^TRANSACTIONS OF THE WAGNER FREE INSTITUTE OF SCIENCE OF PHILADELPHIA. Vol. 3. MARCH, 1895. PHILADELPHIA, I . S. A. : WAGNER FREE INSTITUTE OK SCIENCE, MONTGOMERY AVE. AND lyTII ST. WHGNER FREE INSTITUTE OF SCIENCE PHILADELPHIA. TRUSTEES. SAMUEL WAGNI-K, /'n-sident. RICHARD B. WESTBROOK, Treasurer. JOSEPH WII.LCOX, Secretary. SYDNEY T. SKIDMORE. HARRISON S. MORRIS. SAMTEL T. WACXER. J. VAUGHAN MERRICK, JR. FACULTY. Department of Chemistry, PROE. HENRY LEFFMANN, M. D. Department of Botany and Forestry, PROF. JOSEPH T. ROTHROCK. Department of Geology, PROF. WILLIAM B. SCOTT. Department of Physics and Astronomy, PROF. SYDNEY T. SKIDMORE. Department of Literature and History, PROF. ROBERT E. THOMPSON. Department of Engineering, PROF. SAMUEL T. WAGNER. Honorary Prof, of Invertebrate Paleontology, WILLIAM H. DALL. Actuary and Librarian, Curator of Museum, THOMAS L. MONTGOMERY. CHARLES VV. JOHNSON. 85580 CONTRIBUTIONS TO THE TERTIARY FAUNA OF FLORIDA, WITH ESPECIAL REFERENCE TO THE MIOCENE SILEX-BEDS OF TAMPA AND THE PLIOCENE BEDS OF THE CALOOSAHATCHIE RIVER. BV WILLIAM HKALEY DALL, A. M ., Paleontologist to the U. 5. Geological Survey, Honorary Professor of Invertebrate Paleontology in Wagner Free Institute of Science. ?A PART III. A NEW CLASSIFICATION OF THE PELECYPODA. PREFACE. The following memoir is in continuation of the work on the Tertiary Fauna of Flor- ida, which was published in Parts I. and II., Vol. 3, of these Transactions. In preparing the descriptive portion relating to different groups of the Pelecypoda, a point was reached when it became necessary to consider the general arrangement. As recent morphological and paleontological studies have thrown a new light on the relations of the Pelecypoda, necessitating a revision of the earlier systems ; and as a complete revis- ion is nowhere accessible in print ; it was thought that a statement of the characters chiefly relied on for classifying these animals, with comparable diagnoses of the several families in zoological order, would be useful for students of Paleontology and might form a proper introduction to the descriptive part of this memoir. The data used are derived from original researches and from the literature, and the characters cited in the latter have been, as far as possible, verified by comparison with actual specimens from the collections of the National Museum and the U. S. Geological Survey To Dr. Chas. D. Walcott, Director, and Maj. J. W. Powell, late Director of the U. S. Geological Survey, to the authorities of the Smithsonian Institution and National Museum, thanks are due for assistance rendered in the prosecution of the work. WILLIAM HEALEY DALL. -'70 TABLE OF CONTENTS. Introduction, treating of the parts of the Pelecypod : I'AOB The Valves 486 The Hinge Teeth 490 The Steinrnann Formula 492 Types of Teeth 492 The Pholad myophore 496 The Ligament and Resilium 497 The Adductor Muscles 503 The Siphons 503 The Gills or Branchia 504 The Heart 506 The Nephridia 507 The Foot 507 The Prodissoconch 508 General Classification of the Pelecy- poda : Class Pelecypoda 511 Order Prionodesmacea 511 Order Anomalodesmacea 512 Order Teleodestnacea .. 512 The Paleoconcha 513 Order Prionodesmacea 515 Superfamily Solemyacea 515 Family Soletnyidie 515 A. Ta.xodonta 515 Superfamily Nuculacea 515 Family CtenodoutidcC? 515 Family Nuciilitke 516 Family Ledicke 516 Superfamily Arcacea 516 Family Macrodontidae 516 Family Cyrtodontid* 517 Family Limopsidie 517 Family Arcida- 517 B. Schizodonta 518 Superfamily Pteriacea 518 Family Pterineidae 518 Superfamily Pteriacea, continued. \- H.I-. Family Anibonychiidie 518 Family Pinnidoj 519 Family Conocardiida: 519 Family Penmke 520 Family Pteriidie 520 Family Vulsellidce 520 Superfamily Ostracea 520 Family Ostn-idaa 521 Family Kliginid;e 521 Superfamily Naiadacea 5,21 Family Cardiniid;e 522 ? Family Megalodontida,- 522 Family Unionida: 522 l'"amily Mutelidue 523 Family Ktheriida.- 523 Superfamily Trigoniacea 524 Family Lyrodesmicku 524 Family Trigoniida; 524 C. Isodonta 524 Superfamily Pectinacea 524 Family Pectinidae 525 Family Spondylidae 525 Family Dimyidas 526 Family Limidas 526 Superfamily Anomiacea 526 l''amily Anomiidx 527 D Dysodonta 527 Superfamily Mytilacea 527 Family Modiolopsido; 527 Family Mytilidae 528 Family Dreissensiida^ 528 Family Modiolarcidae 528 Family Prasinidae? 529 Order Anomalodesmacea 529 Superfamily Anatinacea 530 A. Eusiphonia 530 Family Ceromyidie 530 TABLE OF CONTENTS. Superfamily Anatinacea, continued. PAGE Family Pholadomyidae 530 Family Anatinidae 531 Family Periplomidas 531 Family Thraciid;e 531 Family Myochamidae 531 B. Adelosiphonia 532 Family Pandoridse 532 Family Lyonsiidze 532 Family Lyonsiellidae 533 Family Chamostreidae 533 Superfamily Ensiphonacea 534 Family Clavagellidse 534 Superfamily Poromyacea 534 Family Euciroidas 535 Family Verticordiidae 535 Family Poromyidae 535 Family Cuspidariidae 536 Order Teleodesmacea 537 A. Pantodonta 537 ? Family Allodesmidae 537 B. Diogenodonta 538 Superfamily Cypricardiacea 538 Family Pleurophoridae ? 538 Superfamily Astartacea .... 5^8 Family Curtonotid;e ^38 Family Astartidae 538 Family Crassatellitidu.- 539 Superfamily Cyreiiacea 540 Family Cyrenidce 540 Family Sphaeriidys 540 Superfamily Carditacea 540 Family Carditidas 541 Superfamily Chamacea 541 Family Chamidas 541 Family Monopleuridas 542 Family Caprinidae 542 Superfamily Rudistse 543 Family Radiolitidaa 543 Family Hippuritidae 543 Superfamily Lucinacea 543 Family Tancrediidae 543 Family Unicardiidae 544 Family Lucinidau 544 Family Corbidae ? 544 Superfamily Lucinacea, continued. PAGE Family Diplodoutidre 545 Family Cyrenellidx 545 Family Cryptodonticte 546 Superfamily Leptonacea 546 Family Leptonidae 546 Family Galeommidae 547 Family Chlamydoconchidae 547 Family Kelliellida? 548 C. Cyclodouta 548 Superfamily Cardiacea 548 Family Cardiidas 548 Family Adacnidae ? 549 Superfamily Tridactiacea 549 Family Tridacnidas 549 Superfamily Isocardiacea 550 Family Isocardiidae 550 Family Callocardiida- 551 D. Teleodonta 551 Superfamily Veneracea 551 Family Veneridae 552 Family Petricolida? 552 Family Glaucomyidae 553 Superfamily Tellinacea 553 Iramily Tellinida; 553 Family Semelidae 554 Family Psammohiid;e 554 Family Donacid;e 554 Superfamily Solenacea 555 Family Solenidae 555 Superfamily Mactracea 555 Family Mactridae 556 Family Cardiliida;? 556 Family Mesodesmatidre 556 E Asthenodonta 557 Superfamily Myacea 557 F'amily Myacidas 557 Family Corbulidae 557 Family Saxicavidae 558 Family Gastrochaenidae 558 Superfamily Adestnacea 559 Family Plioladidae 559 Family Teredinidae 559 Notes on Nomenclature 561 Index to genera 566 Tertiary Mollusks of Florida. BY W. H. DALL. PART III. A new Classification of the Pelecypoda, with an enumeration of the differ- ential characters of the Orders, Suborders, Superfamilies, and Families, a state- ment of their range in Geological time, and an enumeration under each family of the chief generic groups believed to be referable to it. Preceded by a brief discussion of the features of the Pelecypod organization chiefly available as diagnostic characters. Introductory to the description of the Tertiary Pelecy- poda of Florida. In May, 1889, a Preliminary Catalogue of the shell-bearing Marine Mol- lusks and Brachiopods of the Southeastern Coast of the United States was published by the U. S. National Museum as Number 37 of its series of Bulle- tins. In that work, which, from unavoidable causes, was prepared in great haste by the writer, a new classification of the Mollusca was proposed. Since that time much new material has been examined by various naturalists, bear- ing upon the Pelecypoda, and the writer has systematically studied the sev- eral groups as opportunity offered, with the view of placing the resulting classification upon a firm basis, derived from a consideration of the totality of characters. The completion of this work, so far as our present knowledge permits, has resulted in a revision of the earlier arrangement in many details, and an apparent confirmation of the general principles upon which the earlier system was founded. With the presentation of the data of the system now adopted, the classification is submitted to the judgment of systematists for criticism and amelioration. The bivalve molluscan shell is a defensive covering which, normally, pro- tects the more delicate organs of the body with a permanent shield ; and, when the valves are open, admits of the extrusion of organs connected with alimen- tation, respiration and progression. When the valves are completely closed they form, normally, a defensive armour against enemies and environmental irritation, to the extent of their strength. Leaving out of consideration, mo- mentarily, abnormal degenerate or exceptional modifications of the type due to special circumstances, throughout the following discussion, except where expressly mentioned, attention will be called to the fundamental type, the 486 TRANSACTIONS OF THE WAGNER FREE dynamics of its functions, and the directions and causes of its development and present modification. The Valves. — The bivalve shell reduced to its lowest terms comprises two convex pieces attached to one another dorsally (i) by an elastic ligament external to the cavity between the valves; and (2) by muscles and connective tissues which p.ivs ' from the inner surface of one valve to the inner sur- face of the'op'posite valve. By the contraction of the muscles the margins of 'he'v.ilves ;>re brought into close contact, thereby forming a hollow receptacle in which the soft parts of the animal may be enclosed and obnoxious matters, living enemies, or inorganic material liable to irritate the tissues, may be com- pletely excluded. The elasticity of the ligament, acting on the principle of a C-spring, tends to separate the valves when the tension of the internal adduc- tor muscles is relaxed. The substance of the valve is secreted by marginal glands around the edge of the investing tissue or mantle, and is subsequently reinforced by material supplied by secretion from the general surface of the mantle ; each secretion having a special character, distinguishable in the struct- ure of the shelly deposit. As the animal grows and the original prodissoconch becomes too small to cover the soft parts the valves are enlarged, always at the margin, so that each valve, fundamentally, represents a hollow cone. As growth progresses more rapidly along some portions of the mantle than at others the cones necessarily become oblique, arched, or cycloidally curved. The apex of the cone is the beak or umbo of the shell, the base is the entire margin of the valve. Owing to the necessarily asymmetrical disposition and mode of growth of the various organs of the body, the subcircular outlines of the prodissoconch cannot long be maintained, and the valve becomes modified in outline according to the circumstances of each particular case. The original protopelecypod was small, thin, symmetrical, subcircular or oval, with a short external ligament * equally disposed on each side of the beak along a line (the hinge-line) constituting the axis of motion for the valves in opening and closing. The mantle was not uniformly attached to the shell along a pallial line, as in modern pelecypods, but adhered more or less irregu- larly and was not provided with extrusile siphonal tubes. The adductor muscles were subequal, symmetrical, and situated high up in the valves. The surface of the valves was smooth, or (probably in connection with the develop- ment of tactile papillae on the mantle edge) radiately ribbed. These conclusions are justified not only by theory and by the recent investigations of Jackson and others on the morphology of the prodissoconch, but by the characters of the oldest known pelecypoda, summarized by Neumayr under the name of Paleoconcha. In a limited group, generally characterized by the incubation of the young fry within the valves, the anal chamber, or even in a specially developed bran- * Throughout this work "ligament" refers to the external, and " resilium " to the relatively or actually internal bond between the dorsal margins of the valves. INSTITUTE OF SCIENCE, PHILADELPHIA. 487 chial marsupium, the original prodissoconch is followed by a rounded-tri- angular bivalve shell. The young in this stage, termed a glochidium, may un- dergo considerable developmental change, and remain encysted for a lengthy period on some suitable host, without material change in size or form of its valves. In perfectly preserved specimens the glochidial valves may be dis- tinctly seen at the apex of the umbones. The base of the triangle forms the line of the hinge, the rounded apex opposite corresponds to the ventral border, within it is furnished with a hook or claw-like, sometimes denticulate, process, by means of which it attaches itself to the gills or fins of fishes, where, by proliferation from the epithelium of the host, the glochidium becomes encys- ted. This stage of development was, until recently, supposed to be peculiar to the Naiades, but the writer has recently discovered that a genus of marine pelecypods, probably allied to Avicula and named by Carpenter Philobrya *, also passes through a Glochidium stage, thus adding another link to those which connect the Aviculidce with the Naiades. That this particular stage of growth is due to the habit of encysting itself rather than to the incubation by the parent, is evident from the fact that many other bivalves which protect their young in this manner (Lepton, Parastarte, Thecalia, Milneria, Ostrea) neverthe- less exhibit only a normal prodissoconch. The surface of the glochidial valve is conspicuously punctate, due to a poriferous structure perhaps connected with the larval respiration. I have already shown f that it is absolutely required by the laws of mechanics that the axis of revolution must be a right line and that, therefore, that part of the hinge-line functioning in connection with the ligament in the opening and closing of the valves must be straight. If, as in some forms superficially appears, the ligament seems to be curved, or to extend over a part of the hinge-line which is curved, an examination will show that either that portion of the ligament, which departs from a straight line, is not functional, or that it possesses sufficient elasticity to fall into line when exercising its func- tions. It is obvious, also, that the longer the line covered by a functional liga- ment, the more rigidly will the opening and shutting of the valves be con- trolled ; and, conversely, that the shorter and higher up the ligament the more easily a rocking motion of the valves (which would prevent their exact closing, margin upon margin) may be brought about. To obtain a long straight line on the border of a rounded body the hinge-line must descend, or the outline of the body must be modified. The former, for obvious reasons, is the easier process and through it, as promoted by natural selection, the hinge-line, from being a minute segment of the arc described by the dorsal margin is lowered until it forms a chord truncating part of the arch between the beaks and form- * Originally Bryophila, which proved to be already in use. f Am. Joura. Science, xxjtviii, Dec. 1889, pp. 445-462, also Proc. U. S. Nat. Mus., xll, pp. 232-248, 1889. 488 TRANSACTIONS OF THE WAGNER FREE ing above itself a relatively level area through the necessary flattening of the dorsal margin of the valves. Returning to the general conditions surrounding and impinging upon the developing pelecypod, let us enquire what are the most serious dangers which menace an animal so situated and so defended. It is undeniable that chief among them must be reckoned anything which will prevent an exact closing of the valves, and thus admit not only predaceous annelids and the proboscis of carnivorous gastropods, but the inorganic gravel, mud, or sand which (as every collector knows from frequent experience) rapidly exhausts the vitality of the mollusk by calling for the immediate erection of barriers against the in- vading irritant, the abnormal secretion of shell substance to form these barri- ers, the consequent displacement of the animal from some part of its shell, and the locking up, under a not wholly impervious layer of shell, of accumulations of more or less fetid mud and water from which it can never hope to free it- self. A single grain of sand between the dorsal margins of the valves will prevent their complete closure and leave the animal undefended from its ene- mies. The fundamental importance of guarding against such a disaster cannot be doubted. Hence in this necessity we perceive the lever of natural selection will find a most important fulcrum. The ligament, especially when short, from its elastic nature can never be a perfectly efficient agent in bringing about an exact closure of the valves. Even the adductors, with their essential co-operation, from their own fleshy and extensile nature, cannot absolutely supply the needed rigidity. The asymmet- rical twisting of the valves, a character common to many Paleoconchs, Stavelia, Area tortuosa, and numerous Chinese Naiades, would assist, to some extent, but that it has serious defects as a method is obvious from its disappearance from all the most perfected forms of Pelecypods. Ribbing, with its alternating den- ticulation of the margin, is efficient when the valves are closed, but cannot act when they are open, and it is during the process of closing that the period of danger lies. Neumayr has shown that, among the Paleoconcha, ribbing existed, in vari- ous species, along the dorsal as well as the other margin, and that it produced denticulations there, and that when these denticulations had become a specific fixed character the ribbing disappeared from the area above the hinge-margin. In this way (as analogically in the recent Crenel/a et a/.) the initiation of hinge-teeth began. Such projections, interlocking at a time when the serra- tions of the other margin of the open valves could be of little assistance in securing rigidity, offered a means of defence of the greatest importance when fully developed by natural selection, and which would be useful at every stage of development ; increasing in usefulness with its increase in size, but useful from the very first, just such a feature as lends itself to the fullest operation of natural selection. Once well initiated, its progress was inevitable, and its variety and complexity only a question of time. INSTITl'TK OK SCIENCE. PHlI.ADKI.l'HI A. 489 The kind of teeth initiated at first would depend upon the sculpture and form of the shell modified. It is obvious that with a shell having elevated beaks distant from the hinge-line, and numerous ribs, many of the latter would intersect the hinge-line nearly at right angles, so as to form a series of denticu- lations comparable to those of Crenella, and constituting the prototype of such teeth as were called Taxodont by Neumayr, included in the Prionodesmacea by the writer. If the area between the beaks was smooth or only feebly stri- ated, and ribbing began at the anterior and posterior angles of the umbonal slope, these would necessarily intersect the hinge-line at an acute angle, or even be nearly parallel to it, and plications induced by such ribbing would tend to form in a direction parallel or nearly so to the general line of the hinge (horizontally, instead of vertically), and would appear at the ends instead of the center of the hinge-line. Such teeth are the laterals of Cyrtodonta, Tellina, and the so-called laterals of Unio. If, as in the early Paleoconchs, the hinge is symmetrically disposed with relation to the vertical from the beaks, the laterals thus initiated will be equal and similar ; if the hinge-line is shorter before the beaks the laterals at that end will necessarily be shorter also and less horizontal. If the distance between the beaks is short, thus diminishing the cardinal area over the hinge-line, it will also tend toward producing more oblique crenulations of the hinge than in a species with a wide cardinal area. These results follow necessarily from the most elementary principles of mechanics, as any one may determine for themselves by drawing a circle with numerous radii, extending from the center to the circumference, and cutting off segments parallel to any diameter. The center will represent the beak ; the radii, the ribs ; the chord of the segment cut off, the hinge-line. Do the same with a cone, of which the apex is the center of radiation, and, finally, give the cone a spiral twist ; in the last case the example will come very near the conditions of the bivalve shell, and the sections made will clearly illustrate the principles involved. Of course it need hardly be said to any intelligent biologist that these conditions will produce, not the hinge of any bivalve exactly as we know it, but modifications of the primitive hinge margin, which will be useful from the moment of inception, which natural selection would at once lay hold of, and from development and modification of which all existing types of hinges can be legitimately derived. The general form of the pelecypod depends upon its principal anatomical characters ; the size, number and position of the muscles, the presence, size, and character of siphons, byssus, etc. Consequently to a certain limited ex- tent, especially in the modification of the primitive simple Paleoconchs, the differences of form would march with the respective anatomical differences as, for example, those which retained the simply open mantle and subequal adductors would continue to be of a rounded and symmetrical shape; while those which tended to produce elongate siphons, or in which marked inequality TRANSACTIONS OF THE WAGNER FREE of the adductors developed, would probably present outlines more elongate or triangular. The differences of form would necessarily react upon the develop- ing hinge, from the inevitable action of physical laws, and thus tend to pro- duce in connection with particular lines of evolution of form, particular types of hinge. I have thought that the development of such diverging types of hinge, the pedigree of existing types, would be useful in the classification of the Pelecypoda, and provisionally applied these principles in a tentative classi- fication proposed early in 1 889 (Hull. U. S. Nat. Mus. No. 37, p. 26, May, 1 889 ; and Am. Journ. Sci., Dec. 1889, p. 460). That the tracing out of the line of descent of several general types of hinge (without reference to the specializing effect of later conditions, which often partially mask the type, as in other lines of development) was a sound method, was shown effectively by the fact that the classification derived from it harmonizes in essentials with that which is the result of the most modern researches on entirely different lines; subtraction being made of whimsicalities due to narrowness of view or want of breadth in morphological knowledge. As the multitude of fossils can only be known to us by their hard parts preserved in the rocks, a classification which enables us to follow the line of descent approximately by characters still preserved by the fossils, is not without special advantages to the biologist. If also this classifi- cation be morphologically acceptable on other grounds, there would seem to be no good reason why it should not be generally adopted, with the under- standing that the first attempts at framing it must be subject to correction as our knowledge of the facts increases. The Hinge Teeth. — Two functions are performed by the hinge teeth, each of which has its own dynamic correlations. The first is the guiding back of the closing valves, so that the first effort will bring the appropriate parts into exact apposition. This function is fulfilled especially by long, more or less curved teeth, like those of Yoldia or Ctenodonta among the Prionodonts, and Cardium among the Teleodonts. The second function is the preservation of the apposition after the valves are closed, or, the prevention of any rotatory motion of either valve upon the other in the marginal plane with the ligament as an axis. This function is particularly important in shells which have a smooth inner basal margin and full, equal valves, since such shells are more liable to unequal pressure affect- ing only one of the valves or one valve more than another. Teeth may be quite inefficient to bring about this result, which may, nevertheless, serve very well as guides. For instance the long cardinal teeth of Cardium make excel- lent guides, but help little to prevent rotation. This defect in Cardium is made up for by the presence of lateral teeth, and more especially in many of the spe- cies, by a denticulated basal margin.* *Among all the numerous species of Cfirdium, only one or two are found with teeth obsolete and smooth inner basal margins, and these are chiefly restricted to a sub-Arctic habitat, where enemies are perhaps fewer than in warmer seas, and where the form seems to have persisted chiefly through its great fertility in indi- viduals. INSTITUTE OF SCIENCE, PHILADELPHIA. 491 In order to be effective as an obstacle to rotation in either direction, teetli must alternate and there must be at least three surfaces opposed to one another. That is to say, one tooth by the side of another projecting from the opposite valve (formula^ J°) might prevent L from rotating forward and R from rotat- ing backward, but the converse rotations would not be provided against. With a hinge arranged according to the formula [j™,1,, however, rotation would be op- posed in either direction to an amount equivalent to the torsional strength of the tooth R, or, if the two teeth of L were jointly less strong than the single tooth of R, then their combined strength would measure the total resistance to torsion. It is quite evident, therefore, that alternation is essential to the idea of a perfectly efficient hinge, and must be expected wherever we find a fully developed hinge. In this sense all hinges are Heterodont, and the distinction drawn by Neumayr between Heterodont and Desmodont teeth, so far as their situation is concerned, resolves itself into a comparison between teeth originally laterals and both in one valve, with paired lamina: in the opposite valve, on the one side; and teeth originally cardinals, or, if laterals, then laterals of which one was in one valve and one in the other, with the clasping lamiiue also alternated. The cases where laterals would both be in one valve and the laminae all in the other would be exceptional, because such an arrangement in- volves more or less asymmetry in form and weight of the valve which cannot be regarded as a favorable condition for the animal, although it has prevailed, to some extent, from the earliest ages. Such species are always relatively sed- entary, and the asymmetry is usually proportioned to the immobility of the particular species. An active form, if asymmetrical, would be constantly di- verted from its intended line of motion by the mechanical effect, of the medium in which it moved, unequally exerted upon the respective valves ; and this would obviously be an unfavorable condition, leading to waste of energy and impotency of volition. In the case of the hinge-teeth the asymmetry need not be great and might be remedied by a compensating deposition of material on the lighter valve, as occurs in Trigonia, but this is, as a matter of fact, very exceptional. It would seem as if the tendency to torsional growth exemplified in the spirality of Gastropods was originally anterior to the inception of the Pelecypod type, as it is very common among the Paleoconchs (Antipleura, Dualina, etc.) ; traceable in the sculpture of many Solenoconchs (Dentalnini) and Pteropods ; and grows less prevalent with the progress of the Pelecypoda. Among recent forms it is chiefly confined to representatives of the ancient types (Prionodonta, such as Area, Stavelia and Unio) and is usually absent among the Teleodonts, or most fully perfected modern forms. The asymmetry of the siphonal end of such forms as Tellina, is of a different character from the spiral twisting which involves the whole plane of the valves, as markedly illus- trated by Antipleura. The latter is the tendency referred to in the preceding remarks, though it is not impossible that asymmetry without torsion may be to some extent connected with the torsional tendency. 492 TRANSACTIONS OF THE WAGNER FREE The Steinmann Formula. — As we shall have frequent occasions for using the Steinmann system of formulating the teeth, it may be well to ex- plain it. L will represent the left and R the right valve, and the teeth are represented by units; the sockets into which teeth of the opposite valve fit by zeros; the resilium or chondrophore by c; the laterals by 1 ; the clasping laminae which receive the laterals by m, if single ; ma, if double. Where two Taxodont rows meet on one hinge-margin, and are not separated by a resilium, a period will mark the junction, as in Area or Malletia. Obsolete or feeble teeth may be represented by the italicized symbol for normal teeth. This system is somewhat extended from that originally proposed by Steinmann, but which I have not been able to consult at first hand. The principles in- volved are essentially the same. Some examples will make it clearer. For amorphous, interlocking masses, which cannot be classified as teeth, and are of varied origin, the symbol x is adopted. The enumeration begins at the posterior end, and the right-hand end of the formula is always anterior. The formula for the following Teleodont hinges is as follows : Astarte borealis, {tfy°-^- ; Crassatella antillantm, £'»° J \\ >m ; Venus mercenaria, {(* \\\\\ ', in this case x represents the rough area below the ligament ; Cardium isocardia, [{' "f i J „* ! Tellina intcrrupta Wood, \^\\\\\. The following illustrate types of the Prionodont order ; i, followed by a number in parenthesis, expresses inconveniently long series in a briefer manner : Pectunculus unda,us^\\^\^ Nucvla radiata Hanley, Spondylus spathuliferiis Sby., (crural laminae) j Trigonia niargaritacea, ,™x-| ; The Anomalodesmacea have few and simple teeth, or are frequently edentulous, so that it is hardly worth while to give more than the single form- ula of Corbitla nucleus Jj£-°. Types of Teeth. — The types upon which the shelly processes of the hinge, which we call teeth, are formed, may be classified into several groups. These are not necessarily fundamental ; the teeth, being largely moulded by the dynamics of their situation, change with the influences to which their form is due, and in course of time may become obsolete from disuse (Anodon), or modified so as to simulate the teeth of groups with entirely different pedigree (Nucnla, Mute/a ; Plicatula, Trigonia). In. general, however, at any given time, the types of teeth are good evidence of the relationship of forms to which they are common, especially if the development from the younger stages of the species compared proceeds along similar lines. In the earlier geological ages INSTITUTE OF SCIENCE, PHILADELPHIA. 493 all the characteristics of Pelecypods were in a formative stage, and among these ancient forms variety ran riot. Nearly all the modern types of hinge are fore- shadowed in the Silurian, together with singular forms which have been weeded out by natural selection. Successful development seems to have taken place in three principal lines, or, rather, as the evolution has not been linear, three principal groups, more or less parallel among themselves, yet divergent each as regards the other two. These were regarded by me as Ordinal divisions, and separated in 1889 under the names of Prionodcsmacea, Teleodesmacea, and Anomalodesmacea, respectively. The characteristics of these groups will be discussed later ; suffice it at present to say that they were based not on the forms of hinge-teeth as such, which would have brought together many incon- grous forms and separated near relatives, but on the development of a general type in each case, to which, in spite of present superficial incongruities, the pedigree of existing genera could be referred. So far as the hinges are con- cerned, the Prionodesmacea are the product of evolution applied to the devel- opment of (among other things) teeth transverse to the hinge-margin, of crural or of amorphous teeth ; the Teleodesmacea, of segregation of teeth into different classes on one hinge-plate, including, especially, the utilization of lateral teeth parallel to the hinge-margin; and the Anomalodesmacea, of such experiments in hinge-building as tended to supersede teeth by developing the chondro- phore and resilium, or to retain archaic edentulism by specialties of habitat. A number of types of teeth have been recognized by various writers. For the serial alternating teeth of Ana and its analogues Neumayr proposed the name of Taxodont, or rather classified as Taxodonta the mollusks which possess them. To a portion of the Teleodesmacea he gave the name of Heterudonta on account of the alternation of the cardinals, failing to fully grasp the dynamic principles involved which show that all efficient hinges must be Heterodont. For the bivalves of the Silurian which, in their first stages of dental develop- ment, throw immense light on the evolution of the hinge, and yet are hardly rangeable with modern types, he proposed the name of Cryptodonta. His Desmo- donta, founded on the misapplication of a true and fertile conception, may be mostly ignored. For hinges like those of Schizodus, Myophoria,anA 7>/£W«'a,Steinmann proposed the term Schizodont. To these Neumayr correctly adds the Naiades, while it seems probable that Lyrodesma, Avicnla and its allies should also be included. The more carefully these hinges are studied the more obvious it is that their amorphous character and facile variation distinguish this type of tooth from any other in the modern faunas, though in the Paleozoic beds, in this as in all other cases where sufficiently full data are available, the most dis- tinct types converge. Bittner, in his criticism on Neumayr's classification, was ill-advised in his attempt to harmonize the hinge of Trigonia with that of the Teleodonts. Both are heterodont, as has already been pointed out, like all teeth in the class Pelecypoda ; but the former are certainly more nearly re- 494 TRANSACTIONS OF THE WAGNER FREK lated to the roughened area in Venus mercenaria than to any other part of a Teleodont hinge, and even if dynamically equivalent, morphologically are not homologous with Teleodont cardinals. Another absolutely distinct type of hinge is that which Fischer has named hodont. This is exemplified in the genus Spondylus and a few related forms. Here we have an internal resilium with (in the left valve) first a socket and outside of that a strong tooth, on each side of the pit ; and, in the opposite valve, corresponding teeth and sockets. No other group has the teeth and sockets concentrically arranged and if this distinction from their obviously near relatives, the Pectens, were morphologically true, we should find it difficult to maintain the value of dental types for subdivisions higher than sub-families. It is through a study of the Pectens and very young Spondyli that I have been able to satisfy myself that the so-called teetli of Spondylus (and of some Pectiniforrn relatives) are not homologous with either Prionodont or Teleodont teeth, but are a modification of certain ridges which reinforce the auricles in many Pectens and which I named, in 1886, the auricular crura. I have been able to trace this modification of the crura to a point where it absolutely harmonizes with the incipient teeth of Spondylus s\. an age when the original area-like teeth of Pecten and Spondylus still occupy the cardinal mar- gin. Even in adult Pectens the traces of the true teeth sometimes remain and I have found them quite emphatic even on some well-grown specimens of Spondylus. Consequently we must regard the hinge of Spondylus as a remark- able specialization of certain features of the shell, themselves the result of modifications of the valves initiated through the influence of external sculp- turing, but morphologically distinct from the structures which in other bi- valves we call teeth.* Among the Prionodesmacea, after the Taxodonts and Schizodonts are dis- posed of, dismissing to the former those Paleoconchs which, like Prcecardiuin and Pleurodonta, seem to illustrate the evolution of the Taxodonta, there still remains a group that illustrates the development of the Hctcroinyana repre- sented in the recent fauna by Crenella. These are Prionodont forms in which the valves became markedly inequilateral, so that the anterior cardinal margin was much shortened, and also, by simultaneous umbonal torsion, the rib end- ings and their dental processes became curved. A conspicuous modern exam pie of this type is the little Crenella to which Orbigny gave the name Nuculo- cardia. All the Mytilidce have hinges of this type, the Aviculidce being Schizo- *Sincc arriving at this conclusion 1 recall that Jackson was led to the tame opinion from his studies of young Prionodonts ; Mem. Bost. Soc. Nat Hist. vol. iv, p. 3;tO, 1800. It should be noted that the kpecies arc m,i alike in retaining the archaic denticiilations either in Pecten or SpotntiiliiK. I found them in a specimen of a red Spondylus, 4 mm. long, from the West Indies, and X. Gussoni sometimes shows them very clearly. Amoni: the Peclinirtx P. (Pseudamutrium) t/ialassinus Call, not only shows these teelh plainly in the adult, but up to Ihe time the young are half grown the teeth are functional, as much so as in Numla, and even when the soft parts and resilium are absent the thin glassy valves when opened will sometimes break before the teeth release them, so effectively do they interlock. Cf. Blake Pelecypoda, Bull. Mus. romp. /..ml. xii, p. 221, issii In quite,a number of species no teeth are found. INSTITUTE OF SCIENCE, PHILADELPHIA. 