2, for lutosum, read eburneum. In Fig. 3, for 
eburneum, read lutosum. 



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Inquiries about the meeting should be 
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ship should be sent to the Treasurer, Mr. 
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Angeles, California 90045. 
The President this year is Dr. James H. McLean 
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THE 

NAUTILUS 

Volume 88, number 3 — July 1974 



CONTENTS 



Robert C. Bullock 

A Contribution to the Systematics of Some West Indian 

Latiruf: (Gastropoda: Fasciolariidae) 69 

R. D. Turner and W. J. Clench 

A New Blind Physa from Wyoming with Notes on its 

Adaptation to the Cave Environment 80 

Joseph Vagvolgyi 

Nesupupa galapagensis, a New Indo-Pacific Element 

in the Land Snail Fauna of the Galapagos Islands 

(Pulmonata: Vertiginidae) 86 

Samuel L. H. Fuller 

Neglected Papers on Naiades by W. I. Utterback 90 

Recent Publications 79 

A.M.U. Notice 89 



III 



Vol. 88 (3) 



THE NAUTILUS 



69 



A CONTRIBUTION TO THE SYSTEMATICS OF 
SOME WEST INDIAN LATIRUS (GASTROPODA: FASCIOLARIIDAE) 

Robert C. Bullock 

Department of Biological Sciences 

Florida Technological University 

Orlando, Florida 32816 

ABSTRACT 

Some West Indian members of the taxonomically difficult genus Latirus are 
considered. The two most common species, generally recognized as Latirus 
brevicaudatus (Reeve, 18^7) and L. mcgintyi Pilsbry, 1939, are highly polymor- 
phic and have been described in the literature under a number of names; due to 
the present confusion s^irrminding these species, some nomendatorial changes 
appear necessary, and they are herein called Latirus angulatus (R'dding. 1798) 
and L. cariniferus (Lamarck, 1816), respectively. Latirus (Polygona) bernadensis 
from Barbados is introduced as a new species; Latirus (Polygona) nematus 
Woodring, 1928, originally described from the Bowden Formation, Jamaica, is 
noted for the first time as a member of the Recent fauna. 



INTRODUCTION 

While studying the fasciolariid genus Latirus 
in the western Atlantic, some conclusions have 
been reached pertaining to the subgenera 
Latirus s.s. and Polygona and these results are 
presented in this paper. It is hoped that a 
monograph covering all the West Indian species 
of the genus will be completed in the near 
future. 

The genus Latirus includes a variety of 
fasciolariid species characterized by being spin- 
dle-shaped, generally rather heavy-shelled, and 
with prominent folds on the columella. The 
great diversity of form has encouraged some 
authors to create generic and subgeneric names, 
and some of these appear to be very useful in 
an evolutionary treatment of the group. 

Among the Peristemiinae, the group most 
closely related to Latirus is also composed of 
diverse members and is well represented in the 
New World by the genus Leucozonia. The latter 
group can be distinguished from Latirus by its 
more open siphonal canal, which actually forms 
the lower portion of the aperture; also, there is 
an interesting difference in the radula, the 
small node or cusp on the medial end of the 
lateral tooth being greatly reduced or absent in 
Leucozonia. Some, but not all, Leucozonia 
possess a tooth on the outer lip at the base of 



the aperture. For these reasons, the genus 
Leucozonia [type species Leucozonia nassa 
(Gmelin) from the West Indies] includes 
Leucozonia ocellata (Gmelin), also Caribbean, 
and Leucozonia cerata (Wood), L. rudis (Reeve), 
and L. tuberculatus (Broderip) from the eastern 
Pacific. While some of these generic com- 
binations were noted by Keen (1971) in her 
treatment of eastern Pacific MoUusca, rudis was 
incorrectly considered to belong to Latirtis. 

Other Peristemiinae similar to Latirus, but 
apparently more closely related to Leucozonia, 
include: the Indo-Pacific Latirolagena 
smaragdula (Linnaeus) and the eastern Pacific 
Opeatostoma pseudodon (Burrow) which have a 
typical Leucozonia-tyw radula; and "Latirus" 
amplustris (Martyn), from the Indo-Pacific. It 
should be mentioned here that the generic dif- 
ferences noted above indicate that the radula of 
Latirus gibbulus (Gmelin), the type species of 
the genus Latirus, will prove to be of the 
Leucozonia-tyTpe. The heavy shell of Latirus gib- 
bulus. its reduced spiral and axial sculpture, 
and its open siphonal canal indicate a likely 
Leucozonia affinity. Should the radula of L. 
gibbulus be found to be that of a Leucozonia, it 
would certainly pose an interesting problem 
concerning the correct generic names for the 
species presently considered to be Latirus and 
Leucozonia. The functional significance of the 



70 THE NAUTILUS 



July 22, 1974 



Vol. 88 (3) 




Explanation to Latinis figures 1-11 on opposite page 



Vol. 88 (3) 



THE NAUTILUS 



71 



reduced medial node of the lateral tooth of the 
Leucozonia-type radula is not known, and its 
use as a phylogenetic character is slightly 
questionable due to the limited amount of 
material available for study. 

Genus Latinis Montfort, 1810 

Latinis Montfort, 1810, Conchy liologie systema- 
tique et classification methodique des co- 
quilles 2: 531. Type species, Latirus auranti- 
acus Montfort, 1810, by monotypy [ =L. 
gibbulus (Gmelin, 1791)]. 

Chascax R. Watson, 1873, Proc. Zool. Soc. 
London for 1873: 361. Type species, Chascax 
maderensis Watson, 1873, by monotypy 
[ = Latirus armatiis A. Adams, 1855] ; non 
Chascax Ritgen, 1828 (Reptilia). 

Hemipolygona Rovereto, 1899, Atti Soc. Ligust. 
10:104 (new name for C/ioscox Watson, 1873). 

[?] Ruscida Casey, 1904, Trans. Acad. Sci. St. 
Louis 14: 161. Type species, designated by 
Palmer (1937), Fusus plicata Lea. 

Subgenus Latirus s.s. 

Latirus (Latinis) carinifenis (Lamarck, 1816) 
Figs. 2-6, 9, 11, 18, 22 

1816 Fusns carinifenis Lamarck, Eiicyclopedique 
methodique, pi. 423, fig. 3. Name and figure 
only; locality unknown. Type locality herein 



designated to be Cienfuegos, Cuba. Type not 
in Musee d'Histoire naturelle, Geneva. 

1855 Latirus distinctvs A. Adams, Proc. Zool. 
Soc. London for 1854: 314. Locality unknown; 
type locality herein designated to be off 
Washerwomans Shoals, Key West, Florida. 
Lectotype, herein selected, BMNH 196738/1 
(see Fig. 2). 

1874 Plicatella trochleari^ Kobelt, [in] Martini- 
Chemnitz, Syst. Conch.-Cab. 3 (3A): 79, pi. 
19, figs. 1, 2. Type locality: St. Jan [= St. 
Johns, Virgin Islands]. Location of type 
unknowm. 

1939 Latinis mcgintyi Pilsbry, Nautilus 52: 84, 
pi. 5, fig. 8. Type locality: Lake Worth, 
Palm Beach Co., Florida. Holotype ANSP 
173960. 

Description: Shell highly variable, heavy, up 
to 73 mm in length and 36.8 mm in greatest 
diameter. Whorls 8-9, including IV2 whorls of 
the protoconch. Spire about half the length of 
the shell, but sometimes slightly less. Aperture 
almost square and twice as long as the short, 
thick siphonal canal. Axial sculpture of 8-9 
moderately pronounced, squarish ribs. Spiral 
sculpture of heavy cords which begin at the 
shoulder of the whorl and continue anteriorly 
to the tip of the siphonal canal. 2-3 cords 
visible on the upper whorls, 5 on the body 
whorl, the 2 lowest closer together and being 
characteristic of this species. Between spiral 
cords 6-7 fine threads usually present but may 



FIG. 1. Latirus nematus Woodring, Holotype. 

USNM 369U2. Miocene of Bowden, Jamaica. 

L6X. 

FIG. 2. Latirus cariniferus (Lamarck), Lectotype 

of Latirus distinctus A. Adams, BMNH 

196738/1. 1.7X. Photograph courtesy of the 

British Museum (Natural History). 

FIG. 3. Latirus cariniferus (Lamarck), Steger 

collection no. U16. Matanzas, Cuba. 1.3X. 

FIG. k. Latirus cariniferus (Lamarck), USNM 

36Jf362. Vicinity of Cartagena, Colombia. 1..5X. 

FIG. 5. Latirus cariniferus (Lamarck), Tyj^e 

figure of Fusus cariniferus Lamarck, Encycl. 

Meth. pi. m, fw- 3. I.IX. 

FIG. 6. Latirus cariniferus (Lamarck), USNM 



,589534. Colon, Panama. 1.5X. 
FIG. 7. Latirus angulatus (Rodirig), Type figure 
of Fusus angulatus Roding, Syst. Conch.-Cab. 4, 
fig. 1315. 1.2 X. 

FIG. 8. Latirus angulatus (Roding), specimen in 
MCZ. Just E. of Piscadera baai, Curacao. 
Netherlands Antilles. l.SX. 
FIG. 9. Latirus cariniferus (Lamarck), AMNH 
100.575. W. of Cedar Key, Florida, 20fms. 1.2 X. 
FIG. la Latirus angulatus (Roding), AMNH 
125i89. Curacao, Netherlands Antilles, 6 fms. 1.1 
X. * 

FIG. 11. Latirus cariniferus (Lamarck), MCZ 
23Wh. Cienfuegos, Cuba. 1.3X. 



72 THE NAUTILUS 



Julv 22. 1974 



Vol. 88 (3) 



be entirely absent. Sutural ramp devoid of 
major cords, although possibly with numerous 
spiral threads; at times this area is completely 
smooth. Columella with 2 folds with a weaker 
one below; occasionally 4 strong folds. Outer lip 
crenulated due to spiral sculpture. Within the 
lip are 13-22 irregular lirae which may be very 
weak. Fasciole present, sometimes very 
pronounced. Anal canal partially developed. 

Color white, yellow, or light cream-orange. 
Spiral cords usually the same color as shell, but 
at times white. Many specimens, but not all, 
with a reddish brown bar between each axial 
rib of the earlier whorls. Some specimens have 
brown between the white spiral cords. 
Periostracum thin and light brown. 

Remarks: This is a highly variable species, 
but the two conspicuous, heavy, contiguous 
spiral cords at the base of the body whorl serve 
to distinguish it from all other Latinis. This 
characteristic is observed in Lamarck's figure of 
Fusus cariniferns (Fig. 5), a name which has 
been overlooked by recent authors and misun- 
derstood by earlier ones such as Paetel (1873, 
1888), Tryon (1881), and Melvill (1891). 

Deshayes & Milne Edwards (1843) mentioned 
that Lamarck had confused Turbinella spinosa 
Martyn with this species; they restricted the 
name carinifems to the species figured by 
Lamarck in the Eiicyclopedique Methodique. 

The well-known names mcgintyi Pilsbry, 
trochlem-hi Kobelt, and distinctus A. Adams are 
all herein synonymized with cariniferus since 
they represent only a few of the many 
variations exhibited by this species. The shell of 



cariniferus is somewhat similar to Latinis ar- 
matus A. Adams of the eastern Atlantic and an 
un-named species from Somalia; both, however, 
lack the two prominent contiguous spiral cords 
at the base of the body whorl. Only two 
western Atlantic specimens have been observed 
which lack the contiguous cords (ANSP 314265, 
La Gonave Id., Haiti). Tryon (1881) erroneously 
mentioned Chascax maderensis Watson [ = 
Lafinis amiatus A. Adams] as a West Indian 
species. 

Radular studies reveal that L. cariniferus is 
probably more closely related to L. tumens Car- 
penter from the Panamic Province than to ar- 
matus. The only other member of Latirus s.s. 
from the Caribbean is L. varai Bullock, 1970, 
which may easily be differentiated by its 
stronger spiral sculpture, more rounded whorls, 
and chestnut brown coloration on the axial ribs, 
not between them. 

The fossil record of canm/en^-like Latirus is 
incomplete and known mostly from the 
Pliocene. Pilsbry (1939) described L. maxivelli 
which differs from carinifems by having 
stronger spiral cords and less pronounced axial 
ribs. Latirus ana-petes Woodring, 1964, from the 
Chagres Sandstone (Pliocene) of Panama is also 
an early representative of cariniferus. differing 
by being more attenuate and having strong 
spiral cords. Woodring compared anapetes with 
a very closely related species, taurus Olsson, 
1922, from the Gatun Formation of the Toro 
cays. 

Distribution: From Palm Beach and the west 
coast of Florida in the north, this species ex- 



FIGS. 12. 19. Latirus nematus Woodring. USNM 

JfU9.Jl. Bear Cut, Miami. Florida, 25 fms. 12. 

2.2.X; 19. 1.9X. 

FIG. VJ. Latirus (Polygona) bernadensis Bullock. 

n. sp., Holotype. MCZ 275.i28. Barbados Island, 

Lesser Antilles. 2X. 

FKi. 14. Latirus infundibulum (Gmelin). Finlay 

collection. Ayuadilla, Puerto Rico. 1.2X. 

FIG. 15. Latirus infundibulum (Ctmelin), AMNH 

11520:1 Frmn fish traps in 10 fms.. Guantanamo 

Bay, Cuba. 1.3X. 

FIG. 16. Latirus angulatus (Rodim)). USNM 

6f!:mo. Water Id.. Vi)yin Islands. 22X. 

FIG. 17. Latirus angulatus (Rddim/), USNM 



4U897. Cardenas Bay. Cuba. 1-3 fms. 2lX. 

FIG. 18. Latirus cariniferus (Lamarck). Finlay 

collection. Off Gibara, Oriente. Cuba, KH) fm,^. 

l.:3X. 

FIG. 20 Latirus angulatus (Roding). AMNH 

U0U8. Off Forialeza, Ce.arci. Brazil, 12 fms. 

2.2X. 

FIG. 21. Latirus angulatus (Roding). specimen 

in MCZ. N coast of South Ameriea, dredged. 

2.3X. 

FIG. 22. Latirus cariniferus (Lamarck). DAt- 

tillio collection no. 13^. Cienfuegos Harbor, 

Cuba. 0.8X. 



Vol. 88 (3) 



THE NAUTILUS 



73 




Explanation to Latmis figures 12-22 on opposite page 



74 THE NAUTILUS 



July 22, lWi4 



Vol. 88 (3) 



tends throughout the West Indies, and from 
Yucatan, Mexico, to the northern coast of South 
America, from shallow water to over 100 
fathoms. 

Subgenus Polygona Schumacher, 1817 

Polyyana Schumacher, 1817, Essai d'un nouveau 
sys£eme des habitations des vers testaces, pp. 
73, 241. Type species, Polygona fusifornm 
Schumacher, 1817, by monotypy [ = Latirus 
infundibulum (Gmelin, 1791)]. 

Plicatella Swainson, 1840, Treatise on mal- 
acology, pp. 78, 304. An unnecessary new 
name for Polygona Schumacher. 

Remarks: As Woodring (1928) mentioned, 
Latirus infundibulum (Figs. 14, 15) is e.xtremely 
different from L. 'gibbubu^ the type species of 
Latiiiis. But Woodring admitted that in terms 
of shell morphology there exist species in- 
termediate between Latirus s.s. and Polygona. 
The latter differs from Latirus by being 
smaller, relatively more narrow, having a well 
developed siphonal canal, and usually with 
pronounced brown, rather than white, spiral 
cords. It seems wise at this time to retain the 
use of Polygona at the subgeneric level only. 

Species referable to Polygona appear com- 
monly in the Miocene of the Caribbean region. 
This group, as with other Latim.% includes 
some species having a high degree of in- 
traspecific variation of shell characters. Recent 
West Indian species of Polygona include in- 
fundibulum (Gmelin), angulatus (Roding), 
nematus Woodring, and bernadensis Bullock, n. 
sp.; hemphilli Hertlein & Strong, corwentricus 
(Reeve), and praestantior Melvill are eastern 
Pacific representatives. 

Latirus (Polygomi) angulatus (Roding, 1798) 
Figs. 7, 8, 10, 16, 17, 20, 21, 24-26 

1798 Fusus angulatus Roding, Museum Bolten- 
ianum, p. 118, sp. 1527. Locality not men- 
tioned; type locality herein designated to be 
San Juan baai, Curacao, Netherlands Antilles. 
Location of type unknown. 

1847 Turbinella bremcaudata Reeve, Conchologia 
Iconica 4, Turbinella pi. 10, sp. 50. Locality 



unknown: figured specimen in BMNH. A 
doubtful synonym of Latirus angulatus. 

1847 Turbinella spadicea Reeve, Conchologia 
Iconica 4, Turbinella pi. 9, sp. 44. Locality 
unknown. Possible syntypes in BMNH. 

1940 Latirus cymatius Schwengel, Nautilus 53: 
110, pi. 12, figs. 6, 7. Type locality: off Palm 
Beach, in about 12 fms. Holotype ANSP 
175132. Misspelled cymatias on p. 110, but 
correctly on plate caption. 

Description: Shell small to large, up to 76.5 
mm in length and 34 mm in greatest diameter. 
Spire usually more than half the length of the 
shell, but sometimes less. Whorls 9-10; protoconch- 
consisting of 2 whorls. Aperture oval to 
squarish and greater in length than the short 
siphonal canal. Axial sculpture of 7-8 squarish 
ribs which often are more pronounced just below 
the shoulder of the whorl. Numerous fine 
growth lines usually very conspicuous at the 
suture. Spiral sculpture of 8-10 heavy cords, 4-5 
showing on the upper whorls, interspaced with 
secondary, and sometimes tertiary, threads. 
Columella with 3 folds and a weaker one below. 
Outer lip crenulated, the indentations 
corresponding to the spiral sculpture. Within 
the lip 7-12 lirae run into the aperture. 
Fasciole present. Anal canal partially developed. 

Color light cream-orange to brown. Spiral 
cords and threads reddish brown or at times 
the color of the shell. Shell occasionally banded 
with light reddish brown. Periostracum very 
thin, light brown. 

Kemarks: Much taxonomic confusion has 
existed concerning Latirus angulatus. An in- 
dication of the problems associated with this 
species first came when T. L. McGinty (1966, in 
litt. to Dr. R. D. Turner of Harvard Univer- 
sity), who had been working on Latirus. stated 
that the well known name brevicaudatus could 
refer to a Pacific species. A study of many 
hundreds of West Indian specimens has resulted 
in the conclusion that this relatively common 
species exhibits more intraspecific variation 
than any other Latirus I have observed, and 
not one of the many forms can be rampared 
easily with the clear figure in Reeve (1847) or 
a photograph of the specimen provided me (Fig. 
23) by Dr. Norman Tebble, the former curator 



Vol. 88 (3) 



THE NAUTILUS 



75 



of the MoUusca section of the British Museum 
(Natural History). When I had the opportunity 
to examine the figured specimen first hand, I 
found the Reeve figure to be an exceptionally 
gO(xl one. An additional complication developed 
when it became apparent that the figured type 
of hrepicandatus seemed to have much in com- 
mon with a few Indo-Pacific specimens labelled 
"La^^^/,s• li/ratus Rve." in some museum collec- 
tions. The problem remained: what should be 
done in this particular case, especially since the 
name breincmidatus was prevalent, in spite of 
the other names applied to this species? 

The "type lot" of hrevicaudahis includes ttiree 
specimens. In addition to the previously men- 
tioned figured type, there are two specimens 
(Figs. 24, 26) that are clearly referable to the 
Virgin Island form of "brevicaudatus" (Fig. 16). 
These two specimens are so very different from 
the figured specimen that I find it hard to 
believe that Reeve had access to them when he 
was completing the Turhinella section of the 
Conchologia Iconica. I feel it is likely that these 
two specimens were added to the type lot at a 
later date. 

There are four possible courses of action one 
could take in this particular case: 1) conserve 
the name hrevicaiidatus for the West Indian 
species by continuing to accept the figured type 
as the Caribbean species, 2) conserve the name 
bremcaudatm by ignoring the figured type and 
declaring one of the other specimens to be the 
lectotype, 3) avoid the entire problem by using 
an earlier name, 4) petition the Comission on 
International Zoological Nomenclature to in- 
validate the existing types and establish a 
neotype based on a typical example of 
brevicaudatus. But to conserve the name 
brevicaudatus for the Caribbean species would 
make it unavailable for future use should it be 
found that brevicaudatus actually occurs in the 
Indo-Pacific, which seems likely, or in the 
eastern Atlantic, where it has been reported 
by Nordsieck (1968). 

If one is willing to accept a change of name 
for this West Indian species, the easiest choice 
is to use the next available name. But both 
names from the literature that could be used 
for this species, spadkeus (Reeve, 1847) and 
cymatius Schwengel, 1940, do not represent 



typical forms, and since the great intraspecific 
variation observed is still not clearly un- 
derstood, the use of these names might institute 
confusion. A better solution does exist, however. 
In the Museum Boltenianum, using the name 
Fusus angulatus, Roding (1798) made reference 
to a certain specimen figured by Chemnitz (my 
Fig. 7) in the Systematisches Conchylien-Cabinet 
(vol. 4, figs. 1314, 1315). These two figures, 
which have been cited repetitiously by earlier 
authors as two of a number of figures of 
Latirus polygonus (Gmelin, 1791), are 
definitely not conspecific with Gmelin's abun- 
dant and well understood Indo-Pacific species; 
they represent a large "breincaudatus" nearly 
identical to a typical form occurring in the 
southern Caribbean (compare Figs. 7, 8, and 10). 
The mention by Chemnitz of brown spiral 
threads is especially convincing. 

Because of the uncertainty regarding the use 
of the name brevicaudatus for the Caribbean 
species, and because some typical West Indian 
forms closely match the Chemnitz figure, I have 
decided, with more than a little reluctance, to 




FIG. 23. Latirus brevicaudatus (Reeve), Figured 
type. Locality unknown. IX. Photograph cour- 
tesy of the British Museum (Natural History). 
FIGS. 2Jt, 26. Latirus angulatus (Roding). 
"paratypes" of Turbinella brevicaudata Reeve. 
Locality unknoum. IX. Photographs courtesy of 
the British Museum (Natural Histmij). 
FIG. 2.5. Latirus angulatus (Roding), possible 
syntype of Turbinella spadicea Reeve, fide Dr. 
Norman Tebble. Locality unknown. iX. 
Photograph courtesy of the British Museum 
(Natural History). 



