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 0 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 Delaware Museum of Natural History Kennett Pike, Route 52 Box 3937, Greenville, Delaware 19807 Second Class Postage paid at vy/llmlngton, Delaware Subscription Price: $7.00 (see Inside back cover) 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 D. Free Distribution (including samples) by mail carrier or other means E. Total Distribution (Sum of C & D) F. Office use, left-over, unaccounted and 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. none 625 625 14 639 361 Single Issue 1,000 none 675 675 14 689 311 1,000 1,000 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 $12.50 A national register of malacologists and shell collectors American Malacologists 6314 Waterway Drive Falls Church. Va. 22044 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 0 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 0 Triodopsis trideiUata 1 0 Mesodon andrewsae 3 0 Ventridens sp. (immature) 2 0 Mesodon ferrissi 3 0 M. clauses 1 0 Mesomphix sp. (immature) 2 0 Mesodon rugeli 1 0 Mesomphix sp. (adult) 1 0 M. vulgatus 2 0 Ventridens intertextus 7 0 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 THE NAUTILUS 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 THE NAUTILUS 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. Vol. 88(1) THE NAUTILUS 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. 24 THE NAUTILUS January 29, 1974 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 Vol. 88(1) THE NAUTILUS 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 THE NAUTILUS 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. Vol. 88(0 THE NAUTILUS 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 28 THE NAUTILUS January 29. 1974 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 INFORMATION FOR SUBSCRIBERS The annual subscription rate for The Nautilus is $7.00 for individuals and $12.00 for institutions (do- mestic or foreign). Subscriptions may be commenced in January when a new volume begins. Send check or money order to "The Nautilus" to Mrs. Horace B. Baker, Business Manager, 1 1 Chelten Road, Haver- town, 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 Periodicals, Inc., 16 East 46th Street, New York, N.Y. 10017. 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 pubhshers 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. i APRIL, 1974 THE NAUTILUS Vol. 88 No. 2 A quarterly devoted to malacology and the interests of conchologists 0 Founded 1889 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 K1A-0M8 Dr. WUliam J. Clench Curator Emeritus Museum of Comparative Zoology Cambridge, Mass. 02138 Dr. William K. Emerson Department of Living Invertebrates The American Museum of Natural History New York, New York 1 0024 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 1 0 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 0 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 1 9083 OFFICE OF PUBLICATION Delaware Museum of Natural History Kennett Pike, Route 52 Box 3937, GreenvUle, Delaware 19807 Second Class Postage paid at Wilmington, Delaware Subscription Price: $7.00 (see inside bacl< cover) 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 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*'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 american malacologists All the essential biographic facts about Americas leading mollusk workers, shellfishery experts, paleoconcholo- gisfs and advanced shell collectors are now at your finger tips in this handy guide. ORDER $12.50 A national register of malacologists and shell collectors American Malacologists 6314 Waterway Drive Falls Church, Va 22044 68 THE NAUTILUS April 30, 1974 Vol. 88(2) NEWS LIVING VOLUTES by Weaver and du Pont (1970, 375 pp., 79 colored plates), has had its retail price drastically reduced from $55.00 to $36.00 in order to make it more readily available to malacologists. Send check to the Delaware Museum of Natural History, Box 3937, Greenville, Delaware 19807. 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. WESTERN SOCIETY OF MALACOLOGISTS The Seventh Annual Meeting will be held June 19-22, 1974, at the Kellogg West Con- ference Center on the campus of Californ- State Polytechnic College, Pomona, Califor- ia. The program will feature contributed papers, symposia, displays, and study work- shops on molluscan subjects. In addition to the program of research papers, there will be a concurrently running program of popular presentations on shells or shell collecting. Inquiries about the meeting should be made no later than May 15th and should be directed to the Secretary, Mrs. Edith Abbott, 1264 West Cienega Avenue, San Dimas, California 91773. Applications for member- ship should be sent to the Treasurer, Mr. Bertram C. Draper, 8511 Bleriot Avenue, Los Angeles, California 90045. The President this year is Dr. James H. McLean — editor. / — handsomely bound, gold stamped — full color photo- graphs— fine engravings and space enough to keep a record of everything you plan to do in 1975. Winner of many major awardsthe1975 diary will again emphasize shells as a con- stantly recurring theme in the culture of mankind. jl2 -■^ Order your copy of the 16th edition of the Shell Desk Diary $2.50 order today! No