495 dont. If it be considered desirable to name this type of tooth, perhaps Neu- inayr's term Dysodont may be restricted for the purpose, though his original use of it was coextensive with the Anisomyaria. When the element of torsion is absent the same stock might give rise to forms like Vamtxemia and Macro- don, undeveloped or abberrant Taxodonta. Of the Teleodesmacea in the most perfected forms, the tendency was to form a hinge-plate and in all to separate the guiding, or cardinal, teeth from the fixative, or lateral, laminae. When the cardinals became solid and strong and other features rendered the fixative function of the laterals less important, the latter frequently became obsolete or feeble. Among the early Teleodonts the hinge-plate is less conspicuous and, no doubt, as in other groups, was orig- inally absent. In some forms, in which the thin shell was subjected to con- siderable torsion, a type of tooth was evolved which has persisted in a few in- stances to the present day, and is sufficiently distinct from the ordinary type to deserve a name. This is that flat and twisted form of armature exhibited by Isocardia, and to a less degree by the various forms of Cardium, where the teeth seem to spring from the cavity of the beaks and to be, as it were, twisted into line on the cardinal margin. For these I would'propose the term Cyclodunt. A sharp distinction must be drawn between the transverse striation verg- ing into denticulation which is exhibited by Pcctcn and Spondyliis, and which represents the obsolescent ancestral taxodont dentition, on the one hand, and the transverse striation observable on so many Teleodont teeth as well as with those of some of the specialized Prionodonts.* Crassatellites, Mactru, Unio, Cas- talia, Trigonia and others often show such striations, sometimes very sharply developed. But these are simply the result of transverse friction acting on the proliferations of the mantle between the teeth, induced by the to-and-fro motion of the valves and preserved or emphasized by natural selection as an additional protection against irregularity in opening and closing the valves. These stria: simply aid in guiding the valves and may or may not be developed in closely related species of the same genus. Close study will show that the striations are invariably in the line of motion and parallel to it. It is conceiva- ble that functional teeth might be developed in this way, but only when they were preceded by other teeth upon whose surfaces they might be initiated. True teeth, on the other hand, owe their initiation to the influence of external sculpture upon the hinge-margin and therefore are morphologically different. In the Anomalodesmacea we have a tribe of burrowers which have pre- served to the present day (in spite of much specialization) some of the features which characterized the edentulous Protopelecypods of ancient geological time. The nearly edentulous hinge, the more or less nacreous or earthy texture of the shell, the frequent asymmetry and the subequal adductors high in the shell are all archaic features, and we may suppose that their preservation is •Thi« distinction was overlooked In my early references to the subject. 496 TRANSACTIONS OF THE WAGNER FREE largely due to the protection afforded by the burrowing habit universal in the group. The small teeth, which hardly add to the efficiency of the hinge, may be supposed to be associated with the submersion of the resilium and the de- velopment of a chondrophore, as supposed by Neumayr, but in some cases they may be the remnants of hinge-teeth acquired in the ordinary way in the early geological history of the group. The Pholad Myophore. — In the most specialized group of all Pelecy- pods, the Pholades, a remarkable development of the subumbonal attachment of the mantle has produced a myophore which is sometimes wrongly re- ferred to as a tooth and which in Barnea costata and Zirphtea crispata sup- ports the visceral mass and the enormous fleshy palpi. The exceptional development of this feature is explained by the dynamics of Pholad existence. When we remember that the enormous foot is chiefly employed, during growth, in grinding away the sides of its burrow, and that its action for a long period is incessant and vigorous, it will be realized how important it is for the welfare of the animal that the visceral mass should be well supported and protected against the effect of sudden motions such as, in other mollusks, might en- danger its attachments to the valves. It is not surprising that natural selection should promote the development of any shelly process which is of use in affording this needed support. The initiatory stages of the myophore, as well as of the reflection of the anterior dorsal border of the valves, can be seen in Gastrochcena, especially if a thickened senile specimen can be examined. It may not be out of place here, while speaking of the Pholads, to point out the dynamic influences which have promoted the reflection of the dorsal anterior margin. Observation as well as theory shows, that in order that the rasping action of the foot shall expend itself on the walls of the burrow.it is necessary that the shell as fulcrum should be fixed ; otherwise the animal, instead of being able to rub the foot over the wall, would rub its valves about, while fric- tion would hold the foot relatively still. In ordinary cases the mere elastic tension of the ligament and the relaxation of the adductors would be all that could be reckoned upon to hold the valves against the walls of the burrow. Now if we should have an animal with the anterior adductor so situated on the dorsal margin as to be able to give a positive pull on the valves, so as to hold them open against the walls, instead of a merely negative relaxation, it is obvious that the efficiency of the creature as a boring machine would, at once, be much increased. The more effective the machine the less vital energy and time would be required for its work, and natural selection would at once begin to promote the development of the apparatus in the line indicated. It is prob- able that the dorsal progress of the muscle is initiated by the wide space, or gape, required for the foot to perform its functions in Gastrochcena, which re- duces the space available for the anterior adductor to a narrow triangle close to the dorsal margin. The reflection of the dorsal valve-margin, visible in Gastrochcena, has a use ; it renders the valves when wide open and fixed INSTITUTE OF SCIENCE, PHILADELPHIA. 497 against the walls of the burrow less liable to slip by one another at the dorsal edge, and thus reduce the effectiveness of the animal's grasp of them (if I may use such an expression). The energetic action of the foot and pedal muscles when at work, and the feeble character of the ligament in this genus, would render such an accident likely if the'valves where pressed against one another had merely a thin sharp edge. Their reflection gives a broader bear- ing surface and makes the hinge more secure. The fact that the anterior adductor is so much more nearly dorsal in its situation than the posterior, might possibly even give it a partially opposite pull, which, if true, would be all that would be needed to start the muscle, pushed by natural selection, on its dorsal journey. These hypotheses can be best understood by reading them with the specimens in hand, and I would ask any doubting readers to go over the matter with the shells before them. When once the dynamic influence of action and environment are made clear in a single instance, one can there- after hardly study any feature of the shell without having those influences in mind. The result is a flood of light on many points which have hitherto been accepted as mere inert facts. Given a full knowledge of the animal's motions, efforts and surroundings, with its immediate pedigree, and Lam fully convinced there is no feature of its more external and operative organs and structure which cannot be accounted for by a reasonable hypothesis, based on dynamic principles, promoted by natural selection. The origin of differentia- tion is the impact of forces, which drive, in each case, not all ways, but in one general direction ; which, having been taken, is narrowed to the most desirable path by natural selection. In this way, aided by heredity, all species, genera and groups of every sort have arisen. In given circumstances there may have been more than one path out of the melee, but the choice of paths in every case must have been determined by the preponderating dynamic forces of each particular case. Many superficial characters, especially color, are often the direct result of food or other factors of the environment, but modifications of the hard parts concerned in motion, bones, scales, shells, etc., invariably pro- ceed, as far as my own observation indicates, from a cooperation of force, natural selection and heredity. The Ligament and Resilium. — Embryology shows, according to the observations of Lankester and others, that the shell gland of embryonic Pelecy- pods is a single organ, somewhat saddleshaped, which crosses the whole region which in the adult is umbonal, and from which the paired valves are subse- quently developed. These valves (in Pisidiuiii) are originally somewhat dis- tant from one another and approximate with growth. The shelly matter of the valves in all Pelecypods is deposited upon a horny layer which protects the exterior from attack by acids in the water, wear, etc. ; and it is generally admitted that this layer, called the epidermis or periostracum, is continuous in the embryo and that that portion of it lying between the prodissoconchs (em- bryonic valves) is modified and developed to form the elastic link which 498 TRANSACTIONS OF THE WAGNER FREE connects them, allows them at a later stage to move freely upon it as an axis, and is known as the Ligament. The ligament may therefore be regarded as a fundamental character of the Pelecypoda and is universally present, though in some cases as a mere degraded rudiment (Fholadacea), and, in the case of Clilamydoconclia, where the valves are encysted in separate sacs covered by epithelial tissue, the adductors have vanished and there is no hinge, neverthe- less so strong is the influence of heredity that the ligament persists in a cavity by itself, disconnected from the valves, as a well-developed horny mass with- out function. The absence of a ligament in the Rudistcc, if primitive, would result in a perfectly unique mechanical relation of the valves and muscles, as I have elsewhere pointed out (Am. Jour. Sci., 1889, p. 461), and, considered in connection with their other characters, would effectively separate them from the true Pelecypods as a distinct division of Mollusca. It is, however, proba- bly only an extreme case of specialization. As the most important factor in the mechanism of the valves the ligament has undoubtedly developed with the development of the class and its chief modi- fications date from the earliest period of the development of the group. I have else- where shown that the function of the original ligament was that of an external link between the valves having the essential nature of a C-spring. That is, the insertion of the ligament edges on the external cardinal margins, or, with de- velopment, on thickened ridges, by which these margins are reinforced (the so-called nympha;)to bear the strains to which it necessarily became subjected, resulted in the following conditions : The valves being held together, and, in closing, approximated by the force exerted through contraction of the adductor muscles, the preservation of their precise apposition, marginally, is due to a rotary motion, exerted along the line of folding (or axis) of the ligament, which pulls the attached edges of the ligament nearer to each other and exerts a strain on its cylindrical exterior. This operation, with a thin ligament, in- volves a tensile strain on the whole cylinder ; with a thick ligament the exter- nal layers are strained and the internal layers compressed, so that, to the ten- sile elasticity of the external layers, is added the compressional elasticity of the internal portion. The latter condition is the most common among modern forms, though it is probable that the former was the original type. I have" also shown that the result of the differing strains to which the different layers of the ligament are subjected brings about a difference of structure, and, when the ligament becomes deep-seated for any reason, there is a tendency for the respective parts to separate along the line where the two sets of strains ap- proximate. We then have two elastic bodies, operating reciprocally in oppo- site directions, the outer or ligament proper tending to pull the valves open to a certain distance corresponding to its range of tensional elasticity ; and the other, the " cartilage," * or resilium, tending to push them open, to an extent * The so-called " cartilage," which Is not a cartilage, and which is frequently spoken of as " ligament " or " internal ligament," is In great need of a distinctive name, and I propose that of " resilium," which clearly indicates Its (unction, INSTITUTE OF SCIENCE, PHILADELPHIA. 499 corresponding to its range of expansion. Beyond the normal range in each case the ligament and resilium operate in the reverse sense of that which is respectively their ordinary function. The ligament proper (which will be called simply the ligament, in this piper) is of a more horn)' nature, tough, and semi-translucent beneath its external surface. When dry it has a vitreous fracture and often shows hardly any fibrous texture. Its tendency when functional is to break in planes at right angles to the axis of motion rather than in any other direc- tion. The resilium is distinctly lamellar or composed of parallel fibres, which are apt to give a pearly sheen to its broken surface. There is often a more or less extensive intermixture of lime in its substance, which may be diffused, or may be especially concentrated along the median plane, which is in many cases also the smallest or most constricted part of the cartilage. As may be seen by looking at the unbroken resilium, in Mactra, this organ in such cases has something of an hour-glass shape, the ends which fit into the " cartilage" pits or resilifers being more expanded than the centre between them. The deposit of lime in the form of an accessory shelly piece, usually termed the ossiculnin or htJiodesina, has for its purpose the reinforcement of the resilium. In those cases where the resilium and ligament have not separated, as, for instance, in Unto, it will often be found that a considerable amount of granular limy mat- ter has been deposited on and among the fibres corresponding to the resilium below the ligament. When fresh this may easily be detached, leaving the tougher ligament above uninjured. In the Paleopelecypod the ligament was short and central between and below the beaks of the valves. With the lengthening of the hinge line it be- came elongated ; with the development of asymmetry in the hinge it was shifted forward or back from the beaks, according to the particular case. The long hinge-line is more effective than a short one ; the long line, for reasons men- tioned elsewhere, is more likely to be developed behind the beaks than in front of them. Consequently the influence of natural selection may be surmised in the process of development, which has resulted in the almost universal pres- ence of the ligament on the posterior dorsal line of the shell, or at least behind the umbones. The greater efficiency of a long ligament would tend, when "lire it had been developed, to maintain it and with it the greater length of the side of the hinge where it was seated. However, the rule is not universal, and the nearer we approach the origin of the Pelecypoda the more numerous the exceptions appear, while among those recent groups, which include the more archaic types, several important divergencies may be noted. For the type of ligament which extends on either side of the beaks, Neu- mayr adopts the designation amphidctic, while for the more perfected type which has been withdrawn wholly behind the beaks he uses the term opistlio- dctic. Among modern forms Pectuncitlus offers a conspicuous type of the 5OO TRANSACTIONS OF THE WAGNER FREE amphidetic ligament, while Tellina or Venus may serve as examples of groups with an opisthodetic ligament. In many bivalves a lozenge-shaped cardinal area extends atnphidetically between the beaks, while the ligament is truly and wholly posterior, being visible as an oblique triangular space with its apex at the umbonal point and its base at the hinge-line, of which arrangement Avicula shows an excellent example. Nearly every stage of the recession of the ligament can be ob- served, from truly central to posterior, in Lima and its allies. In general, in spite of these differences, Neumayr alludes to the species having an amphi- detic area as if the ligament partook of the areal extension. No part of the animal has accommodated itself to the dynamic influences attending growth and evolution more effectively than the ligament, and this is probably because strains and stresses are transmitted to it through the rigid valves rather than by the more elastic tissues. The most perfected type of liga- ment is that which may be compared to a cylinder split on one side, attached by the severed edges, one edge to each valve. For this type (Tellina, Psatn- mobia, Cardiuiti) I propose the term parivincnlar ; its long axis corresponds with the axis of motion or vertical plane between the valves. It is always opis- thodetic. Another form is like a more or less flattened cord extending from one umbo to the other (Spondylus, Lima, Avicula), with its long axis transverse to the plane of the valve margins and the axis of motion. This I call alivinc nlar ; it may be central or posterior to the beaks, but, unless very short, is usually as- sociated with an amphidetic area. Lastly, a third form must be noted which consists of a reduplication of the alivincular type at intervals upon the area (Perna,Arca, Fossuld), either amphidetically (Area), or upon the posterior limb of the cardinal margin. This may be designated as ntultivincular. The species of this type begin life with an alivincular ligament. In the Arcidce the cardinal area is often covered with a glossy, dark-col- ored coating which might be mistaken for an outspread ligament from which the true ligament, which is set in grooves hollowed out of the area, might be thought to be representative of a resilium. An examination, however, will show that the glossy coating is merely modified epidermis and is not continu- ous between the valves, which are connected only by the multivincular liga- ments. In some forms, with a rigid hinge and internal resilium, the ligament may degenerate to its archaic epidermic character, as in some species of Spo n- dylns. It is impossible to draw a sharp line between these and similar forms in which the ligament is not quite reduced to the state of epidermis, as in some species of Ostrea. The hinge (or cardinal) area above referred to is in part the morphological equivalent of the lunule of Teleodont pelecypods. In general, when the ligament has become opisthodetic the remnant of the area in front of the beaks forms the lunule and may be called prosodetic. The escutcheon may or may not be homologous with the posterior part of the original area. The latter is an archaic feature which has been lost by the more specialized types of s INSTITUTE OF SCIENCE, PHILADELPHIA. 5OI modern bivalves. Its gradual disappearance may be traced in various Priono- dont genera. In Unio, for instance, the ligament is parivincular and wholly opisthodetic, but in front of the beaks in most species is a depressed space, homologous with the lunule of Venus, over which the epidermis:^ faised in dense elevated lamella: which, to a careless inspection, seepr-like ,a tion forward of the ligament. It was probably this which led Neuiriayr co r tlu- Naiades as having an amphidetic ligament. A careful inspection, especially of fresh specimens, will convince any one that the functional ligament is wholly posterior. Trigonia is in the same condition as far as the ligament is con- cerned. The insertion of the ligament on the cardinal margin and the action of natural selection lead to the formation of nymphae or ligamental fulcra in thin shells, and the development and prominence of these often increases as the shell grows thicker. There seems to be a point, however, beyond which in- creased nymphal surface adds nothing to the security of the hinge, and conse- quently is not promoted. As forms with thicker shells develop, the solidity of the valves is sufficient to resist all strains, and the nymphae are not corre- spondingly increased. But in many such cases the margins of the groove in which the insertion of the ligament lies are elevated, thus protecting the joint externally as well as internally. Dosinia is a good instance of external pro- tection, and many heavy Uniones of the internal. As a large part of the growth of the ligament is at the ends, there is generally a thin, more or less flexible free edge or point medially behind; and, especially in Unio, A thin edge of liga- mentary substance at the hinder end of each nymph. In Unio this may usually be noted, in the heavier and particularly in the alate forms, as a sinus in the pearly surface of the posterior dorsal margin, covered by a brownish veneer of ligamentary substance. It is hardly necessary to repeat the description of the mechanical process by which the resilium is separated from the ligament when the latter is thick and short.* The gradual submergence of the resilium in many forms is read- ily accounted for by the agency of natural selection, when we remember that the nearer the center of the animal the axis of motion is placed, the more effective and rigid its operation with relation to the apposition of the valvular margins. With a well-developed hinge, and deep set resilium, the cardinal functions are often so well performed that the ligament, if parivincular, may degenerate and become no longer functional, or, if narrow, may (as in Rangia or Mnlinia) follow the cartilage below the outer surface of the hinge-plate. In this case it may descend into the same pit (as in Mnlinia), or into a separate cavity (as in Cyclomactrd). These peculiarities will be more fully discussed in treating of the Mactracea. Crassatellites offers a parallel example. In connection with the submergence of the resilium we may consider the reinforcement of the pits in which the ends of the organ are attached to the • See Am. Journ. Sci. xxxviii, 1889, pp. 418-451. 502 TRANSACTIONS OF THE WAGNER FREE shell. Coincidently with its submergence the area of attachment must de- scend from a position on the upper outer margin of the hinge-plate to one upon the plate itself or excavated, so to speak, out of the mass of the plate. The strengtheni'.ig of the hinge-plate to bear the strains resulting from the new position. of the resilium, must proceed, pari passu, with the descent itself. Thus W£ find jn the thin-shelled Anatinacea the pit, being reinforced by a special thickening about it, assumes a spoon-like form projecting from the hinge- plate, generally supplemented by a special prop extending to the surface of the valve, and also in many cases by the formation of an ossiculum which supports the central and weaker portion of the cartilage or even takes its place. Among the various names which have been proposed for this spoon-like process, that of Chondrophore is perhaps the most generally used. It is a curious fact that among the thin-shelled Anatinacea, owing to the sturdy resistance to the clos- ing of the valves offered by the resilium and its accessories, and the dispropor- tionate stress exerted by the adductors, an umbonal fracture just behind the line of the chondrophore has become habitual (Thracia, Anatind). The dan- gers which might threaten the animal from this breach of its defences seem to be avoided by the deposition of conchioline along the fracture and doubtless also by the deep-burrowing habit of these mollusks. Conversely, in heavy shells with a solid hinge-plate and thick umbones adequate to the strains put upon them (Crassatellites, some Mactrida;) no pro- jecting chondrophore, prop or ossiculum is developed, but a flat surface or shal- low pit is sufficient for all purposes. It should be remembered also that in the few thick-shelled Anatinacea (Euciroa, Entodesma) no chondrophore is developed, though the internal resilium is reinforced by a stout ossiculum. It has been suggested by Neumayr and the writer that part of the armature of the hinge, in the shape of teeth, is due to deposits made parallel to or induced by the presence of the chondrophore and resilium. In another part of this paper it is shown that those shelly plates, here named accessory lamellse, are formed thus in the Mactracea, and there is some reason to think that the pres- ence of the resilium in Pecten and Spondylus is not unconnected with those changes of the auricular crura which lead to the assumption of dental func- tions by the latter and to the obsolescence and even disappearance of the true hinge-teeth. But it is well known that submergence of the resilium takes place in various unrelated groups of bivalves, independently, and the writer believes that most of these forms were furnished with teeth at the time these changes were initiated ; and that these teeth, more or less modified or partially displaced, still persist in the dentiferous forms ; while the edentulous genera have seldom developed any teeth which present the appearance of being due solely to the presence of the chondrophore. The nearest approach to a hinge composed of dental lamina: of such an origin is found in Placuna, Placenta and Placiinanoinia, together with the Spondylidce already mentioned; while in the so-called Dcsmodontaot Neumayr, INSTITUTE OF SCIENCE, PHILADELPHIA. 503 as far as they have teeth, exception being made of the accessory lamellae, the hinge is truly heterodont, and in its typical form probably owes nothing to the influence of the internal cartilage, The Adductor Muscles. — The number and position of the adductors was formerly accepted as a fundamental feature in classification. The results of later researches have shown that there are many exceptions to any rule which may be used for classification. The Dimyaria comprise at least one monomyarian family (Tridacnidce), and among the Monomyaria the dimyarian Diinya must find a place. Mulleria is dimyarian when young and monomy- arian when adult. Cklamydoconclia has no adductors at all. For these rea- sons an absolute foundation for classification cannot be afforded by the number of the adductors, yet if allowance be made for degeneration caused by inequi- laterality, torsion, and other causes, the general myarian types fall in fairly well with the larger divisions based on the totality of characters. The Siphons. — In all Pelecypods there must be a path for water to ap- proach the branchiae and another for it to be discharged from the branchial region without again passing over the gills. The Paleoconclia were, doubtless, without siphons, but the necessity for the separation of the two currents is such that the mantle was doubtless in some cases very soon modified to that end. Forms evidently very similar to Leda, which has well-developed siphons, appear very early in Geological time. The fouling of the water which ap- proached the gills, by discharges from the rectum, or its deterioration by mix- ture with that which had already by one passage over the gills been, to some extent, deprived of its oxygen and food-contents, would obviously be a physio- logical misfortune, and injurious to the mollusk, consequently various arrange- ments for preventing this evil were soon developed. In some cases the man- tle-edge, though not actually connected, was sometimes so folded as to practi- cally form two tubes, by one of which water was drawn in and by the other discharged (Trigonia, Unio). Connections were finally established between the partition-like folds of the edges of the opposite lobes of the mantle, and, in the Naiades, these may, at present, be sometimes connected, sometimes discon- nected, in the same species (Castalia, etc.). In various forms, especially the burrowers, the tubes thus initiated were soon modified, developed and im- proved. Long separate tubes enabled the effete products to be discharged in a direction different from that by which fresh water was inhaled. Sensitive papilla? at the orifice of the incurrent siphon enabled the animal to avoid in- draughts of mud or obnoxious substances. In species in which long siphons were not developed, and in some siphonate forms, a partition or septum was often produced which extended forward so as to practically separate the cavity of the mantle into an anal and a branchial chamber (Perna, Lophocardintn, Anatina). But these changes were not respectively confined to the several principal phyla of the Pelecypoda, but were more restricted in their scope. In general among those forms which were most active (Pecten, Lima, Nucula, Trig- 504 TRANSACTIONS OF THE WAGNER FREE onia, some Cardiums), are found the cases where no siphon or septum has been developed ; the less active (Avicula, Pinna, Tridacna, Astarte) have at least a septum of some sort, while the most perfected among the modern types (7W- litia, Mactra, Venus, Mya, Yoldia) have a pair of well-developed siphons, fre- quently supplemented by a septum. These siphons, being a local modification of the mantle margin, receive their musculation from the same source. In general the muscles have spread inward, pan passu, with the increase in length of the organ to be retracted, and their insertion on the valve leaves scars in the shape of a sinus, which is an important aid to classification of the minor groups. It has been sometimes assumed that the absence of this sinus was evidence of the asiphonate character of the species, but the example of Litcina, which has no sinus, and recent re- searches in several other groups show that this is not necessarily true. In Cus- pidaria with long siphons there is no pallial sinus, the retraction of the siphons is accomplished by the contraction of the muscular septum. In Demiatoiitra, with short siphons, the transfer of the muscular retractors from the mantle to the septum can be seen in progress. There is no rule without more or less marked exceptions, consequently the use of this feature in classification must be confined to minor groups. The Gills Or Branchia.— Of late, among morphologists recognixing the partial character of the muscles and siphons as foundations for classifica- tion, there has been a tendency to fall back on the characters afforded by the breathing organs. Embryology shows that the gills take origin as a single ridge on each side of the body, from which single filaments are put forth. Diinya illustrates, among recent mollusks, this type of gill, but as in Dimya the filaments are confined to one side of the ridge forming the base and are of the ordinary filibranchiate type, except in wanting the reflection found in most fili- branchs, it may be surmised that here we have merely a case of reversion to- ward the ancestral type through degeneration of a gill which at one time bore two rows of filaments. In a general way the ctenidium of a recent Pelecypod is composed of a stem carrying a nerve and blood-vessel (sometimes both artery and vein), from which on each side leaflets or slender filaments are given out laterally. In the more archaic types (Nucula, Yoldia, Solemya) these leaflets are plate-like, not organically united except by the stem, though in some cases obtaining some solidarity, as a mass, by the interlocking of very large cilia, distributed in bands or patches on the opposed surfaces of individual plates. In Eiicinxr the stem supports laterally elongated trilobate plates, the outer limb united to the mantle distally, and the inner to each other behind the foot ; the outer lobe corresponds to the reflected portion of its limb in other types of gill. Near the stem a few organic connectives maybe found between opposed plates, and the dorsal edges are knit by longitudinal muscular fibres, sparsely disposed, but the main body of the plates are connected only by bands of inter- INSTITUTE OF SCIENCE, PHILADELPHIA. 505 locking giant cilia near their ventral edges. This form offers one step on the way to a gill intermediate between the foliobranchiate and reticulate types, which have hitherto been separated by a considerable gap. A similar step in the filibranchiate direction is offered by the abyssal Callocardia, which most unexpectedly proves to have a gill wholly distinct from its shallow-water rela- tive Isocardia. In Callocardia the greatly-elongated and reflected ribbon-like plates on either side of the stem are fleshy and free, as in Nucula, without any trace of reticulation, but are united by a slender band of connective tissue (possibly carrying a blood vessel, though none could be detected) at their tips. If the strap-like plates of Callocardia were narrowed until they became rod-like and the distal fibre omitted, there would be hardly anything except the chitinous skeleton of the filibranch to separate the two types of ctenidia. The gap between the gill of Nucula and that of Pecten or Area, has hitherto been very wide, but the discoveries in regard to Eitciroa and Callocardia (cf. IVoc. U. S. Nat. Mus., vol. xvii, 1895) show that the theory which re- garded them as specializations of a single type was not ill-founded. The dis- tribution of these intermediate or subfoliobranchiate gills is not confined to a single order, but they appear in abyssal members of two different orders ; and their nearest shallow-water allies have reticulate gills. This shows, in the opinion of the writer, that systems based on a single character, whether gills, siphons, muscles or what not, are bound to prove unsatisfactory as our knowl- edge of intermediate types advances ; and that almost any group may have among its members some which retain archaicisms longer than the rest. In such cases the persistency of these characteristics should not oblige us to ignore relationship indicated by other features of the animal. Any permanent classification must necessarily be eclectic, considering all characters and dis- tinguishing sufficiently between genetic and adaptive features. The Nuculoid type of gill has been named Foliobranchiate or Protobranchiate, for the inter- mediate forms above mentioned the designation of Subfoliobranchiate may be used. The filamentous gill nominally comprises two series of descending or direct filaments, one on each side of the stem carrying the blood vessel. These may be straight and not reflected, but more usually descend some distance and are then reflected upward externally. The filaments are usually stiffened by minute chitinous rods, but in some abyssal species are soft and perfectly flexi- ble in any direction. To this general type the name of Filibranchiate has been applied. It is confined to the Prionodesmacea. though not all Prionodesmacea are filibranchiate. In the typical ctenidium of this type, exclusive of the stem, the filaments are connected with those adjacent to them only by interlocking cilia disposed in patches or upon the enlarged distal ends of the filaments. Aiwmia, Area and Diinya are examples. The next step is the connection of the successive filaments by vascular branches or connective tissue forming a reticulate gill. This, once initiated, TRANSACTIONS OF THE WAGNER FREE has resulted in a most complex and divergent multitude of subordinate forms >i gill, which are connected by all shades of differentiation with the filibranchi- e gill and with each other. In some forms the ascending external lamina is again slightly reflected at its upper edge, forming the so-called " appendix " Lardmm, Mactra, sp.), in others portions of the laminae are aborted In Lasea the direct external lamina is shortened and its reflected part is absent in some species of Lucina only the direct and reflected inner laminae remain 'while in the Anatmacea the most chaotic condition obtains, some forms havin- both rect and the inner reflected laminae; others having the equivalent of the two direct laminae ; while in still others the branchiae are more or less completely sorted or merged in the peripedal septum. The very great variety which uns in the form and structure of the gills throughout the Pelecypoda as a Class, should be a sufficient warning against the use of their structural differ- nces and minor details as a fundamental basis of ordinal subdivisions The I to be obtamed in the development of gills is the aeration of the circulation and incidentally the avoidance of foul water and the collection by ciliary action food particles. The development of the greatest superficial aerating sur- e with the least expenditure of tissue is capable of being approximately in so many different ways, that there is no occasion for surprise at the nultitude of forms which have been evolved. In cases where the minor struct- f the gill has been taken as a systematic character of primary importance the diagnoses have often been saved from being ridiculous only by ienorine' the exceptions to the rule. The Heart.