76 THE NAUTILUS 



July 22, 1974 



Vol. 88 (3) 



propose the use of the name angulatus (Roding, 
1798) for this species. It is felt that the 
establishment of the name nugiilatm will prove 
not only to have been an expedient move, but 
one that will have promoted nomenclatorial 
stability, one of the ultimate goals of most 
taxonomists. 

As previously mentioned, LatmiH angulatius 
exhibits a great amount of intraspecific 
variation. Typical anyulatus. similar to the 
"paratypes" of hremcauckitus, occur on St. 
Thomas and St. Johns, Virgin Islands (Fig. 16), 
and in the Bahama Islands. The Lesser Antilles 
afford the largest angulatus known, those from 
Curacao (Figs. 8, 10) being especially large and 
identical to the figure in Chemnitz (my Fig. 7); 
these differ from the tjT)ical form only in the 
adult, which has somewhat more swollen whorls 
and slightly more squarish axial ribs. The 
frilled sutural region of Curatjao specimens 
(mentioned by Benthem Jutting, 1920) and those 
from off Florida (Schwengel, 1940) is charac- 
teristic of most angulatus. as well as many 
other Latirns. and its expression is probably 
dependent upon environmental conditions. 

Major variations of angulatus occur 
throughout the rest of its range. Several 
specimens from South America show very 
heavy spiral sculpture and a relatively small 
aperture (Figs. 20, 21). L. ci/watius Schwengel 
from Florida is closer to typical angulatus than 
many of the other variations, and it is herein 
considered conspecific with angulatus. The type 
specimens of cymatius are unicolored Sayal 
brown and heavy-shelled; most specimens 
examined were immature. Numerous forms of 
angulatus occur along the northern coast of 
Cuba (one such form. Fig. 17). 

The identity of Latinis spadieeus (Reeve, 
1847) (Fig. 25) remains a little uncertain, 
although I feel certain that some specimens of 
Latims angulatus will eventually be collected 
that will show Kpadiccus to be conspecific with 
angulatus. Hertlein & Strong (1951) and Keen 
(1971) stated that the west American Latirus 
hcmpfulli Hertlein & Strong, 1951, wa.s the 
spadiceus of authors, but not of Reeve. Some 
older museum collections have some angulatus 
specimens from unknown locality which seem 
referable to spadiceus Reeve. 



Some Miocene and Pliocene Latirus appear to 
be possible ancestors of angulatus. The closest 
relative, L. angulatus santodnmingeiisis Pilsbry 
from the Miocene of the Dominican Republic, 
differs from typical angulatus by having a shor- 
ter, wider siphonal canal and a sharp 
angulation of the axial ribs. Pilsbry 's descrip- 
tion fits some Recent angulatus, and a few 
specimens (fossil?) dredged from the harbor at 
Roosevelt Roads Naval Base, Puerto Rico, ap- 
pear to be intermediate between these two sub- 
species. 

Distribution: From the lower east coast of 
Florida and the Bahama Islands in the north, 
this species is found throughout the West In- 
dian Province, from Yucatan, Mexico, and Cuba 
to the Lesser Antilles and Brazil. Peile (1927) 
recorded a "Latirus sp. near sanguifluus. Rve." 
from Bermuda, but I have been unable to locate 
his specimen. Recently, Waller (1973) collected 
Latirus angulatus off the south shore of 
Tucker's Town, Bennuda, 51 meters depth. Nord- 
sieck (1968) reported this species from the 
west coast of Africa, but the present author has 
seen no eastern Atlantic specimens and cannot 
verify this record. 

Latirt(.'< (Poh/gona) hernadensis Bullock, 

new species 

Fig. 13 

Description: Shell small to medium in size, 
up to 44.2 mm in length and 16.5 mm in 
greatest diameter. Spire slightly greater than 
half the length of the shell. Aperture oval to 
squarish and as long or slightly longer than the 
moderately long siphonal canal. Whorls 9. Axial 
sculpture of 7 broad ribs which are slightly 
more pronounced on the shoulder of the whorl. 
Spiral sculpture of about 8 cords with oc- 
casional secondary cords between; 4-5 cords 
show on the upper whorls, and a number of 
cords, some stronger than others, are prominent 
on the siphonal canal. Columella with 3 folds 
with a weaker fold above and below these. 
Outer lip crenulate due to the spiral sculpture; 
within the lip 6-9 lirae run into the aperture. 
Periostracum thin, light brown. Shell light 
cream-orange, including the spiral cords. Aper- 
ture slightly lighter in color. 



Vol. 88 (3) 



THE NAUTILUS 



MrnsiDvmpnts: Holotype 44.2 mm in length, 
1().5 mm in greatest diameter; paratypes (both 
from the type locality) 36.7 and 36.4 mm in 
length. 

Tifpe locality: Barbados, Lesser Antilles. 

Location of Types: Holotype, Museum of 
Comparative Zoology, Harvard University, 
275428; two paratypes, Mus. Comp. Zool. 275429. 

Remarks: When compared with other West 
Indian Latirus, bernadensis appears most 
similar to L. infundihidum (Gmelin, 1791), but 
differs by being relatively stouter, having 
broader axial ribs, and lacking the brown 
coloration on the stronger spiral cords. L. 
praestantior Melvill, 1892, from West Me.xico is 
closely related, but its spiral sculpture is not as 
strong, especially on the body whorl. This 
species is named after Bemados Island, a name 
for Barbados appearing on an early sixteenth 
century manuscript chart located in the British 
Museum. 

Latirus (Polygona) nematus Woodring, 1928 
Figs. 1, 12, 19 

1928 Latirus (Polygona)- nematus Woodring, 
Miocene mollusks from Bowden, Jamaica. 
Part II, Gastropods and discussion of results, 
p. 254, pi. 15, fig. 6. Type locality: Bowden 
Formation [Miocene], Jamaica. Holotype 
USNM 369442. 

Description: Shell moderately large, up to 
60.4 mm in length, 23 mm in diameter. Spire 
usually about half the length of the shell, but 
sometimes less. Whorls 10, including Wz whorls 
of the protoconch, which is often broken off or 
eroded. Aperture oval and larger than the 
rather short siphonal canal. Axial sculpture of 
8-11 ribs. Numerous fine growth lines are 
present. Spiral sculpture of many cords, usually 
of even thickness, but occasionally showing 
some secondary cords. In the region below the 
shoulder and on the body whorl of some 
specimens, the crossing of the growth lines and 
the spiral cords gives the shell a cancellate ap- 
pearance. Columellar folds 4, with the lower 2 
partially fused. Outer lip minutely crenulate 
with the formation of small teeth arranged in 
pairs. Within the lip 10-14 irregular lirae run 
into the aperture, the anterior one thickened 



and corresponding to the most anterior 
columellar fold and appearing to almost close 
the apertural entrance to the siphonal canal. 
Fasciole well developed; pseudoumbilicus slit- 
like. Anal canal well defined. 

Shell light cream-orange to almost white 
with light orange on the siphonal canal, and oc- 
casionally partially banded with reddish brown. 
Early whorls Sayal brown. Aperture yellowish 
white; columella light orange. Periostracum thin 
and light greenish brown. 

Remarks: Latinis nematus previously was 
known only from the Bowden Formation, and 
this marks the first time it has been reported 
from the Recent fauna. The Recent specimens I 
examined do differ in some respects from the 
fossil form, particularly when immature 
specimens are compared, and I at first thought 
that perhaps they were specifically or sub- 
specifically distinct. Most Recent specimens are 
immature and exhibit quite inflated whorls; the 
immature paratypes of nematus do not have in- 
flated whorls, and are more elongate. It seems 
best in this case to delay introduction of an ad- 
ditional name until more material, both fossil 
and Recent, is available for study. 

When compared with other species, nematus 
can possibly only be confused with some forms 
of angulatus. The latter species usually can be 
differentiated easily by its stronger spiral cords, 
often with intermediate secondary cords which 
are usually brown in color. In addition, the 
axial ribs tend to be somewhat round. In 
nematus. the spiral cords are fine and more 
numerous, lack color, and the axial ribs are 
more squarish in outline. 

Distribution: Known only in the Recent 
fauna from off Miami, Florida, and Gibara, 
Oriente, Cuba. Usticke (pers. comm.) has a 
specimen from the north coast of Puerto Rico 
which is probably this species. 

Specimens Examined: FLORIDA: Miami; 
Miami, 20 fms.; Bear Cut, Miami, 25 fms. (all 
USNM). CUBA: off Gibara, Oriente (Finlay 
collection). 

ACKNOWLEDGEMENTS 

This paper is a revised version of a portion 
of my dissertation of western Atlantic Latmts. 
which was done under the direction of Dr. John 



78 THE NAUTILUS 



July 22, 1974 



Vol. 88 (3) 



H. Dearborn and presented to the Zoology 
Department of the University of Maine at 
Orono, for partial fulfillment of the requirements 
of the Master of Sc-ience degree. 

The loan of specimens and assistance during 
my visits to their institutions were provided 
by: W. J. Clench, R. D. Turner, and K. J. Boss, 
Museum of Comparative Zoolog>', Harvard 
University; J. Rosewater, C. Roper, and J. 
Morrison. United States National Museum of 
Natural History; W. K. Emerson and W. Old, 
American Museum of Natural History; R. T. 
Abbott and R. Robertson, Academy of Natural 
Sciences of Philadelphia; J. Taylor and J. 
Peake, British Museum (Natural History). 
Thanks are also due the private collectors who 
generously loaned or gave specimens from their 
own collections: Mr. John Finlay, Mr. & Mrs. 
Dan Steger, and Mr. Nowell-Usticke. 

Financial aid for this study was provided, in 
part, by: the University of Maine; the Biology 
Department, Harvard University; National 
Science Foundation grant GB27911, Dr. Reed 
Rollins, principal investigator; and a Sigma Xi 
Grant-in-Aid-of- Research. 

Early drafts of this paper were reviewed by 
Drs. J. H. Dearborn, K. J. Boss, and R. D. Tur- 
ner. All conclusions are the responsibility of the 
author. 



LITERATURE CITED 

Adams, A. 1855. Descriptions of twenty-seven 

new species of shells from the collection of 

Hugh Cuming, Esq. Proc. Zool. Soc. London 

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of the island of Curacao. Bijdragen Dierkunde 

25: 1-36. 
Bullock, R. C. 1970. LatiniR varai a new fas- 

ciolariid gastropod from the Caribbean. The 

Nautilus 83: 133-135, 1 fig. 
Casey, L. 1904. Notes on the Pleurotomidae 

with descriptions of some new genera and 

species. Trans. Acad. Sci. St. Louis 14: 

123-170. 
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Conchylien-Cabinet 4. Niimberg, 344 pp., 

39 pis. 



Deshayes, G. P., & H. Milne Edwards. 1843. 
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animaux sans vertebres, 2nd ed., 9. Paris, 
728 pp. 

Hertlein, L. G., & A. M. Strong. 1951. Eastern 
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coast of Mexico and Central America. Part X. 
Zoologica 36: 67-120, pis. 1-10. 

Keen, A. M. 1971. Sea Shells of tropical west 
America, 2nd ed. Stanford, 1064 pp., illustr. 

Kobelt, W. 1874. [in] Martini-Chemnitz, System- 
atisches Conchylien-Cabinet 3 (3A), Turbinella 
and Fasciolaria. Niimberg. 164 pp., .35 pis. 

Kobelt, W. 1876. Catalog der Gattung Turbinella 
Lam. Jahrb. Deutsch. Malak. (iesell. for 1876: 
10-29. 

Lamarck, J. 1816. Tableau encyclopedique et 
methodique des trois regnes de la nature. 
Paris, pis. .391-488. 

Melvill, J. C. 1891. An historical account of the 
genus Latinis (Montfort) and its depen- 
dencies, with descriptions of eleven new 
species, and a catalogue of Latirus and 
Peristernia. Mem. Proc. Manchester Lit. Phil. 
Soc. (4)4: 365-411,1 pi. 

Melvill, J. C. 1892. Description of a new species of 
Lntmi.H. Mem. Proc. Manchester Lit. Phil. Soc. 
(4) 5: 92-93. 

Montfort, P. D. de. 1810. Conchyliologie syste- 
matique et classification methodique des 
coquilles ... 2. Paris, 676 pp. 

Nordsieck, F. 1968. Die europ'aischen Meeres- 
Geh'auseschnecken (Prosobranchia). Stuttgart, 
273 pp., 35 pis. 

Olsson, A. A. 1922. The Miocene of northern 
Costa Rica. Bull. Amer. Paleont. 9 (39): 
309 pp., 32 pis. 

Paetel, F. 1873. Catalog der Conchylien- 
Sammlung. Berlin, 172 pp. 

Paetel, F. 1888. Catalog der Conchy lien- 
Sammlung 1. Berlin, 639 pp. 

Palmer, K. 1937. The Claibomian Scaphopoda. 
Gastropoda and dibranchiate Cephalopoda of 
the southern United States. Bull. .-^mer. 
Paleont. 7 (32): 370 pp., 90 pis. 

Peile, A. 1926. The Mollusca of Bermuda. Proc. 

Malac. Soc. London 17: 71-98. 
Pilsbiy, H. A. 1922. Revision of W. M. Gabbs 
Tertiary Mollusca of Santo Domingo. Proc. 



Vol. 88 (3) 



THENALTTILUS 



79 



Acad. Nat. Sci. Philadelphia 73: 305-435. 
Pilsbry, H. A. 1939. A triad of umbilicate 

Latirus, Recent and Pliocene. The Nautilus 

52: 84-86, 1 pi. 
Reeve, L. 1847. Conchologia Iconica 4: 

Tiirbinella. pis. 1-13. 
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Hamburg, 199 pp. 
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[publication not seen]. 
Schumacher, C. F. 1817. Essais d'un nouveau 

systeme des habitations des vers testaces. 

Copenhagen, 287 pp., 22 pis. 
Schwengel, J. S. 1940. TVo new Floridan shells. 

The Nautilus 53: 109-110, pi. 12 (in part). 
Swainson, W. 1840. A treatise on malacology or 

shells and shell fish. Cabinet Cyclopedia of 

Natural History. London, 419 pp. 
Tryon, G. W. 1881. Manual of Conchology 3. 



Philadelphia, 310 pp., 87 pis. 

Waller, T R. 1973. The habits and habitats of 
some Bermudian marine mollusks. Nautilus 
87: 31-52. 

Watson, R. 1873. On some marine Mollusca 
from Madeira, including a new genus of the 
Muricidae, a new Eulima, and the whole of 
the Rissoae of the group of islands. Proc. 
Zool. Soc. London for 1873: 361-393, 2 pis. 

Woodring, W. 1928. Miocene mollusks from 
Bowden, Jamaica. Part IL Gastropods and 
discussion of results. Carnegie Inst. Washing- 
ton Publ. No. 385, 564 pp., 40 pis. 

Woodring, W. 1964. Geology and paleontology of 
the Canal Zone and adjoining parts of 
Panama. Description of Tertiary mollusks 
(gastropods: Columbellidae to Volutidae). 
U. S. Geol. Survey Prof. Paper 306-C: 241- 
297, pis. 39-47. 



RECENT PUBLICATIONS 



Shoup, Charles S. 1974. A Bibliography of the 
Zoology of Tennessee and the Tennessee 
Valley Region. Publ. NP-19905, National 
Information Center, U. S. Dept. Commerce, 
Springfield, Va. 22151, $7.50. 255 pp., 3350 
entries by subject and localities. About 360 
mollusk papers listed. Excellent. 

(kistropodia, vol. 1, no. 9, Jan. 1974, pp. 85-96. 
Glenn R. Webb, editor. Route 1, Box 148, 
Fleetwood, Pa. 19522. 

Goodhue, William Walter. 1974. The External 
and Internal Morphology of the Common 
Atlantic Squid, Loligo pealii Lesueur. 
Vantage Press, N. Y., 74 pp., 25 photos, hard- 
back, $5.00. 

Jacobson, Morris K. and K. J. Boss. 1973. The 
Jamaican Land Shells Described by C. B. 
Adams. Occasional Papers on Mollusks 
(Harvard), vol. 3, no. 47, pp. 305-520. The 
types of 360 species are discussed, their 
original descriptions reprinted, and most of 
them illustrated. $5.50 to individuals. 

Johnson, Richard I. 1973. Heude's Molluscan 
Types, or Asian Land and Fresh Water 
Mollusks, Mostly from the People's Republic 
of China, Described by P. M. Heude. Special 
Occasional Publication, no. 1, 111 pp. 
(planographed, softbound). $2.50. 

Smith. Shelagh M. 1974. Key to the British 



Marine Gastropoda. Natural History Informa- 
tion Series no. 1, 44 pp., 4 figs. Royal 
Scottish Museum, Chambers Street, Edinburgh 
EHl IJF, Scotland. Difficult to use and re- 
quires consulting expensive library for 
illustrations. 

Pace, Gary L. 1973. The Freshwater Snails of 
Taiwan (Formosa). Supplement 1, Malacologi- 
cal Review. 118 pp., 18 pis., 17 text figs. A 
much-needed and well-done treatment with 
excellent illustrations. A useful handbook for 
parasitologists and malacologists. 

Okutani, Takashi. 1973. Guide and Keys to 
Squid in Japan. Bull. Tokai Regional Fish. 
Research Lab., no. 74, pp. 83-111. 86 
drawings. 

Okutani, Takashi. 1972. Molluscan Fauna on the 
Submarine Banks Zenisu, Hyotanse, and 
Takase, near the Izu-Shichito Islands. Ibid.. 
no. 72, pp. 63-142, 2 color pis. 5 new species, 
including Profundiconus scofndicola. 

Leme, Jose Luiz Moreira. 1973. Anatomy and 
Systematics of the Neotropical Strophochei- 
loidea (Gastropoda, Pulmonata) With the 
Description of a New Family. Arquivos de 
Zoologia, vol. 23, pt. 5, pp. 295-336, 54 illus. 
Megalobulimidae, a new family is separated 
off from Strophocheilidae (sensu Bequaert, 
1948). 



80 THE NAUTILUS 



July 22, 1974 



Vol. 88 (3) 



A NEW BLIND PHYSA FROM WYOMING WITH NOTES 
ON ITS ADAPTATION TO THE CAVE ENVIRONMENT 

R. D. Turner and W. J. Clench 

Museum of Comparative Zoology 

Harvard University 

Cambridge, Mass. 02138 



ABSTRACT 

Physa spelunca, netv species, is described. The ecology of the cave and adap- 
tationt^ of the Physa to the cave environment are disciissed. 



While looking for crustaceans, particularly 
amphipods of the genus Stygobromus. in Low^er 
Kane Cave, Wyoming, Dr. John R. Holsinger 
collected a number of blind Physa which he 
sent to us for identification. There were no 
Stygobromus in the cave and, in fact, other 
than the snails, all he found were a few 
clusters of oligochaetes, probably tubificids. He 
did not find anything in the spring outside the 
cave. 

In his letter to us about the cave Dr. 
Holsinger wrote: 

"Lower Kane Cave is a solution cave developed in 
Paleozoic limestone. It's entrance is situated just 
above and east of the Big Horn River, about 12 
miles east of Lovell and at an altitude of 3,000 feet. 
A stream flows through the cave and passes to the 
surface through a spring just below the entrance. 
The water from this spring flows directly into the 
Big Horn River. The .source of the cave stream is a 
'hot spring' at the far end of the cave, some 1,000 
feet from the entrance. The stream temperature was 
70° to 72° F [21-22° C] and that of the air in the 
cave was 78° to 80° F. The water was hard and 
had a strong sulphurous odor " 

According to Dr. Holsinger, warm or hot cave 
streams are extremely rare. In fact the only 
other such cave with which he is acquainted is 
Warm River Cave in Allegheny County, 
Virginia. Brues (1932: p. 274-277)" listed 19 
species of gastropods occuring in hot springs 
and stated that "Physa seems to be the 
dominate type in thermal waters." In addition 
to thermal tolerance, species in this genus can 
tolerate brackish water, and they are usually 
the last of the snails to succumb when a 
stream becomes heavily polluted. Thus it is not 
surprising that Physa was the only snail found 



in Lower Kane Cave, particularly as the works 
of Henderson (1924, 1936) indicate that 
hydrobiids, species of which commonly occur in 
caves, are rare in this area. He did not list any 
hydrobiids in his Wyoming paper (1918) nor did 
Beetle (1961) report any from streams in the 
Big Horn Mountains. 

In Lower Kane Cave the Physa were common 
on the surface of small rocks submerged in 
rather fast -moving water well-back in the dark 
zone of the cave, some 800 to 900 feet from the 
entrance. Some were found on a colony of 
'tubificid' worms in the sludge at the bottom of 
the stream. 

In the United States the molluscan fauna of 
caves is rather limited and the majority of 
species found are readily identified with those 
living on the surface in the surrounding area. 
Cave specimens are usually somewhat smaller 
and have thinner, lighter-colored shells than 
their .surface living relatives, but are otherwise 
similar (Hubricht, 1940b). Land snails living 
near the entrance or in the twilight zone are 
probably deposited in the cave on debris carried 
in by floods and it is doubtful if they are able 
to maintain themselves for many generations 
(Hubricht, 1941). Eighteen species and sub- 
species of land snails have invaded the dark 
zone of caves in Kentucky, Tennessee and 
Alabama (Hubricht, 1964). Six of them (5 
Hclicodiscus and Carychium stygium Call) are 
known only from these caves. They were found 
feeding on decaying plant material and the 
guano of cave crickets. When discussing the 
wide distribution of Carychium stygium in the 
Kentucky caves, Hubricht (1960) stated that the 
eyes of some specimens were somewhat reduced 



Vol. 88 (3) 



THE NAUTILUS 



81 



but he did not mention any other modifications 
to cave life. 

Freshwater snails, especially Hydrobiidae, 
have become adapted to cave habitats and 
viable colonies are found well-back in the dark 
zone. A white, blind hydrobiid, Fontigens tar- 
tarea, was described by Hubricht (1963) from 
the stream in Organ Cave, Greenbrier Co., West 
Virginia, and Culver (1970) reported it from the 
"Greenbrier Caverns, the Hole (37° 56' 22" N; 
80° 21' 12" W) and Martha's Cave." According 
to J. R. Holsinger (personal communication) 
large populations of troglobitic species of Foii- 
tigen.<< have been found in the cave streams of 
the Applachians in Virginia and West Virginia 
but to date these have not been reported upon. 
Hubricht (1940a, 1971) described three un- 
pigmented, blind Amnicola and Antrobia culveri 
(a new genus and species of blind 
Hydrobiidae) from caves in the Ozark Plateau. 