orders will be accepted after August 1, 1974 each »• sv^ se$ Mail 77001 /our order 1 room 1536 for • •1 copy ••••••• (ies) of the One Shell ed to you in 1975 Shell Desk , • Diary, • Texas • Name 0 Shell The Di Oil ary Company, will be mai Plaza. Houston, • November. (2) J • City • • State Zip : • ••• • •• ••••••• »••• • ••• 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 tluougli 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, wliich 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 oveday, 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 speciahzing in moUusks. This is particularly true of mollusks used in physiological, medical, parasitological, ecological, and experimental projects. The Delaware Museum of Natural History has extensive, modern facilities and equipment for the housing and curating of voucher specimens. 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 publication. JULY 1974 THE NAUTILUS Vol. 88 No. 3 A quarterly devoted to malacology and the interests of conchologists Founded 1889 by Henry A. PUsbry. Continued by H. Burrington Baker. Editors: R. Tucker Abbott and Charles B. Wurtz c EDITORIAL COMMITTEE CONSULTING EDITORS Dr. Arthur H. Clarke, Jr. Department of MoUusks National Museum of Canada Ottawa, Ontario, Canada K1A-0M8 Dr. WUliam J. Clench Curator Emeritus Museum of Comparative Zoology Cambridge, Mass. 02 1 38 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 0 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 Delaware Museum of Natural History Kennett Pike, Route 52 Box 3937, Greenville, Delaware 19807 Second Class Postage paid at Wilmington, Delaware Subscription Price: $7.00 (see Inside back cover) THE NAUTILUS Volume 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 for 18.54: .311-317. Benthem Jutting, T. van. 1920. Marine molluscs 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. Chemnitz, J. 1780. Neues Systematisches Conchylien-Cabinet 4. Niimberg, 344 pp., 39 pis. Deshayes, G. P., & H. Milne Edwards. 1843. [in] J. Lamarck, Histoire naturelle des animaux sans vertebres, 2nd ed., 9. Paris, 728 pp. Hertlein, L. G., & A. M. Strong. 1951. Eastern Pacific expeditions of the New York Zoo- logical Society. XLIII. Mollusks from the west 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. Roding. P. 1798. Museum Boltenianum. Hamburg, 199 pp. Rovereto, 1899. Atti Soc. Ligust. 10: 104 [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 0 I mm 19 rS'iv -.r' 0 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. 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 pubhshers 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 moUusks. This is particularly true of inollusks used in physiological, medical, parasitological, ecological, and experimental projects. The Delaware Museum of Natural History has extensive, modern facilities and equipment for the housing and curating of voucher specimens. Mater- ial should be accompanied by the identification, locality data and its bibhographic reference. There is no charge for this permanent curating service, and catalog numbers, if desired, will be sent to authors prior to publication. 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 EDITORIAL COMMITTEE CONSULTING EDITORS Dr. Arthur H. Clarke, Jr. Department of Mollusks National Museum of Canada Ottawa, Ontario, Canada K1A-0M8 Dr. WUliam J. Clench Curator Emeritus Museum of Comparative Zoology Cambridge, Mass. 02138 Dr. William K. Emerson Department of Living Invertebrates The American Museum of Natural History New York, New York 10024 Mr. Morris K. Jacobson Department of Living Invertebrates The American Museum of Natural History New York, New York 10024 Dr. Aurele La Rocque Department of Geology The Ohio State University Columbus, Ohio 43210 Dr. James H. McLean Los Angeles County Museum of Natural History 900 Exposition Boulevard Los Angeles, California 90007 Dr. Arthur S. Merrill Biological Laboratory National Marine Fisheries Service Oxford, Maryland 21654 Dr. Donald R. Moore Division of Marine Geology School of Marine and Atmospheric Science 10 Rickenbacker Causeway Miami, Florida 33149 Dr. Joseph Rosewater Division of 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. GUbert L. Voss Division of Biology School of Marine and Atmospheric Science 1 0 Rickenbacker Causeway Miami, Florida 33149 Dr. Charles B. Wurtz 3220 Penn Street Philadelphia, Pennsylvania 19129 EDITOR-IN-CHIEF Dr. R. Tucker Abbott Delaware Museum of Natural History Box 3937, Greenville, Delaware 19807 Mrs. Horace B. Baker Business and Subscription Manager 1 1 Chelten Road Havertown, Pennsylvania 1 9083 OFFICE OF PUBLICATION Delaware Museum of Natural History Kennett Pike, Route 52 Box 3937, Greenville, Delaware 19807 Second Class Postage paid at Wilmington, Delaware Subscription Price; $7.00 (see Inside back cover) THE NAUTILUS Volume 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 "bible of shell manuals" American Seashells 670 pp . 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'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 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 0 10.1 0 22.5 2.9 0 0 *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.<;i>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 "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 :■;»' Wfi