— It is probable that in the Proto-pelecypod the heart was double, with a ventricle and auricle on each side connected by an aorta above and one below the rectum. This state of affairs continues in the Area HOC, and 1 of its allies. In the course of development the ventricles have become 1 in the medium line in many groups, their extensions clasping the rec- tum, which thus appears to pierce the ventricle. In Nucnla and Trigonia while an appearance of duplicature persists, the ventricle is practically single and in the vast majority of Pelecypods it is single, both in fact and appearance It has been argued that the radical form was an unpaired ventricle dorsal e rectum, with a single anterior aorta, and this view has certain points in its favor, but on the whole the view here adopted seems at present better sun- ported. If in the process of consolidation the aortal arch below the rectum should by degeneration, we should have a ventricle with an anterior aorta rest- upon the rectum, as is actually the case in some species of oyster. If, on the contrary, the superior arch was aborted, we should have the ventricle ven- tral to the rectum as in Pinna. If one anterior and one posterior limb of the double arch should abort, we might expect a ventricle retaining an anterior and posterior aorta but still 'free from the rectum, as in Nucula, where it lies above the gut, or some oysters INSTITUTE OF SCIENCE, PHILADELPHIA. 507 where it lies below it. In Tridacna, owing to the abortion of the anterior and the displacement of the posterior adductor, together with a rotation which has nearly reversed the animal relatively to the valves when compared with ordi- nary Teleodesmacea, the heart has come to occupy a position which, though morphologically the same, is actually almost reversed with respect to the um- bones. In Teredo, Perna, Avicula and some species of Ostrca, the rectum is dorsal to the ventricle. In Plioladidea the latter is traversed by the rectum in the ordinary manner. In Anoinia the heart is not enclosed in a pericardium, but lies free in the pallial cavity at some distance from the gut. In Euciroa the ventricle is pyriform, free and dorsal to the gut, but in the allied Halicardia it is of the normal type, and embraces the rectum. The fluctuation in structural relations of the Pelecypod heart are such as to give it only a slight value for systematic purposes, though its archaic char- acter, in Nuciila and some Arcacea, accords well enough with the evidence from other sources of their retention of some prototypic features. The Nephridia, or Organs of Bojanus. — While so far not available for classificatory purposes, mention may be made here of the nephridia, which serve as execretory organs independent of the alimentary canal. These are two symmetrically situated organs, lateral to the pericardium, with which they communicate by ciliated canals. Externally they open near and behind the genital openings, close to the cerebrovisceral commissure, or the genital glands may discharge into the channel which serves to carry off the nephridia] secretions. Primitively the oviducts opened directly into the cavity of the nephridia, but at present this arrangement is rare. The cavities of the two nephridia (except in Nuciila, etc.) are frequently united, either by a special channel connecting the two, or the common cavity may have no division during a considerable part of its extent, as in many Anatinacea. The cavity is usually much ramified, divided by bands of connective tissue covered with glandular epithelium, which in many Anomalodesmacea secretes not only liquid excreta, but concentric limy concretions which mrght easily be taken for eggs on a casual inspection. The ramifications of the nephridia extend frequently outside of the visceral mass, between the walls of the mantle. These in the Lyonsiellidtz are produced inward as a free lamina into the peripedal cavity, and form a large part of the septum to which the gills are attached in some species. The nephridia are most simple in the most archaic types, such as Nuciila and Solemya. Most of the blood from the lacunary sinuses passes through the nephridia on its way to the gills, and there can be no doubt that the glands perform a renal function. The more archaic the type, the more simple the form of the nephridium, which gradually approaches the form in which the same organ appears in some Gastropods. The Foot. — In a large majority of the bivalves the foot has the familiar hatchet-shape from which the class name is derived, but as an organ of loco- motion, tactile use, and possibly prehension, it is modified for special uses in 5°8 TRANSACTIONS OF THE WAGNER FREE many forms. It may be supposed that in the prototypic bivalve it had a flat, crawling surface, such as is found in Nucitla, Yoldia, and other recent but archaic forms. It is possible that in the Nucnlidic, Ledidie, Arcidce and Soi- emyidic the existing groove, which, by expansion, can be converted into a flat surface, is a survival. A somewhat similar surface is produced by an ex- pansion of the foot in some species of Macoma, Trigonia, Lepton, Callocardia and Galcoinma, and here can hardly be anything but a special modification of the ordinary type, adapted to the peculiar habits of the species, since there is no permanent groove. The modification of such a surface into the hood-like form which the foot assumes in certain deep-water Pectens would be easy, and in those cases it has the aspect of a sucker. In other groups we find a phalliform ( Verticordia, Poromya), clavate (Ln- cina), or digitiform (Mytilus) organ. In the Solenidte and Mycetopiis the foot is obviously modified for boring purposes, and, in the Pholads, as a triturating organ. We conclude, therefore, that the form of the foot, like that of the heart, is of little service as a basis for systematic classification, except in minor subdivisions. In a few cases, such as Ostrea, it is altogether aborted, though remnants of its retractor muscles exist and are attached to the valves. In a few mollusks, such as Plioladoinya and Halicardia, an accessory fin- like organ, or opisthopodium, is developed at the posterior end of the visceral mass. It is possible the small, valve-like aperture noted in Pa no pea, Lnlraria, and many Anatinacea, may be a reminiscence of a time when the opisthopo- dium was more common and required a foramen in the adherent mantle edge for the performance of its functions. Faint traces of the grooving on the ventral edge of the foot occur in many Pelecypods. The deeply-grooved foot, which can be expanded so that the sides of the groove when in one plane will form a surface upon which the ani- mal may crawl or with which it can push, may in the interest of brevity be called reptary ; the lingrooved foot, which can be expanded as a plane, subrcp- tary. The ProdissOCOnch. — The embryonic shell, corresponding to the proto- conch of Gastropods, has been named by Jackson the Prodissoconch. In general these valves are very uniform in character, as seen on the tips of the uneroded valves of the adult. They are usually rounded or slightly pointed at the umbonal end, in their earliest stages having sometimes a straight, rather long hinge-line. In Solcmya the prodissoconch is elongate, rounded at the ends, with the ventral and dorsil margins nearly parallel, much as in the adult shell. In Pinna the prodissoconch is globular as in most bivalves. In Unio and Anodon a second or nepionic stage is traceable, owing to a semiparasitic habit of the young, which leave the mother and become encysted on the fins or gills of fishes ; during this period the shell remains stationary, though some development of the contained soft parts is in progress. This nepionic stage INSTITUTE OF SCIENCE, PHILADELPHIA. 509 was first described as a parasite under the name of glockidiitm. The only ma- rine form yet shown to possess a glochidium stage is the Aviculoid genus Philobrya Carpenter. It is not found in the South American MutelidcE,vi\\\c\\ have a different type of larva, named by Ihering a Lasidinin. General Classification of the Pelecypoda. — Having referred to the chief features of the pelecypod type which are available for systematic use, and their variations, it remains to adopt for use in the subsequent descriptive portion of this work such an arrangement as shall best express the relations of the groups and at the same time take account of those characters which are available for the Paleontologist. Continued study has confirmed me in the opinion that, in its general features, the classification of 1889 proposed by me, as now revised, comes nearer to meeting the requirements of the case than any other which has fallen under my notice. There are several questions which, i11 the present state of the science, can- not be finally answered, and any decision upon them must be subject to differ- ence of opinion. One of these is the disposition to be made of the synthetic types classed by Neumayr under the name of Paleoconclia. These forms with- out doubt represent more or less clearly the earlier forms, now unknown, from which many of the modern genera have descended. Some of them are off- shoots which came to an end without recognizable descendants. Others com- bine archaic features with peculiar modifications which the action "of natural selection has since eliminated. Few if any of them are sufficiently salient in their characters to permit of being confidently referred to one suborder of the recent fauna rather than another. Some of them exhibit features which recall characteristics of the Taxo- dont forms which were at the same Geological age well established in numer- ous representatives. Others might be taken as the prototypes of Anomalodes- macean or Teleodont genera. Logically all our modern types should converge as we recede in Geological time, and that they do is obvious. Shall we then struggle more or less ineffectually to allot each Paleoconch to its place in the then undeveloped larger groups of later faunas? Or shall we accept the name offered by Neumayr as a temporary resting place for these undifferentiated ancient types ? As a matter of convenience, solely, I am inclined to the latter course, until more is known. Among the Paleoconchs Neumayr was disposed to place the recent genus Solcmyit Lamarck (more correctly Solenomya), which by Fischer was placed near the Anatinidce, in the Anomalodesmacea. For some time I was inclined to adopt this view, rather because Solemya offered such a unique individuality, apart from its purely archaic features, that there did not seem to be any very satisfactory grounds for a different course. But I have finally concluded to regard the genus as a very aberrant Prionodont for the following reasons : The gills and foot agree very closely with those of the Homomyarian Prionodonts. These might, however, be merely archaicisms in common, mutable and exter- 510 TRANSACTIONS OF THE WAGNER FREE nal characters. But the presence of a distinct pleural ganglion, and of an cesophageal dilatation with lateral, possibly salivary glands, which is affirmed for both by recent morphologists, are more deep-seated and important char- acters. As a trifling makeweight it maybe mentioned that in the whole group of Anomalodesmacea there is no instance of such an epidermis as that of Solemya, while in the Prionodesmacea it is frequent ; and Carpenter has shown that the shell-structure is not only externally prismatic but " its internal layer also exhibits in many parts a cellular arrangement that strongly calls to mind the prismatic cellular structure of Pinna and its allies." For these reasons I have decided to return to my first arrangement of 1889 and place Solemya with the Prionodesmacea. The typical form of the genus goes back to the Carboniferous, and there is a variety of forms of the same and later age which, though different, seem to be connecting links be- tween the Solemyacea of that time and other groups. While the imperfections of the following provisional classification are only too evident to its author, and will justly be criticised by malacologists, it has claims to one merit, which is that the groups, whether well or ill, have been comparably defined. If those who have hitherto proposed new systems for this class, had been obliged to differentially define their groups, with strict re- gard to the known facts, the synonymy would be much smaller and the sys- tems fewer. It must be expected in any classification that specialized excep- tions will occur in nearly every large group. That they do is no reflection on the general accuracy of the grouping. But in several recent attempts at dividing the Pelecypods, the so-called definitions are chiefly remarkable for the little they offer that affords a sound basis for an effort to estimate their value. It should be understood that, in the following definitions, characters stated as diagnostic of larger groups are not recapitulated in the diagnoses of their smaller subdivisions, and are then referred to only when specially modified or exceptionally absent. Thus, to obtain all the characters of a family, those of the ordinal, superfamily and other groups, which include the family, must be taken together and modified by the specifications of the family diagnosis. INSTITUTE OF SCIENCE, PHILADELPHIA. 51 1 CLASS PELECYPODA. Aquatic, bilaterally symmetrical, acephalous mollusks, protected by a pair of shelly valves secreted by the lateral portions of the mantle, connected by a ligament, and moved by the contraction of muscles which connect the inner faces of the valves ; feeding by ciliary action anil destitute of a radula or jaw ; breathing by lateral gills, the type of which is a midrib or stem, with a row of transversely oriented leaflets or filaments depending from each side of the stem, single, or mutually combined to form a direct or reflected plate; imper- fectly sensible to light and rarely provided with peripheral visual organs; pos- sessing olfactory organs (osphradia), auditory and equilibrating organs (oto- cysts), tactile papillae and a nervous system composed of (usually three princi- pal pairs of) ganglia united by nerves, but without a pedovisceral commissure; provided with an extensile tactile or locomotor organ (foot) ; a closed, though partly lacunary, circulatory system, containing (usually colorless) hasmo- lymph, and operated by a single or paired cardiac ventricle and two auricles ; a more or less convoluted intestinal canal, with its oral and anal extremities at opposite ends of the body ; a stomach ; paired nephridia, connected with the pericardium, and discharging independently of the rectum ; reproducing with- out copulation, by eggs and spermatozoa ; monoecious or dioecious ; develop- ment external to the ovary ; the post-larval young protected by a prodissoconch, and sometimes exhibiting a nepionic stage ; with a distribution in geological time from the Cambrian to the present day. The class appears to be subdivisible into the following groups, of which the third represents the most perfected (though not always the most special- ized) modern type of Pelecypod. There seems little reason to doubt that all these orders are descended from a Prionodesmatic radical, or prototype, and that, for various reasons, the first and second retain more evident traces of their origin than the third. Order PRIONODESMACEA. Pelecypods having the lobes of the mantle generally separated, or, when caught together, with imperfectly developed siphons ; the soft parts in general, diversely specialized for particular environments ; the shell structure nacreous and prismatic, rarely porcellanous ; the dorsal area amphidetic or obscure, rarely divided into lunule and escutcheon, and when so divided, having an amphidetic ligament ; ligament variable, rarely opisthodetic ; armature of the hinge characterized by a repetition of similar teeth upon the hinge-line, or by amorphous schizodont dentition; habits active, sessile, or nestling, not burrow- ing; monoecious or dioecious. This group, originating with the earliest forms, has retained many archaic features through immense periods of Geological time, developing from age to 512 TRANSACTIONS OF THE WAGNER FREE age remarkable and persistent specializations. Though most of its sub- divisions have arrived at a notable degree of distinctiveness, intermediate forms of ancient date connect them all, more or less effectively, with the parent stem. Order ANOMALODESMACEA. Pelecypods having the mantle lobes more or less completely united, leav- ing two siphonal, a pedal, and sometimes a fourth opening between them ; siphons well developed, always at the posterior end of the body ; two sub- equal adductor muscles ; the shell structure nacreous and celliilo-crystalline, rarely with a prismatic layer; the area amphidetic or obscure, rarely distinctly divided ; the ligament usually opisthodetic, generally associated with an in- ternal resilium, chondrophores and lithodesma; valves generally unequal, the dorsal margin without a distinct hinge-plate, the armature of the hinge feeble, often obsolete or absent ; rarely with lateral lamina; or well-developed dental processes ; the animals usually sedentary burrowers, hermaphrodite and marine. This group is intimately related to many Paleoconcha, except in the presence of a pallial sinus. It retains many archaic characteristics, and in- cludes several of the most peculiarly specialized modern forms. Through the Anatinacea it approximates to the Myacean Teleodesmacea. It is peculiar in the possession of a lithodesma, and in the structure of its gills and hinge. The forms with a reticulate gill have it of a different type from the reticulate gills of the other orders ; those which retain a modified foliobranch gill have it different from the foliobranch gill of Prionodesmacean groups. There are no forms with a filibranchiate gill, or with a typically fully-developed reticulate gill. Order TELEODESMACEA. Pelecypods with reticulate gills, the ventricle of the heart embracing the rectum ; having the lobes of the mantle generally more or less connected and usually possessing developed siphons ; the adductors practically equal ; the shell structure cellulo-crystalline (porcellanous) or obscurely prismatic, never nacreous ; the dorsal area, if present, always prosodetic or divided into lunule and escutcheon ; ligament opisthodetic, with or without separate resilium ; without a lithodesma, rarely with external accessory shelly pieces; armature of the hinge characterized by the separation of the hinge- teeth into distinct car- dinals and laterals, the posterior laterals when present are behind the ligament ; the animals active or nestling, sometimes sessile, but rarely sedentary burrow- ers, rarely inequivalve, usually possessing a hinge-plate and a pallial sinus. The sexes usually separate. This group is doubtfully represented in the Paleo- zoic rocks and especially below the Carboniferous, though foreshadowed by some of the Paleoconcha. Though many of them live imbedded in the surface of the sea-bottom, they are more or less migratory and only a few extremely INSTITUTE OF SCIENCE, PHILADELPHIA. 513 specialized fo rms inhabit permanent burrows of their own excavation. They are sometimes commensal in the burrows of other animals. Similarly, though often byssiferous, especially when young, few of them fix themselves perma- nently by a byssus. With the exception of a few specialized forms they pos- sess a pair of direct and reflected branchial laminae on each side of the body, frequently united behind the foot, forming an anal chamber ; the two sets on one side usually of unequal size, and of the reticulate type. None are known with typically foliobranch or filibranch gills, though some abyssal forms have archaic subfoliobranchiate ctenidia. The Paleoconcha. Prototypic Pelecypods, with thin shells, a simple or obscure pallial line, subequal adductor scars placed high in the valves; dorsal area absent or am- phidetic ; ligament external, variable ; hinge margin edentulous or with poly- morphous teeth formed by modifications of the margin and not set upon a hinge-plate (Neumayr). While the forms included here are not always actually the most ancient, yet in their modifications they indicate clearly the origin of many subsequently developed structures found in Pelecypods of a more modern type ; and by their undifferentiated polymorphic character are difficult to assign a place in any classification based on more fully-developed forms. Neumayr included in the group the following families : Vlastidae. Protomyidae (including Cardiolidae. possibly the recent Soletnya). Antipleuridae. Solenopsidae. Lunulicardiidae. Grammysiidse. Prascardiidae. Posidonomyidse. Silurinidae. Daonellidae. Of some of these there is little doubt that they show taxodont affinities, and others recall Pkoladomya, but the final discussion of these puzzling forms awaits greater knowledge of them and other early bivalves. The subdivisions of the orders will now be considered. No linear ar- rangement is practicable to show all the relationships. The earlier members of the older groups converge, as a matter of course, and are assigned places by an estimation of the preponderance of affinities, which cannot be infallible, and upon which opinions will and must justly differ among students. It is quite possible that, especially among the older forms, the number of families will have to be increased with a future greater knowledge of the fossils. In a few cases, where the author has not felt able to form an opinion, some groups proposed by others have been omitted. In giving a list of genera included in the families adopted, it must be borne in mind that these lists are not intended to be exhaustive, and are given merely to exemplify the types associated under the family name, without pretending to enumerate them all. The larger sub- 5 '4 TRANSACTIONS OF THE WAGNER FREE divisions of the orders have been ranked as superfamilies, rather than sub- orders, as formerly, as it seemed as if this term more fairly expressed their relative rank. No attempt has been made to revise the nomenclature of these lists, except in a few obvious cases ; in general they have been taken from the Manuals. Subgenera have only been mentioned when there seemed to be special reason for so doing, but the writer does not wish to be understood as expressing in this place any fixed opinion as to the validity of the genera cited. When a name, family or generic, is preceded by a mark of interrogation, it will be under- stood that a doubt is intimated as to the proper location of the group in the system ; when the mark of interrogation follows the name, there is question as to its value or validity as a group. In a work of this sort, which necessarily depends largely on the literature for its data, it is not practicable, for reasons of space, to refer every item to its source. All accessible sources have been consulted and especial use has been made, on the paleontological side, of the works of Neumayr, Zittel, Hall, Stol- iczka, Steinmann, Bittner, Paul Fischer, Dr. R. T. Jackson and E. O. Ulrich ; as regards morphology, Owen, Hancock, Deshayes, Paul Fischer, W. Clark, Arthur Adams, Jeffreys, Coupin, Pelseneer, Menegaux, Rawitz, Grobben, J. L. Kellogg and others have been laid under contribution. Whenever alcoholic or fresh material has been accessible, it has been compared directly with the literature, with useful results in many cases. Recent observations by the writer on several deep-sea forms have thrown light on several vexed ques- tions. In general the impression derived by the writer from this review of the characters hitherto available for classification, is confirmatory of the opinion previously expressed, that no classification based on single characters will be permanent and that we may anticipate much from the continued, more thorough and more rational study of the fossil forms taken in connection with their recent analogues. Such work as that of Hyatt, Branco, Waagen and Jackson is the best refutation of the short-sighted and narrow views which have been expressed by sundry budding morphologists, as to the nature and systematic usefulness of the shelly parts of the anatomy. There can be very little doubt that a more thorough exploration of the deep sea will greatly enlarge our knowledge of anatomic modifications in the Pelecypoda, since it would seem that, in that region, not only may certain most interesting specializations abound, but many archaic features, which have wholly disappeared in the com- petitive struggles of the shoal- water fauna, are still retained in an approxima- tion to their original form. The minute study of successive faunas in a single region, which is nowhere more practicable than in the region of our Southern Tertiary, will, without doubt, throw great light on the development of many groups, when studied in connection with the dynamic relations of the parts of the organism. With INSTITUTE OF SCIENCE, PHILADELPHIA. 515 this, and with the help of the morphologists, we may reasonably hope in time to arrive at a rational and genetic classification. Order PRIONODESMACEA I (Without Teeth). Superfamily SOLEMYACEA. Shell thin, elongate, practically equivalve, low-beaked, with a conspicuous epidermis, substance prismatic ; hinge edentulous ; anal and branchial foramina not separated ; gills foliobranchiate ; pleural ganglion distinct, both adductors present; non-byssiferous. FAMILY SOLEMYID^. Shell soleniform, gaping, with the anterior end longer and the epidermis conspicuous, exceeding the valves ; area obscure or none ; ligament amphi- cletic, parivincular, becoming internal posteriorly; mantle lobes united ven- trally, attached in front to the epidermis and valves by a broad surface, leaving no distinct pallial line ; a single posterior siphonal and anterior pedal foramen in the mantle; palpi united laterally above; adductors subequal, with a thick- ened ray in front of the posterior scar ; ventricle embracing the rectum and giving out a single anterior aorta ; foot elongated, having a pedal gland, but no byssus, with a terminal groove which may be expanded to a stellate disk ; animal dioecious, marine, burrowing. Lower Silurian (? Carboniferous) to recent faunas. Ex. Solemya, ? Orthodesma, f Whiteavesia, Janeia. The disk of Solemya must be used as a stilt or excavator, though morpho- logically reptary, as in Nucula. The dorsal aspect of the outer row of gill leaflets is accounted for by the vertical position of the animal in the burrow. Those foliobranchs which crawl in a horizontal posture have both rows of leaflets directed ventrally. II (Dentiferous). A. Taxodonta. Superfamily NUCULACEA. Shell of variable form, closed ventrally, equivalve, with a smooth epidermis; nacreous or porcellanous with tubuliferous external prismatic layer ; taxodont ; area obscure, or none, when present divided into luiHileand escutcheon ; liga- ment variable, amphidetic ; gills foliobranchiate; pleural ganglion distinct; otocysts pervious ; both adductors present and subequal ; foot grooved and reptary, not byssiferous ; marine. ? FAMILY CTENODONTIDyE. Shell nuculiform, with the teeth in a continuous arched series ; no area ; ligament external, alivincular, without an internal resilium ; pallial line simple. Lower Silurian. Ex. Ctenodonta, Cucullella (P. Fischer), t Nuculiles. TRANSACTIONS OF THE WAGNER FREE This group comprises the prototypes of numerous forms which subse- quently developed distinctness. Many forms are described under the name of Ctenodonta which belong in the Nuculidce or Ledidce. There is no harmony between the Manuals but I follow Zittel for Ctenodonta and Fischer in the case of Cucullella, disregarding synonymy. It is possible that with further re- searches the intermediate links may play havoc with this family, but at present it seems convenient. FAMILY NUCULID/E. Shell compact, closed, with the teeth in two series meeting below the umbones, separated by a chondrophore, area represented by an obscure lunule and escutcheon; no ligament, but a wholly internal amphidetic, alivincular resilium ; internal layer of shell nacreous; mantle lobes free, without siphons ; ventricle sub-duplex, dorsal to the rectum, with anterior and posterior aortas ; dioecious. Lower Silurian to recent fauna. Ex. Nucula, Acila. FAMILY LEDIDCE. Like Nuculidce, but with the ligament variable, the resilium sometimes ex- ternal, or absent, the internal layer subnacreous or porcellanous, the ends of the shell partly gaping; the mantle lobes more or less united; with complete, sometimes elongate, siphons; the pallial line usually sinuated; the ventricle embracing the rectum, with anterior and posterior aortas. Silurian to the recent fauna. Ex. Leda, Yoldia, Neilonella, Mallelia, Tindaria, Neilo, Sarepta, etc. In the (Tertiary-recent) genus Malletia, the ligament is external, opis- thodetic and parivincular, but the archaic features of the soft parts are retained. Sarepta, a very minute recent form, has a simple pallial line, but the other characters retain it in this family. A survey of the genera of Ledid® shows gradations leading to Ctenodontidce, Nuc:ilidce and Arddce. Superfamily ARCACEA. Shell of varied form, usually with a pilose epidermis, porcellanous, with tubuliferous non-prismatic external layer; taxodont ; area typically amphi- detic ; ligament external, ali- or multivincular ; gills filibranchiate, with the fila- ments usually reflected ; pleura! ganglion fused with the cerebral ; mantle lobes free, without siphons, the pallial line simple; otocysts impervious; the ventricle more or less doubled, and laterally separated, with both aortas pres- ent; foot variable, deeply grooved ; byssogenous ; marine or fluviatile. FAMILY MACRODONTID/E. Shell arciform, with the posterior hinge-teeth elongated, tending to be parallel to the hinge margin ; ligament multivincular. INSTITUTE OF SCIENCE, PHILADELPHIA. 517 Carboniferous to recent fauna. Ex. Macrodon, Parallelodon, Oinalia, Nemodon, Cucullaria, Cucul/fea, etc. The ancient forms of this group appear to connect with the Pteriacea through Pterinea, to Area through Cuculfcsa. The recent forms, which from their shell characters have been referred to Macrodon, are all small and abyssal. Their soft parts agree with Area and the animal is byssiferous. The relation- ship of this family to the Arcidce is very intimate but not exclusive. FAMILY CYRTODONTID^£. Shell equivalve, short, usually heavy, convex and earthy, without persis- tent epidermis, area small, ligament parivincular ? ; hinge-teeth transitional between the Macrodon and Dysodont type ; adductor scars subequal, the pos- terior larger but less impressed. Lower Silurian and Devonian. Ex. Cyrtodonla, Ischyrodonta, Vanuxemia, Whitella. These forms are evidently intermediate in character. They recall Limop- sis among later types, are nearly related to Macrodontidce, but have not the multivincular ligament; the hinge has Dysodont elements, but the difference of texture and epidermis stand in the way of assimilating them to the Mytilacea. FAMILY LIMOPSID^. Shell pectunculoid, equivalve, or nearly so ; the ligament alivincular, part- ly immersed, its socket approaching a chondrophore ; area small ; foot long, produced at the anterior and posterior ends, arcuate, narrow, grooved, byssifer- ous; palpi reduced ; ventricle embracing the rectum, otherwise as in Arcidce. Trias to recent fauna. Ex. Limopsis, Trigonocazlia, fCnisma, These forms precede the typical Area and have a special facies of their own. The two dental series of the hinge are often discrepant in character or direction, recalling Macrodontidce . FAMILY ARCID/E. Shell trapezoidal or rounded, with the posterior side longer ; ligament usually multivincular ; hinge typically taxodont, with the teeth in two similar series, meeting below the beaks, and approximately vertical to the margin of the valve; ventricle more or less double and dorsal to the rectum ; foot stout, short, deeply grooved. Mesozoic ?, to recent fauna. Ex. Area, Barbatia, Scaphula, Senilia, Argina, Attadara. Pectunculus, etc. Most of the Paleozoic forms are probably Macrodontidce, the Pectunculoid forms precede the typical Areas. The convergence of the types of Arcacea as 5l8 TRANSACTIONS OF THE WAGNER FREE we recede in Geological time is very marked, and we cannot doubt their rela- tionship to the Nuculacea, notwithstanding all changes. The recent abyssal forms often have the gill filaments simple, but in the shallow-water species they are reflected. In recent Pectuncultis the ventricle is more compact about the rectum and the foot recalls that of Nucula, while the adults are not byssiferous. The wide range of variation in those species of Arcacca in which the anatomy has been examined renders generalizations a little unsafe. In general the gills of the abyssal forms are destitute of the chitinous skeleton which supports the filaments in the littoral species, and are more threadlike, and the filaments not always reflected. B. Schizodonta. Superfamily PTERIACEA. Shells of varied form, frequently alate, with a nacreous or subnacreous inner and prismatic outer layer, the epidermis seldom conspicuous ; areaamphi- detic, ligament variable, usually not parivincular ; gills filibranchiate or reticu- late, usually reflected ; pleural ganglion fused with the cerebral ; mantle lobes free, without siphons; pallial line simple; the anterior adductor smaller, or fre- quently obsolete in the adult, though present in the young; generally byssifer- ous ; hinge schizodont or edentulous. The young sometimes showing a dis- tinct nepionic stage. Marine. Owing to the varied significations adopted from time to time for the Lam- arckian Malleacea, I have preferred to use a different term, based on the best- known genus, Avicula Lam. (= Pteria Scopoli), for the present group. FAMILY PTERINEIDyE. Shell Pteriiform, bialate, dimyarian.the anterior adductor smaller; inequi- valve, very inequilateral; dentition obscure; ligament amphidetic, external, multivincular? the byssus passing through a notch in the smaller valve. Lower Silurian to Devonian. Ex. Rhombopteria, Pterinea, Actinopteria, Ptychopteria, ? Leptodesma. In Pterinea and its allies we have the first indications of divergence to what ultimately became taxodont and schizodont dentition. From this assem- blage, as indicated by Jackson, a large proportion of the Prionodesmacea have diverged in various directions. It is probable that from this source the fili- branchiate Taxodonts have sprung, rather than directly from the foliobranchs. FAMILY AMBONYCHIID/E. Shell mytiliform, with no anterior wing, the anterior adductor obsolete ; equivalve, very inequilateral ; dentition obsolete or schizodont ; ligament ex- ternal, multivincular ? byssus passing through a narrow gape between the valves which are otherwise closed. INSTITUTE OF SCIENCE, PHILADELPHIA. 519 Lower Silurian to Devonian. Ex. Ambonychia, Amphicos/ia, Byssonychia, Byssopleria, Opisthoptera, Allonychia, Anoma- lodonla, etc. The typical Ambonychia, according to Ulrich, is edentulous ; the forms ordinarily passing under that name being now referred to Byssonychia. In this group the byssus does not pass through a notch in one of the valves. FAMILY PINNID^. Shell mytiliform, not alate, dimyarian, the anterior adductor smaller; equivalve, truncate and wholly open behind ; edentulous ; area linear ; liga- ment parivincular, internal; shell-structure coarsely prismatic, with a thin, partial nacreous lining; byssiferous; ventricle embracing the rectum, with anterior and posterior aortas ; gills reticulate and plicate, with direct and re- flected laminae, and free distal borders ; foot conical, elongate, grooved, with a profuse silky byssus ; anal end of rectum free, erectile. Devonian to recent fauna. Ex. Palatopinna, Aviculopinna, Pinna, Pinnigena, Alrina. The gills are erroneously stated to be filibranchiate and soldered to the mantle, in a recent morphological introduction to the study of mollusks. FAMILY CONOCARDIID^E. Shell subtrigonal, anteriorly truncate and gaping, the margins of the gape frequently produced into a tube-like rostrum and sharply serrate below, the posterior end usually alate, the wing divided internally by a longitudinal ridge; dimyarian, the anterior adductor scars smaller ; equivalve, more or less gaping behind ; schizodont, with a single anterior lateral and an obscure or obsolete cardinal tubercle ; area ill-defined, amphidetic ; ligament external, parivincular ; shell structure cancellate or built up of hollow prisms, resembling those of Pinna but not solid ; valves thick, internally marginate ; byssiferous ? marine. Silurian to the Carboniferous faunas. Ex. Conocardium, Rhiphidocardium. These remarkable shells have been referred by most paleontologists to the Cardiacea, with which they have no connection whatever except analogy of form with a few, aberrant Cardiida ; an analogy, which does not offer any point of real relationship. Carpenter pointed this out in his work on the structure of shell, but with little effect on the literature. Neumayr was dis- posed to regard them as related to Lunulicardinm, and it is probable that some species of that heterogeneous assembly would more properly be placed in this family. I do not feel positive that this is the final place for this family, but after weighing all the facts have concluded that they would be less obviously out of place here than elsewhere. It is entirely possible that this group may have 52O TRANSACTIONS OF THE WAGNER FREE developed an anterior siphon like Leptonacea, and the serrations of part of the anterior gape are probable evidence of a fibrous byssus. FAMILY PERNIDyE. Shell submytiliform with a broad posterior wing ; monomyarian, the an- terior adductor absent in the adult ; inequivalve, edentulous, with a serial multivincular ligament ; byssiferous, with a moderate gape, or none ; gills re- ticulate, united to each other and to the mantle ; soft parts generally as in Pterndee, Trias to recent fauna. Ex. Perna, Gervillia, Inoceramus, Hornesia, Volviceramus, Crenatu/a, etc. This group differs from the next chiefly by its edentulous hinge and reduplicated ligament in the adult. FAMILY PTERIIDyE. Shell aviculoid, bialate, monomyarian, inequivalve, with an alivincular ligament; the byssus issuing by a notch in the smaller valve; ventricle ven- tral to the rectum, with anterior and posterior aortas ; gills filamentary or imperfectly reticulate, with direct and reflected laminae attached to the mantle, but the tips behind the adductor floating free; foot subcylindrical, small, grooved ; anal end of rectum free, erectile ; the young dimyarian, sometimes passing through a distinct nepionic stage. Lower Silurian to recent fauna. Ex. Pteria, Meleagrina, Philobrya, Malleus, Monolis, Oxytoma, Cassianella, Pseudo- monotis, Aucella, etc. The gills differ in different species, the shallow-water forms often being more or less organically reticulate, while the abyssal forms have the filaments free, or connected only by cilia, like the abyssal arks. FAMILY VULSELLID^. Shell ostreiform, not alate, monomyarian, edentulous, inequivalve, with an alivincular ligament ; without a byssus ; ventricle embracing the rectum ; gills filibranchiate with ciliary junctions ; foot grooved, angularly bent; other- wise as in Pteriid®. Tertiary to recent fauna, in sponges. Ex. Vulsella, Vulsellina. A degraded type which has become specialized through commensalism. Superfamily OSTRACEA. Shell degenerate, sessile, inequivalve, generally edentulous, ala; obsolete; with a subnacreous or porcellanous inner, and prismatic outer layer ; epidermis inconspicuous; area amphidetic, ligament alivincular ; foot and byssus absent, INSTITUTE OF SCIENCE, PHILADELPHIA. 