In 1950 he listed five species (two Amnicola 
and uiidertermined species of Phi/i^a, Ferrisaia 
and Musculium) as living in the dark zone of 
these caves. 

The small size of the species which have been 
able to successfully invade and survive in caves 
is undoubtedly a reflection of the scarcity of 
food in such habitats. No suspension feeding 
gastropods occur in such areas and among the 
bivalves only the Sphaeriidae are found. 

In addition to being unpigmented and being 
one of the smallest species known, the Physa 
collected by Dr. Holsinger appear to be making 
modifications to cave life in the apparent reduc- 
tion of the eye (see figure 19) proportionate 
increase in size of radular teeth (figs. 14-15), and 
an increase in the size of the embryo as evi- 
denced by the size of the protoconch (Figs. 
11-13). This large protoconch suggests that the 
young are more developed at the time of hat- 




Physa spelunca Turner and Cle)ich, new species. 
FIG. 1. Holotifpe. FIGS. 2-9. Series of paratypes 
to sfioir range of variation in the 75 specimens 
collected. FIG. 3. the most elongate. FIG i. The 
largest, thofivgh lacking the spire. FIG. 6. Side 



view showing curvature of the lip. FIG. 7. Dor- 
sal view of typical specimen. FIGS. 5 and 8. 
Specimens showing thickening of the columella 
area. FIG. 9. The smallest specimen collected. 



82 THE NAUTILUS 



July 22, 1974 



Vol. 88 (3) 



ching. Greater size would increase the mobility 
and search-range of the young, and a more fully 
developed radula' would increase the range of 
food-particle size available U) it. Both these fac- 
tors would enhance its chances of survival in 
an environment where food is likely to be 
limited. 

This increase in embryo size agrees with the 
findings of Poulson and White (1969) who 
worked with cave fish and cave beetles. They 
hypothesized that species which successfully in- 
vade caves tend toward smaller population size, 
lower reproduction rates, larger size at hat- 
ching, late maturity and longer life. These 
adaptions to a stable environment and low food 
supply suggest that this new species is opting 
for K selection as proposed by MacArthur and 
Wilson (1967). They are also in agreement with 
the Stability -Time hypothesis proposed by San- 
ders (1968) for many deep-sea infaunal species. 
Further research is needed to test this 
hypothesis for cave snails but to our knowledge 
this is the first time that such adaptations have 
been noted for any troglobitic mollusk. 

The fact that epigean species of Phym are 
opportunistic probably allowed them to invade 
this hot spring cave. They are small-sized 
detritus feeders, capable of surviving under 
varying conditions of temperature, salinity and 
oxygen tension, as noted previously. These are 
characteristics that would preadapt them for 
the cave environment. Further adaptations, in- 
cluding the larger size of the young on hatching 
and the loss of eyes, are in agreement with the 
theories of Barr (1968). Cave mollusks are ideal 
organisms for evolutionary genetic studies such 
as those of Avise and Selander (1972) on cave 
fish of the genus Astyannx, but to date no 
work has been attempted along these lines. The 
large populations of Fontigevs in the caves of 
Virginia and West Virginia mentioned by 
Holsinger would provide material for such a 
study. 

Physa spelunca, new species 
Figs. 2-9, 11, 14, 16-17, 19 

Description Shell reaching 9 mm in length 
and 4.5 mm in greatest diameter (a somewhat 
larger, broken specimen has a body whorl length 
of 7.8 mm and a width of 5.0 mm which would 



Bs^4>4,^ 



O 1 mr 





FIG. 10, Rndular teeth of Physa spelunca 
showing long denticles and apaphi/ses. FIGS. Il- 
ls. Com/xirative sizes of protoconchs in relation 
to adult size. FIG. 11, Physa spelunca, adults 
may reach about 11 mm in length, FIG. 12, 
Physa virgata Gould, adidts reach 18 mm in 
length. FIG. 13, Physa propinqua Tryon adults 
reach 21 mm in length. 

give a proportional total length of about 11 
mm). Shell highly polished, white with a very 
thin transparent periostracum; translucent, 
fragile and smooth. Sculpture consisting of ex- 
ceedingly fine growth lines only, with no 
evidence of spiral sculpture. Whorls 4' 2 to 5, 
rounded, rapidly increasing in size; body whorl 
large, slightly shouldered: spire short, acute: 
spire angle about 65° . Sutures moderately im- 
pressed, aperture ear-shaped. Upper margin of 
thin, outer lip inserting on the body whorl 
well-below the periphery. Parietal callus thin to 
rather thick in older specimens. Columella 
oblique, curved, flattened and continuous with 
the outer lip. Protoconch of about 1'^ whorls, 
rounded, colorless and minutely malleated (see 
figure 11). Radula with v-shaped rows of teeth, 
typical of the genus, the formula being about 
100-1-1(X) in the median portion (Fig. 10 and 
Fig. 14). 

Anatomical notes. Only preserved specimens 
were available for study and these un- 
fortunately were not in ideal condition. The 
animal was a uniform whitish, the tentacles 
short, broad and apparently lacking eyes at the 
base. Histological sections, however, showed a 
distinct eye cup but the retina was not 
developed and the lens was apparently lacking. 
A comparison of the eye of Physn heterostropha 
Say with that of spelunca is shown in Figs. 18- 
19. Digitiitions of the mantle were minute but 



Vol. 88 (3) 



THE NAUTILUS 



83 



this could have been a result of preservation. 

Tlie digestive system appears typical for the 
genus. The crop was packed with debris, 
minute sand grains and what appeared to be 
fungal hyphae. The reproductive system is 
typical for the genus, the male portion being of 
the 'Physodon' type as described and figured by 
Clampitt (1970). The penis sheath is about % 
the length of the praeputium, not constricted 
and is unpigmented. The praeputium has a 
slightly grayish tinge, and the praeputial gland 
is located in the lower half. The vas deferens 
is fine, about 4 times the length of the penis 
sheath, and about one fourth was buried in 
muscles of the body wall. 



5.9 

7.8 



Length 


Width 


9.0 mm 


4.5 mm 


8.3 


4.2 


8.0 


4.2 


8.0 


4.0 


7.5 


4.1 


7.0 


3.3 







Transverse sections through posterior end of 
the odontophore of (FIG. U) Physa spelunca 
nnd (FIG. 15) Physa heterostropha Say shounng 
the lateral incoiling of the radiila when retract- 
ed. These specimens were preserved in alcohol 
and had not been properly fixed for histological 
work. The marked differences in shape may 
well result from differences in fixation and 
probably are of no taxonomic value. It is in- 
teresting to note that the radular teeth of 
spelunca from a specimen 6 mm long are 
proportionally larger than those of 
heterostropha from a specimen 12 mm long, 
suggesting that the cave specimens may be 
feeding on coarser material than surface living 
species. 



3.1 

5.0 (broken specimen, 
body whorl only) 



Type locality. Cave stream, about 800-900 feet 
from the entrance, in the dark zone, in Lower 
Kane Cave, near Kane, about 12 miles east of 
Lovell, on the east side of the Big Horn River, 
Big Horn County, Wyoming, at 3,000 feet 
elevation. Dr. John R. Holsinger, collector, June 
18, 1969. 

Repository of type specimens. Holotype, 
Museum of Comparative Zoology no. 280016; 
Paratypes MCZ nos. 280017-280019. Additional 
paratypes from the same locality are in the 
Museum of Zoology, Ohio State University; 



prostate 




pfoeputial 
glo nd 



Two views of male reproductive system of 
Physa spelunca, typical of the "Physodon" 
group. FIG. 16, Standard dorsal view. FIG. 17, 
Specimen turned to right to show muscle at- 
tachment. 



84 THE NAUTILUS 



July 22, 1974 



Vol. 88 (3) 



Museum of Zoology, University of Michigan: 
United States National Museum, Delaware 
Museum of Natural History and the Academy 
of Natural Sciences of Philadelphia. 

Remark.'^. Physa spelunca is characterized by 
its transparent, colorless, highly-polished shell, 
its relatively blunt apex and large colorless 







I mm 



19 










rS'iv 



-.r' 



1 mm 



Sections through the tentar.les ami eyes of 
Physa heterostropha and Physa spelunca. 
Speeimentt of both spedes were preserved hi 
alcohol and had not been properly fixed for 
histological work. Consequently the quality of 
the sections is poor hnt they are comparable. 
FIG. 18, Physa heterostropha, shouing the lens 
and large heavily pigmented retina. FIG. 19, 
Physa spelunca, lacking both the pigmented 
retina and lens. 



protoconch (see figure 11). Based on the 
characters of the shell and the male reproduc- 
tive system spelunca belongs to the "Physodon' 
species group as modified from Baker (1928) by 
Clampitt (1970). The whorls are shouldered, the 
sutures impressed and the p)enial sheath of the 
male is not constricted (Figures 16-17). 

Baker (1928) described and figured the male 
reproductive system of Physa integra Haldeman 
and P. walkeri Crandall and placed them along 
with other species, the anatomy of which was 
unknown, in his group 'Physodon'. Clampitt 
(1970) reported that P. michiganensis C\er\c\\ and 
P. anntina Lea also had the 'Physodon' type 
reproductive system and anatomical studies by 
Te (1973) in addition to confirming Baker's 
work on integra, showed that P. viiyata Gould 
also belonged in this group. See Clampitt (1970) 
for discussion of the status of 'Physodon'. 

Both P. anatina and P. integra have been 
reported from Wyoming (Henderson, 1918, 1936; 
Beetle, 1961) and both bear resemblances to P. 
spelunca. However, spelunca differs from them 
in being colorless, transparent and nearly glass- 
like; in lacking any indication of spiral sculp- 
ture or of thickened opaque axial lines in- 
dicating former margins of the lip. In addition, 
the columella of spelunca is oblique and curved 
rather than nearly straight, and the protoconch 
is white rather than amber-brown. 

Physa propinqua Tryon, P. gabbi Tryon and 
P. coniformis Tryon, all closely related species 
from the northwestern states and British 
Columbia, are unknovm anatomically but, on 
the basis of shell characters, could belong in 
'Physodon'. Both propinqua and conifoi-nm dif- 
fer from spelunca in having fine axial and 
spiral sculpture, a straight columella, and in 
having the lip extended anteriorly well-beyond 
the base of the columella. Physa gabbi lacks 
spiral sculpture but has pronounced axial 
growth ridges, a strongly twisted columella, and 
more acute spire. Physa imxjata Gould from 
Arizona which is known to have the 'Physodon' 
type anatomy also has both spiral and axial 
sculpture as well as a strongly twisted 
columella. All of these species have small dark 
protoconchs. 



Vol. 88 (3) 



THE NAUTILUS 



85 



ACKNOWLEDGEMENTS 

We are grateful to Dr. John R. Holsinger for 
the receipt of the specimens and for data on 
Lower Kane Cave; to George Te for discussions 
on Pfu/sa classification; to Samuel L. H. Fuller 
for preserved specimens of Phijsa heterastropha 
Say, and to Edward Allen for histological work. 

LITERATURE CITED 

Avise, J. C. & R. K. Selander. 1972. Evolu- 
tionary genetics of Cave-dwelling Fishes of 

the genus Astyanax. Evolution 26: 1-19. 
Baker, F. C. 1926. Nomenclatural Notes on 

American Freshwater Mollusca. Trans. 

Wisconsin Acad. Sciences Arts & Letters, 

22: 193-205. 
Baker, F. C. 1928. The Freshwater Mollusca of 

Wisconsin, Part I. Gastropoda. Wisconsin Geol. 

and Nat. Hist. Survey Bull. 70(1): 1-.507, pis. 

1-28. 
Barr, T. C. Jr. 1968. Cave ecology and the 

Evolution of troglobites. Evolutionary 

Biology 2:35-102 (Dobzhansky, Hecht, Steere, 

editors). 
Beetle, D. 1961. Mollusca of the Big Horn 

Mountains. Nautilus 74: 95-102. 
Brues, C. T. 1932. Further studies on the Fauna 

of North American Hot Springs. Proc. 

American Acad. Arts & Sciences, 67 (7): 

185-303. 
Clampitt, Phillip T. 1970. Comparative Ecology 

of the Snails Physa gipina and Phijsa integm 

(Basommatophora: Physidae). Malacologia 

10(1): 113-151, figs. 1-15. 
Culver, D. C. 1970. Analysis of simple cave 

communities I. Caves as Islands. Evolution 

24:463-474. 



Hendei-son, J. 1918. A Mollusk hunt in 

Wyoming. Nautilus, 32: 40-47. 
Henderson, J. 1924. Mollusca of Colorado, Utah, 

Montana, Idaho and Wyoming. University of 

Colorado Studies 13: 65-223. 
Henderson, J. 1936. Mollusca of Colorado, Utah, 

Montana, Idaho and Wyoming — Supplement. 

University of Colorado Studies 23: 81-145. 
Hubricht, L. Apr. 1940a. The Ozark Amnicolas. 

Nautilus 53(4): 118-122. 
Hubricht, L. July 1940b. The Snails of Ted 

Cave, Tennessee. Nautilus 54(1): 10-11. 
Hubricht, L. 1941. The Cave Mollusca of the 

Ozark Region. Nautilus 54(4): 111-112. 
Hubricht, L. 1950. The Invertebrate Fauna of 

Ozark Caves. National Speleological Society 

Bulletin 12: 2 pages. 
Hubricht, L. 1960. The Cave Snail, 

Carijchium stijgium. Call. Trans. Kentucky 

Acad. Sci. 21: 35-38. 
Hubricht, L. 1963. New species of Hydrobiidae. 

Nautilus 76(4): 138-140, pi. 8. 
Hubricht, L. 1964. Land Snails from the Caves 

of Kentucky, Tennessee and Alabama. 

National Speleological Society Bulletin 26(1): 

33-35. 
MacArthur, R. H. and E. 0. Wilson. 1967. The 

Theory of Island Biogeography. Princeton 

University Press. 203 pages, 60 figures. 
Poulson, T. L. and W. B. White. 1969. Tlie 

Cave Environment. Science 165(3897): 971-980, 

figs. 1-3. 
Sanders, H. L. 1968. Marine Benthic Diversity: 

A Comparative Study. The American Natural- 
ist 102: 243-282. 
Te, George A. 1973. A Brief review of the 

Systematics of the Physidae. Malacological 

Review 6: 61. 



86 THE NAUTILUS 



Julv 22. 1974 



Vol. 88 (3) 



NESOPUPA GALAPAGENSIS. A NEW INDO-PACIFIC 
ELEMENT IN THE LAND SNAIL FAUNA OF THE GALAPAGOS ISLANDS 

(PULMONATA: VERTIGINIDAE)' 

Joseph Vagvolgyi 

Department of Biology 
City University of New York. N.Y. 10301 

ABSTRACT 

Nesopupa galapagensis, a new species of the pulmonate family Vertiginidae is 
described from the Galapagos Islands. This is a new record of the genus Nesopupa, 
typicalhi of Indo-Pacific distribution, in the Galapagos fauna. 



INTRODUCTION 

As the first part of a study of the evolution 
and ecology of the land snails of the Galapagos 
Islands, I have collected on the islands of Santa 
Cruz (Indefatigable), Santa Maria (Floreana. 
Charles), Isabela (Albemarle) and San Salvador 
(Santiago, James) during the summer of 1970. Of 
the material obtained, one finding will be 
discussed below in detail, Nesopupa galapagenais. 
because it represents a new species and a new 
record of an Indo-Pacific genus in the Galapagos 
land snail fauna. 

DESCRIPTION 

The shell: the height is 1.6 - 1.9 mm, the width 
1.0 — 1.1 mm. the width — height ratio, .53 — 




FIG. 1. Nesopupa galapagensis Vagvolgyi new 
species. 1.9 mm Holotype. 



.65; the height of the last whorl including the 
aperture is 0.9 — 1.2 mm, that of the aperture 
alone, 0.6 — 0.7 mm; in percentage of the total 
height these values correspond to 53 — 67 and 35 
— 41%, respectively; the whorl number varies 
from 4' 4 to 5. The shape of the shell is nearly 
cylindrical in 9 specimens, cylindrical-oval or 
oval in the others; the whorls are convex, the 
sutures deep, particularly so in the cylindrical 
specimens; the last whorl ascends upon the 
penultimate one prior to the aperture, slightly in 
the oval specimens, more distinctly in the cylin- 
drical ones. The umbilicus is minute. The aper- 
ture is oval-triangular vdth a notch on the outer 
lip formed by the inward and forward projecting 
middle part of the outer lip (this region is 



|90'4?W 





w _ 


9 





as3 




' Contribution No. 134 from the Charles Darwin Research 
Station. Santa Cruz. Galapagos. Ek^uador. 



FIG. 1 Collecting sites on Isla San Salvador, 
Giddpagos. 



Vol. 88 (3) 



THE NAUTILUS 



87 



sometimes termed "auricle"); the lips are slightly 
reflected; the parietal wall is covered by a weak 
callus that connects the origin of the outer and 
inner lips; the lip swelling is weak but wide, 
deeply receded from and parallel to the edge of 
the lips; corresponding to the lip swelling there is 
a weak and wide annular crest on the outside of 
the shell. The armature consists of a parietal, 
angular and columellar lamella and an upper and 
lower palatal fold; the parietal lamella is large, 
the angular, small; both lie moderately deep in 
the aperture, and are separated from one 
another; the columellar lamella is medium large, 
deeply seated, its inner end is straight; the lower 
palatal fold is large, the upper, medium to small, 
both lie deep in the aperture; a sulcus may 
mark on the outside of the shell the position of 
either palatal fold. Sculpture: the embryonic 
whorls are smooth (SOX magnification); the 
postembryonic whorls have a fine striation and a 
shiny, lustrous appearance except in the region of 
the annular crest where the striation is coarser; 
there is no sign of any pits. The color of the fresh 
shell is dark brown, that of the folds and 
lamellae, very light with a brownish tint. 

Holoti/pe (fig. 1) and paratypes are deposited in 
the collection of the Academy of Natural Sciences 
of Philadelphia, nos. 332451, 332452, respectively. 
Other paratypes in the collection of the Delaware 
Museum, nos. 70650 and of the author. Type 
locality: Peak 2974', central highlands of Isla San 
Salvador (James Island), Galapagos Islands (fig. 
2). 

Material examined: Four samples, 2-32 
specimens each, 38 specimens altogether. 

DIFFERENTIAL DIAGNOSIS 

Nesopupa (Infranesopupa) anceyana Pilsbry 
and Cooke and N. (Infranesopupa) subcentralis 
Pilsbry and Cooke of the Hawaiian Islands 
closely resemble the new species in size (Table 1), 
armature and sculpture; on this basis, N. 
galapagensis is assigned to the subgenus /«- 
franesopiipa. Both species differ, however, from 
the new species in being more oval and having 
shallower sutures, larger aperture and less 
pronounced auricle. Another similar species is A^. 
(Nesodagys) wesleyana Ancey, of the Hawaiian 
Islands, which agrees with A^. galapagensis in 
shape, convexity of the whorls and dentition 



but has fine periostracal riblets and a very 
weak auricle. However, the most similar species 
is an undescribed one, from Surinam, Dutch 
Guiana, South America, in the possession of the 
Academy of Natural Sciences of Philadelphia; 
the only difference is that the outline is a bit 
more oval and the dentition a bit weaker than 
in A^. galapagensis. 

Some species of the genus Vertigo also closely 
resemble A^. galapagenjns in shape, sculpture 
and auricle but their dentition is different. 

The new species does not show a great deal 
of similarity to Nesopupa (Cocopupa) cocosensis 
(Dall) of Cocos Island as one might expect from 
the relative proximity of the areas of 
distribution of the two species. Nesopupa 
cocosensl^ is larger (Fig. 1) and has a pitted 
sculpture. 

ECOLOGY 

Nesopupa galapagensis lives in the high and 
moist central region of Isla San Salvador (fig. 
2). It was found in the thickets and the open 
fields as well. In the former it lived in the lit- 
ter layer and the moss pads growing on trees, 
in the latter, on the ground at the base of the 
grass. The description of the collecting localities 
follows: 

Station 36. A few hundred yards from Peak 
2974', on the southern slope, at about 2900' of 
elevation. Good soil; impenetrable brush, com- 
posed primarily of Psychotria nifipes and Tour- 
nefortia rufosericea. Moss pads on the horizon- 
tal branches of many trees (mostly belonging to 
the species Zanthoxylum fagara). Four squares 
of 25 X 25 cm each were sifted from the litter, 
and 3 moss pads were taken without measuring 
size. July 25, 1970. 

Station 37a. Pampa or open grassy field at 
the southern foot of Peak 2974', at about 2300- 
2400' of elevation. Soil good, wet from several 
days' drizzle (garua). Two samples of 25 X 25 
cm were taken. The pampa habitat may be a 
secondary one; according to some botanists, 
pampas develop only when the original forest 
cover is destroyed by the introduced goats, 
pigs and cattle. July 30, 1970. 

Station 38. Southwestern side of the crest 
between Peaks 2974' and 2965', at about 2600- 
2900' of elevation. Grass, bushes and the giant 



88 THE NAUTILUS 



July 22, 1974 



Vol. 88 (3) 



fern Cyathea make up the vegetation. Five sam- 
ples of the usual size were taken, 2 from grassy 
areas, 2 from the base of bushes and 1 from a 
wash. Soil wet from garua. July 30, 1970. 

Pilsbry noted (1920: 289) that species of In- 
franesopupa are usually found on fronds of ferns 
and leaves of low plants or occasionally on 
trunks of trees. My observations that N. 
galapagensis lives both on the ground and on 
trees are in partial agreement with this. 

DISTRIBUTION 

Nesopupa galapagensis is endemic to the 
Galapagos Islands. It is the only representative 
of its genus there. Its apparent ancestors are 
the species of Infranesopupa in the Hawaiian 
Islands. It thus represents a new Indo-Pacific 
element in the Galapagos land snail fauna. 
Such elements are rare; the only other species 
of Indo-Pacific relationships among the 
Galapagos land snails is Tornatellides 
chathamensis. Numerically the Indo-Pacific 
elements represent somewhat less than 3% of 
the fauna (2 sppcies of the total reported of 76; 
based on Smith 1966). The majority of the 
species are of Neotropical relationships. 