521 valves usually closefitting ; gills reticulate with direct and reflected laminae, at- tached to the mantle and to each other ; mantle lobes free, without siphons ; ventricle generally ventral to the rectum with a single (anterior) aorta ; otocyst absent (? ); rectum sessile at the anal end. FAMILY OSTREID^E. Shell distorted by early adherence to other objects ; monomyarian, the anterior adductor absent ; edentulous, or with obscure schizodont dentition ; dimyarian when young ; the foot obsolete or absent in the adult. Carboniferous to recent fauna. Ex. Oslrea, Gryphcea, Exogyra, Chalmasia. As in all cases where the adult is sessile, there is a development of adap- tive characters as well as degeneration. The species are monoecious or dice- cious and the position of the ventricle varies. Only the fossil forms exhibit any trace of teeth, or foot. Jackson and others have shown that Ostrea is an offshoot from the Pteriid/z rather than the Pectinida, which is further confirmed by Menegaux's investigations. Many of its peculiarities are due to the lateral position fixed by the sessile habit and these are common to most other sessile forms. FAMILY ELIGMID^E. Shell thick, subequivalve, free when adult, resembling Chalmasia\n form, anteriorly with an irregular pedal gape ; edentulous, monomyarian, with the adductor seated on the free extremity of a myophore projecting from the um- bonal cavity ; otherwise like Ostreidce. Oolitic. Ex. Eligmus (Nayadinaf). If the characters of Eligmus have been correctly interpreted, it can hardly be retained in the Ostreidce. Perhaps further investigation of the genus would be profitable. Superfamily NAIADACEA. Shell of varied form, normally equivalve, inequilateral and dimyarian ; rarely alate ; shell substance nacreous and prismatic, with a conspicuous epi- dermis ; area obscure or amphidetic ; ligament parivincular, usually opisthodetic and external ; ventricle embracing the rectum, with anterior and posterior aor- tas ; gills reticulate, with direct and reflected lamina.-, one or both pairs fre- quently utili/.ed as a marsupium ; pleural ganglia fused with the cerebral ; oto- cyst impervious ; pallial lobes usually free, except for an anal siphon, the pallial line simple ; foot normally long, compressed, keeled, the byss us obsolete ; anal end of rectum adherent ; young usually with a distinct nepionic stage ; station usually fluviatile. 522 TRANSACTIONS OF THE WAGNER FREE FAMILY CARDINIIDyE. Shell equivalve, closed, with feeble concentric sculpture or smooth ; di- myarian ; ligament opisthodetic, external ; adductor scars subequal, pedal scars feeble or invisible ; station marine or brackish water. Devonian to the Trias. Ex. Cardinia, Anthracosia, Carbonicola, Anoplophora, Guerangcria, Nyassa, etc. This group has been assimilated to the Unionidee, which their schizodont dentition strongly recalls, and it is possible that the resemblances indicate either the origin of the Unionidee or a parallel line of development from Pterii- da adapted to a marine station. So far as known they were not distinctly nacreous, which, if confirmed, does not favor intimate relationship with the Unionidee. ? FAMILY MEGALODONTIDyE. Shells equivalve, submytiliform, closed, with feeble concentric sculpture or none; dimyarian, with amphidetic area, and external opisthodetic ligament, frequently supported by nymphs ; anterior adductor scars distinct, with a well- marked myophoric ridge and pedal scar, the posterior adductor scars frequently bordered by an elevated crest ; station marine. Silurian to the Cretaceous. Ex Megalodon, Megalomus, Pachyrisma, Durga, Dicerocardium. These shells, which are often very ponderous, sometimes bear a remark- able resemblance to some recent American Uniones. The myophoric ridge is common to very distinct bivalves of many unrelated groups. FAMILY UNIONIDyE. Shell equivalve, dimyarian, typically schizodont, with pseudocardinals and laterals if dentiferous ; conspicuously nacreous; the beaks usually sculptured; ligament opisthodetic, external ; gills attached to the mantle, forming an incom- plete septum ; either or both pairs modified as a marsupium ; lobes of the man- tle united to form an anal siphon, but the functional branchial siphon usually incomplete below ; foot compressed, keeled, large, rarely with a feeble byssus ; usually dioecious ; the young having a distinct nepionic stage (glochidium), during which they are encysted on the fins or gills of fresh-water vertebrates ; station fluviatile. Carboniferous or Jura to the recent fauna. Ex. ? Anthracomya, Unio, Limnium, Anodon, Arconaia, Hyria, Metaptera, Castalia. (='fetraplodoii), Casta/ina, Cristaria, Pseudodon, Solenaia, etc. Some Uniones have a functional byssus of a few threads, and there are always two functional siphons, though the branchial opening is usually incom- plete ventrally. In some species there are one or more small openings in the dorsal mantle margin above and nearer to the beaks than the true anal open- INSTITUTE OF SCIENCE, PHILADELPHIA. 523 in« ; for this no function has been assigned. In Castalia, which is supposed to have two complete siphons, the branchial opening may be complete or in- complete in different individuals of the same species (Ihering). In northern Uniones the outer, in Austral species the inner, gills officiate as a marsupium ; in rare cases both. The specialization of the marsupial gill-sac is often pecu- liar and remarkable. The typical Unto (Margarita/in Schumacher) cannot be generically separated from the forms with " lateral " teeth (Limnium Oken = Unio Auct). The sculpture of the tips of the umbones is probably due to the influence of the hooked or serrated edges of the glochidium valves. The group is characteristic of, though not wholly confined to, the northern hemi- sphere. FAMILY MUTELID^E. Shell and anatomy resembling Unionidce, without pseudocardinals and laterals; when dentiferous having an irregularly taxodont hinge armature, gen- erally partly-closed mantle lobes, a complete branchial septum, more complete siphons, and with the nepionic stage represented by a Lasidium, resulting in unsculptured beaks for the adult shell. Cretaceous to recent fauna. Ex. Leila, Clabaris, Spixoconcha, Iheringella, Fossula, Mycetopus, Mulela, Iridina, Spatha, etc. These types are generally South African, Austral and South American ; Mycetopus is a burrovver and shows the usual degeneration of the hinge arma- ture, common to many burrowers, together with a peculiar specialization of the foot for burrowing purposes. Mr. C. T. Simpson states that no Mutelid, known to be such, has the Unionid type of hinge. FAMILY ETHERIIDyE. Shell sessile, irregularly modified by adherence to other bodies, nacreous, with a tendency to cellularity of structure ; edentulous ; ligament amphidetic, parivincular, deeply sunken, with a large internal resilium, modified by the dis- tortion of the valves ; young regular, equivalve, dimyarian ; the adult irregular, inequivalve, monomyarian (i) or with a very degenerate anterior adductor (2) or with subequal adductors (3); mantle lobes united only for the anal siphon ; foot degenerate or absent in the adult ; branchial septum complete ; gills as in Unionidce ; young byssiferous, larval and nepionic stages unknown; station fluviatile. Recent. Ex. i, Mulleria ; 2, Bartlettia ; 3, Etheria. The young shell of Bartlettia has well marked nymphze and internal resilium. According to P. Fischer, the nepionic stage is carditiform, but I have never been able to see an uneroded specimen. The relationship of the Naiades to Pteria renders the remarkable resemblance of the adult Mulleria 524 TRANSACTIONS OF THE WAGNER FREE to Ostrea less surprising, since Ostrea is now known, also, to be derived from Pteriidce. Superfamily TRIGONIACEA. Shell equivalve, inequilateral, closed, dimyarian, not alate ; shell sub- stance nacreous and prismatic ; hinge-teeth few, subumbonal, typically schiz- odont ; area obscure or none ; ligament parivincular, opisthodetic, external ; ventricle bilobate, embracing the rectum, with anterior and posterior aortas; gills filibranchiate, with direct and reflected laminae, the stems adherent behind the foot ; mantle lobes usually free, but modified on the posterior edges to form functional siphons though without conjunctive partitions ; pallial line usually simple ; foot long, compressed, produced before and behind, capable of sub- reptary expansion ; nonbyssiferous, though possessing an obsolete byssal apparatus; anal end of rectum adherent; young without a distinct nepionic stage ; dioecious ; station marine. FAMILY LYRODESMID^E. Shell with the hinge armature radiating tanlike from below the umbones, teeth 5-9 ; the pallial line feebly sinuate or simple. Silurian. Ex. Lyrodcsma, f Aclinodonla. FAMILY TRIGONIID/E. Shell with few hinge-teeth (f), the mantle lobes wholly free, but so ap- plied to each other in life as to form functional siphons; pallial line simple; palpi not appendiculate. Devonian to recent fauna. Ex. Trigonia, Myophoria, Schizodus, f Cythereodon. The characters of the soft parts in this family are enumerated under the head of the superfamily. The posterior part of the foot in the recent species, as I have personally observed, can be flattened so as to form a disk with crenu- lated edges, resembling the reptary disk of Nucula, but it is not, like the latter, formed by a sulcation or splitting of the foot, and is used as a fulcrum, rather than for crawling, as in some Macomas. It possesses a large blood sinus, as in Cardium, and, like the foot of Cardium, is specialized for use in leaping. The prodissoconch in Trigonia pectinata is of the ordinary smooth, globular type. C. Isodonta. Normal armature of the hinge obsolete, and its functions performed, if at all, by modifications of the auricular crura, which form interlocking processes. Superfamily PECTINACEA. Shell usually inequivalve, flabelliform, more or less auriculate, and mono- myarian ; shell structure subnacreous, corrugated and rarely prismatic, occasion- INSTITUTE OF SCIENCE, PHILADELPHIA. 525 ally tubular ; area, when present, amphidetic ; ligament amphidetic, alivincular ; ventricle embracing the rectum, auricles intercommunicating below it, an anterior and a posterior aorta ; gills filibranchiate, free, the filaments with or without a reflected limb; ganglia normal ; mantle lobes free, without siphons, usually with papillre, ocelli, or other tactile prominences along the margin and with an inner projecting lamina (curtain) near the margin, at right angles to the plane of the valves ; pallial line simple ; foot small, usually subcylindrical. grooved and byssiferous; anal end of rectum usually free for a short distance; motuEcious ; marine. FAMILY PECTINID^E. Shell inequivalve, inequilateral, auriculate, usually closed, monomyarian, usually free ; area amphidetic or obscure ; ligament obsolete externally, the immersed portion forming an internal resilium ; hinge-teeth taxodont in the very young, obsolete later, the crural teeth feebly or not developed ; foot small, the distal end often funicular or hood-like, modified for special uses ; byssus feebly developed, sometimes absent ; soft parts generally as in the superfamily diagnosis. Devonian to the recent fauna. Kx. Plerinopecten, Aviculopecten, Peclen, Pedum, Hinnites, Amusium, Cftlamys, Vola, etc. The direct filaments of the gill are usually reflected in the shallow-water species, but the abyssal forms like Amusium sometimes have them simple and direct only ; the foot is remarkably variable in form ; the byssus issues from a gape between the valves (Amusium) or through a particular notch in the lower valve, in the form of separate threads which are held apart and prevented from twisting by a series of comb-like teeth (ctenolium), which are set on the ventral edge of ths sinus ; it is absent in many adult and some young abyssal species and in the sessile forms. Most of the types are active, Hinnites alone after an active youth becomes sessile. In some species the edges of the mantle have become slightly specialized for siphonal purposes, though the lobes are always free. FAMILY SPONDYLIDyE. Shell inequivalve, nearly equilateral, closed, pectiniform, obscurely auricu- late, monomyarian, sessile ; area amphidetic, much larger on the attached valve ; ligament alivincular, resilium more or less submerged ; byssus obsolete ; ar- mature of the hinge taxodont, but obsolete in the adult and replaced by the typically isodont development of the crura ; gills filibranchiate with a reflected limb ; foot small, subcylindrical with terminal funicle ; other anatomical char- acters like Pectinidce. Trias to recent fauna. Ex. Spondylus, Plicatula. The Osfrea-\\ke features of this group are due to the sessile habit, common to both families. 526 TRANSACTIONS OF THE WAGNER FREE FAMILY DIMYID,£. Shell inequivalve, irregular, closed, auricles not differentiated, ostreiform, dimyarian, sessile ; shell substance subnacreous and fibrous ; area amphidetic, obscure ; ligament obsolete, resilium alivincular, internal ; hinge armature taxodont, obsolete ; crural development feeble ; gills filibranchiate, the stem distally attached to the mantle ; the inner direct filaments wanting, the outer filaments not reflected ; foot and byssus absent ; mantle lobes free with the margin papillose, with a curtain but without ocelli ; anterior adductor distinct, small, posterior duplex, larger ; palpi obsolete ; anal end of the rectum free, erectile. Tertiary to recent fauna. Ex. Dimya (+Marg-ariona), Dimyodon. I have already noted my impression that Dimya is, on the whole, rather a degenerate than an archaic form ; but it is difficult to indicate which of the other families is most nearly related to it. FAMILY LIMID^E. Shell equivalve, auriculate, gaping, pectiniform, monomyarian ; shell sub- stance fibrous, with minute tubules, not nacreous or prismatic ; hinge edentu- lous, or with traces of taxodont armature ; area amphidetic, equal in both valves; ligament alivincular, resilium subinternal ; gills filibranchiate, with di- rect and reflected limbs; ganglia normal, mantle lobes free, with profuse retrac- tile tentacular processes, ocelli and a curtain; foot small, digitiform, grooved, usually byssiferous, the byssus passing through the gape of the valves ; anal end of the rectum free, erectile. Carboniferous to recent fauna. Ex. Plagiosloma, Lima, Litnalula, Linuza. These animals frequently spin a nest of byssal threads like Modiolaria, but are capable of swimming vigorously by opening and closing the valves ; in motion the beaks are posterior. The shells are colorless, the soft parts usually bright colored. Superfamily ANOMIACEA. Shell monomyarian, not alate ; edentulous, or isodont, usually sessile ; shell substance nacreous, tubuliferous, with traces of a prismatic layer ; area obscure, usually small, amphidetic; ligament obscure, with an alivincular in- ternal resilium ; ventricle free from the rectum, not enclosed in a pericardium, but projecting in the pallial chamber, dorsal to the gut, with a single aorta ; gills filibranchiate, with direct and reflected limbs, united to the mantle and to each other; mantle lobes free, without ocelli; otocyst closed; foot small, grooved, digitiform; anal end of rectum usually free, erectile; dioecious, marine. INSTITUTE OF SCIENCE, PHILADELPHIA. 527 FAMILY ANOMIIDyE. Shell variable, when sessile irregular and inequivalve, byssiferous when young ; in most of the genera the byssus becomes modified to a calcified or horny plug passing through a foramen in the attached valve and attached to other bodies, a condition which may be permanent or transient ; area small, amphidetic ; ligament amphidetic, more or less internal, supplemented by an internal resilium, for which the crura serve as chondrophores ; ali- or multivin- cular ; hinge usually edentulous, rarely rugose with amorphous interlocking rugosities ; posterior adductor small, subcentral, in the sessile forms reinforced by the pedo-byssal muscles, which are modified for service as adductors. Devonian to recent fauna. Ex. Limanomia, Anomia, Placunanomia, Pododesmus, ^Enigma, Caro/ia, Mania, Ephippi- um, Placenta, P/acunetna, Hypotrenia, Placunopsis, etc. The inter-relations between the sessile and free forms are so gradual and close that they cannot be separated as families, though extremes are very un- like. In the former the auricular crura are obscure, except in Placunanomia and Carolia ; in the free forms they are well developed, the internal ligament uniting the outer edges in one valve with the inner edges in the other, while the resilium lies between the crura, medially. Placenta seems always free and byssiferous, but all the others, including some species usually referred to Pla- centa, have at some time a byssal foramen and are probably then sessile. Hypotrenia has multivincular ligamentary grooves on the area ; Placimanomia has a singularly amorphous rugose hinge margin, with the rugosities inter- locking; all the others seem to have a flat, striated, narrow area with an eden- tulous hinge. ^Enigma is modified for life on leaves which dip into tidal cur- rents. D. Dysodonta. Superfamily MYTILACEA. Shell anisomyarian, usually equivalve, not alate or notched for a byssus; edentulous or dysodont ; shell substance subnacreous, rarely more or less prismatic, with a conspicuous epidermis ; area amphidetic or obscure ; ligament parivincular, usually opisthodetic, usually external ; ventricle embracing the rectum ; gills usually filibranchiate, usually with direct and reflected limbs ; ganglia normal, mantle lobes without ocelli, more or less free, usually with the anal siphon complete and the branchial incomplete; otocyst impervious ; foot small, digitiform, grooved, byssiferous ; anal end of rectum sessile ; monoeci- ous, usually marine. FAMILY MODIOLOPSID^E. Shell modioliform, usually equivalve, free, thin, with subequal adductor scars ; ligament deep-seated ; hinge edentulous or dysodont ; sometimes bys- siferous. Silurian. Ex. Modiolodon, Afodiolopsis, Modiomorpha, Goniophora, Eurymya, Aristella, Prolobella, fldas. 528 TRANSACTIONS OF THE WAGNER FREE The heavier forms show an obtuse ridge or two extending from the beaks toward the basal margin. The pedal scars are separate from and behind the anterior adductors. These forms, not including some which have been referred to the family, appear to be early prototypes of the Mytilidtz, from which they differ chiefly in those characters which are common to most of the ancient types, such as the subequality of the adductor scars and their more dorsal situation. The recent Idas is very similar. FAMILY MYTILID^E. Shell equivalve, very inequilateral, heteromyarian, slightly gaping, typi- cally dysodont ; area amphidetic or none ; ligament usually external, deep- seated ; rarely with an alivincular internal resilium ; pallial line simple ; ventri- cle with an anterior aorta ; gills attached distally and dorsally, usually with a reflected limb to the filaments ; mantle lobes united below the anal siphon, otherwise free ; a byssus generally present. Devonian to recent fauna. Ex. Naiadites, Myalina, Hoplomylilus, Mytilus, Modiola, Lithophagus, Modiolaria, Cren- ella, Byssanodonta, Stavelia, Dacrydium, Myrina. The pedal protractors in Myalina are set upon a myophore; in Dacryd- ium there is a small subumbonal internal resilium ; though the shell is smooth, the inner faces of the dorsal margin retain transversely rugose areas like those of Dimya. As in other cases some of the abyssal species have no reflected limb to the gill filaments. The shell of Stavelia, as a whole, is spirally twisted like some Paleoconcha. The shell substance of Lithophagus is penetrated by minute tubules. FAMILY DREISSENSIIDyE. Shell mytiliform, equivalve, of prevailingly prismatic substance ; area linear, amphidetic ; ligament subinternal ; anterior adductor and pedal protrac- tors inserted on a myophoric septum ; mantle lobes united to form anal and branchial siphons, and also ventrally with a pedal opening, pallial line usually simple ; gills reticulate, attached to each other behind the foot, otherwise free, distally ; the rest of the anatomy like Mytilus. Tertiary to recent fauna. Ex. Dreissensia, Congeria, Mytilopsis, ? Septifer, ? Dreissensiomya. The tertiary Dreissensiomya has a distinct pallial sinus, the only excep- tion in the Mytilacea to the usual rule, though there is sometimes a faint sinu- osity in Modiolaria. In the American Mytilopsis the myophore for the pedal protractor is distinct from that which supports the anterior adductor. FAMILY MODIOLARCID^E. Shell modioliform, small, equivalve, free, with a narrow byssal gape ; area obscure or none, the space just in front of the beaks usually impressed ;' liga- INSTITUTE OF SCIENCE, PHILADELPHIA. 529 ment amphidetic, subintcrnal ; armature of the hinge obsolete or feebly lamel- lar ; adductor scars subequal, pedal well marked ; gills as in Mytilus, the outer serving as an incubatory sac for the nepionic young, as in Unio ; mantle lobes united to form siphonal and pedal orifices ; foot elongate, thick in front, at- tenuated distally ; the nepionic young ovate, with a long, straight hinge-line. Tertiary to recent fauna. Ex. Modiolarca, Phaseolicama, Kidderia. In Modiolarca there is a minute but distinct impression in front of the beaks, visible best on the edge of the separated valves. The nepionic stage recalls that of Solemya, but is more ovate. FAMILY PRASINIDyE? Shell modioliform, small, equivalve, free, with a narrow byssal gape, area obscure, or none ; a depressed space in front of the beaks ; ligament subinter- nal, opisthodetic? anterior adductor scar absent ? posterior adductor scar low and centrally situated ; soft parts unknown. Eocene to recent fauna. Ex. Prasina, Julia, Berthelinia. The scars are very difficult to make out on these small polished shells (Stoliczka), and it may well be that an anterior adductor exists, in which case the group would be merged in the family Modiolarcidce . The " teeth " are lamellar extensions of the margin of the valve below the impressed area. ;\ni>malomya Cossman, which has been placed in this family, strongly recalls Dacrydium. Order ANOMALODESMACEA. Although this group in the general classification has usually been placed after the forms here included in the Teleodesmacea, no linear arrangement can properly express their natural relations. This and the preceding order repre- sent for us lines of parallel development of the most ancient origin, while the Teleodesmacea probably took their rise chiefly from forms which, genetically, would be included in the present order. The modern Anomalodesmacea are nearly all much specialized and their archaic characters veiled by later adapta- tions. That any have come down to us retaining indications of their archaic character is probably due to the burrowing habit, which has shielded them from many vicissitudes and checked in this way the perfecting processes of selec- tion. The student will understand, therefore, that the present group is here re- garded as having one general origin with the Teleodesmacea, the two being contrasted with the Prionodesmacea, the latter differing more from either than the former differ from each other. Part of the original stock has produced the perfected types of Pelecypods, which have lost all their archaic characters and 53° TRANSACTIONS OF THE WAGNER FREE become the Teleodesmacea, while another part, sheltered by peculiarities of sta- tion and developing adaptive modifications, has lagged behind the others and still indicates in some degree the ancient types from which it sprang. Superfamily ANATINACEA. Anomalodesmacea having reticulate V-shaped gills, of which the left slope of the V is homologized with the inner direct lamina, the right slope with the inner reflected lamina, the right cross-stroke with an inner appendicu- lar extension, and the left cross-stroke with the outer direct lamina, of the typical Teleodesmacean gill ;* not secreting a calcareous tube external to the shell; having the rectum embraced by the ventricle of the heart, usually with an anterior and posterior aorta. A. Eusiphonia. Siphons elongate, the lithodesma, when present, at the anterior end of the internal resilium, and external to the mass of the resilium. FAMILY CEROMYID^. Shell slightly inequivalve, hinge with an obscure projection or edentulous, the cardinal border of one valve covering that of the other valve, which is supplemented by a sort of laminar nymph, the ligament subinternal between them ; area inconstant or obscure ; pallial sinus present ; valves closed or slightly gaping. Trias-Jura. Ex. Ceromya, Gresslyia, Mactromya (pars). FAMILY PHOLADOMYID^E. Shell substance nacreous and cellulo-crystalline; gills completely united behind, forming a septum below the anal chamber ; foot small, with an opistho- podium ; siphons long, united to their tips, not wholly retractile, naked ; ven- tral commissure of the mantle with a pedal and an opisthopodial foramen. Shell thin, equivalve, gaping, edentulous or with an obscure subumbonal tubercle ; ligament and resilium external, opisthodetic, seated on nympha; ; area obsolete or obscure, not amphidetic ; beaks entire ; pallial sinus well marked ; marine. Trias to the recent fauna. Ex. Pholadomya, Proeardia, Arcomya, Guniomya. The granulations of the surface, upon which the above have been divided into two families, do not seem of serious importance, judging by the differ- ences observable in such recent genera as Thracia and Poromya, some of which are granular and others smooth. * These horologies are not perfectly satisfactory, but seem probably correct in the present state of our knowledge. The description, given for the left, should be reversed for the right-hand gill. INSTITUTE OF SCIENCE, PHILADELPHIA. 53! FAMILY ANATINID/E. Soft parts like Pholadomya, the foot small and grooved, the ventral fora- mina small, the siphons with a horny integument, not entirely retractile. Shell subequivalve, truncate or gaping behind, edentulous, the resilium internal between two spoon-like chondrophores, vertically directed and often supported by buttresses ; the ligament obsolete or absent ; area obsolete ; the beaks transversely fissured, pallial sinus well marked ; moniecious, marine. Jurassic to the recent fauna. Ex. Anatina, Periplomya, Cercomya, Rhynclwmyci, Anatiinya, Plalymya. FAMILY PERIPLOMIDyE. Soft parts generally like Anatina, but the siphons separated to their bases, naked and wholly retractile, but not invertible. Shell subnacreous, conspicuously inequivalve, nearly closed, edentulous; the resilium internal, between two anteriorly or vertically directed chondro- phores, often buttressed, the lithodesma rarely wanting ; ligament and area absent ; the beaks fissured, the pallial sinus broad and shallow ; monoecious, marine. Tertiary and recent faunas. Ex. Periploma, Cochlodesma, Bonttca, ? Tyleria. This group has erroneously been described as having the siphons united. FAMILY THRACIID^E. Foot small and grooved, not byssiferous ; without an opisthopodium, but with an opisthopodial foramen in the mantle edge ; siphons long, separated to their tips, naked, invertible to their tips ; mantle openings small ; monoecious, marine. Shell earthy and cellulo-crystalline, not nacreous ; inequivalve, thin, eden- tulous, often with a granular surface ; the ligament and resilium chiefly ex- ternal, opisthodetic, parivincular, seated on posteriorly directed nymphae ; area none, beaks usually entire ; nearly closed valves, pallial sinus present. Jurassic to the recent fauna. Ex. Thracia, Cyathodonta, Corimya, Asthenolha:rus, Bushia. In Asthenothcents the ligament is obsolete and the resilium internal be- tween the face of the lithodesma and the valves. The subgenus Ixartia, exceptionally, has the nymphs projecting into the cavity of the valves, recall- ing Cochlodesma. FAMILY MYOCHAMIDyE. Gills with the external direct lamina adherent to the visceral mass ; foot small, grooved ; compressed, without an opisthopodium, but with an opistho- podial orifice ; pedal orifice small ; siphons moderately long, separated, the branchial with a curtain valve ; marine. 532 TRANSACTIONS OF THE WAGNER FREE Shell very inequivalve, free or sessile, solid, subnacreous, edentulous, the dorsal margins of one valve overlapping those of the other, which fit into corresponding depressions in the shell wall; ligament amphidetic, external or absent ; resilium internal, alivincular; area amphidetic or obsolete, a false area formed on each side of the beaks by the flattened cardinal margin of the valves; shell closed; pallial sinus small. Tertiary and recent faunas. Ex. Myochama, Myodora. The gills and siphons of Myochama are more like those of Tkracia than of the Pandffridce, with which it has usually been associated. The anatomy of Myodora is unknown. Its minute area curiously recalls that of Spondylus. B. Adelosiphonia. Siphons short, the lithodesma dividing the mass of the cartilage mesially. FAMILY PANDORID^. Gills with the external direct lamina small or obsolete, free ; gills united be- hind to form a septum ; foot small, compressed, grooved, not byssiferous ; opis- thopodium and opisthopodial orifice absent; pedal foramen anterior, large; siphons short, separate, papillose ; branchial orifice without a conspicuous cur- tain valve, the tubes contractile only; moncecious, marine. Shell compressed, inequivalve, free, solid, with nacreous and prismatic layers; the dorsal edges of the valves overlapping but not socketed, with denti- form crural ridges on either side of the resilium, but no true teeth ; ligament amphidetic, external, obsolete ; resilium internal, opisthodetic, usually reinforced on its anterior surface by a mesial elongate lithodesma ; area none ; valves closed, beaks entire, pallial line simple. Cretaceous to recent fauna. Ex. Pandora, C/idiophora, Coclodon. Pandora Wardiana A. Adams has no trace of an external direct gill lamina ; in P. inequivalvis L. a narrow strip is present. FAMILY LYONSIID/E. Gills folded, as usual, united and septary behind, attached to the dome of the mantle and to the siphonal septum ; foot compressed, grooved, byssiferous, without an opisthopodium, but with an opisthopodial orifice ; pedal orifice small ; siphons short, separate, papillose, branchial with the valve inconspicu- ous ; moncecious, marine. Shell inequivalve, thin, subnacreous, edentulous; the ligament obsolete, the resilium internal, uniting the edges of a long, mesial lithodesma to a narrow INSTITUTE OF SCIENCE, PHILADELPHIA. 533 chondrophoric submarginal ridge on each valve ; beaks entire, valves almost closed, pa! Hal sinus distinct. Tertiary to recent fauna. Ex. Lyonsia, Mytilimeria, Entodesnia, Endomargarus, Aclinomya. A small Indian species of Lyonsia is said to live in fresh water. Many of the species attach grains of sand to the exterior of the valves, and Mytili- meria lives in a self-made spongy mass of solidified mucus and sand. Nearly all are nestlers. FAMILY LYONSIELLID/E. Limbs of the branchiae spread out, attached to an infolded lamina, project- ing from the tissues of the mantle, which forms part of the septum between the anal and branchial chambers ; palpi large, feebly striated ; foot small, grooved, byssiferous, with or without an opisthopodium, but in either case without an opisthopodial foramen ; pedal foramen large ; siphons short, separate, the branchial papillose, usually with a large and conspicuous curtain valve; monoe- cious, marine. Shell nearly equivalve, subnacreous, with a more or less distinct tubercle in front of the rcsilium on the dorsal margin ; ligament obsolete, cartilage in- ternal with a large lithodesma ; area obscure or none ; beaks entire, valves almost closed ; pallial sinus obsolete. Tertiary to recent fauna. Ex. Lyonsie/ta, Halicardia. Hahcardia has a finlike opisthopodium, which is absent in Lyonsiella' The branchial septum is normally complete, though the stems of the gills are not attached to the siphonal septum, but only the margin of the lamina ; the attachment is very delicate and is often ruptured in well-preserved specimens and, perhaps, even in living specimens. Owing to the large pedal foramen there is no necessity for a fourth opening between the mantle to permit the escape of water on sudden closing of the valves, and so it has disappeared. FAMILY CHAMOSTREID^E. Gills with the external direct lamina free, united behind ; foot small, com- pressed, not byssiferous; opisthopodium wanting, but an opisthopodial fora- men persists ; pedal foramen small ; siphons short, separate, papillose, branch- ial with a curtain valve ; marine. Shell sessile, inequivalve, irregular, solid, subnacreous ; hinge with a tu- bercle in front of the resilium in the right valve, fitting an equivalent socket in the left valve ; ligament obsolete ; resilium strong, internal, submarginal, reinforced by a large lithodesma; area none, valves close fitting, pallial line simple. Recent in Austral seas. Ex. Chamoslrea. 534 TRANSACTIONS OF THE WAGNER FREE The soft parts differ, but the shell of Chamostrea looks much like a sessile Halicardia. Superfamily ENSIPHONACEA. Differing from Anatinacea by the formation of a calcareous tube, which may involve one or both of the valves and which is usually furnished with a perforated anterior disk surrounded by a more or less complete fringe of small calcareous tubules. The formation of the disk in this group is wrapped in mystery, as, in those specimens which have been examined, neither the mantle nor the foot show any papillae or other projections through whose agency the tubules might be formed. In specimens which are enclosed in hard rock the disk is sometimes imperfectly formed. FAMILY CLAVAGELLID^E. Ventricle embracing the rectum ; gills reticulate, with the outer direct lamina reduced, united behind and prolonged into the siphonal conduit ; foot digitiform, grooved, rudimentary ; the mantle with small pedal and opisthopo- dial foramina ; siphons united nearly to their tips, papillose ; the branchial with- out a curtain valve ; monoecious, marine. Shell degenerate, extremely specialized for a burrowing life ; valves nacre- ous, free when young, when adult one or both merged in a calcareous tube anteriorly discoid and fringed, with a narrow pedal foramen in the middle of the disk ; free valves edentulous, the ligament external, opisthodetic, supported by nymphs, the pallial line sinuate ; the tube frequently encrusted with extra- neous material. Cretaceous to recent fauna. Ex. Clavagella, Brechites, Foegia, Humphreyla. In Clavagella one of the valves is not attached to the tube, and the ad- ductor muscles persist. In Brechites both valves are merged in the tube, the anterior adductor degenerates, and the posterior disappears entirely. Superfamily POROMYACEA. Anomalodesmacea having modified foliobranch or lamellar gills, slightly or not at all reticulated, and frequently degenerate or even absent ; the lamellae, when fully developed, attached to one another by interlocking giant cilia, dis- posed in bands or patches and by occasional connective fibres which are not of a vascular nature ; often with a special development or specialization of the branchiosiphonal septum; the valves free, without a calcareous tube external to them ; the mantle lobes united, with siphons and a pedal, but no opisthopo- dial foramen ; the resilium reinforced below by a lithodesma. This group is strongly contrasted with the typical Anatinacea by the sim- ple laminar gills, when present, and by the tendency to obsolescence of the INSTITUTE OF SCIENCE, PHILADELPHIA. 