The marine molluscs of the Galapagos mirror 
this composition. According to Emerson (1967) 
only 25 species or a little more than 4% of the 
600 species reported have Indo-Pacific affinities. 
The similarity may be merely coincidental, 
however. On the one hand, the rarity of the In- 
do-Pacific elements among the marine mollusks 
— as Emerson argues convincingly — is due to 
the scarcity of suitable habitats: coral reefs for 
the reef dwellers common in the Indo-Pacific 
region. His contention is supported by the fact 
that Clipperton Island, which also lies in the 
Eastern Pacific but is a coral atoll, has 47% In- 
do-Pacific elements in its fauna. On the other 
hand, the reason for the scarcity of the Indo- 
Pacific elements among the Galapagos land 
snails appears to be primarily the distance and 
isolation from that region. 

DISPERSAL 

The Hawaiian Islands, where Nesopupa 
galapagensi,s presumably originated, lie roughly 
4000 miles northwest of the Galapagos Islands. 



Geological evidence indicates no previous land 
connection between the two archipelagoes or 
between the Galapagos and the South American 
mainland (McBimey and Williams 1969). Thus 
Nesopupa galapagensis in all likelihood reached 
the Galapagos Islands by overseas dispersal, 
whether by ocean currents, winds, insects or 
birds it is impossible to say. I do not believe, 
however, that human introduction was respon- 
sible, for two reasons. First, because the species 
does not occur near human settlements or 
cultivated areas, in disturbed habitats as in- 
troduced species often do (e.g. species of 
Subulina, Lamellaxis and Dernceras in the 
Galapagos, Smith 1966); rather it occurs in 
remote regions, in the litter layer and moss 
pads which are undisturbed habitats. Another 
habitat where it also occurs, the pampa, may 
be a disturbed one; but even this habitat is far 
away from human settlements. Second, because 
the species has not been found on the 
inhabited, cultivated islands of the archipelago; 
rather, it has been found on San Salvador 
which has been free of cultivation, although for 
a while a salt mine was operated on its south- 
western shore. Admittedly, future collecting 
may discover the species on the inhabited 
'islands as well and this fact may then refute the 
argument. Another possible objection, namely 
that San Salvador has some special ecological 
setting which favors Nesopupa whereas the 
other islands lack such seems to have no 
validity at all as all the islands in question 
have wet zones which at least in basic features 
are counterparts of the wet zone of San 
Salvador. 

The process of overseas dispersal is generally 
considered a fortuitous one and in our case it 
indeed appears to be so. First, because 
Nesopupa galapagemns, after having crossed a 
vast extension of open ocean, only colonized one 
of the 15 major islands of the Galapagos Ar- 
chipelago, not the other 14. Second, it also 
failed to colonize the relatively nearby Cocos 
Island; the latter has been reached in- 
dependently of N. galapagemns by another, not 
closely related, species of Nesopupa, N. cocosen- 
sis. Third, from the Galapagos the species made 
another huge jump across 600 miles of open 
ocean and 1200 miles of land to reach Surinam 



Vol. 88 (3) 



THE NAUTILUS 



89 



(refer tx> undescribed Nesupupa). This in itself 
is remarkable as colonization usually proceeds 
in the opposite direction, from the continents to 
the islands. — It is possible that future collect- 
ing will prove Nesopupa to be a more 
widespread genus in South America than 
hitherto assumed, in which case the origin of 
the Galapagos Nesopupa becomes a mute 
question. However, according to our present 
knowledge, the Hawaiian origin appears more 
probable. 

ACKNO WLEDGEM ENTS 

I gratefully acknowledge the assistance 
received from the Research Foundation of the 
State University of New York. I also thank 
Messrs. Roger Perry and Rolf Sievers of the 
Charles Darwin Research Foundation for their 
help during our stay on the islands, Mr. Daniel 
Weber of the same institution for identifying 
several plants, my wife Alice for help in the 



field work and Dr. Robert Robertson for 
allowing me to use the collection of the 
Academy of Natural Sciences of Philadelphia 
for comparisons. 



AMERICAN MALACOLOGICAL UNION 
40th ANNUAL MEETING 

Springfield, Massachusetts, will be the site of 
this summer's annual meeting of the A.M.U., 
from Saturday, August 3, 1974 (preliminary 
registration, 2:00 to 5:00 p.m.) through Wed- 
nesday, August 7; to be held in the Museum of 
Fine Arts and the Museum of Science in down- 
town Springfield. 1974 President is Harold D. 
Murray, Biology Dept., Trinity University, San 
Antonio, Texas 78284; local host is Earl H. 
Reed, Museum of Science, 236 State St., 
Springfield, Mass. 01103. 



INDO-PACIFIC 
MOLLUSCA 

MONOGRAPHS OF THE MARINE MOLLUSKS OF 
THE WORLD WITH EMPHASIS ON THOSE OF 
THE TROPICAL WESTERN PACIFIC 
AND INDIAN OCEANS 

The most technical and most beautifully illustrated 
journal now being published on Recent and Tertiary 
marine moUusks. Over 20 professional malacologists are 
currently contributing. Edited by R. Tucker Abbott. 
Among the groups treated are Strombidae, Cassidae, 
Tridacnidae, Turridae, Littorinidae, Phasianellidae, and, 
soon to come, Patellidae, Harpidae and Mitridae. 

Issued to date in looseleaf form with three sturdy, 
permanent binders — 1100 pages, 810 plates (31 in full 
color). Limited number of complete sets left, $91.90 U.S. 
(foreign: $94.00), postage paid. Any number of extra 
binders available at $6.00. 



Published by 
The Delaware Museum of Natural History, Box 3937, Greenville, Delaware 19807 U.S.A. 




90 THE NAUTILUS July 22. 1974 

NEGLECTED PAPERS ON NAIADES BY W. I. UTTERBACK 

Samuel L. H. Fuller 

Academy of Natural Sciences of Philadelphia 
Philadelphia, Pennsylvania 19103 



Vol. 88 (3) 



To the list of papers on naiades by W. I. Ut- 
terback which was compiled by Johnson (1969) 
may be added the following, less familiar work. 

1928. Phylogeny and ontogeny of naiades. Pro- 
ceedings of the West Virginia Academy of 
Science 2: 60-67. 

This paper is primarily a recapitulation of 
the naiad classification initiated by Ortmann 
(1910). Since Utterback provides no references 
to authorities other than himself, it is im- 
possible to ascertain the source(s) of some of his 
more intriguing remarks, such as the statement 
that Cumberlandia monodonta (Say) can 
produce two broods of glochidia in a single 
summer. Noteworthy contributions are a 
description of volvocoid naiad sperm bodies (see 
Utterback, 1931) and a discussion of some 
remarkable aspects of the biology of 
Megalonaias gigantea (Barnes). The latter con- 
tribution offers no advance over Utterback 
(1915-1916) or the earlier account by Howard 
(1914). 

1930. A new genus of freshwater mussels 
(naiades). Ibid., 4: 66-69, text figures 1-3. 

This paper is a discussion of Utterbackia, 
which Baker (1928) had already described and 
based on Anodonta imbecilis Say. Superior 
notes on the natural history of this species had 
been provided by Allen (1924) and Tucker (1927, 
1928). 

1931. Sex behavior among naiades. Ibid., 
5: 43-45. 

Little advance is made beyond Utterback's 
(1915-1916, 1928) earlier works. 

1933. New glochidia. Ibid., 6: 32-36, text figures 
A-C. 



Descriptions and discussions of the glochidia 
of seven naiad species and alleged subspecies 
are given. Much of this information had not 
previously been published. 

REFERENCES CITED 

Allen, E. 1924. TTie existence of a short repro- 
ductive cycle in Anodonta imbecilis. — 
Biological Bulletin 46: 88-94. 

Baker, F. C. 1928. The fresh water Mollusca 
of Wisconsin. Part II. Pelecypoda. — Bulletin 
of the Wisconsin Geological and Natural 
History Survey, No. 70: 1-495. 

Howard, A. D. 1914. Ebcperiments in propagation 
of fresh-water mussels of the Quadrula group. 
Appendix IV to the Report of the United 
States Commissioner of Fisheries for 1913: 
1-52. Separately issued as Bureau of Fisheries 
Etocument No. 801. 

Johnson, R. I. 1969. The Unionacea of William 
Irvin Utterback. The Nautilus 82: 132-135. 

Ortmann, A. E. 1910. A new system of the 
Unionidae. The Nautilus 23: 114-120. 

Tucker, M. E. 1927. Morphology of the 
glochidium and juvenile of the mussel 
Anodonta imbecilis. Transactions of the 
American Microscopical Society 46: 286-293. 

Tucker, M. E. 1928. Studies on the life cycles of 
two species of fresh-water mussels belonging 
to the genus Anodonta. Biological Bulletin 
54: 117-127. 

Utterback, W. I. 1915-1916. The naiades of 
Missouri. American Midland Naturalist 4: 
41-53, 97-152, 181-204, 244-273, 311-327. 
339-354, 387-400, 432-464. Repaged and re- 
printed in 1916 by University of Notre Dame 
Press, Notre Dame, Indiana, pp. 1-200. 



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MOLLUSK VOUCHER SPECIMENS 



It is becoming increasingly important for future 
research purposes that an identified sampling of 
species mentioned in pubUcations be deposited in 
a permanent, accessible museum speciaUzing in 
moUusks. This is particularly true of inollusks used 
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The Delaware Museum of Natural History has 



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OCTOBER 1974 



THE 



NAUTILUS 




Vol. 88 
No. 4 




A quarterly 

devoted to 

malacology and 

the interests of 

conchologists 



Founded 1889 by Heni-y A. Pilsbry. Continued by H. Burrington Baker. 
Editor-in-Chief: R. Tucker Abbott 



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Department of Mollusks 
National Museum of Canada 
Ottawa, Ontario, Canada K1A-0M8 

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Museum of Comparative Zoology 
Cambridge, Mass. 02138 

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Department of Living Invertebrates 

The American Museum of Natural History 

New York, New York 10024 

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Department of Living Invertebrates 

The American Museum of Natural History 

New York, New York 10024 

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Department of Geology 
The Ohio State University 
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Los Angeles County Museum of Natural History 
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Biological Laboratory 
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10 Rickenbacker Causeway 

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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 

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Department of Mollusks 
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THE 
NAUTILUS 

Volume 88, number 4 — October 25, 1974 

CONTENTS 

Richard W. Fullington 

Two New Land Gastropods from Texas (Zonitoides and Stenotrema) 91 

Artie L. Metcalf 

Peripheral Species of the Oreohelix metcaifei Cockerell Complex 

(Pulmonata: Oreohelicidae) 94 

E. H. Michelson and Lorin DuBois 

Lymnaca emarginata, a Possible Agent for the Control of the 

Schistosome-Snail Host, Biomphalaria glabrata 101 

G. L. Mackie, S. U. Qadri and A. H. Clarke 

Development of Brood Sacs in Musc7dmm securis (Bivalvia: Sphaeriidae) 109 

R. A. Fralick, K. W. Turgeon and A. C. Mathieson 

Destruction of the Kelp, Laminaria, by Lacuna vincta (Montagu) 112 

David J. Prior 

Role of the Incurrent Slphonal Valve in the Surf Clam, 

Spisula solidissima (Mactridae) 115 

Donald W. Kaufman 

Second Locality Record for Mesodun ieatherwoodi Pratt 118 

Book Reviews 

(of) M. P. and M. H. Oliveira, 108; H. B. Stenzel, 117; G. A. Solem, 120; News 119 



Just 
Published- 



Latest edition of the 
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American 
Seashells 



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5,050 illus.. 

8V2 X 1 1 




AMERICAN SEASHELIS 

Second Edition 
By R.Tucker Abbott 

This updated edition includes more species of 
shells than any other book currently in print in the 
English language. It lists all 6500 known species 
of marine mollusks living in the waters adjacent to 
North America. Shown and described in detail are 
over 3000 of them. Enlarged from the first edition 
to cover four times as many species, American 
Seashells explains the habits, foods, identification 
features, methods of growth, life histories, geo- 
graphical distributions, bathymetric ranges and 
other biological facts concerning the rarest, as 
well as the most common, marine mollusks. Abun- 
dantly illustrated with magnificent color plates, this 
outstanding reference book also brings you the 
secrets of shell collecting, techniques in caring 
for the collection, and methods of study. 

At your bookstore, or write to publisher 
below lor further information 

Dept.LR 

Van Nostrand Reinhold Co. 

450 WEST 33HD STREET, NEW YORK. NEW YORK 10001 



2SB 



Vol. 88 (4) 



THE NAUTILUS 



91 



TWO NEW LAND GASTROPODS FROM TEXAS (ZONITOIDES AND 

STENOTREMA) 

Richard W. P^ullington 

Dallas Museum of Natural History 

Fair Park Station 

Dallas. Texas 75226 

ABSTRACT 

Zonitoides kirbyi fZonitidae) is described from Schulze Cave, approx. 28 miles 
northeast of Rocksprings. Edwards Co., Texas. It is most closely related in form 
to Zonitoides arboreus (Say) but differs by being larger and glossier uith less 
distinct growth lines. Stenotrema leai cheatumi (Polygyridae) is described from 
Palmetto Stute Park, Ottine, Gonzales Co., Texas. It diffeis from the most 
closely related species in form Stenotrema leai leai (Binney) by being much 
smaller, more depressed, and uith a much larger fulcrum. 



An undescribed zonitid was sent to the late 
Dr. E. P. Cheatum by Dr. Walter Dalquest of 
Midwestern University, Wichita Falls. Texas. 
The fossil shells were collected by Dr. Dalquest 
and his colleagues in Schulze Cave which is 
located approximately 28 miles northeast of 
Rocksprings, Edwards County, Texas. Living 
specimens were later obtained from the site by 
the author. Dr. Dalquest's report on the 
statigraphy and vertebrate remains found in 
the cave, was published in 1969. 

According to their report, the cave is of the 
sinkhole type and "probably formed by solution 
from a vertical tissue that penetrated two 
limestone layers of the Upper Cretaceous Ed- 
wards formation." The shells were found in 
association with mammalian bones in a zone of 
matrix designated as layer C. Many of the 
shells were stained by yellowish sediments. A 
part of a bone from a grizzly bear, in this 
same layer, was sent to the Socony-Mobil 
Laboratories in Dallas, Texas for dating. The 
C14 test revealed an age of 9,680 ± 700 years 
BP, which indicated a late Pleistocene age. 

On July 25, 1972, a collecting trip was made 
by the writer accompanied by Dr. E. P. 
Cheatum and Wayne Seifert, staff member of 
the Dallas Museum of Natural History that 
sponsored the trip. The main purpose of the 
trip was to ascertain if the species still lived in 
the cave and if it was extant in the surround- 



ing environs. Equipped with headlights. Seifert 
and myself entered the cave and, in the same 
zone from which the fossil shells had been 
collected, we found living specimens of this 
species. The living snail is described as follows: 
the entire pale-grey body was visible through 
the transparent shell. Each transparent eyestalk 
was capped by the dark eye. The cave was 
damp and fungal growths were abundant. Un- 
fortunately, only one living snail was collected 
and this was an immature form with a shell 
diameter of 3.19 mm. A diligent search was 
made of the area surrounding the cave in hopes 
that we could find the living snail or at least 
dead shells of this species. None were found, so 
the origin of this snail remains a puzzle. 

This species is named for Mr. Hal P. Kirby, 
Director of the Dallas Museum of Natural 
History who has encouraged and greatly aided 
Molluscan research in the Southwest. 

Zonitoides kirbyi neiv species 
Figs. 4-6 

Description-Shell pale, glossy, translucent, and 
weakly sculptured with rather evenly-spaced 
but crowded growth lines which are more 
pronounced on the basal whorl. Under 
magnification, fine parallel striae are visible on 
the upper surface of the whorls exclusive of the 
embiyonic whorl which is smooth. The striae, 
although present on the lower surface of the 



92 THE NAUTILUS 



October 25, 1974 



Vol. 88 (4) 




FIG. 1-3. Zonitoides arboreus (Say); x J^.3; 
FIG. i-6. Zonitoides kirbifi n. sp.; x 3.8; FIG. 7- 
.9, Stenotrema leai cheatumi n. mbttp.; x 2.6; 
FIG. 10-11. Stenotrema leai leai (Binney); x 2.2; 
FIG. 12-13, Stenotrema leai alidae (Pilsbry); x 
2.9. 



whorls, are more subdued. The umbilicus is con- 
tained approximately 3.2 times in the shell 
diameter. The whorls are well-rounded, the aper- 
ture is ovoidal and the peristome is thin. 
Measurements in mm. of holotype: diameter: 
6.3: height: 3.4; aperture height: 2.04; aperture 
width: 1.53. 

Holotype: No. 3286 Dallas Museum of 
Natural History; paratypes in Delaware Mus. 
Nat. Hist. No. 72862; paratypes will be 
deposited in the National Museum of Natural 
History, Carnegie Museum, Museum of Com- 
parative Zoology, Academy Natural Sciences of 
Philadelphia, and the Museum of Zoology, 
University of Michigan. Type locality: Schulze 
Cave, Edwards Co., Texas, July 25, 1972. 

Discussion — Zonitoides kirbifi is most closely 
related in form to Zonitoides arboreus (Say) 
(figs. 1-3), but differs in several respects. Z. kir- 
biji is much larger and glossier with less distinct 
growth lines. It also has a much larger um- 
bilicus which abruptly expands in the last 
whorl. The aperture is very ovately-lunate and 
not deeply rounded - as in Z. arboreus. 
Zonitoides arboreus abounds in the area im- 
mediately surrounding the cave and only dead 
shells were found inside the cave. Z. kirbifi (live 
& dead shells) is found only in the cave. It ap- 
pears that Z. kirbiji may be a form of Z. ar- 
boreus that has been microgeographically 
isolated long enough to become a separate 
species. 

Stenotrema leai cheatumi new subspecies 

Figs. 7-9 

An undescribed polyg>'rid was collected by 
Dr. E. P. Cheatum and myself in Palmetto 
Park at Ottine, Gonzales County, Texas, on 
November 11, 1971. The locality is an 
ecologically isolated area that is low, swampy 
and thickly studded with shrubs and trees. 
Palmetto plants are extremely abundant. The 
surrounding environment is typical of the 
Texan Biotic Province as defined by Blair 
(1952) but being much drier. The undescribed 
snails were abundant on the moist ground un- 
der palmetto plants and under rotten logs. 

Description — The shell is umbilicate, with a 
low, convexly conoid spire and 5.5 rather 
closely-set whorls. Except for the embryonic 



Vol. 88 (4) 



THE NAUTILUS 



93 



whorl, the remaining whorls are covered with 
irregularly-placed growth lines which, although 
not coarse are more conspicuous on the basal 
whorl. Under magnification the embtyonic 
whorl is beset with fine radiating lines crossed 
by delicate striae confined to the embr>'onic 
whorl; a few very short hairs are present on 
the ventral surface of the basal whorl and on 
the upper surface of the last two whorls. The 
aperture length is 4.25 mm., and the slightly 
curved white parietal tooth is 2.38 mm. long, 
resting obliquely on the exceedingly thin 
parietal callus. The umbilicus is openly per- 
forate with the exception of a flare-out of the 
lower lip which covers the inner edge of the 
umbilicus. The white peristome is thickened 
within and reflected on its outer and inner 
margin thus leaving a conspicuous groove just 
back of the outer lip. The umbilicus is con- 
tained approximately five times in the shell 
diameter. A large white rounded fulcrum is 
present which extends fi'om the top of the basal 
whorl to its floor. Holotype measurements in 
mm.: diameter: 8.2; height: 4.6; No. of whorls: 
5.5. 

Holotype: No. 3288 Dallas Museum of 
Natural HistoiT; paratxTDes in the Delaware 
Mus. Nat. Hist. No. 72861; paratypes will be 
deposited in the National Museum of Natural 
History, Carnegie Museum, Museum of Com- 
parative Zoologv', Academy Natural Sciences of 
Philadelphia, and the Museum of Zoology, 
University of Michigan. The t\T)e locality is 
Palmetto Piirk, Ottine, Gonzales Co., Texas. 
November 11, 1971. 

Discussion — Stenotrema leai cheatumi is 
most closely related in form to Stenotrema leai 
leai (Binney) (fig. 10-11). Stenotrema I. cheatumi 
differs in the following respects: it is smaller, 
more depressed than S. I. leai and has, on the 
average, fewer whorls, is much less hirsute, and 
has a much larger fulcrum. Radially-lengthened 
granules are absent on the embrj-onic whorls 
but cross-striae are present. S. I. cheatumi dif- 
fers from S. leai aliciae (Pilsbn,-) (fig. 12-13), in 
the same features that differentiate it from 5. 
I. leai. 



The Stenotrema leai complex is as yet 
unresolved. Pilsbry (1948) made S. monodon 
(Rackett) synonomous with S. leai. Pilsbry in 
1940 differentiated & leai leai from S. leai 
aliciae in that, "the parietal tooth is higher in 
S. monodon, and the axial end continues in a 
tapering ridge, at the end curving partly 
around the axis." S /. leai is also separated 
from 5. /. aliciae by its open umbilicus while 
the umbilicus of S /. aliciae is generally im- 
perforate. In Texas, 5. leai leai is usually found 
only as a fossil, while S. /. aliciae is usually 
found only in the living state (Cheatum and 
Fullington, 1971). In almost any series from the 
same locality, variants may be found that con- 
form to either 5. /. leai or S. I. aliciae. Due to 
these facts, I am giving S. leai cheatumi only 
subspecific rank until the Stenotrema leai com- 
plex is further studied. 

I am naming this subspecies in honor of the 
late Dr. E. P. Cheatum. This article was ac- 
tually begun by him but he was unable to 
finish it. The work on the two gastropods 
named here was the last of many such en- 
deavors accomplished by Dr. Cheatum. 

LITERATURE CITED 

Blair, W. F. 1950. The Biotic Provinces of 

Texas. Te.xas Jour. Sci. 2(1): 93-117. 
Cheatum, E. P. & R. W. Fullington. 1971. The 

Recent and Pleistocene Members of the 

Gastropod Family Polygyridae in Texas. 

Dallas Museum of Natural History, Bulletin 

I, Part I, pp. 41-43. 
Dalquest, W., Edward Roth and Frank Judd. 

1969. The Mammal Fauna of Shulze Cave, 

Edwards County, Texas. Bulletin Florida 

State Museum, 13 (4): 205-276. 
Pilsbry, H. A. 1940. Land Mollusca of North 

America (north of Mexico). Acad. Nat. 