535 gills, and to the substitution of a fleshy or muscular partition in the place of the ordinary branchial septum. FAMILY EUCIROID^. Ventricle dorsal to the rectum with a single anterior aorta ; foliobranchiate with the laminae extended laterally, each with a lateral equivalent of a re- flected lamina attached to the mantle and to the siphonal septum ; labial palps developed ; foot digitiform, grooved, not byssiferous, without an opistho- poclium ; the pedal foramen large ; siphons short, separate, the branchial large without a conspicuous curtain valve ; monoecious, marine. Shell subcquivalve, nacreous and cellulo-crystalline, externally granulose ; hinge with a strong tubercle in the right valve before the resilium and the dor- sal margins modified to over and underlie each other ; ligament obsolete; resil- ium opisthodetic, internal, with a strong lithodesma ventrally ; area obscure or absent; a depressed false lunule before the beaks ; valves closed, pallial sinus shallow, obscure. Tertiary to recent fauna. Ex. Pecchiolia, Euciroa. FAMILY VERTICORDIID/E. Ventricle embracing the rectum, probably with two aortas; gills folio- branchiate, simple, without a lateral reflected extension, adnate on the an- teriorly extended fleshy imperforate siphonal septum; palps obsolete; foot digitiform, not byssiferous ; without an opisthopodium ; pedal foramen small; siphons short, separate, papillose ; branchial without a conspicuous valve ; monoecious ? marine. Shell as in Euciroida, variable. Tertiary to recent fauna. Ex. Verticordia., Trigonulina, Haliris. FAMILY POROMYID^E. Ventricle embracing the rectum, with two aortas ; gills degenerately folio- branchiate, lamellfe planted in patches symmetrically on a muscular septum, separating the anal and branchial chambers, each patch consisting of a few close set short lamellae arranged in a single row with orifices between them lead- ing into the anal chamber, or reduced to simple protuberant lips surround- ing single perforations of the septum ; palps present, large ; foot small, grooved, pointed, not byssiferous, without an opisthopodium ; siphons short, separate, the branchial with large papillae and a prominent curtain valve ; moncecious, marine. Shell subequivalve, rounded, nacreous and cellulo-crystalline, granular or smooth externally ; hinge with obscure tubercles in front of the resilium and the dorsal edges of the valves as in Verticordiida. Ligament external, opistho- S36 TRANSACTIONS OF THE WAGNER FREE detic; resilium subinternal below the ligament, with a small lithodesma ; area obscure or absent; a depressed false lunulein front of the beaks; valves nearly or quite closed ; pallial sinus small or obsolete. Cretaceous to recent fauna. Ex. LiopiMa, Cymel/a, Psilomya, Poromya, Dermalomya, Cetomya, Cetoconcha, f Bas- terotia. The septum in this group is of compound origin, but in what proportion the original gills contribute to it remains to be determined. FAMILY CUSPIDARIIDyE. Ventricle bilobate, embracing the rectum or dorsal to it, with two aortas; gills obsolete or absent, represented only by the ciliated foramina in a muscu- lar septum; palps degenerate or obsolete; foot small, digitiform, grooved, with a minute byssus but no opisthopodium ; siphons united, long or short, with a few papilla: and obsolete curtain valve ; monoecious, marine. Shell subequivalve, rostrate, earthy or cellulo-crystalline, rarely with sur- face granulations ; hinge edentulous or with subumbonal desmodont tubercula- tion, sometimes buttressed ; ligament subinternal, anterior to the beaks or ob- solete ; resilium internal with a mesial or ventral lithodesma ; arcaamphidetic or obscure ; valves closed except at the tip of the rostrum ; pallial line simple, the retraction of the siphons usually effected by the contraction of the septum, which latter leaves a scar on the valves resembling a pallial sinus. Jurassic to recent fauna. Ex. Cuspidaria, Cardiomya, Leiomya, Luzonia, Plectodon, Tropidomya, ? Plectomya, Hal- onympha, Myonera, etc. In the larger species of Cuspidaria, the ligament as distinguished from the resilium is entirely prosodetic or anterior to the beaks, and fairly well devel- oped ; in most of the species it is obsolete or absent, but always anterior when present. It is the only instance I have observed where a ligament, not amphi- detic, is anterior. Led by observations on Lophocardhtm and Verticordia, in which the sep- tum is obviously a forward extension of the siphonal septum, I have heretofore claimed a similar origin for the septum of Cuspidaria. The researches of Grobben have led him to the conclusion that it is branchial in its origin, as claimed by Pelseneer. The gills, as shown by embryology, are originally cutic- ular proliferations from the inner surface of the mantle. Lyonsiella (alaskana} and Halicardia show curious inwardly projecting laminae from the mantle taking part in the formation of their septa. Now if the respiratory lamellae be- come obsolete and the fundamental mantle surface from which they originally sprang becomes modified into a muscular organ with special functions, this latter can only be said to be derived from the gills in a sense which ignores the origin of the gills. INSTITUTE OF SCIENCE, PHILADELPHIA. 537 The only parts of the septum in Cuspidaria and Cetoconcha which can really be said to be derived from the gills, as such, are the margins of the foram- ina, including the foramina themselves, as Grobben's sections show clearly. To regard as derived from the gills the muscular fascia which cross and curve over the septum seems to the writer illogical and not accurate. The ques- tions involved, however, can only be satisfactorily settled by studies of the development in younger stages. The ordinary retractors of the siphons remain represented in some species by a few short fibres, as shown by Grobben in C. citspidata, but these are only feebly functional, and do not sinuate the pallial line. The strong septal mus- cles pull directly on the siphonal septum, and in Dermatoinya,a.s I have shown elsewhere, a sort of transfer of muscular fibre from the pallial to the septal area seems to be going on behind the siphons. Those species of Poromya which have strong siphonal retractors have few muscular fibres in the septum and vice versa. Under the facts as now known there seems to be no warrant, as Grobben observes, for assigning an ordinal weight to the group called by Pelseneer Septibrancliia. The fact that the gill-structure is more nearly foliobranchiate than reticulate is of more importance, though Pelseneer has not recognized it in his classification. Order TELEODESMACEA. A. Pantodonta. Laterals exceeding two in any one group. FAMILY ALLODESMIDyE. Shell rounded ; valves equal, free, closed, with feeble concentric sculpture ; area linear, amphidetic ; ligament subexternal, parivincular, opisthodetic ; ad- ductor scars subequal, pedal scars above and distinct from the adductors ; pal- lial line entire ; hinge with one or two lateral laminae on each side of the beak, tlu- posterior below the ligament, received into corresponding grooves on the right valve; cardinal teeth radially grooved, one or two in each valve, those in the right valve stronger. Silurian. Ex. Or/hodonlisctts, Allodesma. This family, as suggested by Neumayr, probably exemplifies the first step in the development of the Teleodesmacean hinge. But it must be admitted that its amphidetic though linear area, the occasional multiplication to three of the lateral laminae, and the subligamentary location of the hinder lamina:, are very reminiscent of the prevalent Silurian schizodont type, and the family can be admitted to the Te4eodesmacea only as a probable ancestor, rather than a perfectly developed type of the modern assemblage. 538 TRANSACTIONS OF THE WAGNER FREE B. Diogenodonta. Laterals normally one or two, and cardinals three or less, in any one group. Superfamily CYPRICARDIACEA. Lobes of the mantle partially closed ventrally ; anterior lateral laminae ab- sent, or grouped with the cardinal teeth, short and obscure. FAMILY PLEUROPHORIDyE? Gills with the outer limb appendiculate, smaller than the inner, united behind the foot to each other and to the siphonal septum; palpi moderate ; foot compressed, grooved, sometimes byssiferous ; mantle with a moderate pedal and two siphonal openings, the siphonal orifices usually not produced into tubes ; dioecious, marine. Shell substance cellulo-crystalline ; valves equal, free, closed ; adductor scars subequal, free from the pedal scars; pallial line entire, or feebly sinu- ated ; area obscure; ligament external or seated in a groove, parivincular ; margins of the valves usually plain ; hinge with one left and two right poste- rior laminae, the anterior laminae absent or confused with the cardinals ; two or three cardinal teeth in each valve, of which the posterior in both valves is sub- parallel to the dorsal shell-margin, and in the right valve is usually bifid. Devonian to recent fauna. Ex. Subfamily Pleurophorincz ; Pleurophorus, Cypricardella, Paleocardila, Mecynodon, Anisocardia, Astartella, (Cypricardia=) Trapezium, Coralliophaga. Subfamily Veniellina ; Veniella, Venilicardia, (Cyprina—) Arclica. Superfamily ASTARTACEA Lobes of the mantle free ventrally; lateral laminae obscure, when present distant from the cardinals. FAMILY CURTONOTIDyE? Shell short and heavy, with subterminal beaks; valves free, equal, closed ; area obscure; ligament as in Astartidce ; adductor scars, especially the ante- rior, deep ; pallial line simple ; hinge-plate broad, without lateral laminae, the formula of the cardinals J^Jjp or \^\\\ marine. Devonian and Carboniferous. Ex. Curtonotus, Prosoccelus, Proloschizodiis, Kejersteinia, This group is inserted in conformity with the opinion of Neumayr, who regards it as the radical of the Astartidce. FAMILY ASTARTIDCE. Gills not united behind the foot, the outer limb smaller, without appendix ; palpi moderate ; foot compressed, grooved, not byssiferous ; lobes of the man- INSTITUTE OF SCIENCE, PHILADELPHIA. 539 tie free ventrally, not produced into siphons ; the anal orifice complete ; the branchial papillose, functional, but incomplete below; direcious, marine. Shell substance cellulo-crystalline, with a pronounced epidermis ; shell rounded or subtriangular, usually with concentric or not radial sculpture ; valves equal or subequal, free, closed ; area distinct; ligament and resilium ex- ternal, parivincular, opisthodetic ; beaks prosoccelous ; adductor scars sub- equal, with a distinct anterior pedal scar ; pallial line simple; hinge-plate dis- tinct, hinge with anterior and posterior laminae and their respective sockets, variably disposed with respect to the valves, and usually more or less obsolete ; cardinal teeth not bifid at the summit, the full cardinal formula {roTTrro. 'Dut t'le terminal teeth frequently obsolete. Triassic to the recent fauna. Ex. Aslarte, Pachytypus, Plesiastarte, Goodalliopsis, Crassalellina, Micromeris, Eriphyla, Preconia, ? Plychomya, ? Plionema, Opis, Seebachia, Woodia. A number of genera have been associated with Astarte which probably be- long elsewhere. A very careful scrutiny is often necessary to determine the true tooth-formula, as the armature of the hinge is frequently more or less obsolete. The teeth are frequently marked with strong transverse striation in the line of motion. FAMILY CRASSATELLITID^. Anatomy as in Astartidtz (the anal siphonal orifice sometimes incom- plete ?) ; marine. Shell as in Astartidce, but the valves always somewhat unequal, and usually more or less rostrate, the beaks compressed, erect or opisthoccelous ; ligament internal, more or less obsolete ; resilium large, wholly internal, attached at each end to a chondrophoric pit in the hinge-plate behind the cardinal teeth ; lateral laminae and sockets usually alternated in the valves, the hinge plate heavy, flat ; the posterior cardinal in the right valve very small or obsolete, with no distinct socket in the opposite valve ; full cardinal formula I. 1010 U 1 0 1 0 f Lower Cretaceous to recent fauna. Ex. (Crassalella=) Crassalellites, Pseuderiphyla, Scambulaf, Anlhonyia. The earlier forms of this family have a small resilium close to the nearly marginal ligament. With time, later ones show a gradual descent of these organs, until in some of the more specialized modern forms there is no appreciable ligament remaining and the resilium has become large and deeply immersed. The change is so gradual that no sharp line can be drawn and the various names applied by Conrad to the early phases can only be regarded as of tri- fling value. The parallelism between this group and the Mactridtonidsis, Atactodea.Mesodesma, Donacllla, Taria, Paphies. Da-ci lines ; Ex. Dai'ila, Anapella. Erviliiiiir ; Ex l''.>vilia, Cfcce/la. E. Asthenodonta. Hinge often essentially Mactroid, but usually degenerate or obsolete, owing to modifications due to the burrowing habit. These secondary adaptive modi- fications have led to the association of the following types with the genetically distinct Anomalodesmacea, which also exhibit them and for the same reason. Superfamily MYACEA. Burrowing, long siphoned, frequently inequivalve Pelecypods, usually with the mantle lobes largely united below, more or less united siphons and degen- erate hinge apparatus. FAMILY MYACID/E. Gills normal, plicate, usually not extended into the cavity of the branchial siphon, united behind and forming an anal chamber ; palpi large, more or less united behind ; foot small, grooved, byssiferous when young, but not in the adult; mantle edges smooth, thick, duplex, largely united; siphons united, with a horny tunic, not wholly retractile; no sensory lamina: behind the branchial foramen ; anal end of the rectum free ; dkecious, marine. Shell substance cellulo-crystalline, earthy, with a conspicuous epidermis; valves unequal, more or less elongate, rounded in front and gaping behind ; adductor scars subequal ; pallial line sinuated ; shell margins plain ; area obso- lete or none ; ligament and resilium internal, opisthodetic, attached in the left valve to a projecting chondrophore, merging with the dorsal margin behind, and in the right valve to an inconspicuous, usually subumbonal, chondrophore ; hinge edentulous. Tertiary and recent fauna. Ex. Mya, Cryptoinya, P/afyodon, Sphenia, Tugonia. Sphcnia retains the byssus when adult and is a nestler, the others are burrowers ; in Tugonia, of which the anatomy is unknown, the chondrophore of the right valve is well developed. FAMILY CORBULID^. Gills short, arranged as in Mya ; foot compressed, grooved, often byssifer- ous ; mantle edge papilliferous, largely united ventrally ; siphons short, united, with papilliferous tips, naked, wholly retractile; anal end of rectum sessile; dioecious, marine or estuarine, rarely fluviatile. 558 TRANSACTIONS OF THE WAGNER FREE Shell small, but much as in Mya, but the pallial sinus feeble or obsolete; the ligament usually stibexternal, separated from the resilium, which is inter- nal, alivincular and amphidetic ; the chondrophore is received into a socket of the opposite valve, not merged with the valve margin ; hinge with one or two subumbonal projecting teeth, and rarely obscure traces of laterals ; the poste- rior gape inconspicuous. Triassic to the recent fauna. Ex. Paramya, ? Pleuromya, Corbulamella, Corbulomya, Anisolhyris, Himella, Bothrocor- bula, Corbula, Erodona, ? Basterotia. The Cretaceous Corbulamella has an anterior myophore ; Basterotia is ex- ceptional in having the ligament external, on distinct nymphs, but may not belong to this family. The most salient shell character of this group is the strong dentiform process in front of the chondrophore. FAMILY SAXICAVID^. Resembling Mya, but the gills extended into the cavity of the branchial siphon; foot small, digitiform, grooved, byssiferous when young; siphons united, not wholly retractile, generally tunicate ; mantle lobes smooth-edged, largely united (sometimes with an opisthopodial orifice ?) ; dioecious, marine. Shell substance as in Mya ; epidermis conspicuous ; valves equal, free, rude, and often irregular, more or less elongated and gaping, not fully covering the animal ; adductor scars often irregular, the pallial line discontinuous or irregu- lar, the sinus distinct ; shell margins smooth ; area obsolete ; ligament and resil- ium external, parivincular, seated on strong nymphs, sometimes widely ex- tended ; hinge without laterals, with few feeble or obsolete subumbonal cardinals. Cretaceous to recent fauna. Ex. Glycimeris, Saxicava, ? Cyrlodaria. Hancock refers to an opisthopodial orifice in " Panopea," but I have found none in P. generosa Gld. In Cyrtodaria the pedal orifice is anterior, the hinge edentulous, and the epidermis leathery, while the others have a ventral pedal orifice, obscure hinge-teeth, and a papery epidermis. FAMILY GASTROCH/ENID^ ? Gills as in Saxicavida, prolonged into the branchial siphon ; foot digitiform, small, not grooved or byssiferous ; mantle edges thick, smooth, united, with a small pedal foramen; siphons naked, united, not wholly retractile; dioecious, marine. Shell substance as in Saxicava ; valves equal, widely gaping in front; adductor scars unequal, the anterior smaller; pallial sinus deep, margins sim- ple"; area none; ligament and resilium external, parivincular; hinge with a sin- INSTITUTE OF SCIENCE, PHILADELPHIA. 559 gle obsolete cardinal, or wholly edentulous ; animal frequently forming an ex- ternal protective tube to supplement its burrow, but to which it is in no way attached. ? Permian, Triassic to recent fauna. Ex. Gastrochcena, Rocellaria, Fistnlana, Spengleria, Cucurbilula. This group stands between the Myacea and the Adesmacea, verging on the latter. Many of its characters are adaptive and are repeated in the En- siphonacea, but morphologically its relations to Saxicavidce seem close. Superfamily ADESMACEA. Gills with direct and usually reflected laminae, long, united, extended into the branchial siphon ; posterior adductor usually in front of the visceral ganglion, anterior adductor external to the cavity of the valves, exerted in a contrary sense to the posterior muscle; hinge-margin reflected, edentulous ; ligament obsolete ; a myophoric process extending freely into the valve from the subumbonal cavity. FAMILY PHOLADID^. Gills not fused in the median line, extending well forward into the oral region, palpi large, partly supported by the styloid myophore ; foot large, modified in front as a triturating organ ; behind usually grooved but not bys- siferous ; mantle lobes united except for the pedal orifice, smooth or papillose, duplex at the margin, the inner fold conspicuous; anterior adductor covered by the mantle and often by accessory shelly deposits ; siphons united to their ends, naked or tunicate, without " pallets," largely retractile ; dioecious, marine, boring in hard or solid substances, Shell cellulo-crystalline, with a thin epidermis ; valves more or less gap- ing in front and behind, with inconspicuous beaks and reticulate, often spinose sculpture, but not colored ; in the adult supplemented by accessory shelly pieces, always attached to the valves, but not by an exterior shelly tube like that of Gastrocfuznidce ; the antero-dorsal margins more or less extensively reflected, the postero-ventral approximated ; pallial line sinuated ; area none ; ligament and resilium usually absent, an obsolete remnant of resilium and chondrophore sometimes present in the left valve. Carboniferous to recent fauna. Ex. Turnus, Pholas, Zirphtea, Talona, Pholadidea, Jouannetia, Xylophaga, Martesia, Par- afthulas, Teredina, etc. FAMILY TEREDINID/E. Pedal ganglia obsolete, the visceral behind the posterior adductor; ven- tricle of the heart ventral and posterior to the rectum, elongate, with a single anterior aorta (equivalent to a fusion of the two aortas of ordinary forms) ; gills fused in the median line, with direct but not reflected laminae, the external limb reduced, situated behind the viscera and extended into the branchial siphon ; 560 TRANSACTIONS OF THE WAGNER FREE palpi normal, not united behind ; foot rudimentary, not grooved or byssiferous ; siphons greatly prolonged, united nearly to their ends, naked, bearing distally a pair of calcareous shields or " pallets," moved by a special set of muscles; mantle edges smooth, united, except at the pedal foramen ; anterior adductor degenerate, attached on the anterior edges of the valves and covered only by the mantle ; dioecious, the larval young retained for a time within the branchial cavity of the parent ; boring, chiefly in wood; usually marine, rarely fluviatile. Shell much reduced, equivalve, auriculate, widely gaping, the valves ap- posited ventrally only on the surface of a parietal tubercle ; adductor scars un- equal, the anterior marginal, very small ; pallial line coincident with the valve margins ; a styloid myophore projecting from the cavity of the beaks ; mantle secreting a calcareous lining to the burrow; pallets variable in form, the valves without attached accessory shelly plates; area none, hinge-margin reflected, edentulous, the ligament absent or obsolete. Carboniferous ? Jurassic to recent fauna. Ex. Teredo, Calobates, Seplaria, Xylotrya, Nausitoria. A species of this group has been found in the Ganges, and another in the Zambesi, in perfectly fresh water, hundreds of miles from the sea. The paleo- zoic species are known only by burrows, which are of somewhat doubtful origin. In conclusion the reader is reminded that this summary represents not the entire truth in regard to the groups characterized, but only an approxima- tion to our present knowledge of them. The marshalling of the characters here given will doubtless do much to call attention to discrepancies and errors hitherto unchallenged, and, by its very defects, lead to an amelioration of the system. INSTITUTE OF SCIENCE, PHILADELPHIA. 561 NOTES ON NOMENCLATURE. In 1877 the writer reported to the American Association for the Advance- ment of Science on the state of opinion among American men of science in re- gard to the matter of Rules for settling questions of nomenclature in Zoology and Botany. Since then he has added a good deal to his experience in ques- tions of nomenclature, and concludes that a statement of the principles upon which points of nomenclature have been settled in this memoir may be of use to students who have to use it. The subject is one upon which opinions change with experience. Conclusions which seem axiomatic with the begin- ner are questioned more or less seriously, or even rejected, by the maturer student. With the more minute study of groups names have greatly multi- plied, and it daily becomes more necessary to adhere to some fixed standard. Those familiar with the history of the subject know that the earlier naturalists had no clear conception of the importance of a fixed nomenclature, that the idea has grown in comparatively modern times, and that different branches of Zoology have developed their nomenclature with some differences of detail, which the writer believes it best to recognize, without insisting on an abso- lutely common standard in all details. Such differences are those exhibited in the literature of Gall-insects, Microlepidoptera, Echinoderms and modern Botany. The following notes may, therefore, be understood as intended to apply strictly to the literature of Mollusca, though very largely applicable to all bumches of Zoology, and to represent the results of a somewhat wide experi- ence in that field. The occasion for scientific nomenclature is the necessity of having a sin- gle fixed name for a zoological entity, which will have a single fixed meaning when used, without reference to the language or nationality of the user. The idea involved \s fixity of the name, and, therefore, its availability for world-wide use among scientific men. Our first and fundamental rule, therefore, must be: I. The object of nomenclature is the fixity of scientific names. To this it necessarily follows that whatever disturbs the fixity of a name which is entitled to be used, is opposed to the fundamental principle of nomen- clature, and the burden of establishing his right to disturb rests upon the dis- turber. Our second rule or axiom of nomenclature is : II. Other things being equal, the prior name is entitled to precedence. This is universally admitted, and all the other rules of nomenclature have 562 TRANSACTIONS OF THE WAGNER FREE as their object the determination (i) of what constitutes a scientific name, and (2) how to determine its priority. III. A name to be valid must be binomial (if relating to a genus and species) ; must be in Latin form (at least superficially) ; must be defined or suffi- ciently identified, with the object to which it is applied, for recognition in the absence of specimens of that object, and must be printed and pub- lished so as to be accessible to scientific men. In the case of fossils it has been pretty generally conceded that a figure must be given to validate the description and enable it to stand, if in conflict with a subsequent name for the same object accompanied by a figure. (This latter rule is not retroactive, and dates from the Bologna Geological Congress.) IV. Binomial nomenclature in mollusks dates from the tenth edition of Linne's Systema Naturae, 1758. There is practically no difference of opinion about this point among modern students of mollusks, and there are reasons why it is important that this date should be assented to, but it would require too much space to detail them here. The writer, in conformity with the first clause of Rule III, rejects all names not given by binomial authors, or by authors in works not consistently binomial (though trinomials for subspecific names are not inimical to this rule). Such names do not belong to nomenclature and, if used by a binomial author subsequently in a different sense, are not pre-occupied by reason of the non-binomial use; or if used m the same sense, take date only from the epoch of their use binomially. The second clause of Rule III is more important than is commonly sup- posed, and has been frequently violated with apparent unconsciousness. The writer holds that no vernacular names whatever should have any standing in scientific nomenclature when proposed, unless (i) they have an accidentally Latin form, or (2) unless they are intentionally modified to give them such a form. If vernacular names be admitted in the way in which they have often been used for Mammals, there is no reason why any vernacular term should not claim recognition, to the eventual destruction of Latin nomenclature. The only exception to this lies in the use of proper names of persons and places, which are acceptable when provided with the proper Latin suffixes, which should be attached to the name as a whole (unless it terminates in a silent - vowel, which may be retained or omitted as euphony may dictate), without subjecting the name to a Latin transliteration; unless the said name be one which belongs to a language which does not use the Roman alphabet. Ori- ental and Slavonic names, which use an alphabet which is either not Roman, or Roman without Roman values to the letters, must be transliterated so as to exhibit their phonetic value. The requirement of a Latin form, however, does not involve (i) the modification or rejection of an old-established name because of its not conforming to the rule established long after it was proposed. Thus INSTITUTE OF SCIENCE, PHILADELPHIA. 563 such names as Kcllia and Rissoa, which, by the rule, should be Kellyia and Rissoia, may justly be held to have established themselves by prescriptive right and to be in no need of emendation. The more basic principle, that of fixity of the name, should rule here. But when a proper name has been mutil- ated, ungrammatically misused, or is contested on account of error from the time, of its proposal, as in the cases of Drcisscua, Valencicnncnsis and Totteni- aua, we hold that emendation is proper, and write Drcissensia, Valencienncsia and Totlenia. The requirement of Latin form does not necessarily extend to details of internal construction, and a Greek word put according to rule into Latin form, becomes, for the purpose of nomenclature, a Latin word, and, we hold, may (though not without opprobrium) be compounded with another intrinsically Latin word, without necessarily rendering the compound rejectable. Fixity of names is far more important than purity of construction and the nomencla- ture should not be subject to the whims of philologers, however unpleasant the barbarisms may be, unless the external form of the word is absolutely in conflict with the Latin usage. The writer heartily agrees with Adanson that names having no meaning are the best (when Latiniform) if the alterna- tive be the constant changing of them to suit the classicists. Elisions for brev- ity or euphony, even if not authorized by the rules of Latin construction, should not cause a name to be rejected, Solccnrtits should not be elongated into Si'lcnociirtns, nor should the indices be thrown into confusion by the materializ- ing of an omitted aspirate in a Greek transliteration, making, for instance, Hor- iostoma out of an innocent Oriostoina. The Greeks themselves were by no means of one mind about the aspirate. There was a time when nomenclature was a comparatively small affair and the inconvenience caused by striving after an elegant Latinity was small. But, with the tens of thousands of names which have been proposed, changes have now a very different importance to the worker, and should no longer be required on trivial or anything but really necessary grounds. The third clause of Rule III, requires a sufficient definition or identifica- tion of a name. When an author proposes a genus and gives no definition or reference to the literature other than the name of a species as, for instance, " Spizclla monticola Linne," it would seem to be very clear sailing. But every one who has had to hunt up details of nomenclature has found cases where it was quite clear that the species supposed to be, say " monticola Linne," was really something quite different, and the genus maker was building on an ig- norance of the true monticola. That such wretched work should not be al- lowed to confuse the nomenclature, it has been, as the writer thinks very just- ly, required that some attempt at a differentiation of a genus should be required of its author before his name should be held to have acquired a scientific basis. By the enforcement of such a rule some of the worst nuisances in the lit- 564 TRANSACTIONS OF THK WAGNER FREK erature of mollusks, chiefly auctioneers' and amateurs' catalogues, are removed from the path of the worker. As to the requirements for publication, it is now admitted with practical unanimity that the actual date of publication in print is the only date to be con- sidered in discussing the priority of a published name; and, where this date is uncertain, no name of certain date and possible priority should be rejected, if in use, until a certainty is established for the competitor. Some authors, probably little realizing the mischief they were doing, have rejected names because they differed only in gender, from other prior names. This is in opposition to the general usage of naturalists, to the funda- mental object of nomenclature, and does not appear to have any warrant in usefulness to science, or in any other direction. Such proceedings cannot be accepted. Two names are either identical or not. If identical, one is a syn- onym ; if not identical, it can stand ; other things being equal. The moment one allows uncertainty of application to enter into the office of a rule, there follows mischief more or less extensive. It must be tested by the question (i) is it necessary? and (2) if not unavoidable does it make for fixity of nomenclature? If the second question is answered in the negative, the change is condemned ipse facto. The determination of priority is often a very complex matter. The writer has come to the conclusion that : V. If once a synonym, a generic name must be regarded as always a synonym. Formerly, on various grounds, the writer hesitated to take this position, but has been gradually forced to believe that safety lies that way alone. VI. The first species in a list, where no type is mentioned under a new genus, is not necessarily to be taken as the type. The type of the first reviser of the genus should stand unless there are weighty reasons to the contrary. In Linnean groups, unless the type has been otherwise fixed, his rule should be followed to take the most common, best known or officinal species, but if another has been deliberately selected by a reviser, the latter must stand. In present-day work there can be no excuse for the non-specification of a type by the author of a genus. VII. The author having proposed a genus has no further authority over it. He may not alter the name, change the selected type, or do anything which he might not be authorized to do to a genus proposed by some one else. VIII. In selecting a type, a species not mentioned by the author of the genus in the original list of species given when the genus was proposed, can- not be chosen. IX. If a genus is divided and portions of it erected into new genera, a portion must be left to bear the original name. INSTITUTE OF SCIENCE, PHILADELPHIA 565 X. Ill compounding invalid genera the oldest name (and not a new one) must be taken for the consolidated group. If a new genus be proposed old genera cannot be referred to it as subgenera, the later name must take the subordinate place. No one has the right to gather a score of old names, reduce their nominal rank, and then propose a new name to include the whole assembly. XI. That a genus has the same name as one of its species is not a sufficient reason for changing either name. XII. Names of higher rank than genera are not subject to the rule of strict priority on account of the mutability of their limits. Family and sub- family names should, as far as possible, be based on the name of the largest, most characteristic, best known or oldest genus included in them. The writer would advise persons desiring fuller information to refer to the above-mentioned report to the American Association for the Advancement of Science* (which may be obtained of the Permanent Secretary, Salem, Mass.), or to the more recent Code prepared for and adopted by the American Orni- thologists' Union,f which introduces several very welcome ameliorations into the earlier code. There are a few points upon which the writer differs from the A. O. U. Code, which may be specified. First, there seems no necessity for regarding generic names of different genders as synonymous when they do not otherwise differ. To treat them as identical is opposed to the usage of the majority of naturalists as well as to the fundamental principle of fixity, so justly insisted on by the authors of the Code. Second, the writer cannot admit the propriety of accepting vernacular names for genera and species when they are not in Latin form. He does not see any intrinsic difference between two ver- nacular words introduced separately and two introduced in connection. If Patelle viride be (as it should be) rejected as vernacular, why is not Patella viride or Patelle virdis half vernacular and equally rejectable to the extent of the offending half? To say that in either of the latter instances the vernacular word is introduced " as if it were a Latin word " (cf. Code p. 19) is to make an assumption and introduce uncertainty. The vernacular word to have any standing, unless adventitiously of Latin form, should be altered to such form or rejected. From this point of view, which is believed to be that of the great majority of naturalists, Canon XXXI of the Code can only be accepted with certain modifications. In other respects the writer heartily agrees with the views expressed by the distinguished authors of the Code, and would suggest the desirability of conformity with the rules which they have prepared. •Nomenclature in Zoology and Botany, Salem, Dec., 1877, 8vo, 56 pp. fThe Code of Nomenclature adopted by the American Ornithologists' Union, New York, the A. O. U., 1892, 8vo, 72 pp. INDEX To names of genera mentioned in the preceding summary of the Families of Pelecypoda. Ahra page 554. Acila 516 Actinodonta 524 Actinomya 533 Actinopteria 518 Adacna 54-3 Aenigma 527. Allodesma 537. Allonychia 519. Allopagus 548. Ambonychia 519. Amphiccelia 519. Anmsium 525. Anadara 517. Anapel'a 557. Anatimya 531. Anatina 531. Anatinella 556. Anomalodonta 519. Anomalomya 529. Anomia 527. Anthonyia 539. Anthracomya 522. Anthracosia 522. Antipleura 513. Anisocardia 538. Anisothyris 558. Anodon 522. Anodontites=Anodon Anoplophora 522. Aplodon=Spi xoconcha. Apricardia 542. Area 517. Arcicardium 549. Arcomya 530. Arconaia 522. Arctica 538. Argina 517. Aristella 527. Arnaudia 543 Asaphis 554. Aspergillum=Brechites. Astarte 539. Astartella 538. Asthenothzerus 531. Atactodea 557. Atrina 519. Aucella 520. Avicula 518. Aviculopecten 525. Aviculopinna 519. Axinopsis 545. Axinus 546. Azara=Erodona. Barbatia 517. Baroda 552. Bartlettia 523. Hasterotia 536, 558. Batissa 540. Bayleia 542. Beguina 54 1 . Berthelinia 529. Biradiolites 543. Bontaea 531. Bothrocorbula 558. Brechites 534. Bushia 531. Byssanodonta 528. Byssocardium 550. Byssonychia 519. Byssopteria 519. Caecella 557. Calobates 560. Callocardia 551. Callogonia 551. Calyptogena 54 1 . Caprina 542. Caprotina 542. Capsa 554. Carbonicola 522. Cardilia 556. Cardinia 522. Cardiola 513. Cardiomya 536. Cardissa 549. Cardita 541. Carditamera 541. Carditella 541. Cardium 549. Carolia 527. Cassianella 520. Castalia = Tetraplodon. Castalina 522. Cercomya 531. Ceromya 530. Cetoconcha 536, 537. Cetomya 536. Chalmasia 521. Chama 542. Chamostrea 533. Chlamydoconcha 547. Chlamys 525. Choristodon 553. Circe 552, 554 Clavagella 534. Clementia 552. Clidiophora 532. Clisocolus 550. Cnisma 517. Cochlodesma 531. Codakia 544. Ccelodon 532. Conchocele 546. Congeria 528. Conocardiutn 519. Coralliophaga 538. Corbicella 545. Corbicula 540. Corbis 545. Corbula 558. Corbulamella 558. Corbulomya 558. Corimya 531. Ctenodonta 515. Crassatella 539. Crassatellina 539. Crassatellites 539. 