Sci., Philadelphia, Monograph no. 3, 1 (2): 

676-681. 
PilsbiT, H. A. 1948. Land Mollusca of North 

America (north of Mexico). Acad. Nat. 

Sci., Phildelphia, Monograph no. 3, 2(2): 

1099. 



94 THE NAUTILUS 



October 25, 1974 



Vol. 88 (4) 



PERIPHERAL SPECIES OF THE OREOHELIX METCALEEI 
COCKERELL COMPLEX (PULMONATA: OREOHELICIDAE) 

Artie L. Metcalf 

Department of Biological Sciences 
University of Texas at El Paso 79%8 

ABSTRACT 

New data is presented concerning past and present distribution of land 
snails of the Oreohelix metcalfei Cockerell complex, especially as regards species 
on the periphery of the range of the complex. Two new species are described: 
Oreohelix caballoensis and 0. confragosa. Some trerds concerning evolution of 
the shells are noted. 



INTRODUCTION 

Treated herein are several taxa of the 
Oreohelix metcalfei Cockerell complex of land 
snails (Pulmonata: Stylommatophora: 

Oreohelicidae). These taxa occur, living and 
fossil, in several mountain ranges of south- 
central New Mexico and seem restricted to 
areas of limestone bedrock. 0. metcalfei was 
described by Cockerell as a subspecies of 0. 
strigosa (1905:113-114) from a specimen collected 
by 0. B. Metcalfe from "Mountains near 
Kingston, New Mexico," in the east-central 
foothills of the Black Range in Sierra County 
(Fig. 1). 0. B. Metcalfe (not to be confused with 
the present author) collected botanical and 
other specimens in south-central New Mexico in 
the early 190()'s. Pilsbr>' (1939:509-514) re- 
cognized several subspecies of 0. metcalfei and 
one related species as appertaining to the com- 
plex. 

Major aims here are to present additional 
data regarding the distribution of the complex 
and to point out the existence of fossil 
localities, of small extent areally and easily 
overlooked. Hopefully this may contribute to an 
eventual thorough analysis of the entire 0. met- 
calfei complex. Such an undertaking would 
require much additional field work in the fast- 
nesses of the Black R;inge (Fig. 1) where access 
is largely by hiking and horseback. This Range 
comprises the Black Range Primitive Area of 
approximately .300 square miles plus an area of 
approximately equal extent outside the 



Primitive Area. Until such time as a definitive 
analysis is undertaken it remains highly 
problematic as to which taxa in the complex 
more properly deserve specific recognition and 
which should only be considered subspecies of 
0. metcalfei This is, of course, a common 
problem in the systematics of montane snails, 
which in their evolutionary zeal have taken lit- 
tle heed of the strictures of binomial or 
trinomial nomenclature. Herein two new names 
are provided chiefly as a utilitarian measure to 
facilitate future revisions. As a practical ex- 
pedient, I refer to species rank several kinds 
from mountains or mountain groups peripheral 
to the Black Range (Fig. 1) and separated from 
it by extensive intermontane basins. Variants 
from the Black Range itself are considered as 
comprising a number of subspecies of 0. met- 
calfei as treated by Pilsbry (1939) for all taxa 
of the complex except 0. pilsbryi Ferriss, which 
he relegated to species rank. 

I thank Mr. William de Socarraz for 
preparation of micrographs and Drs. Arthur H. 
Harris and Richard D. Worthington for 
providing me with some of the specimens 
reported. 

Abbreviations used for museums in which 
materials have been deposited are: AN- 
SP = . Academy of Natural Sciences of 
Philadelphia; DMNH = The Delaware Museum 
of Natural History; MALB = Museum of Arid 
Land Biology, The University of Texas at El 
Paso. 



Vol. 88 (4) 



THE NAUTILUS 



95 



DESCRIPTIONS OF NEW SPECIES 

Oreohelix caballoensis yiew species 

Figs. 2, 3 

Desicription of Holotype: (Fossil shell, ANSP 
332307) Shell heavy, moderately elevated, convex 
dorsally and ventrally, 19.4 mm in diameter 
and 12.0 mm in height; slightly angular 
peripherally; last whorl descending markedly to 
aperture; aperture 9.0 mm wide and 8.1 mm 
high; umbilicus relatively narrow, 6.0 mm wide, 
contained 3.2 times in diameter; relatively 
tightly whorled. wdth 5.15 whorls; embryonic 
whorl with low, regular wrinkles, grading to 
low, regularly-spaced riblets on second whorl, 
remainder of dorsal surface with low, irregular 
growth striae, becoming coarser towards aper- 
ture; ventral surface relatively smooth except 
for occasional growth striae (spiral striae not 
observed); shell generally white but light tan on 
first 2^2 whorls dorsally and with two reddish 
brown bands, one immediately below peripheral 
angularity on body whorl, intersecting upper 
edge of lip and obscured from that point on, 
proximally; the other a lighter spiral band in 
center of dorsal whorls from beginning of whorl 
three, distally, fading near aperture on body 
whorl. Type locality. Locality 1 in "List of 
Localities," hereafter, and in Fig. 1. 

Variation: (Paratypes: DMNH 70647 and 
MALE 3343, Loc. 1; ANSP 332308 and MALE 
3631, Loc. 2). Only three entire mature shells 
and several broken shells were obtained at the 
type locality (Loc. 1). Paratypes (also fossil) 
from Locality 2, in the lower western foothills 
of the Caballo Mts., seem to have been slightly 
smaller at maturity with more tightly whorled 
shells. For ten specimens from this locality, 
diameter/number of whorls averaged 3.22, while 
three measurable specimens from the type 
locality averaged 3.46. Umbilicus is relatively 
larger for specimens from Locality 2, with 
diameter/width of umbilicus averaging 3.27 for 
ten specimens against 3.89 for the three 
specimens from Locality 1. 

Comparisons: Compared to the subspecies of 
0. metcalfei 0. caballoensis most resembles 0. 
m. hermosensis Pilsbry and Ferriss and 0. m. 
cuchillensis Pilsbry and Ferriss. These kinds are 
from northeastern foothills of the Elack Range 



and the nearby Cuchillo Mts. (Fig. 1), ca. 30 
miles northwest and north-northwest, respec- 
tively, of the northern part of the Caballo 




FIG. 1. Map of south-central New Mexico in- 
dicating features mentioned in text. Cantovr-s at 
5000. 7000 and 9000 feet indicated by contour 
lines, uith elevations between .5000 and 7000 feet 
dotted and elevations above 9000 feet bkwk. 
Resenums on Rio Grande iiidicated by wavy 
lines. Localities mentioTied are indicated by 
number and black dot. Inset at lower light is 
of central and noi-ther-n pari of Caballo Mts. 
(.5000 and 7000 feet contour lines indicated) and 
of Caballo Reservoir. 

Abbreviations: BP— Brushy Peak of Caballo 
Mts.: C Res. = Caballo Reservoir: E B 
Res. = Elephant Butte Reservoir: M=Mountmns: 
Mag. M.=Magdalena Mts.; PAM=Pinos Altos 
Mts.: THM=Tres Hermanas Mts. 



96 THE NAUTILUS 



October 25, 1974 



Vol. 8X (4) 



Range and seem a likely source for propagules 
reaching the Caballos. Shells of 0. m. her- 
mosensis and 0. m. curhillensis are, however, 
more depressed with a slightly larger umbilicus 
than in 0. cahalloensis. 

Etjfmolofjii: From Cabnilo (Sp., horse), in 
reference to the Caballo Mts., in which the 
species occurs. 

Oreohelix confragosa new species 

Figs. 4-7, 9 

Desicription of Holotypp: (Fre.sh shell with 
desiccated soft parts, ANSP 332309). Shell 



hea\7, convex dorsally and ventrally, 17.7 mm 
in diameter and 10.3 mm in height, bearing 
rounded keel peripherally at ca. mid-height, 
keel reduced to an angularity on distal-most 
part of body whorl, keel bordered by spiral, oc- 
casionally coarsely punctate grooves above and 
below, these also fading out on last ' 4 of body 
whorl; aperture round except for slight 
angularity in outer lip at position of keel, 8.2 
mm wide and 8.3 mm high; umbilicus relatively 
narrow, 4.7 mm wide, contained 3.8 times in 
diameter; 5 whorls; embryonic whorl with 
regular, smoothly arcuate wrinkles, these 




FKJS. 2. -i. Holotupe of Oreohelix caballoen- 
sis n. Ap.. (194 'mm diameter). FIG. h- Em- 
bryonic whorls of Oreohelix confragosa n. sp. 
(scanning electron micrograph. l(X)X). FIGS. 5, 
6. Holotype 0/ Oreohelix confragosa n. sp.. (17.7 
mm dia.meter). FIG. 7. Fossil .'Specimen of 
Oreohelix confragosa n. sp. from Locality A, 
(17.6 mm diameter). FIG. 8. Fossil specimen of 



Oreohelix florida Pilsbry from Tres Hoynanas 
Mtf!.. Locality 6. (16.6 mm diameter). FIG. 9. 
Apiccd whorls of Oreohelix confragosa n. sp. 
(scanning electron micrograph. .V)X). FIG 10. 
Fossil specimen of Oreohelix florida Pilsbry 
from Cooke Range, Locality 5, (21.1 mm 
diameter). 



Vol. 88 {\) 



THE NAUTILUS 



97 



wrinkles becoming liigher and sinuous at 1 to 
m whorls (sinuosity in riblets caused by their 
intersection with two very low spiral ridges and 
with the spiral groove atop keel), wrinkles 
grading into sharp, well-defined riblets at 1^4 to 
2V2 whorls, these riblets fading out at 2';; to 
2^/4 whorls with irregular coarse growth 
wrinkles on remaining whorls dorsally; ex- 
ceedingly fine, close-spaced spiral striae visible 
at many places on both dorsiil and ventral sur- 
faces of shell; irregularly round to elongate 
scattered pits on both surfaces; coarse growth 
wrinkles on ventral surface; shell generally 
whitish, with extremely faint, diffuse, grayish 
brown band immediately below keel on 
proximal half of body whorl, covered proximally 
by upper margin of lip; a few light gray spots 
on ventral surface with a faint, shadowy, gray 
spiral band (with interruptions) on proximal H 
of body whorl; dorsally, initial 2'/2 whorls light 
grayish brown, irregular gray to brownish gray 
splotches on whorls 2*2 to 4 and a few gray 
spots on proximal part of body whorl. Type 
locality. Locality 3 in "List of Localities" and 
in Fig. I. 

Genitalia: (Data from paratypes from 
Locality 3; see Fig. 11). Penis swollen in middle 
part but narrowed distally, bearing a small 
lateral cornuted appendix distally; internally, 
wall of proximal 45% bears fleshy longitudinal 
folds, while that of the distal 55% bears 
"checkrows" of small quadrate papillae, except 
for one longitudinal groove that is free of 
papillae; area of tract joining penis to 
epiphallus slightly inverted back into penial 
cavity; retractor muscle strands attached to 
both penis and epiphallus at their area of junc- 
ture; epiphallus short and stout and vas 
deferens relatively short as in 0. metcalfei 
radiata and 0. pilsbnfi (Pilsbry, 1939; Fig. 331); 
free oviduct short, talon darkly pigmented. 
Lengths for some organs for three specimens 
with shell diameters of 14.0, 14.5 and 17.3 were, 
respectively: penis: 6.4, 7.5, 8.2; epiphallus: 2.2, 

2.6, 2.5; vas deferens: 4.7, 6.5, 5.9; vagina: 2.4, 

2.7, 3.3; free oviduct: 1.7, 1.5, 2.1; spermathecal 
duct and sac: 7.8, 8.4, 11.5. 

Variation: (Paratypes: ANSP 332310, DMNH 
70649, Dallas Museum of Natural History 3867, 
MALB 3495, Locality 3; ANSP 332311 and 



MALB 3494, Locality 4). For 30 paratypes from 
the type locality (Loc. 3) the following propor- 
tions were obtained (mean outside parenthesis; 
range inside parenthesis): Diameter/number of 
whorls: 3.54(3.16-4.02); Diameter/width of aper- 
ture: 2.34(2.12-2.50); Diameter/height of aper- 
ture: 2.33(2.14-2.63); Diameter/lieight of shell: 
1.76(1.53-1.97); Diameter/width of umbilicus: 
3.67(3.32-4.19). Proportions of fossil shells from 
L<_)cality 4 are similar to the above but shells 
are slightly less tightly coiled, more depressed 
and with relatively larger apertures but smaller 
umbilici. For 20 specimens from Locality 4 
proportions were: Diameter/number of whorls: 
3.42(3.01-4.01); Diameter/width of aperture: 




2.5 mm 



FIG. 11. A. Genitalia of Oreohelix confragosa 
new .ipecies (paratype and topotype). Ab- 
breviations: a=atrium: e= epiphallus; hd=/ier- 
maphroditic duct; lp= lower pari of penis; 
o=free oviduct; p=prostate; pr=penial retrac- 
tor: sd= spermathecal duct; t = talon; 
a = uterus; uii= upper part of penis; \ = vagina; 
vd = vas deferens. 

B. Longitudinal section of penis nf 0. con- 
fragosa showing lou:er. costulate and upper 
papillose areas, diverted distal end and small 
l(it( rol appendix. 



98 THE NAUTILUS 



October ^5, 1974 



Vol. 88 (4) 



2.12(1.98-2.39); Diameter/height of aperture: 
2.17(2.01-2.39); Diameter/height of shell: 
1.81(1.62-2.01); Diameter/width of umbilicus: 
3.83(3.40-4.50). 

Fossil shells from Locality 4 retain, even in 
their fossil condition (Fig. 7), a well-defined 
reddish brown band below the keel. An 
equally well-defined brownish band is located 
centrally on the dorsal surface of all whorls 
succeeding the first two. A brown band is also 
found below the keel on younger (up to en. 4) 
whorls on living (topotypic) specimens. In larger 
living specimens the ultimate (usually fifth) 
whorl covers much or all of this band. On 
younger shells, also, a dim brown band is ob- 
servable on the upper surface of whorls as in 
fossils from Locality 4. This band fades with 
age, however, and is usually indiscernible on 
older shells. In regard to banding, then, living 
specimens seem ontogenetically to pass through 
a stage when they resemble the fossil specimens 
from Locality 4 as well as the more heavily 
banded "peripheral" species mentioned hereaf- 
ter. Pilsbry (1939:413) discussed loss of the sup- 
posedly primitive bands in some kinds of 
Oreofielix. 

Embryos closely resemble those figured by 
Pilsbry (1939: Fig. 333) for 0. m. radiata and 
0. m. herynosensk. Young shells up to ca. two 
whorls bear several spiral rows of hairlike 
cuticular processes ventrally and on the keel 
and on each of two or three low spiral ridges 
dorsally (ridges observable in left part of Fig. 
9). Short cuticular hairs are also produced on 
the keel of the third whorl and these persist in 
the shelter of the sutural depression on 
specimens up to 15 mm in diameter. Fig. 4 in- 
dicates presence of minute pustules on dorsal 
surface of the embryonic whorl at its origin. 

Shells commonly exhibit rough radial 
corrugations and areas in which the outermost 
shell layers are broken or missing. Pits, scars 
and other irregularities also are common, these 
accumulating and becoming especially noticeable 
in older shells. The common occurrence of such 
areas suggested the name confragosa. L., 
broken, rough, uneven. 

Comparisons: 0. cor\fragom seems closer to 
the nominal subspecies of 0. metcalfei than to 
any of the other named taxa of the complex. 



However, it is not as sharply keeled as is 0. m. 
metcalfei and it is more convex (less pyramidal) 
dorsally. The surface of confmgom is more 
roughly sculptured radially, the distinct sub- 
carinal brown spiral band of 0. m. metcalfei is 
similar to that of fossil specimens of O. con- 
fragosa from Locality 4 but is lacking on adults 
from the type locality. 

DISCUSSIONS 

The 0. metcalfei complex seems to include 
the following components (locality numbers and 
geographic features mentioned are indicated in 
Fig. 1). 

(1) In the Black Range and nearby Cuchillo 
Mts. occur six subspecies of 0. metcalfei 
Cockerell. These are, in addition to the nominal 
subspecies, acutidvicu,% concentrica, cnchillensis. 
hermosensis and radiata, all described by 
Pilsbr>' and Ferriss. One species, 0. pilsbri/i 
Ferriss, was also ascribed to the complex bv 
Pilsbry (1939:514). 

(2) In several isolated mountains to the south 
of the Black Range occur fossil or dead, 
bleached shells here assigned to OreoheUx 
florida Pilsbry. 0. florida is a relatively distinc- 
tive member of the 0. metcalfei complex, being 
robust, having the highest spire of any member 
of the complex, lacking spiral striae and 
possessing coarse, radial growth lines. As such, 
it seems deserving of specific status. Pilsbry 
(1939:513) described 0. metcalfei florida from 
the Florida Mts.. Luna County, from old, 
bleached shells (ANSP 103243). He also assigned 
two fossil shells from the Tres Hermanas Mts. 
ra. 25 miles southwest of the Florida Mts. to 
this taxon. I have taken one additional fossil 
specimen at Locality 6 in the Tres Hermanas 
Mts. (MALB 2642). I have also taken fossil 
specimens (DMNH 70648; MALB 3634) at 
Locality 5 in the Cooke Range, located between 
the Florida Mts. and the Black Range. Thus, O. 
Jlonda .seems formerly to have penetrated south- 
ward at least some 70 miles along these 
isolated montane "islands." It is doubtful 
whether it is still living in any of them, 
however, as the Tres Hermanas Mts. are a low 
and arid range and the Cooke Range lacks 
limestone in its higher, more mesic parts. Baldy 
Peak in the Florida Mts., a high, isolated. 



Vol. 88 (4) 



THE NAUTILUS 



99 



massive limestone outcrop, may have been the 
last refuge of the species but collections made 
in this century suggest that 0. florida is no 
longer living there. In 1970 I found only a few 
weathered fragments on the north side of Baldy 
Peak (MALE 1201). Pilsbry (1939) did not 
illustrate 0. metcalfei florida. Figs. 8 and 10, 
herein, show shells from the Tres Hermanas 
Mts. and Cooke Range, respectively. 

(3) The localities cited herein for 0. 
caballoensis extend the range of the 0. met- 
calfei complex to the east. This is the only 
member known to occur east of the Rio Grande 
Valley. It is doubtful that the complex ever ex- 
tended any farther east as the next mountain 
range eastward, the San Andres Mts., seems, on 
the basis of fossils recovered, to have been 
inhabited only by 0. socorroe'tms. discussed 
below. 

(4) Localities of occurrence indicated for 0. 
confragosa extend the range of the 0. metcalfei 
complex to the west into the Pinos Altos Moun- 
tains. 

(5) In the Magdalena Mts., some 50-60 miles 
north-northeast from the indistinct northern 
end of the Black Range, occurs Oreohelix 
magdalenae Pilsbry, shells of which, although 
slightly smaller, are close to those of 0. m. 
cuchillensis and 0. caballoensis. Pilsbry 
(1939:515) considered 0. magdalenae to be a 
subspecies of 0. socorroensis Pilsbry. This seems 
improbable, however, as (a) shells of the two 
differ morphologically, with 0. socorroensis 
being more depressed, strongly carinate, with 
well developed spiral striae and lacking the 
brown banding of 0. magdalenae and (b) 0. 
socorroensis seems to occur only east of the Rio 
Grande Valley, chiefly as a fossil in mountains 
surrounding the Tularosa-Hueco Basin (Metcalf 
and Johnson, 1971:102-103), whereas 0. 
magdalenae seems to occur only in the 
Magdalena Mts., west of the Rio Grande Valley. 
Probably 0. socorroensis dispersed southward 
from a northern source in the 0. yavapai 
neomexicana Pilsbry complex, whereas 0. 
magdalenae seems more likely a northeastern 
derivative of the 0. metcalfei complex. 

The 0. metcalfei complex probably has had 
its center of dispersal in the relatively large, 
high and complex massif of the Black Range 



from which it seems to have radiated 
propagules in all directions (Fig. 1). Most of the 
peripheral kinds (0. magdalenae. 0. caballoensis 
and 0. florida along with 0. m. herrnosensis 
and 0. m. cuchillensis of the eastern foothills 
and adjacent ranges of the Black Range) show 
considerable similarity in having elevated, 
biconvex shells, in lacking a keel, in possessing 
relatively smooth shells lacking spiral striations 
and in possession of prominent brown spiral 
bands. Kinds of the central Black Range, on the 
other hand, exhibit to various degrees 
depression and carination of the shell, develop- 
ment of elaborate spiral and/or radial striae, 
ridges and grooves and the loss of brown band- 
ing. 0. confragosa seems closer to the first 
(peripheral) group discussed but does possess 
fine spiral striae. Brown banding is extremely 
weak in living specimens of 0. confragosa but 
fossils have better developed bands, suggesting 
that evolution towards loss of banding has 
taken place. 

It seems probable that in the 0. metcalfei 
complex shells of the "peripheral group," many 
of which are known only as fossils, are more 
conservative. Convei-sely, members of the com- 
plex inhabiting the Black Range in the highest, 
best watered part of the distributional range of 
the complex seem to show evidence of a greater 
degree of speciation than their more con- 
servative, peripheral relatives. 

Probably ancestors of the 0. metcalfei com- 
plex managed to occupy in one or more 
Pleistocene pluvial episodes a number of 
mountain ranges in the region, possessing at 
that time the shell characters suggested above 
as being "conservative." Subsequent desiccation 
in one or more interpluvial episodes has 
resulted in extinction in some and restriction of 
range for other members of the complex. 
Peripheral representatives in smaller, lower 
mountains have been especially adversely af- 
fected. In the Black Range "heartland" of the 
complex, however, survival has been more suc- 
cessful and speciation has been relatively ac- 
celerated. 

LIST OF LOCALITIES 

1. Sierra Co.; 107° 14' W Long, 32° 56' 13" 
N Lat; 6200' elev.; Caballo Mts., from hillslope 



100 THE NAUTILUS 



October 25. 1974 



Vol. 88 (1) 



colluvium of Pleistocene age at mouth of 
canyon on northwest side of Brushy Mt. This is 
a straight box canyon, the first canyon N of 
prominent mine on W face of Brushy Mt.. and 
debouches near la.st "0" in "6000" elevation 
designation on Upham 15' Topo. Quad. A few 
specimens were also taken at mouth of a more 
tortuously branched canyon, located .65 mi. S, 
in colluvium. 

2. Sierra Co.; SW'/4.NE'4,SWV4, Sec. 28, T. 16 
S. R. 4 W; 5000' elev.; western foothills of 
Caballo Mts.. 2 mi. SSE of E end of Caballo 
Reservoir Dam, from Pleistocene hillslope 
colluvium on steep hillside ca. 100 ft. below 
massive limestone rimrock at top of prominent 
cuesta east of extensive mining area. 

3. Grant Co.; near center of NE'/4, Sec. 12, T. 
17 S, R. 12 W; 6700' elev.; Pinos Altos Mts., .3 
mi. WSW of west side of ruins of Georgetown 
(abandoned mining village) on S (N-facing) wall 
of Willow Springs Canyon, below massive 
limestone outcrop; snails living under flat 
limestone rocks derived from the cliffs above 
and strewing the slope; dominant plants on 
slope were Junipemt^ monosperma, Pinm eduli^. 
Quercus gambelii, Yucca baccata, Garrya 
wrightii and Symphoricarpos sp.; collected Sept. 
15. 1973. 

4. Grant Co.; .45 mi. S of NE comer of Sec. 
26. T 17 S, R. 11 W; 6000' elev.; from whitish 
hillslope colluvium of Pleistocene age im- 
mediately NW of intersection of N.M. Hwy. 90 



with paved road leading to Sun Lorenzo and 
Mimbres, at base of escarpment flanking Mim- 
bres Valley on W side (E side of Pinos Altos 
Mts.). 

5. Luna Co.; SE'/4,SE'/4.NW'/4. Sec. 24, T. 20 
S, R. 9 W; 660(r elev.; Cooke (or Cook) Range; 
cuts along road in steep hillside W of and 
above abandoned mining village of Cooke (Cook) 
at head of prominent NE-draining gulley (with 
trail shown on Lake Valley 15' Topo. Quad.) in 
central part of village; road cuts in Pleistocene 
hillslope colluvium of salient whitish color 
(visible several miles away) that contains 
fossils. 

6. Luna Co.; center, N boundarv of SE' 4. Sec. 
26, T. 27 S, R. 9 W; 4.540' elev.; NE part of 
Tres Hermanas Mts.. in alluvium exposed in 
arroyo bank immediately S of mine that is. in 
turn, WSW of Lindy Ann Mine (both shown on 
North Peak 7.5' Topo. Quad.). 

LITERATURE CITED 

Cockerell, T. D. A. 1905. A new (hrohelix. 

The Nautilus 18:11.3-114. 
Metcalf, A. L. and W. E. Johnson. 1971. 

Gastropods of the Franklin Mountains. El 

Paso County, Texas. Southwestern Natur. 

16:8.5-109. 
Pilsbry, H. A. 1939. Land Mollusca of North 

America (North of Mexico). Acad. Nat. Sci. 

Philadelphia Monogr. l(l):xvii + 573 p. 



Vol. 88 (4) 



THE NAUTILUS 



101 



LYMNAEA EMARGINATA. A POSSIBLE AGENT FOR THE CONTROL 
OF THE SCHISTOSOME-SNAH. HOST, BIOMPHALARIA GLABRATA' 

E. H. Michelson and Lorin DuBois 

Department of Tropical Public Health 

Harvard Sc'hool of Public Health 

665 Huntington Avenue 

Boston, Massachusetts 02115 

ABSTRACT 

Lymnaea emarginata cuntrolled labomtori/ populations of Biomphalaria 
glabi-ata by de^troijiny the /offer's C(/,(;-ma,s,sp.s. Previous exposure to B. glabrata 
efig-masses accelerated predatioii hij L. emarginata. This phenomenon was con- 
sidered to be due to sensitization rather than conditioning, since repeated ex- 
posures could not be correlated unth an increase in the efficierwy of preda.tion. 
L, emai-ginata was capable of distinguishing between the egg-masses of B. 
glabrata and Helisoma caribaeum, and destroyed primarihi those of the former: 
however, neither the cyg-iuu.^ses nor their products appeared to attract the 
pn (Idtor. 



Gastropod mollusks exliibit a greater diversity 
of diet and of feeding mechanisms than, 
perhaps, any other group of animals (Owen, 
1966). However, to our knowledge, there are no 
freshwater gastropods which nonnally act as 
"true" predators; i.e., actively seek prey. An ex- 
ception may be Marisa cornuarietis (Linne) and, 
possibly, other members of the Pilidae (Paulinyi 
and Paulini, 1972). Chernin et al. (19.56) 
demonstrated that M. coniuarietis controlled 
Biomphalaria glabrata (Say) populations by 
ingesting their egg-masses and newly hatched 
snails. They believed this "predation" to be ac- 
cidental and due to the Marisa's insatiable ap- 
petite for vegetation and its proclivity for con- 
tinuous browsing. On the other hand, Demian 
and Lutf>' (1965 a & b) reported that Marisa 
deliberately preys on young and older snails 
and can be "conditioned" to "prefer" a snail 
me;d to its normal herbivorous diet. Ob- 
sen'ations. in our laboratory, indicated that a 
North American pulmonate snail. Liimriaea 
cii/argiuata Say, would feed avidly upon the 
egg-masses of B. glabrata. 

In the present study we asses.sed the ability 



of L. emarginata to destroy B. glabrata egg- 
masses, the effect of sensitization on the rate of 
pi'edation, and determined if this predation 




Thes«> studifs were :»iipp<irted in part by Research (ii'ant 
.■\I.-lKI.5l:? anil Training Grant A !-()()( U(i from the NIAID. 
r.S. Public Health .Service. 



DAYS 

FICt. 1. Mean shell measurements of Biompha- 
laria glabrata populations comprised of 10 B. 
glabrata (A). 10 B. glabrata plus 20 L. 
emarginata (B), and SO B. glabrata (C). Ex- 
periment 5. 



in2 THE N'AITILUS 



October 25, 1974 



Vol. 88 (4) 



TABLE 1. Destruction o/B. glabrata eggs by L. emarginata. Twenty snails were used in each trial. Ex- 
periment 1. 



Trial 



Eggs 



(masses) 



fo eggs destroyed by day: 

2 3 4 



1 


221 


(12) 


- 


- 


43.4 


84.2 


2 


257 


(8) 


5.1 


- 


- 


32.3 


3 


191 


(6) 


- 


34.6 


- 


- 


4 


114 


(3) 


9.6 


14.0 


39.5 


54.4 


5 


110 


(4) 


76.4 


95.5 


99.1 


100 


6* 


190 


(5) 


19.5 


42.1 


78.9 


97.9 



Snails used in this trial were the same as in trial 4. 
'Snails used in this trial were starved for 24 hrs prior to testing. 

could, in fact, limit or control the size of B. 
glabrata populations. 



MATERIALS AND METHODS 

A Puerto Rican strain (PR-1) of Biom- 
phaknia glabmta (Say), a Virgin Island strain 
(CB) of Helisoma Caribaeum (Orb.), and a North 
American strain (Michigan) of Lymnaca 
emarginata Say were maintained as described 
(Michelson, 1966). The snail we call L. 
cmanpnata is placed by some workers in the 
genus Stagnicola (Inaba, 1969; Burch, 1960 a & 
b) and is considered by Walter (1969) to be a 
synonym of L. catascojrium Say. 

All experiments were conducted in a tem- 
perature controlled room (25 ± 1° C). In some 
experiments, 6(X) and 1000 ml beakers were 
used as aquaria; in others, 3-liter plastic tubs. 
Aquaria were filled with equal parts of "con- 
ditioned" aquarium water and distilled water, 
were exposed to 12 hr of fluorescent light daily, 
and for some experiments continuously aerated. 
Snails were fed excess amounts of romaine let- 
tuce during the experimental period. All snails 
were measured with Vernier calipers or an 



ocular micrometer (nearest 0.1 mm) and eggs 
were examined and counted with the aid of a 
stereomicroscope (xl5). Egg-masses were collect- 
ed on sheets of plastic-film as described by 
Olivier and Haskins (1960). No attempt was 
made to match the stage of embr\'onic develop- 
ment in the eggs of different masses. 

EXPERIMENTAL STUDIES AND RESULTS 

Observations on feeding behavior: 

B. glabrata egg-masses and individual L. 
emanjinata were confined to small Petri dishes 
(.50 mm) and observed with the aid of a 
stereomicroscope. In most instances, the snail 
moved randomly about the dish until an egg-mass 
was encountered. An exploratory period followed 
in which the snail stroked the mass with its ten- 
tacles, occasionally crawled part-way onto the 
mass or across it to the opposite side, and finally 
adopted a position in which the labial flaps and 
mouth were in juxtaposition to the edge of the 
mass. Feeding was initiated by the rapid flexing of 
the radula and the movement of the jaws. The 
snail rasped through the external and egg mem- 
branes and then devoured the egg contents and em- 
br>'o. No preference was noted for eggs at a par- 
ticular stage of development and eggs of all ages 
were eaten. Destruction of the mass was not a con- 
tinuous process, but occurred at intervals with the 



Vol. 88 (4) 



THE NAUTILUS 



103 



TABLE 2. JTie effect of repeated exposure to B. glabrata egg-masses on the ability of L. emarginata to 
seek and destroy the eggs of B. glabrata. Experiment 2. 



Trials and groups* Eggs (masses) 



io eggs destroyed by day: 

12 3 4 



1, exposed 
non-exposed 


110 
109 


(4) 
(4) 


73.6 

33.0 


85.5 
75.2 


98.1 
80.7 


100.0 
90.8 


2, exposed 
non-exposed 


106 
104 


itJ 


17.0 

4.8 


18.9 
4.8 


84.0 
28.9 


100.0 
51.9 


3. exposed 
non-exposed 


112 
112 


ai 


100.0 



0.9 


44.6 


68.8 


4. exposed 
non-exposed 


68 
75 


Bi 


60.3 
14.5 


72.1 
15.8 


94.1 
28.0 


- 


5. exposed 
non-exposed 


84 
81 


gj 


63.1 
29.6 


90.5 
50.6 


100.0 
55.6 


- 


Mean values 
exposed 
non-exposed 






62.8 
16.4 


73.4 
29.5 


95.1 
47.6 


100.0 
82.5 



'10 snails were used in each group, and the exposed snails of trial 1 were used as the e.xposed group for each subsequent trial. 



snail leaving and then returning after a period of 
browsing. 



EXPERIMENT 1 



L. 



Defitniction of B. glabrata eggs by 
emarginata in the presence of vegetation. 

Small squares of plastic-film, each containing a 
single egg-mass, were anchored to the bottoms of 
l-liter beakers containing 900 ml of water. Twen- 
ty L. emarginata (8.0-11.0 mm in alt.) were in- 
troduced into each beaker and an abundant supply 
of lettuce added. Efeg-masses were examined daily 
for 4 days to determine the number of eggs 
destroyed. The data (Table 1) clearly indicates that 
L. emarginata preys on B. glabrata eggs, even in 
the presence of excess vegetation, and is capable of 
destroying 50% or more of the test samples after 4 
days. Except in one trial (#5), none of the L. 
emarginata had had previous exposure to B. 



glabrata egg-masses. This trial suggested that 
previous exposure to B. glabrata egg-masses may 
"sensitize" L. emarginata to actively seek and 
destroy such eggs. 

EXPERIMENTS 2 & 3 

Effect of pre-exposure on the rate ofpredation. 

The following experiments were designed to test 
the hypothesis that L. emarginata pre-exposed to 
B. glabrata egg-masses became sensitized and thus 
destroyed egg-masses more rapidly than non- 
exposed snails. A group of 10 snails were exposed 
for 4 days to B. glabrata egg-masses. The same 
group of "exposed" snails were then used in 6 con- 
.secutive trials and their predatory activity com- 
pared with groups of non-exposed snails. Trials of 
"exposed" and "non-exposed" snails were run 
simultaneously in 1-liter beakers containing 900 
ml of water and an abundance of lettuce. 



ini THE NAUTILUS 



October 25, 1974 



Vol. 88 (1) 



TABLE 3. The effect of previous exposure to B. glabrata egg-masses on the ability of L. emarginata to 
seek and destroy the eggs of B. glabrata. Experiment 3. 



Trials and groups* 



Eggs'' 



% eggs destroyed, on day 1: 



1, exposed 
non-exposed 

2, exposed 
non-exposed 

3, exposed 
non-exposed 

4« exposed 

non-exposed 

5. exposed 
non-exposed 

6. exposed 

non-exposed 

7. exposed 
non-exposed 

8. exposed 
non-exposed 



101 
100 

100 
97 

96 
103 

101 
100 

101 
100 

99 
102 

98 
103 

100 
100 



63.4 
4.0 

31.0 
3.1 

30.2 
1.0 

9.9 
30.0 

18.8 


10.1 


22.5 
2.9 






*5 snails were used in each group per trial. 

+ 8 egg-masses were used for each group in all trials. 

Results (Table 2) appear to indicate that "ex- 
posed" snails find and destroy egg-masses more 
quickly than do "non-exposed" snails. Since it was 
possible that the snails of the "exposed" group 
were in some manner atypical, another ex- 
periment was set up to overcome this contingency. 
In this experiment (#3), 8 groups of pre-exposed 
snails were compared with similar groups of non- 
exposed snails. F]ach group consisted of 5 L. 
emarginata (7.0-9.5 mm in alt.) and the trials were 
conducted in 600 ml beakers filled with 500 ml of 
water and a supply of lettuce. 

The results (Table 3) clearly support the 
premise that pre-exposure to B. glabrata eggs in- 
creased the rate of destruction of such eggs by L. 
emarginata. The rate of egg destruction by "ex- 



posed" snails was found to be significantly greater 
than that of "non-exposed" snails when the data 
was analyzed by the Wilcoxsin rank test for un- 
paired measurements: p = 0.02. 
EXPERIMENT 4 

Selectivity of L. emarginata ./"or planorhid egg- 
masses. 

This experiment was designed to determine if L. 
emarginata was selective in its choice of egg- 
masses or would attack any planorbid egg-masses. 
Trials were set up as in Rxperiments 2 and 3, but 
used either H. caribaeum egg-masses or a mixture 
of H. c(tribacHm and B. glabrata masses. Results 
are summarized in Table 4 and indicate that L. 
emarginata preys only to a limited extent on the 
eggs of H. caribaeum. Moreover, when both tyjies 
of egg-ma.sses were presented simultaneously, only 
those of B. glabrata were eaten. 



Vol. 88 (4) THE NAUTILUS 105 

TABLE 4. Faiiiin' ofL. emarginata to dcMroii Helisoma caribaeum ('g(i-ma.<;<!f's. Kriicriincnf .',. 



Trial* 
and Egg 
type 



Eggs 



(masses) 



% eggs destroyed by day: 
12 3 4 



1. 
2. 

3. 
4. 
5. 
6. 

7. 



H. caribaeum 



H. 


caribaeum 


H. 


caribaeum 


H. 


caribaeum 


H. 


caribaeum 


H. 


caribaeum 


H. 


caribaeum 


B. 


and 
glabrata 


H. 


caribaeum 


B. 


and 
glabrata 



46 
46 
41 
53 
94 
88 

50 
53 
53 
52 



(3) 

(3) 

(3) 

(4) 

(10) 

(8) 

(4) 

(4) 

(3) 

(3) 










































1.9 


1.9 


1.9 











3.2 











6.8 














9.4 


34.0 


50.9 


64.2 





1.0 


1.0 


1.9 


5.4 


19.2 


21.2 


23.1 



"S snails were used in trials 1 + 2, 5 in trials 3 + 4. and 10 in all others. 
+ In these trials both t\T3es of egg-masses were placed in the same beaker. 



EXPERIMENTS 5 & 6 

Cdutriil (if B. glabrata populatinns by L. 
emarginata. 

The following series of experiments explore 
whether or not the predation exercised by L. 
( itKuyimita is sufficient to limit the growth of 
B. (jlabmta populations. Two 3-liter aquaria 
were set up so that "A" contained only 10 B. 
glabirita (mean diam. = 7.8 mm) and "B" con- 
tained 10 B. glabrata (mean diam. = 7.8 mm) 
plus 20 L. emarginata (mean alt. = 11.8 mm). 
Snails of both species were approaching sexual 
maturity at the onset of the experiment, and 
eggs deposited by both species w'ere permitted 
to hatch. The experiment ran for 6 wks, at 
which time all snails and egg-masses were iden- 
tified and counted. 

The results of- the experiment w'ere as 
follows: 1) aquarium "A" contained, in addition 



to the original 10 snails, 1225 new- B. glabrata 
and 59 egg-masses; 2) aquarium "B" contained 
10 and 16 respectively of the original snails, 
190 new B. glabrata, 244 new L. emarginata, 4 
B. glabrata egg-masses, and 8 L. emarginata 
egg-masses. Thus, in the presence of L. 
emarginata, B. glabrata increased only 19-fold 
as compared to a 122.5-fold in the control 
aquarium. In a replicate experiment, the B. 
glabrata population increased 11.5-fold in the 
mixed-species aquarium, whereas, the controls 
showed a 99.8 fold-increase. 

The previous experiment failed to rule out 
the possibility that the slower rate of growth of 
the B. glabrata population in the mixed-species 
aquarium was related as much to "crowding" 
by L. emarginata as to predation. Experiment 
6, therefore, was designed to determine if the 
"crowding phenomenon" (i.e., concomitant reduc- 
tion in growth and fecundity) observed in 



106 THE NAUTILUS 



October 25. 1974 



Vol. 88 (4) 



TABLE 5. TTie effect ofL. emarginata on the fecundity of a population of B. glabrata. Summary of ob- 
servations over a period of 9 weeks. Experiment 6. 



Criteria of 








Fecundity 


of Populations 






fecundity ° 


10 


B. glabr 
(A) 


ata 


10 
20 


B. 


glabrata + 
emarginata 

(B) 


30 


B, glabrata 

(c) 


Total egg-masses 




193 








llo 




323 


Total eggs* 




4509 








3098 




5572 


Mean eggs/snail 




459.4 








322.7 




186.4 



'In populations A and C, egg deposition began during the 3rd week of the experiment; in B during the 4th week. 
Based on mean number of surviving snails per week. 



crowded mono-specific populations of pulmonale 
snails (Chernin and Michelson, 1957; 
Szumelwicz, 19.58; Wright, 1960; Shiff, 1964; 
Jobin and Michelson, 1969; Sturrock and 
Sturrock, 1970) would also operate in mixed- 
species populations. Accordingly, three 3-liter 
aquaria were set up as follows: "A" with 10 B. 
glabrata, "B" with 10 B. glabrata and 20 L. 
emntr/inata and "C" with 30 B. glabrata. The 
experiment ran for 9 weeks and was replicated 
twice. Egg-masses were removed weekly and 
eggs counted. 

The results indicate that L. emarginata did 
not exert a "crowding effect" on the B. glabrata 
population with respect to growth (compare A 
and B in Fig. 1). However, the differences be- 
tween the means of populations A and C were 
highly significant when analyzed by the students 
"t" test; p = < .01. Egg production (per 
snail) of the isolated B. glabrata populations 
was, as expected, greater in the less crowded 
aquarium ("A") than in the more crowded 
aquarium ("C"); however, fecundity was lower 
than expected in "B" considering that the 
growth of the B. glabrata population was not 
inhibited by the presence of L. emargiiuita 
(Table 5). Replicate experiments gave essentially 
the same results. 



MISCELLANEOUS EXPERIMENTS 

Efforts to di^uise the egg-masses of B. 
glabrata by immersing them, for 1 hr. in an ex- 
tract prepared from L. tniarginata egg-masses 
failed to protect them from predation. 

To determine if a chemo-attractive substance 
was released by egg-masses of B. glabrata. we 
employed a plastic maze (Michelson, 19<i(l) and 
used as bait either intact egg-masses, punctured 
egg-masses, or filter paper discs impregnated 
with egg extracts. Eiich bait was tested in 21 
individual trials and employed a new snail (7.0- 
9.0 mm) for each trial. No evidence of a 
chemo-attractive response was elicited from L. 
emarginata. 

DISCUSSION 

Our data indicate that Lymnaea cmaniiiiata 
was effective in controlling laboratory 
populations of Binmphalaria glabrata. Control 
appeared to be exercised as a result of egg 
destruction, and was not associated with a reduc- 
tion of fecundit\' imposed by crowding. 
Although previous exposure to B. glabrata egg- 
mas.ses appears to enhance L. emarginata'ft 
ability to destroy eggs, "conditioning", in the 
sense that repeated exposures can be directly 



Vol. 88 (4) 



THE NAUTILUS 



107 



correlated with an increase in effectiveness, has 
not been demonstrated. Our observations sup- 
port the studies of Wells and Wells (1971) and 
of Cook (1971) that pulmonate snails can be 
sensitized, but are incapable of being con- 
ditioned. L. emarginata appeared to be able to 
differentiate between H. cnrihaeum and B. 
glabrata egg-masses, attacking only tho.se of the 
latter. However, we could detect no chemo- 
attractant emitted from the egg-masses of B. 
glabrata. and recognition may be tactile. In 
nature, L. emarginata and species of Helisoma 
occur together; whereas, species of Biomphalaria 
are restricted geographically to the tropics and 
sub-tropics. One might speculate, therefore, that 
the predation of B. glabrata egg-masses is an 
adaptive mechanism by which L. emarginata 
limits potential competitors. 

L. emarginata appears to be restricted to the 
Northern Temperate Region of North America 
and has been found rarely below 40° North 
Latitude (LaRocque, 1968; van der Schalie and 
Berry, 1973). Recently, van der Schalie and 
Berry (1973) have shown that this species, in 
the laboratory, has optimal longevity and 
reproductive potential at temperatures ranging 
from 22° -26° C; at temperatures approaching 
30° C, marked mortality occurs. It should be 
noted, however, that contrary to popular belief, 
many aquatic habitats in the Tropics rarely 
have temperatures which regularlv e.xceed 
28 C (Jobin, 1970). 

Although L. emarginata could be reared at 
tropical temperatures in the laboratory and 
showed no evidence of stress, there is no in- 
dication that the control exercised by this snail 
in the laboratory could occur under natural 
conditions. In fact, the ability of L. emarginata 
to serve as a host for non-human schistosomes 
(McMullen and Beaver, 1945) may preclude its 
use as a control agent. Nonetheless, in this era 
of environmental sensitivity, alternatives to 
molluscicides warrant further attention. 

LITERATURE CITED 

Burch, J. B., 1960a. Chromosome morphology of 
aquatic pulmonate snails (Mollusca: 
Pulmonata). Trans. Amer. Microscop. Soc, 
79:451-461. 