568 Crenatula 520. Crenella 528. Cristaria 522. Cryptodon 546. Cryptomya 557. Cucullsea 517. Cucullaria 517. Cucullella 515. Cucurbitula 559. Cultellus 555. Cumingia 554. Curtonotus 538. Cuspidaria 536. Cyamium 547, 548. Cyathodonta 531. Cyclina552. Cymbophora 556. Cyniella 536. Cypricardella 538. Cypricardia 538 Cyprimeria 552. Cyprina 538. Cyrena 540. Cyrenoida 545. Cyrtodaria 558. Cyrtodonta 517. Cythereodon 524 Dacrydium 528. Daonella 513. Darina 556. Davila 557. Dermatomya 536, 537. Diceras 542. Dicerocardium 522. Didacna 549. Dimya 526. Dimyodon 526. Diplodonta 545. Ditypodon 540. Divaricella 544. Donacilla 557. Donacopsis 540. Donax 554. Dosinia 552. Dreissensia 528. Dreissensiomya 528. Durga 522. Eastonia 556. Echinochama 542. Egeria 554. Eligmus 521. Elizia 554. TRANSACTIONS OF THE WAGNER FREE Endomargarus 533. Endopleura 554. Ensis 555. Entodesma 533. Entovalva 547. Ephippium 527. Ephippodonta 547. Eriphyla 539 Erodona 558. Ervilia 557. Erycina 547. Erycinella 547. Etheria 523. Ethmocardiiim 549. Euciroa 535. Eupera 540. Eurymya 527. Exogyra 521. Fabella 547. Felania 545. Fimbriella 545. Fistulana 559. Foegia 534. Fossula 523. Fragum 549. Galeomma 547. Gastrana 554. Gastrochsena 559. Gemma 552. Gervillia 520. Glabaris523. Glaucomya 553. Glycimeris 558. Gnathodon=Rangia. Goniomya 530. Goniophora 527. Gonodon 544. Goodalliopsis 539. Gouldia 552. Grammysia 513 Gratelupia 552. Gresslyia 530. Gryphsea 521. Guerangeria 522. Halicardia 533, 536. Haliris 535. Halonympha 536. Hemicardium 549. Hemidonax 544. Heterocardia 556. Heterodiceras 542. Heterodonax 554. Hiatula 554. Himella 558. Hindsiella 547. Hinnites 525. Hippopus 550. Hippu rites 543. Hoplomytilus 528. Hornesia 520. Humphreyia 534. Hypotrema 527. Hyria 522. [chthyosarcolites 542. Idas 527. Iheringella 523. Inoceramus 520. Iphigenia 554. Iridina 523. Ischyrodonta 517. Isocardia 550. Isodonta 554. Janeia 515. Joannisia 545. Jouannetia 559. Julia 529. Kefersteinia 538. Kellia 547. Kelliella 548. Kidderia 529. Labiosa 556. Lasea 547. Leda 516. Leila 523. Leiomya 536. Leptesthes 540. Leptocardia 549. Leptodesma 518. Lepton 547. Leptosolen 555. Libratula 547. Lima 526. Limasa 526. Limanomia 527. Limatula 526. Limnium 522. Limnocardium 549. Limopsis 517. Liocardium 549. Liocyma 552. Liopistha 536. Lithocardium 550. INSTITUTE OF SCIENCE, PHILADELPHIA. 569 Lithophagns 528. Lophocardium 536, 549. Loxoptychodon 540. Lucina 544. Lucinopsis 552. Lunulicardium 513. Lutetia 548. Lutetina 547. Lutraria 556. Liuonia 536. Lyonsia 533. Lyonsiella 533, 536. Lyrodesma 524. Maconia 554. Macroclon 517. Mactra 551, 556. Mactrella 556. Mactromya 530. Mactropsis 557. Mactrotoma 556. Malletia 516. Malleus 520. Margariona 526. Manjaritana 523. Martesia 559. Mecynodon 538. MetkSa 544. Megalodon 522. Megatomus 522. Meiocardia 550. Meleagrina 520. Meretrix 552. Mesodesma 557. Metaptera 522. Micromeris 539. Milneria 541. Miltha 544. Miodon 540. Modiola 528. Modiolarca 529. Modiolaria 528. Modiolodon 527. Modiolopsis 527. Modiomorpha 527. Monia 527. Monopleura 542. Monotis 520. Montacuta 546. Mulinia 556. Mulleria 523. Mutela 523. Mya 557. Myalina 528. Mycetopus 523. Myochama 532. Myodora 532. Myonera 536. Myophoria 524. Myrina 528. Myrtoea 544. Mysella 547. Mytilimeria 533. Mytilopsis 528. Mytilus 528. Xaiadites 528. Naranaio 553. Nausitoria 560. Xayadina 52 1 . Neilo 516. Neilonella 516. Nemodon 517. Neocorbicula 540. Novaculina 555. Nucula 516. Nuculites 515. Nyassa 522. Oedalina 554. Omalia 517. Oncophora 554. Opis 539. Opisthoptera 519. Orthodesma 515. Orthodontiscus 537. Ostrea 521. Oxytoma 520. Tachycardia 541. Pachyrisma 522. Pachytypus 539. Palffiocardita 538. Palaeopinna 519 Pakeosolen 555. Pandora 532 Panopea 558. Paphies 557. Papyridea 549. Paracyclas 544. Parallelodon 517. Paramya 558. Parapholas 559. Parastarte 552. Pecchiolia 535. Pecten 525. Pectunculus 517. Pedum 525. Periploma 531. Periplomya 531 Perna 520. Petricola 553. Pharella 555. Pharus 555. Phaseolicama 529. Philis 546. Philobrya 520. Pholadidea 559. Pholadomya 530. Pholas 559. Pinna 519. Pinnigena 519. Pisidium 540. Placenta 527 Placunanomia 527. Placunema 527. Placunopsis 527. Plagiodon=Iheringella. Plagioptychus 542 Plagiostoma 526. Platyodon 557. Platyniya 531. Plectodon 536. Plectoniya 536. Plesiastarte 539. Pleuromeris 541. Pleuromya 558. Pleurophorus 538. Plicatula 525. Plionema 539. Pliorhytis 554. Pododesmus 527. Polyconites 542. Poromya 536, 537. Posidonomya 513 Prasina 529. Praecardium 513. Preconia 539. Procardia 530 Prolobella 527. Pronoella 552. Prosoccelus 538. Protocardia 549. Protomya 513. Protoschizodus 538. Psammobia 554. Psephis 552. Pseudedmondia 544. Pseuderiphyla 539. Pseudodon 522. Pseudomonotis 520. Psilomya 536. TRANS. WAGNER FREE INST. SCIENCE, PHILA. Pteria 518, 520. Pterinea 518. Pterineopecten 525. Pteropsis 556. Ptychomya 539, 552. Ptychopteria 518 Pythina 547. Radiolites 543. Raeta 556. Raetella 556 Rangia 556. Reqtiienia 542. Resania 556. Rhipidocardium 519 Rhombopteria 518. Rhynchomya 531 Rocellaria 559. Sanguinolaria 554. Sarepta 516. Saxicava 558. Saxidomus 552. Scaldia 544. Scambula 539. Scaphula 517. Scintilla 547. Scrobicularia 554. Schizodesma 556. Schizodus 524. Schizot!i;erus Tresus. Seebachia 539. Semele 554. Senilia 517. Septaria 560. Scptifer 528. Serripes 549 Silenia -;Cetoconcha. Silurina 513. Siliqua 555. Solecurtus 555. Soleniya 515. Solen 555. Solenaia 522. Solenopsis 513. Souleyetia 554. Spaniodon 547. Spatha 523. Spengleria 559. Spha:ra 545. Sphaeriella 545. Spha?riola 545. SphzErium 540. Spheuia 557. Spisula 556. Spixoconcha 523. Spondylus 525. Sportella 547. Standella 556. Stavelia 528. Strigilla 554. Sunetta 552. Tagelus 555. Talona 559. Tancred ia 544. Tanysiphon 553. Tapes 552. Taria 557. Tellidora 554 Tellina 554. Tenea 545. Teredina 559. Teredo 560. Tetraplodon 522. Thecalia 541. Theora 554. Thracia 531. Thyreopsis 547. Tindaria 516. Tivela 551, 552. Toucasia 542. Trapezium 538. Tresus 556. Tridacna 550. Trigonia 524. Trigonocoelia 517. Trigonulina 535. Tropidomya 536. Tugonia 557. Turnus 559. Turlonia 548. Tylerias3i. Ungulina 545. Unicardium 544. Unio 522. Valletia 542. Yamixemia 517. Yelorita 540. Yeloritina 540. Yenericardia 541. Veneriglossa 552. \'enerupis 552. Veniella 538. Yenilicardia 538. Venus 551, 552. Verticordia 535, 536. Yesicomya 550. Ylasta 513. Vola 525. Volviceramus 520. Yulsella 520. \rulsellina 520. Whiteavesia 515. Whitella 517. Woodia 539. Xylophaga 559. Xylotrya 560. Yoklia 516. Zenatia 556. Zirphxa 559. Washington, D. C., April 17, 1895. TRANSACTIONS OF THE WAGNER FREE INSTITUTE OF SCIENCE OF PHILADELPHIA VOL 111. PART IV. APRIL, 1898 WAGNER FREE INSTITUTE OF SCIENCE MONTGOMERY AVE. AND SEVENTEENTH ST. PHILADELPHIA CONTRIBUTIONS TO THE TERTIARY FAUNA OF FLORIDA WITH ESPECIAL REFERENCE TO THE SILEX BEDS OF TAMPA AND THE PLIOCENE BEDS OF THE CALOOSAHATCHIE RIVER INCLUDING IN MANY CASES A COMPLETE REVISION OF THE GENERIC GROUPS TREATED OF AND THEIR AMERICAN TERTIARY SPECIES BY WILLIAM HEALEY DALL, A.M. I'AIIDNTDLOGIST TO THE UNITED STATES GEOLOGICAL SURVEY; HONORARY PROFESSOR OF INVERTEBRATE PALEONTOLOGY IN WAGNER FREE INSTITUTE OP SCIENCE PART IV. I. PRIONODESMACEA : NUCULA TO JULIA II. TELEODESMACEA : TEREDO TO ERVILIA WAGNER FREE INSTITUTE OF SCIENCE OF PHILADELPHIA TRUSTEES SAMUEL WAGNER, President. RICHARD B. WESTBROOK, Treasurer. JOSEPH WILLCOX, Secretary. J. VAUGHAN MERRICK, JR. S. T. SKIDMORE. HARRISON S. MORRIS. SAMUEL TOBIAS WAGNER. FACULTY HENRY LEFFMANN, A.M., M.D., President of the Faculty. S. T. WAGNER, B.S., C.E., Secretary of the Faculty. * HENRY LEFFMANN, A.M., M.D., Professor of Chemistry. J. T. ROTHROCK, M.D., S. T. SKIDMORE, A.M., Professor of Botany. Professor of Physics. W. B. SCOTT, A.M., ROBERT ELLIS THOMPSON, A.M., Professor of Geology. Professor of History, Literature, and Political Economy. S. T. WAGNER, B.S., C.E., THOMAS H. MONTGOMERY, Jr., Ph.D., Professor of Engineering. Professor of Biology. WILLIAM HEALEY DALL, A.M., Honorary Professor of Invertebrate Paleontology. THOMAS L. MONTGOMERY, A.B., CHARLES W. JOHNSON, Actuary and Librarian. Curator of Museum. PREFACE r I ""HE following pages are in continuation of the work on the Tertiary Fauna of Florida which was published in the preceding parts of this volume. As it was thought by persons interested that the title of the work insufficiently indicated its present scope, it has been supplemented by one or two explanatory lines on the title-page. When this work was begun the scheme included chiefly a description of the entire invertebrate fauna of the Pliocene beds of the Caloosahatchie, the silex beds of Ballast Point, and other Floridian localities explored by Mr. Joseph Willcox, Professor Heilprin, the writer, and others, with such refer- ences to allied forms as might be necessary for the proper elucidation of the material. As time went on, however, the interest aroused by the explorations of the Wagner Institute and its friends, and by the United States Geological Survey in Florida and adjacent parts of the Coastal Plain, resulted in bringing in a constantly increasing mass of material. In particular, the existence of Upper Oligocene beds in Western Florida, containing hundreds of species many of which were new, added two populous invertebrate faunas to our Tertiary series. It was found that a number of the species belonging to these beds had bec'n described from the Antillean Tertiaries. Hence it became necessary, in order to put the work on a sound foundation, not only to review the species of any given group known to occur in the United States, but also to extend the revision to the Tertiaries of the West Indies. Owing to the chaotic condition of our Tertiary Paleontology, especially the Post-Eocene faunas, this work has involved an enormous amount of drudgery, occupying the writer's leisure to an extent not anticipated at the outset. It is believed that the results will be beneficial in clearing the way for subsequent students and putting the nomenclature on a more permanent and reliable basis. The clearing up of the strati graphical relations of many of the older species is quite as important as the description of the numerous viii PREFACE new ones which have turned up in the course of the work. It is hoped that another part will conclude this series of papers, and comprise, besides the remaining descriptions, a summary of the faunal population of each of the principal Neocene horizons. To Dr. Charles D. Walcott, Director of the United States Geological Survey, to the authorities of the Smithsonian Institution and National Museum, and to numerous private correspondents and colleagues, thanks are due for facilities accorded and assistance rendered in the prosecution of the work. WILLIAM HEALEY DAI.L. TERTIARY FAUNA OF FLORIDA * Order PRIONODESMACEA. Superfamily NUCULACEA. FAMILY NUCULID^. Genus NTJOULA Lamarck. Nucula Lam., Prodr. Nouv. Class. Coq., p. 87, 1799. Type Area nucleus Linne. Nuculana Link, Rostock-sammlung, p. 155, 1807. Glycymeris Da Costa, British Conch., p. 170, 1778, ex parte. IN 1 778 Da Costa proposed for the Chama glycymeris of Belon (1553) and the Area nucleus of Linne a genus under the name of Glycymeris. In his System of Conchology published two years previously Da Costa had not adopted the Linnean nomenclature, but in his British Conchology and later in the Museum Colonnianum, which tradition says Da Costa edited from a manuscript of Hwass for Humphrey, he used the binomial system. The name Glycymeris had not previously been used by any binomial author, for Klein, who is sometimes erroneously cited for scientific names, cannot by any stretch of courtesy be truthfully called binomial. In the same work Da Costa used the generic name Pectimcnlus, subsequently applied by Lamarck (1799) to the orbicular Arks, for the group which had already received the name of ]\-nus from Linne. Da Costa's Glycymeris was intended to include all the rounded bivalves with a Taxodont hinge. Those of the type of Chama glycymeris were erected by Lamarck into a genus Pectuiiculus in 1799, leaving, according to modern rules of nomenclature, for Glycymeris Da Costa only the Area nucleus and its congeners. I confess I am unable to see how a con- sistent application of our rules, if we accept Pcctuncnlus Lamarck, can avoid the use of Glycymeris for the group usually called Nucula. Pectuuculus pre- ceded Nucula in Lamarck's Prodrome, and consequently must first be disposed 57i TRANSACTIONS OF WAGNER 572 TERTIARY FAUNA OF FLORIDA of. If, on the principle of '' once a synonyme always a synonyme," we reject Pectunculus Lamarck, on the ground that the name had already been used for another group by Da Costa in binomial form, we could then retain Lamarck's Nitcula at the cost of adopting Glycymeris for the group usually called Pec- tunculus, which is probably the least inconvenient arrangement of the two. According to Herrmannsen Glycymeris was used by Belon, or Belloni, in a quasigeneric sense two hundred years before its use by Klein ; so, even if we resort to non-binomial authors, the latter's name would have no standing. This is probably the reason why Da Costa, who was a man of erudition not prejudiced against the non-binomial writers, adopted the name in its original sense. I have already pointed out that the name Nucnlana of Link is merely a modification, on the score of taste, of Nuatla Lamarck. Link was enumerat- ing the Rostock collection, and since it happened that they had only one species, N. rostrata (since separated as Leda by Schumacher), to represent the genus, it follows the modified name ; but there is nothing in this fact nor in the diagnosis of Link to intimate that he intended to subdivide the original Nucula. Link altered many names in this fashion, of which Achathun, for Achatina Lam. ; Anatium, for Anatlfera Lam. ; Cassidca, for Cassis Brug. ; Cerium, for Cerion Bolt. ; Harpalis, for Harpa Lam. ; Limaria, for Lima Lam. ; Nassaria, for Nassa Lam. ; Pectinium, for Pecten Mull. ; P/ciirotoim; for Plenro- toma Lam. ; Tridaclme, for Tridacna Lam. ; Unioniim, for Unto Retz., etc., are examples. For this reason I can only regard Nucnlana as an absolute and exact synonyme of Nucnla Lamarck. Subgenus ACILA H. and A. Adams. The divaricately sculptured Nuculas in this group, in the recent state, are Pacific in their distribution ; one species, N. divaricata Hinds, extending from Korea (as N. mirabilis Ads. and Rve.) to the China Seas (N. insignis Gould) and probably to the Bay of Bengal (N. Fitltoni Smith), reaches a length of thirty millimetres; another, distinguished by smaller size, more ^vate "form, and a fine, regular, concentric over obsolete divaricate sculpture, is only known from Northern Japan (N. japonica Ball) ; another still (N. divaricata Val., + cas- trensis Hinds, + Lyalli Bd.) extends from the Aleutian Islands to California. In time the group recedes to the Cretaceous, with a much wider geographical range; two species are known from the Greensand of Europe, one (N. Ermaui Girard) from the Upper Cretaceous of Alaska at Atka Island, another from the FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA "3 Chico of California (N. truiicata Gabb) which is reported by Gabb to extend upward into the Tcjon Kocene (Pal. Cal., i., p. 198, pi. 26, fig. 184 ; ii., p. 197). An examination of undoubted Cretaceous specimens of N. truiicata shows that the species differs from the Tertiary forms by its more impressed escutcheon, its finer and more delicate divaricate sculpture, and its more prominent close set, regular and even concentric sculpture. Those I have seen are also smaller. They are quite distinct from N. Ennani, which may eventually prove to be of Tertiary age. Sonic confusion has been caused by the too inclusive manner in which Gabb has treated the fossil forms of the Pacific coast. ( I find a large Eocene species which is not distinguishable from N. decisa Conrad, the latter being a second name for N. divaricata Conrad (1848), not of Valenciennes (1833), nor of Hinds (1843), which was afterwards named N. Conradi by Meek (S. I. Miocene Checklist, p. 27, 1864). This probably extends into the Miocene, and to assist in clearing up the difficujty I have included a figure of it (plate 40, figures I, 3). In unmistakable Miocene of Oregon, on the Nehalem River, near Mist, Columbia County, another form is found of smaller size and much coarser sculpture, the posterior end more distinctly rostrate, but other- wise very similar, for which I propose the name of Nucttla (Acila) cordata (plate 40, figure 4). The interesting point, however, is that none of the fossil forms can be properly united with the recent N. divaricata Val. in spite of Gabb's opinion. The latter is a more trigonal, compact, and less rostrate form, and clearly distinct. The fossil forms are more closely related to the recent species of Japan than to the existing west American shell. Like many other Pacific groups, Acila extended to the Antillean region through the gaps between the Central American archipelago in Oligocene times. It is represented by N. Sclioinburgki Forbes, from the San Fernando beds of Trinidad, which differs from the west American fossils by its more rostrate shell, and by N. tnbcirulata Gabb, from the Oligocene of Hayti. It is possible that deep-sea dredgings will eventually reveal a surviving species in the abysses, but to the present time no recent species is known from the Atlantic and only the N. Cobboldite from the Pliocene of the British Crag beds. No east American fossil species is known at all from the continent of North America. The species have, as a rule, twenty to twenty-two anterior and nine to eleven posterior teeth; the posterior tooth in the left valve nearest the chondrophore is larger than those immediately behind it. All the species have concentric sculpture. TRANSACTIONS OF WAGNER 574 TERTIARY FAUNA OF FLORIDA Subgenus NUCULA s. s. The Neocene species of Nucula are quite puzzling, owing to the close similarity of all the species in a general way, and the variability of each in minor details. Nucula proxima Say. Nucula proxima Say, Journ. Acad. Nat. Sci. Phila., ist Ser., ii., p. 270, 1822 ; Tuomey and Holmes, Pleiocene Fos. S. Car., p. 53, pi. 17, figs. 7-9, 1855 ; Emmons, Geol. N. Car., p. 287, fig. 208 B, 1858 ; Dall, Hull. 37, U. S. Nat. Mus., p. 42, pi. 56, fig. 4. Nucula obliqua Say, Am. Journ. Sci., ii., p. 40, 1820 ; not Lam., 1819. Older Miocene of New Jersey at Shiloh and Jericho, Burns ; Yorktown beds of Virginia, Harris; north end of the Dismal Swamp, Virginia, Shaler; Pliocene of the Caloosahatchie and Shell Creek, Florida, Willcox and Dall ; Pleistocene of Simmons Bluff, South Carolina, Burns; recent: (typical form) from Charlotte Harbor, Florida, northward to North Carolina in two to one hundred fathoms ; (var. trunadiis Dall) from Long Island Sound northward to Nova Scotia. If a geographical series of this species be examined, it will be noticed that the northern specimens are almost smoothly truncate behind, the es- cutcheon is not impressed to any marked degree, and there is no angle at the margin below the escutcheon. On the other hand, the specimens from the southern coast, whence Say's type was derived, have a thinner shell with an impressed escutcheon, the middle of which pouts more or less strongly; the valve-margin below the escutcheon has a projecting angle ; the shell is some- what compressed, compared with the northern form, and has a paler and more delicate epidermis. Several of these characters are correlatives of the latitude, but the extreme forms without a connecting series would be taken by any careful observer for distinct species. Most of the conchologists of the United States having resided north of Delaware, the northern form is the more familiar both in books and collections, but it is not the original type, and I have therefore given it a varietal name. The fossils, so far as yet observed, are all more like the variety trunciilns, corresponding to the cooler temperature of the sea in this region during Miocene times, while the Pliocene specimens are rather undersized, which may have been the result of the increasing temperature which characterized that epoch in Florida. There is little doubt that the original Nucula obliqua of Say, from the Miocene of Petersburg, Virginia, was a variety of N. proxima ; at any rate, the FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA specific name had been used by Lamarck a year before it was applied by Say to the fossil, so that for the American shell the name must be discarded. Nucula Shaleri Dall. PLATE 40, FIGURE 6. Nth ulti S/ia/eri Dall, Am. Journ. Sci., xlviii., p. 298, Oct., 1894. Miocene gravelly conglomerate of Chihnark, Martha's Vineyard, and in the Pliocene of Gay Head ; J. B. Woodvvorth. This large species belongs to the group of N. decussata and antiqitata Sby., of which the recent representative on our coast is the small N. crenulata Hinds. Lon. of shell 15, alt. 11, diam. 7 mm. There are eight to eleven anterior and sixteen to twenty posterior teeth. Nucula chipolana n. s. PLATE 32, FIGURE 10. Oligocene (" Old Miocene") of the Chipola beds, Calhoun County, Florida, and of the lower (Chipola) bed at Alum Bluff, Appalachicola River, Florida; Burns and Dall. Shell small, solid, polished, with faint radial stria? more conspicuous ventrally, and more or less obvious incremental lines ; breaks turgid, low ; posterior end of shell obliquely truncate, flatfish ; base arcuate, anterior dorsal line sloping, anterior end attenuated and rounded; there is no defined lunule; the escutcheon is elongate-cordate, ill-defined, the margins in the middle line slightly pouting; internally polished, hardly pearly, with the basal margin finely sharply crenulate; the chondrophore small, narrow, and very oblique, anteriorly directed ; anterior teeth narrow, slender, about thirteen, posterior teeth four or five. Lon. of shell 4, alt. 2.75, diam. 20 mm. The chief characteristics of this small species are its elongated form and i fine radial stria;. Nucula si nar ia n. s. PLATE 32, FIGURE 7. Oligocene of the Alum Bluff beds on the Yellow River at Oak Grove, Santa Rosa County, Florida, and Miocene of the St. Mary's River, Maryland ; Burns and Harris. Shell small, solid, trigonal, polished, with fine radial strito, more distinct near the basal margins, and faint, concentric, rather irregular furrows, obsolete TRANSACTIONS OF WAGNER 576 TERTIARY FAUNA OF FLORIDA over most of the valve, but tending to be stronger near the anterior and posterior slopes ; here and there one crosses the whole shell like the indication of a resting stage ; dorsal slopes nearly straight, base arcuate, ends rounded ; lunule absent, escutcheon impressed; striated, the margins not pouting in the middle ; beaks prominent, obtuse ; interior brilliantly pearly, muscular im- pressions deep; the basal margin finely crenulate; hinge strong, wide; the chondrophore oblique, heavy ; anterior teeth wide, strong, about seventeen, posterior about seven. Lon. of shell 4.75, alt. 4, diam. 2.5 mm. This species differs from the preceding by its more trigonal, heavy, and pearly shell, its wider and proportionately heavier hinge, and its impressed instead of merely flattened escutcheon. The Maryland specimens are usually larger and more worn than the types from West Florida; both retain a purplish tint in their nacre. Nucula taphria n. s. PLATE 32, FIGURE 14. Miocene of Magnolia and the Natural Well, Duplin County, North Caro- lina ; Burns. Shell small, very solid, rounded cuneiform, with few strong, distant con- centric grooves, like marks of resting stages, which extend clear over the shell, otherwise smooth ; beaks prominent, turgid ; lunule absent ; escutcheon faintly indicated ; posterior end subtruncate, anterior produced and rounded, base moderately arcuate ; interior hardly nacreous, muscular impressions large and distinct ; basal margins entire ; hinge strong and heavy ; chondro- phore wide, distinct, a little oblique ; anterior teeth thirteen, posterior six or seven. Lon. of shell 2.9, alt. 2.25, diam. 1.5 mm. This interesting species is related to the recent N. delphinodonta Mighels, which is a more rounded and less oblique shell, without the strong concentric grooves of N. taphria. Nucula prunicola n. s. PLATE 32, FIGURE 9. Miocene of Plum Point, Maryland, Burns; and one mile south of Plum Point, Harris. Shell small, inflated, polished, very inequilateral ; surface with obsolete, obscure radial striae, stronger where they cross between the concentric ridges and near the ventral margin ; beaks, dorsal slopes, escutcheon, and the poste- rior two-thirds of the sides of the shell smooth or nearlv so; on the anterior FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA third sculpture of moderately elevated concentric lamellae separated by wider radially grooved interspaces ; these lamella: break off abruptly anteriorly, and posteriorly become gradually obsolete in front of the middle of the shell ; they are strongest in front and near the margin ; lunular area lanceolate, large, not impressed, marked by the cessation of the lamellae ; escutcheon roundly cordate, impressed ; the margins pouting in the middle ; there is no circum- scribing line; beaks turgid, recurved; interior brilliantly pearly, the basal margin strongly crenulate, the muscular impressions feeble ; base arcuate, ends rounded ; chondrophore narrow, not prominent, anteriorly directed ; the anterior line of teeth long, slightly arched, the posterior meeting it at nearly a right angle, short, straight; anterior teeth about twenty, posterior six or seven. Lon. of shell 6, alt. 4.5, diam. 3.75 mm. This is a very remarkable species which cannot be confounded with any other recent or fossil in the United States. Other Tertiary species of Nucula known in North America and the Antillean region are as follows: From the Eocene: N. ainda Lea, Midway and Claibornian ; N. mediavia Harris, Midway ; N. magnificat Conr. (+ N. Sedg- u'ickii Lea), and N. nwnroensis Aldr., from the Claibornian ; N. meridionalis Mey. and Aldr., and N. spheniopsis Conr., from the Jacksonian ; from the Oligocene : N. vicksburgcnsis Conr. ; from the Miocene : N. diaphana and N. dolabclla H. C. Lea, and N. citnciformis Conr. (1848, Astoria), not of Sowerby ; from the Pliocene: N. cxigua Sby. (San Diego, California, Well), N. baccata Guppy, N. crcmtlala Hinds (+ N. vieta Guppy and N. tcnuisculpta Gabb), and N. liuionciisis Gabb ; N. cxpansa Rve. is reported from the Pleistocene of Hudson Bay, also with N. tennis Mtg., its variety injlata, and N. antujiia Morch, from the Leda clays of the northeastern United States and Canada. It is not necessary to mention here the species described as Nucula and since referred to Yo/iiia or Lcda, which will be found under those genera respectively, but I may note that N. cariiiifcra Lea is the young of Limopsis caucus Conr., N. ceqnilatera H. C. Lea is a Crenclla, and N. pectuncitlaris Lea should be referred to Trinacria. FAMILY LEDIDyE. Genus LEDA Schumacher. This genus is the \rnciilana of Adams, Meek, and others, but not of Link. It has been divided by authors into a multitude of sections, subgcnera, TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA 'etc., some of which are convenient, but all intergrade as far as can be judged from the shells, though the extreme forms are very distinct. The number of species is probably larger than that of any other American Tertiary genus. They often require very critical treatment, and, unfortunately, very few have been adequately described, figured, or compared. Descriptions based on internal casts are of value only as indicating the presence in the horizon concerned of the genus or its near relatives. It would be impossible to identify a species from such data with any certainty. Yet quite a number of names in American lists rest on no better basis. A thorough review would probably increase the number of species while rejecting a certain pro- portion as unidentifiable. Much carelessness has also been shown in using preoccupied specific names for new American forms. Both Gabb and Conrad have given entirely distinct species at different times the same specific name, and names already applied by European writers to species of Lcda have been repeatedly used for new species here. A few of these errors will be corrected here, but the subject needs a monographic revision. Among the older Eocene species Leda milamensis Harris, L. quercollis Harris, L. Aldricliiana Harr. (flongatoidea Aldr. var. ? Harr., Midway, Bull. 4, not of Aldrich), L. saffordana Harr. (= protexta Gabb, pars), L. robusta, L. corptilentoidea, and L. elongatoidea Aldr. have been described ; to which will be added here two apparently undescribed forms from Wood's Bluff. The Claiborne and Jackson, or Middle Eocene group, has a larger number, some of them very peculiar species, of which we may enumerate Leda albi- rnpiana and L. (Adrana) aldricliiana Harris, L. (pqitalis Conr. (non Reuss ? — (- ? media Lea, non Wissm.), L. baslropensis Harr., L. bella, L. aclata (not of Hinds), and L. calcarensis Conr. ; L. cultclliformis Rogers, L. hoiistonia Harr., L. improcera Conr., L. {Adrana ?) lisbonensis Aldr., L. inagna and media Lea (? + carolinciisis Conr.), L. Vamtxcmi Ball (L. initcronata Conr., 1847, not of Sowerby, 1825), L, opj/leiita Conr., L. parva Rogers, L. pltma, plicata, pulcher- rima, and semen Lea, L. semenoidea Aldr., L. snbtrigona Conr., L. smirna Dall (L. eborea Conr., 1860, not of Conr., 1846), L. linifera Conr., L. mater Meyer, L. multilineata Conr., and a new form now described from Wahtubbee. The Oligocene, except in the Antilles, is less populous with Leda, but offers L. parilis and serica (not sericca) Conr. from the Vicksburgian, which also includes L. multilineata Conr., and from the Upper Oligocene L. actita Conr. (1832, not of Sby., 1837, or Gabb., 1873), L. floridana Conr. (probably never described), L. flexnosa Heilprin, and L. tellinida Conr. From the Oligocene FREE INSTITUTE OF SCIENCE =579 TERTIARY FAUNA OF FLORIDA of the Antilles we have L. indigcna Dall (L. bisulcata Guppy, 1867, iiot of Meek, 1861), L. clara Guppy, L. illecta Guppy, L. Packcri Forbes (+ incognita Guppy), L. pcltclla Dall (pi. 32, fig. 5 ; = acnta Gabb, 1873, not Conr., 1832), L. Giippvi Dall (CiTfi'inj'a led&formis Guppy), L. pcrlcpida Guppy, and an un- described specie.s of Tindaria. There are several Darien species, probably new, but as yet represented by material insufficient for full description. In addition to the species which persist from the Oligocene and the new forms about to be described, the following are known from the North Ameri- can Miocene : L. acittidcits and carinata H. C. Lea, L. concentrica Say (+ chorea Conn, 1 846), L. liciata Conr., L. vitrca Orb. (+ Milleri Gabb), and the Cali- fornian L. penita Conr. In the Pliocene there appear newly only L. inccnensis Gabb of Costa Rica, and on the Pacific side L. pcruviana Dall (acnminata Nelson, 1870, not von Buch, 1845) and /„. taphria Dall (/.. clt>rtlaiidica Hitchcock, and is the Y. arctica of several authors, but not of Gray. Yoldia TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA albaria Conrad, from the New Jersey marls, was originally named protcxta, and belongs to the genus Led a (q. .'.). Yoldia Cooperi Gabb, a fine species, erroneously referred afterwards to Y. imprfssa Conrad, is found recent and in the later Tertiaries of California. Y. imprcssa Conrad was described from the Eocene of Oregon. Y. Icevis Say, which has been confused with its probable descendant Y. liinatnla Say, is abundant in the Miocene of the eastern United States. Y. abrupta Conrad (1848, not of Dana, 1847) is an obscure species from the Oregon Tertiary. Y. nasnta and oi'alis Gabb were described from the Oligocenc of St. Domingo. The earliest Tertiary species I have noted from our own country is Y. Kindlci Harr., from the Midway Eocene of Ten- nessee. Yoldia chorea (Conrad) Harris is a Lcda, but judging from the figure (Bull. Amer. Pal., iv., pi. 4, fig. 10), the species doubtfully referred to Lcda clongatoidca Aldr. by Professor Harris, and which he has since named Yoldia Aldrichiana, belongs to the genus Yoldia. From the Claibornian we have the rare Y. claibonicnsis Conrad ; from the Oligoccne of the Antilles Y. Crosbyana Guppy; Y. serica Conrad is a good species from Reel Bluff; and Shell Bluff, Georgia, and the Floridian Chipola beds have a species apiece. Y. cor/'i/- Icntoidca Aldr., with eborea Conrad and similar forms, are better placed in the genus Leda. This genus has been variously subdivided, especially in Professor Verrill's paper above alluded to, but a conservative view, taking into account the variable characters exhibited by the respective species and the indubitably close relations with Leda, obliges me to withhold from the most marked of the several groups a more than sectional value, and to regard a large pro- portion of the names as synonymes. The following arrangement, based on the above considerations, may, perhaps, be accepted. Genus YOLDIA Holier, ]S.j2. Two species were referred by Mollcr to his new genus, one of which was, according to Morch, Y. glacialis Wood (=K " arctica Gray," Moller), and the other a young specimen of ]". thracitzformis Storer (= Y. angidaris Moller). The original Nucida arctica Gray is indeterminable from the brief diagnosis, and was not figured. It has been identified by several naturalists (Hanley, Smith, and others) with Y. kyperb&rca Torell, and by others with K glacialis Wood (+ Y. tmncata Brown, -|- )" portlandica Hitchcock). From Moller's description of his Y. arctica as " planiuscula, laevi, nitida, luteo-vel fusco I-UHH INSTITUTE OF SCIENCE TERTIARY HAUNA OK H.ORIDA virente," and the number of teeth he ascribes to it, I feel compelled to believe that it could not have been Y. glacialis, whatever Gray's N. arctica was.* Sections : A. Yoldia s. s. Type ) . liypcrborca (Loven MS.) Torell. Shell elongate, smooth, compressed, more or less pointed behind, having a deep pallial sinus and with a wide pedal and moderate si- phonal gape. Ex. Y. lu'rix Say, Miocene, Virginia. B. Cncstcrinin Ball. Type )". arctica Brod. and Sby., Zool. Journ., 1829; (not of Gray, Parry's Voy. App., 1824) == Y. scissnrata Ball. Shell like Yoldia with incised sculpture not in harmony with the incre- mental lines over more or less of the external surface. Ex. Y. lanceo- lata J. Sby., Pliocene. 0. Orthovoldia Verrill. Type Y. scapiua Ball: Shell smooth, without rostrum or carina, the ends bluntly rounded. Eocene, recent. D. Yoldiclla Verrill. Type )'. lucida Loven. Shell small, rounded ovate, smooth, with obscure rostration feebly developed, with a small or indistinct pallial sinus ; resilium well devel- oped, short, sometimes partly visible externally. These are mostly small deep-sea forms, of rather generalized character, which verge on Malic tin in their ligamental features, and are very much like the young of some of the larger forms. Professor Verrill ascribes to them a feeble external ligament, but it seems to me more like the continuous peri- ostracum which is visible in a fresh specimen of Y. thracitcfonnis, and which has no real ligamentary function. The dorsal valve margins do not entirely close over the resilium, though its attachments appear to be wholly internal. E. l\'ii/(iii(iia Morch. Type Y. g/nciatis Wood ( j 5'. portla udii -a Hitchcock, Pleistocene and recent. Mcguynlilitt Verrill). Shell convex, more or less abruptly truncate behind, the rostral part laterally compressed ; the pallial line with a deep sinus. The gaping of the valves in )'. thracueformis is merely a specific character and varies in the same species and in different ages of the same individual. * In this also I agree with Hanley and Smith in referring Cray's species to ihe hypertorea group rather than to that of truncata ISrown, as supposed by Torell, Jeffreys, and Morch. Yoldia arctica lirod. and Sby. (1829) is a totally distinct species, which I have named Y. scissunita. 