Burch, J. B., 1960b. Chromosome studies of 



aquatic pulmonate snails. The Nucleus, 
3:177-208. 

Chernin, E., E. H. Michelson, and D. L. 
Augustine, 1956. Studies on the biological 
control of schistosome-bearing snails. I. The 
control of Australorbis glabratux populations 
by the snail, Marim cornuarieti.'i. under lab- 
oratory conditions. Amer. Jour. Trop. Med. 
Hyg., 5:297-307. 

Chernin, E., and E. H. Michelson, 1957. Studies 
on the biological control of schistosome- 
bearing snails. III. The effects of population 
density on growth and fecundity in Austra- 
lorbis glabratus. Amer. Jour. Hyg., 65:57-70. 

Cook, A., 1971. Habituation in a freshwater 
snail (Limnaea t^tagnaiui). Anim. Behav., 
19:463-474. 

Demian, E. S., and R. G. Lutfy, 1965a. Preda- 
toi-y activity of Marisa cornuarietis against 
Bulinus (Bulinus) truncatus. the transmitter 
of urinary schistosomiasis. Ann. Trop. Med. 
Parasit. 59:331-336. 

Demian, E. S., and R. G. Lutfy, 1965b. Factors 
affecting the predation of Marisa romuarietis 
on Bulinus (B.) truncatus, Biomphalaria 
alexandrina and Lymnaea caillaudi Oikos, 
17:212-230. 

Inaba, A., 1969. Cytotaxonomic studies of 
lymnaeid snails. Malacologia, 7:143-168. 

Jobin, W. R., and E. H. Michelson, 1969. 
Operation of irrigation reservoirs for the 
control of snails. Amer. Jour. Trop. Med. 
Hyg., 18:297-304. 

Jobin, W. R., 1970. Population dynamics of 
aquatic snails in three farm ponds of Puerto 
Rico. Amer. Jour. Trop. Med. Hyg., 19:1038- 
1048. 

LaRocque, A., 1968. Pleistocene Mollusca of 
Ohio. Geological Surv. Ohio, Bull, 62. Pt. 
3, pp. 357-553. 

McMullen, D. B., and P. C. Beaver, 1945. 
Studies on schistosome dermatitis. IX. The life 
cycles of three dermatitis-producing schisto- 
somes from birds and a discussion of the sub- 
family Bilharziellae (Trematoda: Schisto- 
somatidae). Amer. Jour. Hyg., 42:128-154. 

Michelson, E. H., 1957. Studies on the biological 
control of schistosome-bearing snails. Predators 
and parasites of freshwater Mollusca: A review 
of the literature. Parasitology, 47:413-426. 



108 THE NAUTILUS 



October 25, 197 



Vol. 88 (J) 



Michelson, E. H.. 1960, Chemoreception in the 
snail Auatralorbis glabratus. Amer. Jour. 
Trop. Med. Hyg.. 9:480-487. 

Michelson, E. H., 1966. Specificity of hemo- 
lymph antigens in taxonomic discrimination 
ot medically important snails. Jour. Parasit., 
52:166-472. 

Oliver-Gonzalez, J., P. M. Bauman, and A. S. 
Benenson, 1956. E^ffect of the snail Marim 
ciirnnarietis on A>i><trrilnrbis glabratuti in 
natural bodies of water in Puerto Rico. 
Amer. Jour. Trop. Med. Hyg., 5:290-296. 

Oliver-Gonzalez, J., and F. F. Ferguson, 1959. 
Probable biological control of Schistosomiasis 
niansom in a Puerto Rican watershed. Amer. 
Jour. Ti-op. Med. Hyg., 8:5(;-:)9. 

Olivier, L.. and W. T. Haskins, 1960. The 
effects of low concentrations of sodium penta- 
chlorophenate on the fecundity and egg 
viability of Australorbis glabratus. Amer. 
Jour. Trop. Med. Hyg., 9:199-205. 

Owen, G., 1966. Feeding. Chapt. I in Physioloyn 
of Molluscs ed. K. M. Wilbur and C. M. 
Yonge, vol. II, Academic Press, New York 
and London. 

Paulinyi, H. M., and E. Paulini, 1972. Labora- 
tory observations on the biological control of 
Biomphalnria glabrata by 2 species of 
Pomncea (Ampullariidae). Bull, World Health 
Org.. 46:243-247. 

Radke, M. G., L. S. Ritchie, and F. F. 



Ferguson, 1961. D monstrated control of 
Australorbis glabratus by Marisa cornuarietis 
under field conditions in Puerto Rico. Amer. 
Jour. Trop. Med. Hyg., 10:370-373. 

Shiff. C. J., 1964. Studies on Bulinus 
(Physo'psis) globosus in Rhodesia. II. Fac'ir 
influencing the relationship between rate and 
growth. Ann. Trop. Med. Parasit., 58:106-115. 

Sturrock, R. F., and B. M. Sturrock, 1970. 
Observations on some factors affecting the 
growth rate and fecundity of Biomphalnria 
glabrata. Ann. Trop. Med. Parasit., 64:349- 
355. 

Szumlewicz, A. P.. 1958. Studies on the biology 
of Australorbis glabratus. schistosome-bearing 
Brazilian snail. Rev. Mai. e. Douncas Trop., 
9:495-529. 

Van der Schalie, H., and E. G. Berry 1973. The 
effects of temperature on growth and repro- 
duction of aquatic snails. Sterkiana, No. 50, 
92 pp. 

Walter, H. J., 19(i9. Illustrated biomoi-phology 
of the 'Augnlota" like form of the basomma- 
tophoren snail Liimyiaea catascnpinm Say. 
Malacological Review, 2:1-102. 

Wells, M. J., and J. Wells, 1971. Conditioning 
and sensitizaMon in snails. Anim. Hehav., 
19:305-312. 

Wright, C. A., 19* ftie crowding phenomenon 
in laboratory c inies of freshwater snails. 
Ann. Trop. Ml-' ^'arasit.. 54:221-232. 



BOOK REVIEW 



DICIONARIO CONQUILIO e MALACOLOGKU 
Bg Maury Pinto dc Oliveira and Maria 
Helena Rodriques de Oliveira. 197i. 190 
pp. Mimsterio da Educa^ao. Univ. Fcdrnd 
Juiz de Fora, Miims Gerais, Brazil. Paper- 
back. 



Tliis handy dictionary and glossary of con- 
chological and anatomical terms will serve 
well those who consult the Portuguese litera- 
ture of mollusks. Also included are the Portu- 
guese names for various geographical regions. — 
A'. Tuvkcr Ahhott. 



Vol. 88 (1) 



THE NAUTILUS 



109 



DEVELOPMENT OF BROOD SACS IN MUSCULIUM 
SECURIS BIVALVIA: SPHAERIIDAE 

G. L. Mackie', S. U. Qadri and A. H. Clarke" 

Biology Department, University of Ottawa 
Ottawa, Ontario, Canada 

ABSTRACT 

In Musculiuni securis (Prime) brood .sar.s develop from and remain associated 
with certain filaments of the inner gill. Brood sacs do not migrate along 
the filamenU as reported in the literature for other species of Sphaeriidae, 
but remain stationary. The brood sacfilament relationship enables detennina- 
tions of the numbers of litters produced by back-calculation of brood sacs. 



INTRODUCTION 

Sphaeriids are ovoviviparous with the ferti- 
lized egg developing in brood sacs on the inner 
gill of the parent until the young are mature 
enough to be released to the outside. Okada 
(1935) and Gilmore (1917) have described the 
structure and development of three types of 
brood sacs (primary, secondary, and tertiary) 
which occur during larval development of 
sphaeriids. The development of brood sacs in 
M. secmis is markedly different from descrip- 
tions in the literature of other sphaeriids but 
the structure appears to be similar. The pre- 
sent paper reports these differences and des- 
cribes the significance of brood sac development 
in life history studies. 

MATERIALS AND METHODS 

Four populations of M. securis were studied. 
Two populations were from temporary forest 
ponds, one from a permanent pond, and the 
fourth from a river bed. All habitats are within 
a 45 km radius of Ottaw-a, Ontario, and are 
described by Mackie (1973). Samples of 30-100 
clams were removed from each habitat usually 
at two week intervals during the summer and 
one month intervals during the winter. Each 
specimen was isolated and preserved in a two 
dram vial containing HT/n ethanol. 

The shell length (anterior to posterior) of 
each adult was measured to two decimal 



OOBSOANTEBIOR Fnr.r qf 




'Present address: Department of Zoology, Universit.\- of 
Guelph. Guelph. Ontario. Canada. 

- Present address; National Museum of Natural Sciences, 
National Museums of Canada. Ottawa, Ontario. Canada. 



FIG. 1. Position of the brood sacs and their 
relation to the gill filaments of the inner gill. 
DF: degenerating filaments. DPS: developing 
primary sac. E: embryo. FL: fetal larvae. 
IG inner gill, OG outer gill PGF gill fila- 
ments supporting primary sac. PL: prodis- 
soconch larvae. PS: primary sac. SGF: gill fila- 
ments supporiing secondary sac: SS secondary 
sac. TGF: gill filaments supporting tertiary 
sac. See text for explanation of a, b. c. d e. 
and f 

places in millimeters with a Precision Tool 
and Instrument Co., Ltd. microscope micro- 
meter, model 14. The left and right inner gills 



110 THE NAUTILUS 



October 25, 1971 



Vol. 88 (4) 



£ 6 
E 



2 5H 

UJ 
01 

I/) 
< 

UJ 

2 4 

u 
< 

§3 

O 
cc 

Q 

z 2 
< 



O 



oH 




Height a- f 



Height a-c 

Height Q-b 



LENGTH OF 

FIG. 2. Growth of the inner gill and various 
aspects of the first and second brood sacs in 
relation to growth in shell length of parenbi 
of Musculium securis. See text and Fig. 10 
for explanation of af. a-b, e-f and df. 

were excised from each parent and the brood 
sacfilament relationship was determined in the 
following manner. Filaments were numbered 
consecutively beginning at the dorso-anterior 
edge of the gill (Fig. 1). Brood sacs were des- 
ignated as first, second, third, or fourth, depen- 
ding on the sequence in which they developed. 
Data was recorded to show which brood sac 
was associated with which filaments in each 
parent. 

In addition, several measurements were taken 
to determine the relationship between the 
growth in height of inner gills and brood sacs 
and the growth in .shell length of parents. 
Referring to Fig. 1, the total height of the gill 
(a-f) and the height of brood sacs (b-d and 
c-e), were measured in parents of several ages. 
Only the first two sacs were measured because 



4 

PARENT 



— r- 
5 



Height e-f 
Heiijiht d-f 



mm 



M. securis usually produces only two litters 
(Mackie, 1973). The lengths a-b, a-c and d-f. 
e-f are measures of growth of first and second 
brood sacs in the dorsal and ventral directions, 
respectively. 

There were no significant differences (P>fl.05) 
in the brood sacfilament relationship nor in the 
relationship between the growth of gills and 
brood sacs and the growth of parents among 
populations. Therefore, clams from each habitat 
were combined and treated as a sample popu- 
lation. 

RESULTS 
In M. securis the brood sacs are associated 
with certain filaments of the inner gill (Fig. 1). 
Of an estimated 10,000 brood sacs examined, 
all develop from either two or three gill fila- 
ments. Counting down from the dorso-anterior 
edge of the gill (Fig. 1), the first sac usually 
develops on the 7th and 8th gill filaments, the 
second on the 9th and 10th, the third on the 
11th and r2th, and the fourth on the i;3th and 



Vol. 88 (4) 



THE NAUTILUS 



111 



14th gill filaments. Each sac remains associated 
with the filaments from which it arises until 
the sac ruptures, releasing the enclcsed pro- 
dissoconch larvae. Occasionally brood sacs de- 
velop from three filaments so that the first 
sac is on filaments 7, 8, 9, the second on 10, 11, 
the third on 12, 13, and the fourth on 14, 15, 
16 or the first is on 7, 8, and the second on 
9, 10, 11, the third on 12, 13, and the fourth on 
14, 15, 16. Nearly all combinations of gill fila- 
ments occur e.xcept two adjacent sacs each co- 
cupying three filaments. 

Measurements of 150 parents showed that the 
growth of brood sacs and gills are directly 
related to the growth of parents (Fig. 2). 
Also the growth of brood sacs is linearly re- 
lated to the growth of gills (Fig. 2). The dis- 
tance between the dorsal edge of the gill 
(a. Fig. 1) and the dorsal edge of the first 
sac (b. Fig. 1) decreases with increasing age 
of the parent, indicating that the sac advances 
dorsally (Fig. 2). However, the distance between 
the ventral edge of the first sac (d, Fig 1) 
and the ventral edge of the gill (f. Fig. 1) 
remain constant and is exactly one half 
the length of the gill in all parents (Fig. 2). 
Since the gill grows in a ventral direction 
(Raven, 1958), the brood sacs must advance 
in the ventral direction at an identical rate. 

DISCUSSION 

Okada (1935) does not associate the brood 
sacs with gill filaments in M. heterodon but 
maintains that "the sac moves upwards along 
the descending lamella" by formation and re- 
formation of new sac stalks. This does not 
occur in M. securis since the ventral edge of 
the sacs advance ventrally (i.e. dowTiwards) 
at an identical rate of the growth of gills. More- 
over, there is no evidence of the sac stalks 
forming and reforming since the sacs are 
always attached dorsally and ventrally to the 
gill filaments. Okada (1935b) also states that 
the sacs move from "the lower part to the upper 
part of the branchial chamber". This cannot 
occur in M. securis because the sacs remain 
attached to the filaments from which they 
arise. Rather, the sacs merely enlarge with 
the growth of the enclosed larv^ae. 

Since brood sacs are associated with certain 
gill filaments, the numbers of litters produced 



by a parent can be determined by back cal- 
culation of brood .sacs. Thus, parents that have 
produced one litter will not have brood sacs 
on filament numbers 7 and 8, but will have 
brood sacs on filaments 9-14, 9-15, or 9-16. 
Similarly, parents that have produced two lit- 
ters will not have brood sacs on filament num- 
bers 7 and 8 nor on 9 and 10. This technique 
can be applied to parents in which brood sacs 
develop from two filaments. For parents in 
which brood sacs develop from three filaments, 
two litters were produced if filament numbers 
7, 8, 9, 10. 11 have no brood sacs (we have 
never seen the 12th filament used in the for- 
mation of the second brood sac), three litters 
if filament number 7-13 inclusive (or 7-14 
inclusive) have no brood sacs. Usually sac 
remnants remain to determine whether a sac 
has developed from two or three filaments. Lf no 
sac remnants are present, one only needs to refer 
to filament numbers 8, 10, and 12, since they are 
always present in the formation of the first, second 
and thrid brood sacs, respectively, regalrdless of 
the number of filaments used in sac development. 
If indeed the 12th filament is used in the develop- 
ment of the second brood sac, errors would be 
introduced into the estimation of the third and 
fourth litters. This is particularly true if sac rem- 
nants are not present to determine the number of 
filaments used in sac development. 

ACKNO WLEDGEM ENTS 
The research was supported by the National 

Research Council of Canada, Grant No. A 

2386 awarded to S. U. Qadri. 

LITERATURE CITED 

Gilmore, R. J. 1917. Notes on reproduction and 
growth in certain viviparous mussels of the 
family Sphaeriidae. The Nautilus 31: 16-30. 

Mackie, G. L. 1973. Biology of Musculmm 
securis (Pelecypoda: Sphaeriidae) in two 
temporary forest ponds, a river, and a perm- 
anent pond near Ottawa, Canada. PhD dis- 
sertation, University of Ottawa, Ottawa. 175p. 

Okada, K. 1935. Some notes on Musculium hetero- 
don (Pilsbry), a freshwater bivalve. II. The gill, 
breeding habits and marsupial sac. Sac. Rpt. 
Tohoku Imp. Univ. Ser. 4, Biol. 9: 375-391. 

Raven, C. P. 1958. Morphogenesis: the analysis 
of molluscan development. Pergamon Press, New 
York. 311 p. 



11-2 THE NAUTILUS 



October 25. 1974 

DESTRUCTION OF KELP PCjI'ULA^'ONS 
BY LACUNA VINCTA (MONTAGU) 

Richard A. Fralick. Kenneth W. Turgeon and Arthur C. Mathieson 

JacLson Estuarine kibn'atury 

University of New Hampshire, Adams Point 

New Hampshire 03824 



Vol. 88 (4) 



1,2 



ABSTRACT 

,4 localized po/julation expansion of Lacuna vincta (MuntayiiJ 
has caused a marked depletion of kelp populations near Newcastle Island, 
New Hampshire. .4.s many as 277 snails per Laminaria plant were observed. 
Tfie stipes and blades of Laminaria plants become riddled with holes (up 
to 12 holes/25 cm^) from L. vincta; eventually only residual holdfasts and 
stipes remain. A grazing rate of 0..i26 cm- of Laminaria saccharina blades/ 
snail/day was recorded in the laboratory. Respiration studies indicate that 
L. vincta is an osmoconforming species with a salinity optimum of about 
25 %o. It is suggested that the popndation increase of L. vincta may have been 
initiated after a period of extensive rainfall, - i.e. reduced salinities. Lacuna 
vincta may be a major grazer of seaweeds in a variety of locations. 



WTiile conducting subtidal studies of the benthic 
marine algae of New Hampshire we have 
observed extensive grazing of Laminaria 
populations by the prosobranch gastropod. 
Lacuna vincta (Montagu). The gastropod is a 
small (L0-L5 mm wide and L0-L8 mm long) lit- 
torinid snail (Fig. 1) that is often found in 
limited numbers on kelps and other seaweeds 
along the northeast coast of North America 
(Miner. 1950). During 1972 we have obsen'ed a 
"population e.xplosion" of L. vincta at Newcastle 
Island. New Hampshire (43° 04' 05" Latitude 
and 70 ° 42' 45" Longitude), and a marked 
depletion of in situ kelp beds. Subsequently we 
have seen continued destruction of kelp 
populations at Newcastle Island, as well as at 
adjoining open coastal and estuarine sites in 
Southern Maine and New Hampshire. 

In June, 1972, we examined 64 randomly 
collected specimens of Laminaria saccharina 
and L. digitata within a 100(.) m" area at 
Newcastle Island at 3 to 6 m below mean low 
water. All of the plants exhibited severe 
damage, for their fronds and stipes were rid- 
dled with round or ellipsoidal holes that were 



;3-10 mm in diameter (Fig. 2 and 3). As many 
as 12 holes per 25 cm' were found on many 
blades. The majority of the holes penetrated 
through the entire plant(s). In most cases the 
blades were more heavily grazed than other 
portions of the plants. The intercalary 
meristem, or the transitional zone between the 
blade and stipe, was rarely damaged. At sites 
with heavy grazing only residual holdfasts and 
stipes of Laminaria were present. 

During July, 1972 we found as many as 277 




FIG. 1. Two New Hampshire specimens of 
Lacuna vincta (Montagu). 30 X. 



Published as .Jackson Estuarine Lab<iratory Scientific 
Contribution Number 2. 



Published with the approval of the Director of the New 
Hampshire .Agricultural Experiment Station as Scientific 
G)ntribution Number (iTT ■ 



Vol. SS (1) 



THE NAUTILUS 



U:] 



snails per Laminai'ia saccharina plant at 
Newcastle Island - at 3 to 6 m below mean low 
water. In the early part of the summer few 
snails were fovmd on the understory vegetation 
beneath the kelp canopy. However, as the sum- 
mer progressed a variety of economically im- 
portant species such as Chondru^ fr/,s'p(;,s, Gigar- 
tina stellata and Rhodymenia palmata 
(Mathieson, 1969) also showed extensive grazing 
by Lacuna vincta. 

Kain (1971) and R. Waaland (personal com- 
munication to A.M.) also report abundant 
populations of L. vincta on seaweeds in Norway 
and Washington, U.S.A., respectively. Thus, 
Lacuna may be a major grazer of seaweeds in a 
variety of locations. Kain and Svendsen (1969) 
record e.xtensive grazing by the gastropod 
Patina pellucida on Laminaria hyperborea in 
western Norway and Great Britain: they state 
that P. pellucida may cause considerable loss of 
plants due to weakening of the holdfast or 
damage to the frond or stipe. In Great Britain 
they observed that the animals initially settled 
on the frond and then migrated to the holdfast, 
where they created large cavities. Preliminary 




observations indicate that L. vincta may show a 
similar pattern of attachment and migration on 
New England kelps. According to Kain (1971) 
0. Vahl (unpublished daUi) has found con- 
siderably higher densities of L. vincta than P. 
pellucida on Laminaria hijpcrborpa populations 
in Norway, and the holes it makes are much 
deepei' than those of P. pellucida. 

Preliminary culture e.xperiments were con- 
ducted in August and September, 1972, in order 
to determine grazing rates of L. vincta on 
Laminaria sacchaiina. A small section of 
frond (25 cm") was p'aced in a crystallizing 
dish with 200 ml of filtered sea water (30 %.) 
and 10 snails. The dishes were incubated at 
300-400 foot-candles and at 10° C in a Sherer- 
Gillete Incubator. After 5 days the fronds were 
remeasured and the consumption of plant mate- 
rial was determined. An average grazing rate of 
0.326 cm'-'snail/day was recorded. It should be 
emphasized that this is an approximation and 
further studies should be conducted to deter- 
mine the effects of differential temperatures, 
salinities and plant materials on grazing. 

Respiration rates of L. vincta at IOC and in 
three different salinities (20, 25, and 30 %, ) 
were measured in a Gilson Differential 
Respirometer (Model GRP-14), according to the 
methods outlined by Mathieson and Burns 
(1971). The temperature was maintained at 
about 0.1 C; it was the same as the ambient 
temperature when the snails were collected. 
Two flasks containing ten snails per flask were 
run at each of the test salinities. The 
respiration rates for the three salinities were 
recorded simultaneously in the same in- 
strument. Figure 4 illustrates the results of the 




i !</< 




FIG. 2. A Laminaria saccharina plant showing 
severe damage from L. vincta. 



FIG. 3. A stipe of Laminaria saccharina 
riddled by L. vincta. 



114 THE NAUTILUS 



October 25, 1974 



Vol. 88 (4) 



150' 



> 

"5 

o 

t— 

E 
O 



100' 



50' 



20 25 

SALINITY (%o) 



30 



FIG. 4. Respiration of L. vincta at lOC and 
in three different salinities. 

experiment. The lowest respiration rates were 
found at 20 %« and the highest was recorded 
at 25 %o . The results suggest that L. viwta is 
an osmoconforming species with a salinity op- 
timum of about 25 %o. 

In conclusion the extensive grazing of 
seaweeds at Newcastle Island, New Hampshire, 
appears to be directly associated with a 
localized population expansion of L. vincta. Our 
laboratory studies confirm the field observations 
that L. vincta was the causative organism. It 
should be emphasized that previous seasonal in- 
vestigations at Newcastle Island (Mathieson, et 
ai. in press) have never shown extensive 
seaweed grazing by L. vincta It is suggested 
that the population increase of Lacuna may 
have been associated with a spring season 



(1972) with abnormally high rainfall, and thus 
periods of reduced salinities. Our respiration 
studies confirm the tolerance of L. vincta to 
low salinity regimes recorded prior to the 
period of severe grazing. It is apparent that 
further studies of gastropod/algal grazing 
should be conducted in the New England area. 

ACKNO WLEDGEM ENTS 

We would like to thank Dr. R. D. Turner. 
Museum of Comparative Zoology, Han'ard 
University and Dr. R. T. Abbott, Delaware 
Museum of Natural History, for confirming 
the identification of Lacuna vincta and en- 
couraging our study of its grazing on seaweeds. 

LITERATURE CITED 

Kain, J. M. 1971. Synopsis of biological data on 
Laminaiia hypeborea, FAO, United Nations, 
Fisheries Synopsis no. 87, 63 pp, Rome. 

Kain, J. M. and P. Svendsen. 1969. A note 
on the behavior of Patina pellacida in Bri- 
tain and Norway. Sarsia 38: 25-30. 

Mathieson, A. C. 1969. The promise of seaweeds. 
Oceanology International Jan./Feb., pp 37-39. 

Mathieson, A. C. and R. L. Bums. 1971. Ecology 
of economic red algae. I. Photosynthesis 
and respiration of Chondnis crispus Stack- 
house and Oigartina stellata (Stackhouse) 
Batters. J. Exp. Mar. Biol. Ecol. 7: 197-206. 

Mathieson, A. C, E. Hehre and N. B. Reynolds. 
Investigations of New England marine algae 
I. A floristic and descriptive ecological study 
of the marine algae at Jaffrey Point, New 
Hampshire. Nova Hedwigia (in press). 

Miner, R. W. 1950. Field book of seashore 
life. G. P. Putnam's Sons, New York, 888 pp. 



Vol. 88 (4) 



THE NAUTILUS 



115 



ROLE OF THE INCURRENT SIPHONAL VALVE IN THE SURF CLAM. 
SPISULA SOLIDISSIMA (MACTRIDAE) 

David J. Prior 

School of Biological Sciences 

University of Kentucky 
Lexington, Kentucky 40506 

ABSTRACT 

Observations of the behavior of the surf clam, Spisula solidissima have indicated 
that debris such as sand may be entrapped in the incurrent siphon cavity temporarily 
before being expelled by a jet of ivater from the mantle cavity. Vie morphology 
and responses of the incurrent siphonal valve are well suited for mediation of a pos- 
sible sand storage behavior. The incurrent siphonal valve is positioned across the 
opening between the incurrent siphon cavity and the mantle cavity, hence can. when 
extended, separate the two caiitie.s. Extetmon (closing) of the valve occurs in response 
to mild tactile stimulation of the siphons. Contraction (opening) of the valve only 
occurs in response to strong tactile stimtdation. The responses of the incurrent si- 
phonal valve and the adductor muscles (which cause the jet of ivater) are co-ordinated 
in such a way that during the cleaning reflex the valve is open when shell valve 
adduction occurs thus allowing free passage of water out of the mantle cavity. 



While studying the neural control of siphon 
withdrawal in the surf clam, Spisula solidissima 
(Dillwyn), it was necessary to examine siphonal 
behavior in detail, (Prior, 1972). 

The siphons of Spisula respond in a 
progressively more complex fashion as the in- 
tensity of tactile stimulation of the siphonal 
tentacles (papillae) is increased. In response to 
touching a single siphonal tentacle with a glass 
stylus the siphon apertures close (a local reflex 
mediated by peripherally located neurons). As 
the intensity of tactile stimulation is increased 
(touching several tentacles or the inner wall of 
the incurrent siphon) the siphon musculature 
responds with progressively greater contractions 
until finally, the siphon retractor muscles 
respond, withdrawing the siphons into the man- 
tle cavity. 

Often in response to gentle tactile 
stimulation, such as touching several tentacles, 
siphon closure is rapidly followed by con- 
traction of the adductor muscles, which by 
drawing the shell valves together, cause the ex- 
pulsion of a jet of water out the incurrent 
siphon (the excurrent siphon remains closed). 
This "Cleaning reflex" occurs regularly and 



serves to eliminate feces and debris, such as 
sand, drawn in through the incurrent siphon. 

In one of the very few reports on ob- 
servations of Spisula in their natural habitat, 
Jacobson (1972) describes the siphonal behavior 
of young individuals in a sandy intertidal zone. 
During the intei-wave periods the clams kept 
their siphons open. But in response to each 
sand laden wave, the siphons were observed to 
close rapidly. The siphons remained closed until 
the sand settled and was no longer being roiled 
about. Jacobson further noted that at somewhat 
regular intervals a small jet of water, laden 
with sand grains, was ejected from the in- 
current siphon (the cleaning reflex). Jacobson 
points out that this cleaning reflex is of adap- 
tive value in that it minimizes the build up of 
sand in the mantle cavity. Furthermore, he 
suggests that sand is probably stored briefly in 
the incurrent siphon before being expelled, as a 
further means of preventing accumulation in 
the mantle cavity. 

The present report describes the anatomy and 
general responses of a muscular flap of tissue 
(incurrent siphonal valve) in Spisula that is 
positioned across the opening of the incurrent 



116 THE NAUTILUS 



October 25, 1974 



Vol. 88 (4) 




SRM 



FIG. 1. .4 schematic of the posterior end of a 
clitni with the incurrent siphon (IS) and 
excinrtnt siphon (ES) in an extended positian. 
One of the siphon retractor muscles (SRM), 
ivhich adhere to the inner surface of the shell 
valves, is indicated. The incurrent siphonal 
valve (ISV; stipled) is shown patiialbj extended 
across the opening between the siphan cainty 
and the mantle cavity. The incmrent siphonal 
valve is attached to the lateral walls of the in- 
current siphon and to the septum between the 
incurrent and excurrent siphons. 



siphon leading to the mantle cavity (a 
detailed report of the electrophysiological 
properties of the muscle fibers will appear 
separately; Prior, 1974). This valve is attached 
to the base of the muscular wall separating the 
two siphonal cavities and to the lateral walls of 
the incurrent siphon cavity (Fig. 1). The valve 
protrudes across (partially occluding) the inner 
incurrent siphon opening. The incurrent 
siphonal valve is composed of two bundles of 
smooth mu.scle fibers and a diffuse array of 
muscle fibei-s sandwiched between two layers of 
epithelium (Fig. 2). 

The activity of the incurrent siphonal valve 
was examined by removing from the animal the 
entire siphonal apparatus (mantle musculature, 
siphon retractor muscles and intact visceral 
ganglion) to a wa.x dish of cold (10° C) sea 
water. With this sort of arrangement the ten- 
tacles and inner walls of the siphons could be 




FIG. 2. This is an illustration of the incinrent 
siphonal valve (ISV) as seen by looking into the 
t'xttnial ixj)ening of the incurrent siphon (see 
arrow in Figure 1.}. The ISV (stipled area) is 
composed of a pair of distinct valve muscle 
bundles (VMB) and diffuse muscle fibers that 
are spread throughout the valve sandwiched 
between two epithelial layeis. 

tactily stimulated while observations were being 
made on the activity of the siphonal valve. 

In response to gentle tactile stimulation of 
siphonal tentacles the dispersed muscle fibei-s of 
the valve contract, resulting in extension of the 
flap across the incurrent siphon cavity. This 
movement of the valve effectively separates the 
incurrent siphon cavity from the mantle 
cavity. 

In response to stronger tactile stimulation 
(e.g. poking the siphon wall with a stylus) the 
paired muscle bundles of the valve contract in 
synchrony. The contraction of these muscle bun- 
dles causes withdrawal of the valve; thus 
opening the passage between the siphon and 
mantle cavities. 

It is interesting to note that in the intact 
animal, the cleaning reflex requires contraction 
of the incurrent siphonal valve to allow egress 
of the jet of water from the mantle cavity. 
Equally pertinent is the fact that the neurons 
controlling the posterior adductor muscle (the 
contraction of which is involved in the ex- 
pulsion of water from the mantle cavity) are 
activated only by strong tactile stimulation 
(Mellon. 1967; Mellon and Prior, 1970). The 



Vol. 88 (4) 



THE NAUTILUS 



117 



activity of these motoneurons (hence the 
posterior adductor muscle) is inhibited by weak 
tactile stimulation of the siphons. Therefore, 
a correlation exists between the responses 
of the motoneurons that activate the adductor 
muscle (involved in the explusion of water 
in the cleaning response) and the responses 
of the siphonal valve muscle which must be 
open to allow the exit of water. 

The responses of the incurrent siphonal valve 
are in concert with the responses of the adductor 
muscle, both contracting in response to strong 
tactile stimulation. 

On the basis of the foregoing observations, 
I suggest that the incurrent siphonal valve might 
temporarily entrap sand particles, thus pre- 
venting their entrance into the mantle cavity. 

The siphonal valve could respond to sand 
grains falling on the siphons (presumably a weak 
tactile stimulus) by extending across the incur- 
rent siphon cavity, entrapping the sand within 
the cavity. A subsequent contraction of the 
adductor muscles, synchronized with contraction 
(opening) of the siphonal valve muscle bundles, 
would expel a jet of water and the previously 
entrapped sand; the cleaning reflex. 

Thus, the incurrent siphonal valve seems well 
suited for mediation of the "sand storage" sug- 
gested by Jacobson on the basis of behavioral 
observations. 



A portion of this study was done at the Marine 
Biological Laboratory, Woods Hole, Massa- 
chusetts. This work was supported by NIH 
Biomedical Sciences Support Grant 5 S()5 
RRO7114-06 to the University of Kentucky and 
a Grass Foundation Fellowship in Neuro- 
physiology. 

LITERATURE CITED 

Jacobson, M. K., 1972. Observations on the 
Siphonal Behavior of Young Surf Clams, 
Spisula Solidissima. The Nautilus 86 (l):25-26. 

Mellon, DeF., 1%7. Analysis of Compound Post- 
synaptic Potentials in the Central Nervous 
System of the Surf Clam. Jour. Gen. Physiol. 
50 (3):759-778. 

Mellon, DeF. and Prior, D. J., 1970. Comixjnents 
of a Response Programme Involving Inhibitory 
and Excitatory Reflexes in the Surf Clam. 
Jour. Exp. Biol. 53:711-725. 

Prior, D. J., 1972. Electrophysiological Analysis 
of Peripheral Neurons and Their Possible 
Role in the Local Reflexes of a Mollusc. 
Jour. Exp. Biol. 57: 133-145. 

Prior, D. J., 1972. A Neural Correlate of Stimulus 
Intensity Discrimination in a Mollua-. Jour. 
Exp. Biol. 57:147-160. 

Prior, D. J., 1974. An Analysis of Electro- 
physiological Properties of the Incurrent 
Siphonal Valve Muscle of the Surf Clam. 
Spisula solidissima (in press). 



BOOK REVIEW 



OYSTERS (TREATISE ON INVERTEBRATE 
PALEONTOLOGY). By H. B. Stenzel. 1971. 
Part N, Bivalvia, vol. 3. pp. 953-1221 153 pis. 
in text. Geological Society of America. P. 0. 
Box 1719. Boulder. Colo. 80302. 

This excellent and well-illustrated systematic 
treatment of the subfamily Ostreina appeared 
three years ago but is still deserving of a re- 
view. Nearly half of the volume is a splendid 
treatment of the anatomy, distribution, ecology 
and phylogeny of the oysters. New genera and 



subgenera are proposed, including Hyotissa 
for Mytilus hyotis Linne, and Neopycnodonte 
for Ostrea cochlear Poli. Our Caribbean Coon 
Oyster, formerly Ostrea frons Linne, is now in 
the genus Lopha Roding and the subfamily 
Lophinae. The volume contains an index and 
errata and revisions to the earlier two bivalve 
volumes 1 and 2 of Part N. 

R. Tucker Abbott 
Delaware Mvseum of Natural History 



118 THE NAUTILUS October 25, 1974 Vol. 88 (4) 

SECOND LOCALITY RECORD FOR MESODON LEATHER WOODI PRATT 

Donald W. Kaufman 

Department of Zoologj-, University of Texas 
Austin, Texas 78712 



Mesodnn leatheru'oodi Pratt was recently 
described from specimens collected at a single 
locality in western Travis County, Texas (Pratt, 
1971). It is of interest to report the occurrence 
of M. leatherwoodi in the Pedernales Falls 
State Park, Blanco County, Texas which is 
approximately 13 miles upstream from the type 
locality. Four specimens were found near the 
Pedernales Falls within 1 m of each other at 
the base of a large rock on August 6, 1972. The 
collection site was above flood debris along the 
river suggesting that the snails were from the 
general area of the Falls, although, the shells 



may have been washed down from the oak- 
juniper community higher on the river bank. 

The specimens have been deposited in the 
collection of the Foil Worth Museum of Science 
and History (catalog number 94V-3101). W. L. 
Pratt verified the identification of the 
specimens. 



LITERATURE CITED 
Pratt, W. Lloyd. 1971. Mesodon leathenvoodi 
a new land snail from central Texas. The 
Veliger 13 (4): 342-343; 1 pi. 



INDO-PACIFIC 
MOLLUSCA 

MONOGRAPHS OF THE MARINE MOLLUSKS OF 

THE WORLD WITH EMPHASIS ON THOSE OF 

THE TROPICAL WESTERN PACIFIC 

AND INDIAN OCEANS 

The most technical and most beautifully illustrated 
jdurnal now being published on Recent and Tertiary marine 
mollusks. Over 20 professional malacologists are currently 
contributing. Edited by R. Tucker Abbott. Among the 
groups treated are Strom bidae, Cassidae, Tridacnidae, Tur- 
ridae. Littorinidae. Phasianellidae, Patellidae, Harpidae, 
and soon to come. Mitridae. 

\?suc<\ to date in l(Hiseleaf form with three sturdy, perm- 
anent binders — ]'M> pages, S)i)7 plates (4.3 in full color). 
Limited number of complete sets left. $10.5.90 U.S. (foreign: 
.$108.00), postage paid. Any numbers of extra binders 
available at $6.00. 



Published by 
The Delaware Museum of Natural History, Box 3937, Greenville, Delaware 19807 U.S.A. 




Vol. 88 (4) 



THE NAUTILUS 



119 



DEATH NOTICE 

We regret to announce the death of John 
Quincy Burch, at Seal Beach, California, on 
August 7, 1974, at age 80. An obituary is 
planned for a future number of The Nautilus. 
Further information is found on page 220 of 
American Malacologists. 



NEWS 

Research on an index patterned after C. D. 
Sherborn's INDEX ANIMALIUM is underway 
at the National Museum of Natural History, 
Washington, D. C. 20560, U.S.A. The coverage 
is Mollusca only, and plans are to include 
original references for names of species and 
subsequent references to publications including 
illustrations. The period of chronological 
coverage begins in 1850, where Sherborn ended, 
and continues through 1870 to provide an over- 
lap with the ZOOLOGICAL RECORD. 

Persons having knowledge of or access to 
obscure pertinent references are invited to 
correspond with the compiler, Florence A. 
Ruhoff, Department of Invertebrate Zoology, 
Mo Husks. 



American Malacologists has proved to be very 

useful and interesting book for all those who 

correspond with other collectors or those who 
do research on the history of malacology. 




american malacologists 



EDITOR-IN-CHIEF 
R. Tucker Abbott 
duPont Chair ol 
Malacology, 
Delaware Museum 
ol Natural History 



a national register of living 
professional and amateur 
conchologists 



$12.50 



plus biographies of 500 great, 

as well as little-known, 

American malacologists of the past 



American Malacologists 

P.O. Box 4208 
Greenville, DE 19807 



AMERICAN MALCOLOGISTS 
1975 Supplement 

The managing editorship and main office of 
the national register of amateur and professional 
malacologists have now been entirely trans- 
ferred to Dr. R. Tucker Abbott, P. 0. Box 
4208, Greenville, Delaware, 19807. All cor- 
respondence, listings, and orders should be 
sent to the new address. 

A supplement for 1975 is now being prepared 
and will be ready for mailing in early spring. 
The cost will be only $1.00, and it will con- 
tain address changes and a listing of the 
names, address and interests of new registrants. 
A special discount of 20% is now offered on 
the purchase of the 1974 hardbound, 494-page 
volume to those who send in for a free appli- 
cation form. The new reduced price is $10.00, 
plus 50 cents for postage and handling. 



Price Reduced: 

LIVING VOLUTES 

A Monograph of the Recent Volutidae 

of the World 

by Weaver and duPont 

A classic identification book with 
375 pages and 79 full-color plates. Form- 
erly $55.00, now only $36.00, plus post- 
age (25 cents in the U.S.). Order now from 
your local bookdealer or: 

Delaware Museum of Natural History 
Box 3937, Greenville, DE. 19807, U.S.A. 



120 THE NAUTHA.- 



October 25, 1974 



Vol. 88 (4) 



INTRODUCING MOLLUSKS 




By G. Alan Solem, 

Field Museum of Natural History, Chicago 

An excellent introduction for both tfie amateur and 
professional, this book provides wide-ranging in- 
formation on mollusks and their probable patterns 
of evolution. It not only relates the major ecological 
shifts and structural adaptations of mollusks. but 
also explores the basic living problems faced in 
colonizing a new region and tells how they were 
solved by different molluscan groups. 

Writing from a rich background in the field of mol- 
lusks and their shells, the author sets forth new 
ideas about what the first mollusk might have 
looked like and why it eventually had a spiral 
shell. He further speculates on the origin of 
snails, why pulmonate snails are so successful on 
land, and why so many land snails evolved toward 
slugdom. 

Profusely illustrated with unique and attractive 
drawings and photographs, this volume will be 
welcomed by anyone interested in the evolution, 
ecology, and diversity of mollusks. 

1974 289 pages $9.95 

Available at your bookstore or from Dept. 358 

WILEY- INTERSCIENCE 

a division of John Wiley & Sons 

605 Third Avenue 

New York, N.Y. 10016 

In Canada: 22 Worcester Road. Rexdale. Ontario 

Price subject to change without notice 



® 



092 A4779-WI 



BOOK REVIEW 

THE SHELL MAKERS - Introducing 
Mollusks By G. Alan Salem, rii + 289 pp.. 
1-36 figures (1^2 in color). 197U. John Wiley 
and Sons, Inc., 605 Third Avenue, New York, 
N. Y. 10016. Hardback, $9.95. 

There has long been a need for a good ac- 
count of the evolutionary development of the 
Mollusca, and this book adequately fills that 
niche. There is a refreshingly large amount 
of information new to the zoological reader, 
much of which is illustrated by excellent 
drawings. The author is probably the world's 
leading expert on land mollusca and has the 
distinction of having pioneered in the use of 
the scanning electron microscope for 
studying mollusks. 

The photographs and interpretations of the 
ultra-microscopic features of the radulae and 
shell sculpturing are significant advances in 
the field of mollusks. Other valuable parts of 
the book contain an account of the evolution 
of the shell-less pulmonates and a discussion 
of the adaptive thresholds in the development 
of the various classes of mollusks. 

The book is well-written and not without 
humor. Some of the chapter headings are 
"On Becoming Sluggish", "The Slow and the 
Quick" (referring to chitons and cephalopods), 
and "To Scrape a Living." I heartily recom- 
mend this book, not only as background (and 
"foreground") reading for college courses in 
malacology and evolutionary biology, but 
also to amateur conchologists who admire shell 
makers. 

R. Tucker Abhutt 

duPont Chair of Mdltwoloyy 

Delaware Museum of Natural Hiiitory 



INFORMATION FOR SUBSCRIBERS 



The annual subscription rate for The Nautilus is 
$7.00 for individuals and $12.00 for institutions 
(domestic or foreign). Subscriptions may begin in 
January. Send check or money order to "The 
Nautilus" to Mrs. Horace B. Baker, Business 
Manager, 11 Chelten Road, Havertown, Pa. 19083. 

Back issues from volume 72 to date are 



obtainable from the Business Manager. Volumes 1 
through 71 (if available) may be obtained in 
reprint or original form from Kraus Reprint Co., 
Route 100, Millwood, New York 10546. 
Advertising rates may be obtained from the 
Business Manager or Editor. 



CONTRIBUTORS 



Manuscripts: Authors are requested to follow the 
recommendations of the Style Manual for Biological 
Journals, which may be purchased from the American 
Institute of Biological Sciences, 2000 "P" Street, 
N.W. Washington, D.C. 20036. Manuscripts should be 
typewritten and doublespaced; original and one copy 
are required, to facilitate reviews. Tables, numbered 
in arable, should be on separate pages, with the title 
at the top. Legends to photographs should be typed 
on separate sheets. Explanatory terms and symbols 
within a drawing should be neatly printed, or they 
may be pencilled in on a translucent overlay, so that 



the printer may set them in 8 pt. type. There is a 
charge of 50 cents per word for this extra service. All 
authors or their institutions will be charged 50 cents 
per line of tabular material and taxonomic keys. The 
publishers reserve the right, seldom exercised, to 
charge $32 per printed page. 

An abstract should accompany each paper. 

Reprints and covers are available at cost to 
authors. When proof is returned to authors, 
information about ordering reprints will be given. 
They are obtained from the Economy Printing Co., 
Inc., R. D. 3, Box 169, Easton, Maryland 21601. 



MOLLUSK VOUCHER SPECIMENS 



It is becoming increasingly important for future 
research purposes that an identified sampling of 
species mentioned in pubUcations be deposited in 
a permanent, accessible museum speciaUzing in 
mollusks. This is particularly true of mollusks used 
in physiological, medical, parasitologjcal, ecological, 
and experimental projects. 

The Delaware Museum of Natural History has 



extensive, modern facilities and equipment for the 
housing and curating of voucher specimens. Mater- 
ial 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 pubUcation. 




WH 17XX 



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