3 TRANSACTIONS OF WAGNER 596 TERTIARY FAUNA OF FLORIDA Y. niontcrcycnsis Dall, otherwise very close to Y. thraciieforiiris, does not gape perceptibly more than Y. glacialis. The soft parts of Y. thracueformis differ in no essential respect from those of l\>rtlandia glacialis. I cannot regard the differences of any of the above forms as of more than sectional value. They all intergrade in a large series of species. Yoldia Isevis Say. Nucula lizvis Say, Journ. Acad. Nat. Sci. Phila., ist Ser., iv., p. 141, pi. x., fijj. 5, 1824. Miocene of Maryland (Say); St. Mary's County, Maryland; York River, Virginia; Warwick and Dismal Swamps, Virginia; Burns, Harris, Haldeman, etc. This species is probably the ancestor of the Pleistocene and recent Y. limatula Say. It differs from the latter by its proportionally larger chon- drophores, smaller and more numerous teeth, somewhat more pointed pos- terior end, and less compressed escutcheon. A very large series compared shows these differences to be constant. Yoldia psammotsea n. s. PLATE 34, FIGURE 20. Claiborne sands, at Claiborne, Alabama ; Burns. Shell smooth, or with faint incremental lines, inequilateral with low beaks, the dorsal and ventral margins subparallel ; valves elongated, rounded in front and behind, the posterior part somewhat compressed and attenuated ; anterior end with a moderate gape; hinule and escutcheon elongated, very narrow, almost linear. Lon. 21, alt. 9, diam. 6 mm. This species is represented by two specimens with the valves closed and filled with a rather hard matrix, so that the hinge characters are inaccessible. It is clearly distinct from any of the described species of the American Eocene, and peculiar in its elongated solenoid form. It cannot be confounded with K clailwnu-iisis Conrad, from the same horizon. It would find a place in the section Orthoyoldia Verrill. Yoldia frater n. s. PLATE 32, FIGURE i. Oligocene of the Chipola beds in Calhoun and Walton Counties, Florida, Dall, Burns, and Johnson; also in the Alum Bluff sands at Oak Grove, Santa Rosa County, Florida, Burns. Shell polished, thin, elongate, much resembling Y. Itci'is, from which it is FREE INSTITUTE OF SCIENCE SQ7 TERTIARY FAUNA OF FLORIDA distinguished by the less arcuate base, more attenuated anterior end, some- what more compressed form, and, in the great majority of specimens, by having on the convexity of the beaks and the early part of their posterior slope a concentric sculpture of fine even riblets with about equal interspaces. There is also on the escutcheon an elevated radial line, absent on the corre- sponding part of )'. /«"'«, which also attains a nearly one-third larger size when full grown. There are about twenty-six teeth on each side of a small subumbonal chondrophore. Lon. 19, alt. 8, diam. 4 mm. This shell is perhaps the ancestor of Y. Uevis, from which it can usually be readily distinguished by its more rectangular form and sculptured umbones. Yoldia tarpseia n. s. Chesapeake Miocene of the upper bed at Alum Bluff, Calhoun County, Florida; Ball and Burns. Shell small, smooth, ovoid, moderately convex, rather solid for its size, with the ends rounded, the posterior smaller, the base evenly arcuated ; lunule very narrow ; escutcheon smooth, or marked only by lines of growth, with a single lamellose elevated line very close to the shell margin, which in young or worn specimens is often obscured; beaks low, hinge-line nearly straight, pallial sinus rounded, deep, nearly reaching the vertical of the beaks; about twenty anterior and eighteen posterior small, narrow teeth, separated by a sub- umbonal chondrophore. Lon. of a large specimen, 14.25 ; a perfect but smaller one measures, Ion. 9.5, alt. 5, diam. 3 mm. This shell recalls )". sapotilla Gld., and bears to Y. hrvis much such a relation as ) ' saputilla does to Y. Hinatiihi Say. Subfamily MALLETlIN-flS. Genus PLEURODON S. Wood. on Wood, Charlesworth's Mag., iv., p. 230, 1840. (Type /'. nvu/is Wood, op. fit., p. 230, suppl. pi. xiii., fig. I a-n>i(crifii Lea), G. idoiica Conr., all Claibornian, and G. fil<>su Conr., from the Jacksonian. The latter appears to include as synonymes " Glossns" jUt>stis Conr. (in Wailes's Rep., 1854), Axiiuca Ji/osa Conr. (Pr. Ac. Nat. Sci., ix., p. 166, 1858), Axiiuea iiii't/iiistria and iin/>lixtria Conr. (Am. J. Conch, i., p. 139, 1865). The two latter names were given to mutations which intergrade completely according to the large scries I have studied. In the Vicksburgian Oligocene G. arctata Conr. (1848, of which Aximea intcrcostata Gabb is a synonym, as well as the unfigured A. bdlascitlpta Conr.), a very variable species, is found. It has been with little warrant united by Gabb with the Cretaceous G. liainnla Morton of the Prairie Bluff horizon. TRANSACTIONS OF WAGNER 608 TERTIARY FAUNA OF FLORIDA The small Vicksburgian G. niississippicnsis Conr. recalls the rounded form of the Eocene G. trigonclla, In the Upper Oligocene of Bowden, Jamaica, is found the well marked G. acitlicostata Sby., described from St. Domingo, and G. jamaicensis Dall. From the same horizon in St. Domingo Gabb has described G. approximate. The Eocene Pectiincithts circitlus Conr. (Mort. App., p. 7) has never been described or figured. An anonymous species from the Midway formation is mentioned by Harris in his monograph of that horizon. In the Upper Tertiaries of the Pacific coast are a number of ill-defined species. Pcctiuiciifns patnlns Conr. was described (1849, Geol. Wilkes Expl. Exp.) from an internal cast; P. nitcits Conrad, which follows it, is equally unrecognizable; G. KasJicvarovi Grewingk (Beitr., p. 352, 1850) is a well marked, strongly ribbed, probably Miocene species from Alaska; P. barbarcnsis Conr. (P. R. R. Rep., vi.,p. 314, 1856) is hardly recognizable, and is referred to P. patuhts by Gabb. There are several Chico-Tejon species. The recent Axiiuca intermedia of Carpenter has been reported from the Californian Pliocene. Glycyxneris jamaicensis n. s. Oligocene of the Bowden marl, Jamaica. This species has been referred to G. pcnnacca Lam. by Guppy and Gabb, but appears to be distinct. The specimens I have examined are all of moderate size, nearly circular, quite convex, externally sculptured with fine, even, radiating strife, impressed at intervals so as to give the effect of obsolete ribs, which arc more apparent on the middle of the shell; on the beaks some of the threads are stronger; umboncs low and plump ; cardinal area impressed, narrow, short, and smooth ; teeth small, uninterrupted, about twenty-four in all, the line gently arcuate; inner margin fluted, with a slight insinuation near the base in front. Lon. 35, alt. 33, diam. 22 mm. Glycymeris pennacea Lamarck. Pectunc ulus pennaceus Lam., An. s. Vert., vi., i, p. 51, 1819 ; Reeve, Conch. Icon. Pe,titn- culus, pi. v., fig. 24, 1843. Pectunculus caroliniunus Conr., Med. Tert. No. I., cover p. 3, 1839. Pectunculus carolincnsis Conr., Mecl. Tert., p. 63, pi. 35, fig. 2, 1840; Am. Journ. Sri., xli., p. 346, 1841. rfctinifiilus linfatits Heilprin, Trans. Wagner Inst., i., p. 103, 1887; not of Lamarck or Reeve. Not P. carolinensis Holmes, P. -PI. Fos. S. Car., p. 15, pi. iii., fig. 4, 1860. FREE INSTITUTE OF SCIENCE 609 TERTIARY FAUNA OF FLORIDA Miocene of North Carolina, at Wilmington, Conrad ; Pliocene of Domi- nica, West Indies, Guppy ; Pliocene of the Caloosahatchie marl, Heilprin ; recent in the West Indies. This species is easily recognized by its nearly smooth surface and angulated outline. It appears to be rare. G-lycymeris parilis Conrad. Pcclum-ulHs fiarilis Conr., Proc. Acacl. Nat. Sci., i., p. 306, 1841 ; Med. Tert., p. 64, pi. 36, fig. 2, 1840. Older Miocene of Maryland at St. Mary's River and Plum Point, Tilgh- man's Station, Skipton, and Blake's Cliffs; Burns and Harris. This characteristic species is rarely found in thoroughly good preser- vation. G-lycymeris laevis Tuomey and Holmes. /\'itnn, ii/i/s /1,-i'ix T. and IT., Pleioc. Fos. S. Car., p. 50, pi. 17, fig. 5, 1857. FcctHiicnlus Virginia- Wagner (name only) on unpublished pi. 3, fig. 5, fide Bronn, Ind. Pal., i., p. 940, 1848 ; ii., p. 283, 1849. Miocene of Waccamaw, South Carolina, Tuomey, and of Virginia (Wagner). This species differs by its smaller size and more wedge-shaped form from G. parilis, and from the young of G. parilis of the same size by its subtrian- gular rather than circular outline, absence of any small ribs, and especially by its broader cardinal area and steeply arched line of larger hinge-teeth. Wagner's name, though earlier, was never accompanied by any description. The plates are still in thjf possession of the Wagner Institute, and have no names engraved upon them, so the name given by Tuomey and Holmes takes precedence. (Sec Trans. Wagn. Inst., v., p. II, pi. 3, fig. 5, 1897.) Glycymeris americana Defrance. /'•(/mi, it /us ,iiii,-rii-,is*its Cnnr., Med. Tert., p. 64, pi. 35, fig. 3, 1845. /'. /niiiK't-rsia; Tuomi-y and Holmes, Pleioc. Fos. S. Car., p. 51, pi. 17, lig. oV, 1857 ; not of Deshayes, 1835, or Dubois ; (internal cast of young />t /'. liinntlitx Conr., Med. Tert., p. 72, pi. 41, fig. 4, 1X45. TRANSACTIONS OF WAGNER 6lO TERTIARY FAUNA OF FLORIDA P. quintjiicriigiifas Conr., Am. Journ. Sci., xli., p. 346, 1841 ; Med. Tert., p. 63, pi. 34, fig. 3, 1845 ; Tuomey and Holmes, Pleioc. Fos. S. Car., p.. 49, pi. 17, fig. 4, 1857. P. undatus Dall, Bull. Mus. Comp. Zool., xii., No. 6, 238, 1886, ex parte. Miocene of Jericho, New Jersey ; of Calvert and Charles Counties, Mary- land ; Prince George and Dinwicldie Counties, the banks of the Nansemond River near Suffolk, and on the York River, and Petersburg, Virginia ; Wil- mington and Cape Fear, North Carolina; Pliocene of the Waccamaw beds, South Carolina, and of the marls of the Caloosahatchic, Florida; living on the southeastern coast of the United States, in fifteen to sixty-five fathoms, from Cape Hatteras to the West Indies. When I wrote my report on the Blake Pelccypoda, I had not had an opportunity of studying well preserved G. pcnnacca, and was in doubt as to its relations. I also accepted the traditional identifications of the names given by Linnaeus, Lamarck, and other early writers to our American species. It would seem that several of these names can never be absolutely determined, and in the present synonymy I have dropped them and adopted the earliest name which unmistakably refers to our shells. The unusually long synonymy which the present species possesses arises from two causes, — carelessness and ignorance of the changes due to age. The large Glycymcris has two sorts of modifications, — one which is due to variation, and the other correlated with growth and senility. In the very young shell the surface sculpture is always sparser, more un- even, and sharper ; in the adolescent specimen the ribs are usually well marked and extend clear to the base ; the teeth are delicate and not inter- rupted by an invasion of the cardinal area. In the adult this invasion begins, but otherwise the hinge is normal, the ribbing begins to become obscure dis- tally, and the cardinal area enlarges. In the senile shell the cardinal area is very large, only the ends of the arch of teeth remain, and these teeth arc usually enlarged; the concentric sculpture, due to intermittent instead of steady marginal growth, becomes conspicuous. Individuals vary in regard to strength of sculpture and its lateral exten- sion ; the two ends of the shell are rarely as clearly ribbed as the middle, and sometimes have no ribs. The size of the hinge-teeth varies considerably be- tween different specimens of the same size of shell ; in general a larger car- dinal area and greater expansion of the valves near the hinge-line is correlated with larger teeth. Specimens differ in amount of inflation and in outline from nearly circular to transversely oval, and even sometimes a little oblique. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OK FLORIDA When these two sets of mutations are surperimposed it naturally happens that the extreme instances are quite unlike ; without connecting links one would, as Conrad and others have done, suppose them to represent distinct species. A very careful and conscientious scrutiny of a large number of specimens has resulted in the above synonymy. G. fiassa is the normal adult; (i. Icnti/iini/is, the senile adult; G. Iricaiaria is a half-grown, well developed form; G. carolincnsis Holmes is a variety with feeble ribbing, obsolescent at the ends of the shell ; G. tnuisi'crsa T. and H. (non Deshayes) is founded on the internal cast of a rather wide young shell ; G. tiiiniiliis Conr. is founded on a rather inflated half-grown specimen. The only form which may possi- bly be varietal, but which I am inclined to refer to some pathologic cause, is G. qitinqiicntgata. This is almost entirely confined to Duplin County, North Carolina. Well-marked specimens have on each dorsal slope, from the beaks laterally, three to six little irregular ripples, which are much more conspicu- ous in the young. These might indicate the presence of some parasite in the individual. They are never uniform or regular; some specimens have them only on one side, in others they are obsolete, and, finally, others do not have them ; and between the normal aincriaina and the quinquerugata without rug;e there is absolutely no distinction to be made. The recent shell is iden- tical with Miocene specimens and reaches fully as large a size. The preceding species have more or less distinct radial striation, whether there are ribs or not ; in those that follow there is no radial striation but more or less distinct, fine, concentric sculpture and strong radial ribbing. Glycymeris subovata Say. /',;/i/ihi//i/s sul'c^'d/ns Say, |oiirn. Arad. Nat. Sci., 1st Ser., iv., p. 140, pi. IO, fig. 4, 1824; Conrad, l-'os. Ten. I'onn., p. 17, pi. 2, fig. 3, 1832; Med. Tert., p. 62, pi. 34, ML;, i, 1845 ; Kninions, C.col. Rep. N. Car., p. 286, tig. 207, 1858. G. eubovata var. Tuomeyi Dall. r?i'tu>i,-ulffs sitlwatus Tuoim'y and Holmes, I'leioc. Fos. S. Car., p. 47, pi. 17, fig. I, 1857. G. subovata var. plagia Dall. if "Oligocene : Vicksburgian of Martin Station, Florida ; Chipolan of Chipola Rfver and Alum 151 uff, Calhoun County, and Oak Grove, Santa Rosa County, Florida; Miocene of Walton County, Florida; of Dargan Point and Darlington, South Carolina; of Duplin County, Edgecombe County, Green County, and Wilmington, North Carolina; of Grove Wharf, James River, 4 TRANSACTIONS OF WAGNER 6l2 TERTIARY FAUNA OF FLORIDA Bellefield, Yorktown, and other points on the York River and on the Eastern Shore of Virginia, and Davis's Mill, Choptank River, Maryland. Variety plagia Dall, Edgecombe County, North Carolina. Variety Tiioincj'i Dall, Petersburg, City Point on James River, and near Suffolk, Nansemond River, Virginia. Shell asymmetrically developed, inequilateral, the impressed lines more or less arcuate and obsolete on the produced anterior side. This species is the oldest of those which reach the Upper Miocene. The Chipola specimens are slightly smaller than the average Miocene shell, but this may be an accident of collecting; otherwise they agree very well with Miocene specimens. The normal adult is subcircular, with radiating impressed lines, the inter- spaces being gently rounded and rather wide. The grooves are closer at the ends of the shell and the interspaces less rounded. In the young the shell seems to have close-set rounded ribs ; in senile specimens the radial grooves are obsolete towards the base. The principal mutations of the normal adult are greater or less prominence of the rounded interspaces, greater persistence distally of the grooves, and smaller or larger, sparser or more crowded, hinge- teeth and areal grooving. In the variety Tuomeyi the alternate interspaces are not rounded but flat, forming channelled spaces, subequal to and between the ribs, which are often more or less flattened on top and obsolete distally. In the variety plagia the shell is obliquely produced with the grooves obsolete laterally. The Oak Grove series contains many specimens in which intercalary incised lines appear on the rounded interspaces distally and the lines are much crowded at the ends of the shell. An occasional specimen turns up where the whole shell is nearly smooth, the incised lines being obsolete. In this state it is much like G. Icevis T. and II. externally, but larger and more rounded dorsally. Glycymeris pectinata Gmelin. Area pectinata Gmel., Syst. Nat., vi., p. 3313, 1792. Pectunculus aratus Conr., Am. Journ. Sci., xli., p. 346, 1841 ; Med. Tert., p. 62, pi. 34, fig. 2, 1845 ; Tuomey and Holmes, Pleioc. Fos. S. Car., p. 50, pi. 17, fig. 6, 1857. Pectunculus pectinifonnis Orb. , Moll. Cuba, ii., p. 313, 1853; IK it of Lamarck. I't-ctunculus ihini,^li>nt-nsis Holmes, P.-PI. Fos. S. Car., p. 16, pi. 3, fig. 5. 1860. Pectunculns pectinatus Dall, Hull. Mus. Comp. Xool., xii., No. 6, p. 239, 1886. FREE INSTITUTE OF SCIENCE 613 TERTIARY FAUNA OK FLORIDA Miocene of Wilmington, Cape Fear, and Duplin County, North Caro- lina; Pliocene of the W;iccamaw beds, South Carolina, and of the marls of the Caloosahatchie and Shell Creek, Florida. Recent, in two to one hundred and seventy-five fathoms, from the vicinity of Cape Hatteras, North Carolina, to the West Indies, Nicaragua, and Barbadoes. The differences upon which Conrad founded his species aratus are such as may be observed in any large series of the recent pectii/atiis. The ribs vary from twenty to forty in number, very greatly in prominency and adjacency, and the incremental lines from obscure to sublamellose. The truncation varies in amount and sharpness. In a variety carinata, the^ ribs, instead of being rounded, are more or less carinate, like those of acuticostata. All the differ- ences of the fossils can be paralleled in the recent shells. G-lycymeris duplinensis n. s. PLATE 34, FIGURES 6, 7. Miocene of the Natural Well and Magnolia, Duplin County, North Carolina ; Burns. Shell small, rounded-triangular, solid, moderately convex, with pointed, small, low beaks and a flattened lunular area; sculpture of strong, distally bifurcated radial ribs, separated by slightly narrower channelled interspaces ; nine anterior and nine posterior ribs on the lateral slopes are smaller, while on the middle of the shell are about ten larger ribs ; transverse sculpture of regularly spaced, elevated concentric lines overrunning the whole shell ; cardinal area small and short, with -three or four concentric angular grooves; teeth small, vertically striated, six or seven on each side, the line strongly arched and uninterrupted ; anterior margin straight, base rounded, posterior slightly arcuate; basal inner margin with about ten flutings. Largest valve, Ion. 9, alt. 10, diam. 6.5 mm. This pretty little species is readily distinguished from any of the varieties of G. pcctinata by its bifurcated and prettily sculptured ribs. It seems to be rather abundant at the locality mentioned. Subfamily ARCIN./E. ('•onus ARC A (Linne) Lamarck. .\y,-ii (I..) Lamarck, I'rocliomo, p. 87, 1799. Type ./. //<<«' T.imic. In the selection of the " Noah's Ark Shell" as the type of the restricted genus, Lamarck followed the ancient usage and continuous practice of natur- TRANSACTIONS OF WAGNER 614 TERTIARY FAUNA OF FLORIDA alists. Bruguierc placed this species first in his list in 1789. Poli, who did not adopt the Linnean nomenclature but had two genera, one for the shell and one for the soft parts, called it Dapline and Daplincodci-ina in 1795. In 1835 Swainson gave it the name of Byssoarca ; it was included in his section /,(•>• mn'ii -tiles by Blainville in 1825, though he did not name it Navicitla, as sometimes stated. Cyplioxis Rafincsquc, 1819, was probably intended to cover fossil species of this type, but as no described species were referred to it, it remains unrecognizable; T/tyas Gray (Figures of Moll. An., v., p. 24, pi. 358, fig- 4, 1857) is another synonyme, but the name was used for another group in 1835; Browne was not a binomial writer, and his Cibota, used by Morch in 1852, also falls into synonymy. Lastly, Areoptcra Heilprin, based on the following species, does not present, when a large series is compared, any con- stant characters which would separate it from the restricted genus Area. Before proceeding to describe the species collected it is necessary to review the nomenclature and settle on the characters of the subdivisions to be adopted. This has been a work of considerable labor; the inaccuracy of the diagnostic characters given in the text-books is so astonishing, when they are compared with a series of the species, that one is tempted to believe such diagnoses are written without any reference to specimens or, at best, with only a single specimen for comparison. The examination of over one hundred species of fossils and a majority of the known recent species of Area has en- tirely confirmed the opinion expressed by several authors, that a gradual transition may be traced between the groups which have been described as genera and subgcnera with extremely few exceptions. Subgenus BARBATIA (Gray) Adams. Batbatia Gray, Synops. Brit. Mus., 1840, p. (?) ; //;/,/., 1X44, p. Si. Type .!>;,! harhata L., H. and A. Adams, Gen. Rec. Moll., ii., p. 534, 1858. The type form of this group is tolerably regular and seldom deformed, like the typical Arks, from the anfractuosities of its station ; the reticulated sculpture shows few irregularities; the cardinal area is narrow with numerous grooves for the resilium, which form a series of elongated concentric lozenges on the area ; the shell is not conspicuously truncate or keeled ; the teeth are small and vertical in the middle of the series and towards the end diverge distally and become larger and more distant. In some species these distal teeth are often broken up, like those of CitenlLca, but this feature is not con- stant in the species. Several groups or sections arc recognizable, though FRKh: INSTITUTE OF SCIENCE 615 TERTIARY FAUNA OF- FLORIDA J they merge into one another through their peripheral species. Such are the following : Group of A. barbata L. (Barbatia s. s.). This includes A. (B.) tnifsissippiensis Conrad from the Vicksburgian Oligocene. Group of A. canditia Gmelin (Calloarca Gray, 1857, + Plagiarca Conrad, 1875).* This includes A. ciicnlloidcs Conrad (+ A. lima Conrad, 1847, not of Reeve, 1844, = A. Conradi Desh.) from the Jacksom'an ; A. mary- laudtca Conrad and A. arciila Heilprin, Upper Oligocene and Older Mio- cene; and several other species. Litharca (lithodomus) Gray, 1840, is probably based on a specimen of A. Candida, which had grown in the burrow of a Lithodomus. Upper Cretaceous to recent. Group of A. propatitla Conrad (Granoarca Conrad, 1862) = A. hians Tuomey and Holmes, 1855, not of Brown, 1842 ; nor of Reeve (? = A. protracta Rogers, 1837, not of Conrad, 1847). Miocene. Group of A. ccntcnana Say (Striarca Conrad, 1862). Miocene. Group of A. donaciformis Reeve (Acar Gray, 1847, ~f~ Daphnodenna Morch, 1853, + Fossularca Cossmann, 1887). Eocene to recent. In Striarca the lozenge occupied by the ligament and its transverse grooves for the resilium cover the entire cardinal area ; in typical Acar the lozenge is obliquely directed backward, leaving the anterior part of the area bare; in Fossularca the lozenge is small, very short, and directly between the beaks, leaving a bare space before and behind it. A. ccelata Conrad (A. Adainsi Shuttleworth) is a typical Fossularca. Group of A. heterodonta Desh. (Lcs Cncullaires Desh., 1860; Cncullana Conrad, 1869, + Nemodon Conrad, 1869). Cretaceous (Ripley) to recent. In the Barbatias as well as in Glycymcris (Pcctiiiiciilns auct.) the growth of the shell often results in a greater or less absorption of the middle part of the series of teeth ; the distal teeth are always more or less oblique, especially those behind the beaks. In Cncullaria the latter are almost, if not quite, */>/,;;' iiirca is based on Barbatia carolineiisis Conrad, 1875 (Ripley beds of North Carolina), not Area carolincnsis Wagner, 1847, nor A. (Noc/ia) carolinensis Conrad of 1862. Polynemn Conrad (Kerr. Geol. Rep. N. Car., 1875, App. A., p. 4), based on Bm-hntiii lint™ Conrad, 1875 (not Area li>iti- 32'*. 1886. TRANSACTIONS OF WAGNER 620 TERTIARY FAUNA OF FLORIDA Not Area avintlcffonnis Nyst, Tabl. Synopt., p. 12, 1848; = Area aviculoides Reeve, 1844, not of De Koninck, 1844. Arcoptera avicutaformis Harris, in Dana, Man. Geol., 4th ed., p. 900, fig. 1510, 1895. Pliocene marls of the Caloosahatchie, Shell Creek, and Myakka River ; Heilprin, Willcox, and Dall. This fine species is quite variable in the development of the extended wings which suggested Professor Heilprin's name. In many specimens the posterior wing does not exceed that usual in A. occidcntalis, while in others it may extend an inch beyond the rest of the shell. The anterior wing is less prominent and a little more constant, but is frequently paralleled by fossil and even by recent specimens of A. occidentalis Phil. So far as yet known, this species is confined to the Floridian Pliocene. The character of the cardinal area is similar to that of A. note. Area occidentalis Philippi. Area occidentals Phil., Abbild. u. Beschr., iii., p. 14, pi. xvii. /;, fig. 4 a-c, 1847. Area zebra Swainson, Zool. 111., No. 26, pi. 118, 1831 ; ex parte. Area noce of many authors, not of Linne. Oligocene of the Bowden beds, Jamaica, Guppy, Henderson, and Simp- son ; Miocene (?) of Curasao, U. S. Fish Commission ; Pliocene of the Caloosa- hatchie marls, Florida, Dall ; Pleistocene of the Florida Keys, Yucatan, and most of the West Indian Islands ; recent in the Antilles generally, and along the eastern coast of the United States northward to the vicinity of Cape Hatteras, North Carolina. A careful comparison shows that the American shell should not be united with the Mediterranean A. nocz. The restricted A. zebra, according to Swain- son, comes from the Mediterranean, but Reeve refers it to Manila. The west American recent analogue appears distinct. Although in taking up the species I doubted if the Bowden fossil could be the same as the recent shell, I am obliged after careful comparisons to regard them as identical. The species is very rare in the Caloosahatchie marls, and only represented in my collection from them by a few young valves. Area umbonata Lamarck. PLATE 38, FIGURES 4, 4 a. Area umbonata Lam., An. s. Vert., vi., p. 37, 1819; ibid., 2d ed., vi., p. 432, 1835 (syn. partim excl.) ; Philippi, Abbild. u. Beschr., iii., p. 13, pi. xvii./), fig. 3 a-c, 1847. Area noce Stimpson, S. I. Checklist, E. Am. Mar. Shells, p. 2, 1860. FREE INSTITUTE OF SCIENCE 621 TERTIARY FAUNA OF FLORIDA .-hnr imbncata (Brug.) Dall, Hull. U. S. Nat. Mus., No. 37, p. 40, 1889; Heilprin, Trans. Wagner Inst., i., p. 118, 1887. Area Listeri (Tryon) Heilprin, Trans. Wagner Inst., i., p. 118, 1887. Barbatia Ilonat -jyi Gabb, Geol. San Domingo, p. 254, 1873. Oligocene of the Chipola beds, Calhoun County, Florida ; of the Ballast Point silex beds, Tampa Bay, Florida ; of the Alum Bluff sands at Oak Grove, Santa Rosa County, Florida. Also in the Pleistocene of the Florida Keys and the Antilles, and living from Cape Hatteras, North Carolina, south to Santa Caterina, Brazil, and throughout the Antilles. Like all the group, this nestling species is variable in form according to its station, but I have been unable to find any characters to separate the fossil and recent shells when allowance is made for the deformations alluded to. It may be distinguished from A. aquila Heilprin by the less alate anterior end and smoother ribs, otherwise they are closely allied. The name imbricata, cited as of Bruguiere, is somewhat doubtfully applicable to this shell, and no diagnosis was given in the Encyclopedic Methodique. It probably retreated to warmer waters during the Miocene invasion of Florida and did not succeed in returning until the end of the Pliocene, as it has not turned up in the Caloosahatchic marls. The form doubtfully identified by Professor Heilprin with A. Listen is connected by a fuller series with the others. Area aquila Heilprin. PLATE 31, FIGURE 12. Area aquila Heilprin, Trans. Wagner Inst., i., p. 97, pi. 12, fig. 31, 1887. Pliocene marls of the Caloosahatchie River, Florida ; Willcox and Dall. This very neat species appears to be somewhat rare, and has only been found at the original locality as yet. Area paratina n. s. PLATE 33, FIGURE 14. ? = A. (Byssoarca) protracta Conr., Journ. Acacl. Nat. Sci. Phila., 2d Ser., i., p. 126, pi. '3. nS- 36, 1848 (not of Rogers, 1837) = subprotracta Heilprin, 1881. Oligocene of the Chipola beds on the Chipola River, and of the lower bed at Alum Bluff, Calhoun County, Florida; Dall and Burns. Shell elongated, not very thick or high, not much distorted, but with a variable byssal gape, inequilateral, the beaks at or near the anterior fourth ; moderately alate in front and behind ; beaks low, pointed, not inflated, their TRANSACTIONS OF WAGNER 622 TERTIARY FAUNA OF FLORIDA apices slightly prosogyrate, cardinal area long, narrow, lozenge-shaped, flattish, with longitudinal stria;, the site of the resilium marked on each valve by two grooves forming a small triangle, within which are traces of the inception of other grooves; sculpture chiefly of fine radial riblets overrunning and some- what imbricated by not prominent lines of growth ; the radials which end on the margin of the byssal foramen are perceptibly finer than the rest, those on the posterior dorsal slope are more or less fasciculated, the ends of the fascicles dentating the posterior margin ; on the dorsal anterior part the riblets increase somewhat in size, but are not fasciculated ; the dorsal border in front is anterior to the rest of the margin ; between the dorsal posterior extreme and the ventral posterior angle there is often an irregular but not deep emargina- tion ; the borders of the byssal foramen are irregularly emarginate ; interior smooth, the margin denticulated by the sculpture except at the foramen ; hinge-line straight, minutely denticulate ; the teeth in the centre smaller, those towards the ends inclined outward slightly, above, and a little larger; there are about twenty-three anterior and forty posterior teeth, with no marked hiatus between the series. Lon. of shell 28, alt. of hinge-line 8.5, of beaks IO, diam. at the umbonal part IO mm. It is quite possible that the shell grows to a considerably larger size. This species is distinguishable at once from the A. occidentalis of the same size by its uniformly more delicate and much more numerous ribs, and by its greater length in proportion to its height. It is also usually less alate behind, and of more uniform, undistorted shape. Differences of form and proportion seem to separate it sufficiently from A. subprotracta Heilprin. Area halchetigbeensis Harris from the Lignitic or Chickasawan stage is shorter and more finely sculptured, though closely related. Area bowdeniana n. s. PLATE 33, FIGURE 12. Oligocene of the Bowden beds, Jamaica, and Pliocene of Limon, Costa Rica ; Bland, Henderson, and others. Shell small, inflated, somewhat irregular, very inequilateral, the beaks almost posterior ; dorsal slope conspicuous ; its outer border with a stout keel and its surface somewhat excavated ; beaks small, pointed, prosogyrate ; car- dinal area wide, lozenge-shaped, flattish, with a few grooves for the resilium forming a smaller lozenge near the beaks ; sculpture as in A. nnibonata, the imbrications close and subnodulous ; shell not alate in front and with the FREE INSTITUTE OF SCIENCE 623 TERTIARY FAUNA OF FLORIDA anterior margin nearly vertical from the hinge-line ; posterior end obliquely truncate, the basal angle most extended, the dorsal one forming nearly a right angle ; anterior teeth ten, posterior twenty-seven, with no noticeable hiatus in the line, the teeth resembling those of A. paratina but proportionally larger; interior smooth, the posterior end with a few flutings, the rest of the margin entire ; the byssal foramen narrow and its margins encroaching only moder- ately on the valves. Lou. 15, alt. of hinge-line 6, of beaks 8, diam. (greatest posteriorly) 9 mm. This odd little shell is peculiar in being narrower near the very anterior beaks and widest about the middle of the posterior slope. It appears to be easily discriminated from the other species of this variable group known to the region. Subgenus BARBATIA (Gray) Adams. Section Calloarca Gray. Barbatia (Calloarca) marylandica Conrad. />'ix\-(W/vw iiiiirv/iiin/ii'it Conrad, r'os. Medial Tert., p. 54, pi. 29, fij;. I, 1840. Hiiri'iitin iiiai-vliiiitiica Conr., Proc. Acad. Nat. Sci. Phila. for 1862, p. 580, 1863. * Oligocene of the Ballast Point silex beds, Tampa Bay, the lower (Chipola) bed at Alum Bluff, the Chipola marl of the Chipola River, Florida ; older Miocene of Jericho, Cumberland County, New Jersey ; Middle Miocene of Plum Point, Calvert Cliffs, and Centreville, Maryland ; Willcox, Burns, Dall, and Harris. Possibly also in the Jacksonian. Careful comparisons of typical material show no specific differences between the Miocene and Oligocene shells. Barbatia (Calloarca) irregularis n. s. I'l.ATK 3.5, Kir.URK 5. Oligocene of the silex beds at Ballast Point, Tampa Bay (fragment) ? Pliocene marls of Shell Creek, Alligator Creek, and the Caloosahatchie ; Dall and Willcox. Shell thin, elongate, irregularly distorted; beaks prosogyrate ; at the anterior third rather low and compressed ; cardinal area long, rather narrow, with very numerous (twelve) concentric grooves ; surface irregular, sculptured with numerous fine radiating, somewhat imbricated ribs, of which those in front of the beaks and on the posterior dorsal slope tend to be larger and more elevated; there is a tendency to alternate or pair among the ribs in some specimens ; the imbrications or nodules on the ribs are somewhat TRANSACTIONS OF WAGNER 624 TERTIARY FAUNA OF FLORIDA regularly spaced and correspond to elevated concentric lines in harmony with the lines of growth ; the posterior dorsal slope is bounded by rounded ridges radiating from the beaks ; the posterior cardinal margin is elevated and angular with more or less of a depression between it and the radial ridge on each side; the byssal foramen is wide and irregular; the hinge-line is long and straight ; the teeth, vertical and very small medially, are sometimes obso- lete in the middle of the hinge; distally they become rather distant and quite oblique, as well as larger; the internal margin, though irregular, is not fluted. Lon. of adult 51, alt. 25, diameter 20 mm. This species is distinguished from B. marylandica by its smaller altitude, its coarser and more prominent sculpture, and more irregular hinge ; the beaks are also more anterior. Barbatia (Calloarca) areula Heilprin. PLATE 33, FIGURE 4. Area amila Heilprin, Trans. Wagner Inst., i., p. 118, pi. 16, fig. 65, 1887. Oligocene of the Ballast Point silex beds, Tampa Bay, Florida; Willcox. Shell subovate, thin, inflated, the beaks low and prosogyrous ; the cardinal area narrow and very closely and minutely furrowed longitudinally, the fur- rows showing a slight angle behind the beaks ; sculpture of close set, fine radial ribs, rather regularly imbricated at successive lines of growth ; on the poste- rior dorsal slope are six or eight nodulous larger ribs ; the beaks are situated a little behind the anterior third; byssal foramen narrow, very anterior ; hinge with a few large A-shaped teeth at the ends, the middle teeth vertical, small, or even obsolete rnesially ; margins of the valve slightly or not at all crenu- lated by the sculpture. Length of shell 47, of hinge-line 30, height 31, diameter 26 mm. This species is very evenly and regularly fluted at the imbrications, dif- fering in that respect from any of the other species mentioned here. It is notable also for its inflated and thin valves and the bluntly truncate posterior end, though the latter may be abnormal. Barbatia (Calloarca) cuculloides Conrad. Area cuculloidts Conr., Fos. Tert. Form., No. 3, p. 37 (not fig'd), 1833. Byssoarca lima Conr., Journ. Acad. Nat. Sci. Phila., 2d Scr., i., p. 125, pi. 13, fig. 23, 1848 ; not Baibalia lima Rve., P. Z. S., 1844. ( 'in K/liearcn lima cl itit'iilloidcs Conr., Am. Journ. Conch., i., p. II, 1865. FREE INSTITUTE OF SCIENCE 625 TERTIARY FAUNA OF FLORIDA Naviaila aspersa Conr., Wailes, Agr. and Geol. Mississippi, p. 289, pi. 14, fig. 5 (young shell), 1855. \\v;>iiitla iis/ii-nt Conr., I'roc. Acacl. Nat. Sci. Philn., vii., p. 258, 1855 • not slrca aspera Phil., Moll. Sicil., 1836. Upper Eocene (Jacksonian) near Claiborne, Alabama; Jackson, Missis- sippi ; Cleve County, Arkansas ; and in the Lower Oligocene at Vicksburg, Mississippi. This fine shell was separated from the true Arks by Conrad because in the fully adult specimens the distal teeth are usually (though not invariably) broken up into granular parts. This -character occurs occasionally in individ- uals or particular species in most groups of the genus Area and is too mutable to be taken as a basis for a genus. The other Vicksburg species, Karbatia iiiississipfiensis Conr. (op. tit., 1848, p. 125, pi. 13, fig. 32), is distin- guished from A. atciilloidcs by its smaller size, finer sculpture, and the absence of any radial ridges setting off a posterior area as in the latter species. These ridges are very strong in the young, in which also the distal teeth are entire, giving the young shell such a different aspect that Conrad described it as a distinct species. Conrad described another Area, belonging to the section Scapharca, under the specific name of tiiississippiensis, in the same paper (p. 125, pi. 13, figs. 1 1, 15), which appears to be that figured by Lesueur in his Walnut Hills Fossils, pi. 5, fig. 8, 1829. This species may take the name of A. (Scaphatra) Lcsiicuri. The Barbatia inississippiensis was also well figured by Lesueur on the same plate, figure 9. The Area rhouiboidclla Lea, Contr. Geol., p. 74, pi. 2, fig. 52, from the Claibornian appears to be referable to Scapharca. We have it also from Lisbon, Alabama, the Eocene of Orangeburg, South Carolina, and according to Haldeman from the Eocene of Virginia, the exact locality not being recorded on the label. I suppose it must have been through an accidental confusion that Cossmann came to identify B. cnctilli>idcs with this species. Omitting to notice that Conrad described his shell as two and a half inches long, Gregorio (op. cit., pi. xxiv., figs. 17-20) has figured a specimen of A. rlioniboidclla three millimetres long as A. cuculloidcs Conrad. It seems singular that he should not have noticed its practical identity with the figure of Lea which he reproduces on the same plate (fig. 28). Cossmann has very properly united the two, though he did not see that neither represented A. cuculloidcs of Conrad. Gregorio's figure very fairly represents A. rluiniboid- , which, however, reaches a length of over twenty millimetres in the adult TRANSACTIONS OF WAGNER 626 TERTIARY FAUNA OF FLORIDA state. It is possible it may be a Barbatia, to which group I at first referred it, but after a complete study of all our fossil Tertiary species I concluded it would best be referred to ScapJiarca. Barbatia (Calloarca) phalacra n. s. PLATE 33, FIGURE 3. Oligocene of the Chipola marls, Chipola River, and of the Oak Grove sands, Florida ; Burns. Shell thin, moderately convex, equivalve, inequilateral ; the prosogyrate beaks within the anterior fourth low and somewhat compressed ; sculpture of very numerous fine, even, mostly dichotomous riblets without nodules or reticulation over the whole shell, crossed only by feeble incremental lines; cardinal area very narrow with a few longitudinal grooves; hinge-teeth small, short, and vertical mesially without any gap in the series, distally longer, larger, and more oblique ; hinge-line £f of the whole length ; internal margin of the valves smooth, byssal gape inconspicuous. Lon. 23.5, alt. n, diam. 9 mm. This is a very modest and neat little species which does not seem identi- fiable with any of the others. It is, perhaps, nearest to B. mississippicusis Conrad, but is smaller, less flattened, and more regular. Barbatia (Calloarca) Candida Gmelin. Area Candida Helblingi, Chemnitz, vii., p. 195, pi. 55, fig. 542. Area Candida Gmelin, Syst. Nat., vi., p. 3311, 1792. Area Helblingii Bruguiere, Ency. Meth., p. 195, 1797. Area jamaicensis Gmelin, Syst. Nat., vi., p. 3312, 1792. Oligocene of the Bowden beds, Jamaica, of the Chipola beds at Alum Bluff and on the Chipola River, Florida ; Pliocene of Trinidad ; Pleistocene of the Antilles generally, and recent from Cape Hatteras, North Carolina, to Brazil at Santa Caterina, and possibly the African coast. The fossils show no diagnostic features by which I can separate them from the recent shells. There are some difficulties in the nomenclature of this species which I have not the literature to straighten out. As far as I am now able to ascer- tain, the first name applied to this shell was Candida, and the first binomial Latin name was that of Gmelin. It is a well-known West Indian species conspicuous for its large size, white shell, and compressed, flattish valves. It is quite possible that some of the early authors named this wide-spread species FREE INSTITUTE OF SCIENCE 627 TERTIARY FAUNA OF FLORIDA more than once, and in this connection the A. ovata and complanata should be examined. Another species which seems distinct is represented in the collection by a number of young valves from the Oligocene of Bowden. Section Granoarca Conrad. Barbatia (Granoarca) propatula Conrad. .l/,,i /»v/>. Area liimila Conr., Fos. Ten. Form., p. 15, pi. i, fig. i, 1832. New Berne, North Carolina. Miocene : North Carolina, at Wilmington, New Berne ; Virginia, at various points on the York and James Rivers ; also in Maryland and South Carolina, and at Heislerville, Cumberland County, New Jersey. Pliocene : De Leon Springs, Florida, Wright ; in the marls of the Caloosahatchie and TRANSACTIONS OF WAGNER 632 TERTIARY FAUNA OF FLORIDA Shell Creek, Willcox and Dall ; near Brunswick, Georgia, Couper ; Wacca- maw beds, South Carolina, C. W. Johnson. Area limula var. platyura Dall. Pliocene of the Caloosahatchie and Alligator Creek ; Willcox and Dall. Shell with the posterior end of the cardinal border elevated and forming nearly a right angle with the posterior margin of the valves, thus giving the posterior part of the shell a higher and more angular look, which at first seems very distinct. Area limula var. fllosa Conrad. Noetia ponderosa Say, var. N. carolinensis Conr., Proc. Acad. Nat. Sci. Phila. for 1862, p. 290 ; not Area carolinensis Wagner, 1847. Area carolinensis Heilprin, Proc. Acad. Nat. Sci. Phila. for 1881, p. 450. Noetia filosa Conrad, Kerr's Geol. Rep. N. Car., App. A, p. 20, pi. 4, fig. 3, 1875. Miocene of North Carolina: at Sullivan's marl-pit, Green County, North Carolina, eight miles east of Snow Hill ; Burns. This variety has more numerous (thirty-five) ribs when adult and a less angular outline than the typical form. Area limula is, with little doubt, the progenitor of A. ponderosa Say, from which it differs by a more quadrate outline and more anterior beaks. The sculpture is usually more elegant, but specimens of A. ponderosa occasion- ally turn up which exhibit equally fine reticulation and divarication of the ribs. A variety analogous to platyura is possessed by all the species of Noetia, but is perhaps more conspicuous in A. limula. I have not found this species in any positively Post-Pliocene beds ; in such it is represented by A. ponderosa. From A. incite, when adult, A. limula is distinguished by its smaller and shorter cardinal area and usually by its considerably larger si/.e ; the line of teeth is shorter and the teeth are larger and wider, and more horizontally extended at the ends of the series. Area (Noetia) incile Say. Area incile Say, Journ. Acad. Nat. Sci. Phila., ist Ser., iv., p. 139, pi. 10, fig. 3, 1824. Miocene of Maryland. Conr., Fos. Tert. Form., p. 16, pi. 2, fig. I, 1832; Fos. Medial Tert., p. 56, pi. 29, fig. 5, 1840. James River and Smithfield, Virginia. octiii protexta Conr., Kerr's Geol. Rep. N. Car., App. A, p. 19, pi. 3, fig. 5, 1875. Miocene of North Carolina. FREE INSTITUTE OF SCIENCE 6T.T. TERTIARY FAUNA OF FLORIDA Jo Miocene of Maryland, Virginia, and North Carolina, Say and Conrad ; near Darlington, South Carolina, at various points near and at the Natural Well, Duplin County, North Carolina; Petersburg, Dinwiddie, York River, and borders of the Dismal Swamp, Virginia, and Choptank, Maryland, Harris, Burns, and others. There can be no doubt that Conrad's N. protexta is identical with A. incilc. This species has not yet turned up in the Floridian Miocene, but a knowledge of it is necessary to discriminate between the species of Noetia. Area (Noetia) ponderosa Say. Area fonifi-rosa Say, Journ. A cad. Nat. Sci. Phila., 1st Ser. , ii., p. 267, 1822. Recent in Florida. Area eontraria Reeve, Conch. Icon., Area, pi. 8, fig. 55, 1844. Area, elegans, 1'hil. Zeitschr. Mai., 1847, p. 92. Area ponticrosa Tryon, Am. Mar. Conch., p. 178, pi. 36, figs. 467-8, 1874. Pleistocene of Cape May and Atlantic City, New Jersey ; of Maryland, near Cornfield Harbor, at Wailes Bluff, on the Potomac River; of Simmons Bluff, South Carolina; and many points on the coast of Florida; recent on the eastern coasts of North America from Cape Cod to Yucatan. This is the type of the subgenus. In this species the beaks are more nearly in the middle of the shell than in either of the others. The ligament does not occupy the whole of the cardinal area, and the greater portion of it is in front of the beaks and strongly transversely striated. The borders of the adductor scars are sometimes marked by an elevated ridge as strong as in many Cuculla_>as. It is curious that Conrad should state (Proc. Acad. Nat. Sci., 1862, p. 290) that he had not seen a recent specimen of this species, and that he supposed it to be extinct. It is probable that he was thinking of A. licnosa Say when he recorded these remarks, as the present species is almost the commonest recent species of our shores. There can be little or no doubt that the names of Reeve and Philippi are based on young specimens of this somewhat variable shell. Subgenus SCAPHARCA Gray. Section Ctincarea Dall. Scapharca (Cunearca; cumanensis Dall. Area iiiii>n^rna C.uppy, Proc. Sci. Assoc., Trinidad, p. 163, Dec., 1867; Geol. Mag., Dec., 1874, p. 451 ; not of Say. TRANSACTIONS OF WAGNER 634 TKRTIARY FAUNA OK FLORIDA Oligocene of Cumana, Venezuela, Guppy ; island in Lake Henriquillo, St. Domingo, Rowell. Shell small, resembling S. incongnta Say in miniature, but with higher, more prominent, and uncompressed beaks, with the ribs of the posterior slope of the right valve smooth instead of nodulose ; the valve higher and shorter, with the beaks more anterior, and the hinge-line somewhat shorter. Lon. of adult shell 26, alt. 25, diam. 21 mm. With a rather close general resemblance to A. incongnia Say, this little species differs in details, which, taken in connection with the great disparity in size and the geological horizon, authorize us to regard it as distinct. Scapharca (Cunearca) initiator n. s. PLATE 32, FIGURE n, Oligocene of the Chipola beds, Chipola River, Florida; Burns. Shell small, solid, oblique, with prosogyrate beaks, somewhat impressed mesially near the apices of the valves ; right valve ovate-rhombic with twenty strong, rounded, nodulous, radial ribs, separated by wider interspaces ; left valve decidedly smaller, with the ribs smooth, squarish, and without nodules, except a few on some of the shorter anterior ribs ; cardinal area wider in front of the beaks, narrower behind them ; margins of the valves internally fluted ; hinge-line short, with about twenty-two subequal vertical teeth. Lon. (of left valve) 5, alt. 4.7, diam. 5 mm. This little shell was at first thought to be the young of a larger species, but nothing allied to it of a larger size has turned up at any locality in the formation, while its solidity gives it a mature appearance. The cardinal area differs in form from any of the known species in the adult state. Scapharca (Cunearca) scalaris Conrad. Area scalaris Conr., I'roc. Acad. Nat. Sci. Phila. , i., p. 324, 1843; Fos. Medial Tert., p. 59, pi. 31, fig. I, 1845 ; Emmons, Geol. N. Car., p. 285, 1858 ; Tuomey and Holmes, Pleiocene Fos. S. Car., p. 43, pi. 16, fig. i, 1856. Miocene of Petersburg, Virginia, Tuomey; of Duplin County, North Carolina, Burns, and of the upper bed at Alum Bluff, Florida, Dall. This species is doubtless the ancestor of S. scalarina Heilprin, the young of which it much resembles, though sufficiently distinct from the adult. Scapharca (Cunearca) scalarina Heilprin. Area scalarina Hp., Trans. Wagner Inst., i., p. 94, pi. 12, fig. 29, 1887. FREE INSTITUTE OF SCIENCE 635 TERTIARY FAUNA OF FLORIDA Pliocene marls of the Caloosahatchie, Florida ; Heilprin, Willcox, and Ball. This magnificent species is the largest and most distinct of the entire group, and so far has been obtained only on the Caloosahatchie River. The S. iiicottgnia has not yet been found in these marls. Scapharca (Cunearca) incongrua Say. Area hiion^rua Say, Journ. Acad. Nat. Sci. 1'hila., ii., p. 268, 1822 ; Reeve, Conch. Icon., Area, pi. viii., fig. 50, 1844. Not Ana braziliana Reeve, Conch. Icon., Area, pi. iii., fig. 17, 1844, =A. nodosa Wood. ? Area braziliana Lam., An. s. Vert., vi., p. 44, 1819; Phtlippi, Abbild. u. Beschr., i., Area, p. 2, pi. i, fig. 3, 1843. Upper Miocene of the Galveston artesian well (?), Singley ; Pliocene of Port Union, Costa Rica, Gabb; typical specimens from Pleistocene of Wailes Bluff, Maryland, Simmons Bluff, South Carolina, Burns, and Brunswick, Georgia, Couper; recent from North Carolina south to Texas, and (var. ? brarjliana) from Texas south and east to Cape Roque and south to Rio, Rio Grande do Sul, San Paulo, and Santa Caterina, Brazil (Ihering). This species is a very puzzling one, and a large geographical series is required to determine its exact limits. The figure given by Reeve is poor, and has probably helped to continue the confusion. The typical //. incongrua is quite variable in form, and I have not seen specimens which could be unhesitatingly referred to it from older beds than the Pleistocene, or more southern localities, living, than the coast of Texas. Here it is mixed with specimens of the braziliana type, towards which the incongrua tends to vary. The Costa Rica Pliocene fossils are exactly like braziliana ; the Antillean shells also, while varying a good deal, retain the dimensions of braziliana and more or less of its other characters. It is probable that the two forms would better be kept apart, at least until more is known. Scapharca (Cunearca) alcima Dall n. s. PLATE 31, FIGURKS 5, 7. Pliocene marls of the Caloosahatchie at Alligator Creek, Florida; Dall. Shell of moderate size, short, high, inflated, with elevated prosogyrate beaks ; left valve with thirty strong, squarely nodulous, radial ribs somewhat narrower than the interspaces, without obvious concentric sculpture, front edge rounded, posterior less rounded and longer, meeting the base at a rather TRANSACTIONS OF WAGNER 636 TERTIARY FAUNA OF FLORIDA blunt angle, this part of the shell being somewhat produced; right valve with twenty-seven less prominent ribs, of which the posterior dozen have the nodules obsolete or absent and those on the anterior ribs somewhat less marked than on the other valve ; cardinal area short, wide, with the beaks incurved over it ; inner margin of the valves sharply fluted ; hinge-teeth slightly larger and more oblique distally, in general nearly vertical, close set, and about thirty-two in number, not obviously divided in the centre. Lon. 27, alt. 27, diam. 22 mm.; Ion. of hinge-line 15 mm. This is one of those species on the border-line of groups which make it so difficult to divide the Arks into clear-cut sections ; it has the hinge, cardi- nal area, and discrepant sculpture of Cunearca ; the valves are slightly unequal, and it seems most properly assigned to a place in this section. It is obviously a form ancestral to such species as Area Chemnitzi Phil. (A. bicops Orb., + A. antillarum Dunker, fide Kobelt, + A. Orbignyl Kobelt), which is referred to Anoinalocardia (= Anadard] by Ihering, and is found recent in the West Indies. This species, which has been distributed under the (MS. ?) name of A. rhombica Rawson, is also inequivalve, with discrepant sculpture, and prob- ably should be referred to this section. From A. Chemnitzi the present species differs by its larger size, more oblique shape, narrower and more numerous ribs. Area filicata Guppy from the Eocene beds of Manzanilla, Trinidad, is probably, though much smaller, a precursor of the above-mentioned species. Section Scapharca s. s. Scapharca (Scapharca) lienosa Say. Area lifnosa Say, Am. Conch., iv., pi. 36, fig. i, 1832 ; Tuomey and Holmes, 1'leioc. Fos. S. Car., p. 40, pi. 15, figs. 2, 3, 1855 ; Kmmons, Geol. N. Car., p. 284. fig. 204, 1858. Scapharca lienosa Meek, Smithsonian Checkl. Miocene Fos., p. 6, 1864. Area florid an a Heilprin, Trans. Wagner Inst., i., p. 97, 1887 ; not of Conrad, Am. Journ. Conch., v., p. 108, pi. 12, fig. 2, 1869 (as Anomalocaniici) = A. sccticostata Rve., Icon., fig. 38, 1844. Miocene of York and James River, Virginia, of Wilmington and Duplin County, North Carolina, and of the upper bed at Alum Bluff, Florida; Plio- cene of the Waccamaw District, South Carolina, the Caloosahatchie River, Alligator and Shell Creeks, Florida ; Tuomey, Burns, Willcox, and Ball. Not known in the recent state. FREE INSTITUTE OF SCIENCE 637 TERTIARY FAUNA OF FLORIDA This species has always been rather rare, and has been confounded with its undoubted descendant, the Area floridana of Conrad, found living in Florida waters. Nevertheless, the recent and the fossil shells are readily dis- tinguished on comparison. It is probable that the rarity of the living shell has prevented the comparisons being made. This species had previously been named sccticostata by Reeve, from a specimen of which the habitat was unknown. This name, of course, will have to be adopted. In A. licnosa there are about forty ribs in a specimen one hundred and eight millimetres long; these ribs are deeply grooved down the centre, and the ridges on either side of the grooves are likewise longitudinally grooved with one or two incised lines. The interspaces between the ribs are narrower than the ribs ; the beaks are less anterior than in A. sccticostata. In the latter the ribs are much narrower than their interspaces, flat-topped, and distally for a little more than half their length in the adult the top of the rib has a broad, shallow channel. In no case are there any subsidiary grooves. Minute con- centric ridges are quite obvious in both species, but the fossil has the ridges more generally and conspicuously beaded. In other respects the shells are extremely similar. Scapharca (Scapharca) hypomela n. s. PLATE 33, FIGURE i. Oligocene of the Ballast Point silex beds, Tampa Bay, of the lower bed at Alum Bluff, and of the Chipola marl, Chipola River, Florida. Shell of moderate size, long, inflated, with rather low, mesially com- pressed, prosogyrate beaks ; left valve with about forty-three deeply chan- nelled, flat-topped ribs with fine, regular, concentric beading, except on the posterior slope, where the ribs are lower, flatter, and obsoletely channelled ; near the margin some of the ribs have a second set of finer grooves ; hinge- line straight, anterior end descending vertically, then obliquely rounded into the base, which is nearly parallel with the hinge-line; the posterior end descends more obliquely and the basal angle is prolonged a little and rounded ; the interspaces between the ribs in both valves are very narrow, and on the right valve the beading is less conspicuous ; the cardinal area is somewhat concave, flattish, with three or four concentric grooves in loxenge form ; teeth of the hinge similar, numerous, not interrupted, short, vertical, the distal teeth a little longer and more oblique ; margin of the valves fluted, the right valve slightly smaller than the other. Lon. 50, alt. 25, diam. 2O mm. TRANSACTIONS OF WAGNER 638 TERTIARY FAUNA OF FLORIDA This species has the appearance of being the Oligocene ancestor of the Miocene A. licnosa, from which it differs by its smaller size, closer and rather narrower ribbing. Scapharca (Scapharca) latidentata n. s. PLATE 36, FIGURE 15. From the Oligocene of Ballast Point, Tampa Kay, of the lower bed at Alum Bluff, and in the Chipola marls of Florida, and probably from the Oak Grove sands in western Florida. Shell small, ovate, moderately convex, with low, quite anterior, mesially sulcate, prosoccelous beaks ; left valve with about thirty rounded, radiating, undivided ribs, separated by slightly wider interspaces, and crossed by numerous smaller concentric ridges which become beatllike on the ribs and vary in prominence in different specimens; base evenly arcuate, ends rounded ; cardinal area narrow, impressed, smooth, with one or two grooves behind the beaks, but none elsewhere; valves slightly twisted, so that the basal margin is not in a single plane; line of teeth interrupted a little behind the beaks, the anterior series having the anterior and posterior teeth larger and the intervening teeth thinner and more closely adjacent, all nearly vertical ; posterior teeth vertical, shorter, the series longer, the teeth smallest proxi- mally and regularly increasing in size towards the distal end of the series, equidistant and regular; inner margin of the valve deeply fluted. Lon. 18, height 1 1, diain. 9 mm. This little shell looks a good deal like the young of Anadara aresta Ball, but has the beaks less central, less prominent, and distinctly impressed mesially, giving a somewhat bilobed aspect to the very young. Scapharca (Scapharca) callicestosa n. s. PI.ATK 34, FIGURES 17, 18. Upper bed (Miocene) at Gaskin's Wharf, on the Nansemond River, sixteen miles below Suffolk, Virginia ; F. Burns. Shell of moderate size, rather thin, rhomboidal, with small, prominent, mediosulcate, prosoccelous beaks situated at about the anterior third of its length ; left valve with about thirty-seven squarish subequal radial ribs, sepa- rated by narrower channelled interspaces ; on the tops of these ribs are four longitudinal threads, the inner pair larger and more prominent but separated by a somewhat deeper sulcus than those external to the inner threads ; con- centric sculpture of fine, close, rounded, slightly elevated threads, which over- FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA run the whole shell, ribs, and interspaces, and at short intervals, at the inter- section with the inner pair of rib-threads, they become minutely nodulous, while the reticulations have a punctate appearance, giving a surface somewhat like fine lace and peculiar, as far as observed, to this species ; cardinal area short, rather narrow, with sharply elevated boundaries and a single incised set of grooves forming a lozenge-shaped figure anteriorly ; hinge-line short, teeth in two adjacent series, anterior with fifteen, posterior with twenty-six or twenty-seven teeth set vertically, a little oblique at the distal ends of the series ; each individual tooth more or less grooved or striate in the direction of motion, as in some recent species ; anterior end of shell produced, rounded ; posterior end subtruncate, base slightly arched ; inner margin of the valves with rather long, deep flutings, corresponding to the external ribs. Lon. 32, alt. 27, diam. 20 mm. (twice the diameter of the single valve). A single valve of this very elegant species was obtained by Mr. Burns. Its sculpture differentiates it from all our other Tertiary species. Area calli- filcnra Conrad, in which the ribs have a minute nodular sculpture, has the radial threading predominant, while in this species the concentric threads over- run all the rest. The two species are entirely distinct otherwise. Scapharca (Scapharca) idonea Conrad. .•hrti idoiii-a Conrad, Fos. Tert. Form., p. 16, pi. I, fig. 5, 1832. Area stillicitiiiiin Conrad, op. fit., p. 15, pi. I, fig. 5 (young shell). Ai'tti itlenca Conrad, Fos. Med. Tert., p. 55, pi. 29, fig. 3, 1840. Sni/i/itirri! iilonea Conrad, I 'roc. Arad. Nat. Sci. Phila. for 1862, p. 579, 1863. The typical form has twenty-five ribs, and has been obtained from the Miocene of St. Mary's River, Maryland, and the upper bed at Alum Bluff, Florida. The more elongated variety, with thirty-one ribs, figured in the Medial Tertiary, is also found at St. Mary's, at Windmill Point, and in Surry County, Virginia, and in the Miocene of Alum Bluff, Florida. A somewhat more angular type than either of the above is obtained from the Miocene of St. Mary's River, Maryland. The species is one of the most abundant and finest of the Chesapeake Miocene. Scapharca (Scapharca) carolinensis Wagner. PLATE 33, FIGURE n. Area <,iro/iii<-nsis Wagner, Trans. Wagner Inst., v., p. 9, pi. I, fig. 4; Bronn, Index Pal. Nom., p. 93, 1848 ; Syst., p. 283, 1849. TRANSACTIONS OF WAGNER 640 TERTIARY FAUNA OF FLORIDA Miocene of North Carolina? Wagner; of York River, Virginia, station 2250, Harris; of Duplin County, North Carolina (young), Burns. Shell large, solid, squarish, moderately inflated, with subcentral, proso- crelous, rather elevated beaks ; left valve with about thirty ribs, with subequal interspaces, the anterior ribs squarish, with a shallow median sulcus near the margin, and irregular concentric ripples ; the ribs of the middle of the valve not sulcate, with less rippling, more closely adjacent, the interspaces very squarely channelled ; the posterior ribs smaller, rounded, and more closely set ; cardinal area short, rather wide, smooth, or longitudinally striate, with three concentric lozenge-shaped groovings ; hinge-line short, solid ; the teeth not interrupted, strong, about forty-five in'all, the anterior more vertical, the middle teeth inclining towards the middle line of the area, the posterior teeth distally, more oblique and longer ; margins of the shell strongly fluted. Lon. 56, alt. 55, diam. 43 mm. (type specimen). As this species seems never to have been described, the references in Bronn being merely to Wagner's unpublished plates, I have given a diagnosis from Professor Wagner's original type specimen, and refigured the interior of the left valve. The shell is remarkable for its squarish form, which is rather distantly approached by some specimens of A. idonca. It is singular that in all the years which have elapsed since this shell was collected and figured by Professor Wagner no one has recognized or described it. Scapharca (Scapharca) dodona n. s. PLATE 31, FIGURKS i, 8, Sa. Oligocene marl of Oak Grove, Santa Rosa County, Florida ; Burns. Shell small, solid, inequilateral, inflated, and rounded in front, pointed and attenuated behind; with mesially impressed, prosoccelous beaks; left valve with thirty-six squarish radial ribs, each with a deep central groove longitu- dinally, the portions on each side with a shallower longitudinal sulcus, so that each rib, except in young shells, is composed of four threads set in two pairs ; the ribs separated from each other by channelled interspaces about half as wide as the ribs ; concentric sculpture of numerous rather close set, regu- lar, blunt, elevated lines, which appear on the riblets as fine undulations ; beaks at the anterior third ; cardinal area, with a raised margin, lozenge-shaped, rather wide, slightly narrower behind the beaks, with about four rather wavy sets of concentric grooves ; hinge-line short, solid, the teeth not interrupted, larger distally, the most anterior tending to break up into granulations, about FREE INSTITUTE OF SCIENCE 641 TERTIARY FAUNA OF FLORIDA fifty in all, subvertical, shorter in the middle of the hinge ; margins of the valve deeply fluted ; right valve with wider interspaces and narrower, often tripartite, ribs. Lon. 40, alt. 28, diam. 30 mm. This fine shell has a neat and elegant surface sculpture, and is one of several which the Oak Grove marl contains and which appear to be new. Scapharca (Scapharca) santarosana n. s. PLATE 31, FIGURES 2, 10. Oligocene of the Chipola River marl, of the lower bed at Alum Bluff, of the Sopchoppy limestone, and of the Oak Grove sands, Santa Rosa County, Florida; Burns and Dall. Shell small, short, plump, rostrate, with moderately elevated, mesially sulcate prosocojlous beaks ; left valve with thirty elevated, squarish, radial ribs, separated by slightly narrower channelled interspaces ; the ribs on the posterior slope are low, smaller, and nearly smooth ; those on the middle of the shell have mostly near the margin a shallow mesial sulcus ; in those still more anterior the sulcus is deeper and wider, dividing each rib over most of its length into two more or less rounded riblets ; concentric sculpture of regu- larly spaced elevated lines, which on the ribs appear as prominent ripples ; right valve having the ribs narrower and less strongly sculptured, and the sulci less distinct ; cardinal area short, with about three concentric grooves ; beaks within the anterior fourth ; hinge-line short, with about fifty-seven rather irregular, closely adjacent, nearly vertical teeth, longer and more oblique dis- tally ; margins strongly fluted ; base flexuous, posterior end narrow, pointed, without any marked angle at the end of the hinge-line. Lon. 36.5, alt. 28, diam. 28 mm. This species is most nearly related to A. stainiuata Dall, from which it can be distinguished especially by its lower beaks, more oblique posterior slope, more flexuous base, and attenuated posterior end. Scapharca (Scapharca) staminata n. s. PLATE 31, FIGURES u, 13. Oligocene of the lower bed at Alum Bluff, and perhaps at Roberts, Kscambia County, Florida. Shell of moderate size, plump, rhombic, with well-elevated, hardly sulcate, slightly prosoctulous beaks, situated in the anterior third of the length ; left valve with twenty-eight or twenty-nine radial ribs, the posterior of TRANSACTIONS OF WAGNER 642 TERTIARY FAUNA OF FLORIDA which are smooth and almost rounded; those on the middle of the valve are squarish, with wider channelled interspaces, and rippled or furnished with transverse nodulation above, which grows stronger and more crowded ante- riorly ; the ribs are not sulcate or dichotomous, and hardly differ on the two valves; hinge-line straight, rather long, and with conspicuous angles at the ends ; anterior end of the valve rounded, base nearly parallel with the hinge- line, posterior end somewhat produced ; beaks narrow, cardinal area with from three to five sets of lozenge-shaped groovings ; hinge strong, the teeth in two adjacent series, somewhat oblique, smaller mesially, at the anterior end of the hinge sometimes more or less broken into granules ; inner margin of the valves fluted, interior radially striate. Lon. of a large valve 47, alt 37 mm. ; Ion. of figured shell 39, alt. 30, diam. 28 mm. This species differs from A. santarosana, which occurs in the same beds, by its more rhombic form, proportionately longer hinge-line, and unsulcate ribs. It is also a larger and less elegantly sculptured shell. A. staininea Say, of which staminata may prove to be an Oligoccne race, has a proportion- ately longer hinge-line, is more sharply truncate behind, and more obliquely rounded in front, the beaks are less elevated and wider, the ribs anteriorly are only sparsely and feebly nodular, while the aspect of the whole shell is less elegant. Scapharca (Scapharca) staininea Say. Area staininea Say, Am. Conch., iv., pi. 36, fig. 2, 1832. Area elcvata Conrad, Fos. Med. Tert., No. I, cover, 1840. Area triyiictni Conrad, Proc. Acad. Nat. Sci. I'liila., i., p. 305, 1843 ; Kos. Med. Tert., p. 59, pi. 31, fig. 2, 1845. Scaphiin-a triqitetra Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 580, 1863. Miocene of Calvert Cliffs, Choptank River, and Jones's Wharf, near Ccn- treville, Maryland ; of York River, Virginia, and Walton County, Florida ; Say, Burns, Harris, and Johnson. The differences between this and A. staminata are detailed under that species. Scapharca (Scapharca) chiriquiensis C.abb. A. chiriquiensis C.abb, Proc. Acad. Nat. Sci. Phila., xii., p. 567, 1861. Oligocene of Chiriqui, Central America, and of an island in Lake Ilenri- quillo, St. Domingo ; Gabb and Rowell. The absurdity of referring this species to A. grandis Broderip is evident on a comparison, and the A. patricia of Sowerby (Quart. Journ. Geol. Soc. FREH INSTITUTE OF SCIENCE 643 TERTIARY FAUNA OH' FLORIDA London, vi., p. 52, 1850) not being figured, the number of ribs and the pro- portional measurements being omitted from Sowerby's diagnosis, can hardly be identified, though it probably resembles this species, which has about thirty rounded ribs with subequal channelled interspaces, the anterior ribs being granulose or nodiferous, the shell remarkably high, short, solid, and wide. The measurements of a well-grown specimen are: alt. 42, Ion. 45, and diam. 44 mm.; the length of the cardinal area is 28 mm. It is one of the species on the border line between Scapliarca and Aiiadara, the two valves being similarly sculptured and almost equal. Scapharca (Scapharca) Lesueuri Dall. I.i-Mieur, Walnut Hills Fos., pi. v., fig. 8, 1829. . I >'i'ii mississippicnsis Connul, Journ. A cad. Nat. Sci. I'hila., 2d Ser., i., p. 125, pi. 13, figs. II, 15 ; Proc. Acad. Nat. Sci. I'hila., iii., p. 294, 1848. Not Byssoarca mississippiensis Conrad, Journ. Acad. 1. c., p. 125, pi. i, fig. 323. AiitiinalocartUit niisxissif>l>ii'iisis Conrad, Am. Journ. Conch., i., p. II, 1865. Not (.'iii'itllirarcti missi$sif>f>i<'tisis Conrad, Am. Journ. Conch., i., p. II, 1865. Vicksburgian Oligocene of Mississippi. It is obvious that the same specific name cannot be used twice in the same genus for a valid species, and so I have proposed to call the present one Area Lesucnri, in honor of the excellent naturalist who was the first to call attention to it. Scapharca (Scapharca) arata Say. Ai'tii iini/n Say, Journ. Acad. Nat. Sci. I'hila., 1st Ser., iv., p. 137, pi. 10, fig. I, 1824; Conrad, Fos. Med. Tert., No. 3, p. 58, pi. 30, fig. 6, ^45. Miocene of St. Mary's County, Maryland; Burns. This species is the oldest of the group to which it belongs, which includes A. improcera, A. bnccula, A. plicatitra, etc., and which is represented in the recent fauna by A. transversa Say. Scapharca (Scapharca) improcera Conrad. Area iinfnvicra Conrad, Fos. Mcd. Tert., p. 60, pi. 31, fig. 5, 1845. S,,i/i/iarcii improcera Conrad, Proc. Acad. Nat. Sci. I'hila. for 1862, p. 579, 1863. . l/-,;i filifiitura (juvenis) Hcilprin, Proc. Acad. Nat. Sci. I'hila. for 1881, p. 451. Upper Miocene of Warwick, Virginia; of Duplin County and Wil- mington, North Carolina; of Timminsville and Darlington, South Carolina, Hums; Pliocene of the Caloosahatchie River and Shell Creek, Florida, Dall and Willcox. 6 TRANSACTIONS OF WAGNER 644 TERTIARY FAUNA OF FLORIDA This shell should not, in my opinion, be united with A. plicatura, as has been done by Heilprin. When properly discriminated it is a smaller and more rhombical shell, with lower and more anterior beaks, and more produced and pointed posterior end; the base and hinge -line are nearly parallel, and the latter is narrower in specimens of the same size than in A. plicatura. Both have about thirty-five ribs, but in A. iinprocera these are plain, while in A. plicatura the anterior ribs are prettily nodulous. Area bnccula Conrad (Fos. Med. Tert, p. 60, pi. 31, fig. 4) appears to be a short, heavy, stunted, and abnormally thickened variety of this species, such as might be produced by an unfavorable environment. It is confined to the Upper Miocene marls of Duplin County, North Carolina. Scapharca (Scapharca) plicatura Conrad. Area plicatura Conrad, Fos. Med. Tert., p. 6i,pl. 32, fig. 4, 1845; Heilprin, Proc. Acad. Nat. Sci. Phila. for 1881, p. 451, ex parts. Area lineolata Conrad, Fos. Med. Tert., p. 61, pi. 32, fig. 3, 1845 ; not of Roemer, 1836. Area sublineolata Orbigny, Prodr. Pal., iii., p. 125. Area aquicostata Conrad, F'os. Med Tert., p. 60, pi. 31, fig. 6, 1845 ; Tuomey and Holmes (?), Pleioc. Fos. S. Car., p. 44, pi. 16, figs. 3, 4, 1856. , Area brevidesma Conrad, Fos. Med. Tert., p. 62, pi. 32, fig. 5, 1845. Upper Miocene of Duplin County, North Carolina, of the Sumter Dis- trict, South Carolina, and of De Leon Springs, Florida ; Pliocene of the Waccamaw beds of South Carolina ; Burns and Johnson. This is a considerably larger species than A. improccra, more rounded and with a tendency to nodulation of the ribs. I am somewhat doubtful if the shell figured by Tuomey and Holmes is to be identified with it. It has a very close resemblance to A. arata Say, and is much larger than any specimens of plicatura I have seen. The sculpture of the two valves in plicatura is markedly discrepant, which is not the case in iinproccra. In this, the former more nearly approaches A. tmnsrcrsa, but the latter has reverted to the rhombical form of iinprocera. Scapharca (Scapharca) campyla n. s. PLATE 31, FIGURES 3, 4; PLATE 32, FIGURE 22. Pliocene of the Caloosahatchie, Shell Creek, Alligator Creek, and Myakka River, Florida ; Willcox and Dall. Shell of moderate size, solid, rather rude, the posterior end strongly twisted to the right, the beaks low, and the form somewhat compressed ; the FREE INSTITUTE OF SCIENCE 645 TERTIARY FAUNA OF FLORIDA umbones are very slightly bent forward, and are situated at about the anterior third ; left valve with about thirty low, flat radial ribs, becoming wider and sparser posteriorly, crossed by rather rude incremental lines, but not nodulous or dichotomous, and with subequal, rather shallow channelled interspaces; the right valve is similarly sculptured and somewhat smaller; cardinal area rather long, narrow, with numerous slightly angular, longitudinal grooves; ends of the hinge-line moderately angular, anterior end of shell rounded, posterior produced, base flcxuous, inner margins fluted; teeth numerous, small, uninterrupted, nearly vertical, the distal ones larger and tending to break up into granules. Lon. of a large valve 50, alt. 34 mm. ; of figured specimen, Ion. 38, alt. 27, diam. 20 mm. This species is one of the most abundant in the Floridian Pliocene, and is easily distinguished from any other by its compressed appearance and twisted shape. Some of the allied species have a slight flexuosity, but in none is this feature so pronounced as in A. cauipyla, A variety with thinner shell and narrower and slightly more elevated ribs was at first thought to be distinct, and may be named var. cerctea. It is figured plate 32, figure 22. Scapharca (Scapharca) subsinuata Conrad. .In, i sitlisiniMta Conrad, Fos. Med. Tert., p. 62, pi. 32, fig. 6, 1845. Pliocene of the Croatan beds, near New Berne, North Carolina. I have seen only one specimen of this shell, which was identified by Conrad and has been many years in the National collection. It is very close to A. arata Say, from which the individual referred to differs chiefly by having two or three more ribs, and in being somewhat less angular at the posterior end of the hinge-line. A good series would probably connect them. A species near to this is represented in the Upper Miocene fauna of the deep artesian well at Galveston, Texas, but the specimens arc too young to be specifically identified. Scapharca (Scapharca) transversa Say. Ana trans-wsa Say, Journ. Acad. Nat. Sci. I'liila., ist Sen, ii., p. 169, 1822; Conrad, Fos. Tert. Form., p. 15, pi. I, tig. 2, 1832; Tuomey and Holmes. 1'li-ioc. Fos. S. Car., p. 42, pi. 15, fig. 6, 7, 1856; Kmnions, Kep. C.col. N. Car., p. 285, 1858. Pliocene of Myakka River and Do Land, Florida ; Pleistocene of North Creek, Little Sarasota Bay, Florida; of Simmons Bluff, South Carolina, Wailes Bluff, Maryland, and Sconset, Rhode Island. Recent from Cape Cod TRANSACTIONS OF WAGNER 646 TERTIARY FAUNA OF FLORIDA south to Key West, Florida, and southwest to Vera Cruz and the Gulf of Campeachy, Mexico, in shallow water. This is not the Area tmnsversa of Portlock (1843), nor of Rogers (Dec., 1839). The latter, a CncnlUea, has been renamed A. (C.) Rogi-rsiana by Nyst (Tabl. Synopt. Arcacees, p. 63, 1848), and A. (C.) Rogers i by Heilprin (Proc. Acad. Nat. Sci. Phila. for 1881, p. 449). This species has the rounded nodulous ribs and discrepantly sculptured valves of A. plicatura, with the more rhombic form and solidity of A. impro- cera, with both of which it is doubtless genetically connected. It is not known below the Upper Pliocene. Scapharea (Scapharca) halidonata n. s. PLATE 33, FICURE 24. Oligocene of the Bowden beds, Jamaica, and of Curasao ; Henderson, Simpson, etc. Shell subequivalve, ovate, oblique, inflated ; beaks rather high, strongly bent forward, almost reaching the anterior fourth of the length ; left valve larger, with about thirty-four clear-cut, elegantly sculptured radial ribs ; the anterior dozen ribs are usually dichotomous or deeply sulcate ; the ribs on the middle of the shell are grooved with one or two shallow, sharp, incised lines; the more posterior ribs are wider and flatter with three or more grooves ; those on the posterior dorsal slope are angular, narrower, and usually have not more than one groove, which is nearly obsolete ; the con- centric sculpture is of evenly spaced, fine, elevated lines arched in the inter- spaces and finely nodulating the anterior ribs; the sculpture is similar on both valves; the anterior end of the shell is rounded, the base arcuate, the posterior end oblique above and produced below ; the ends of the hinge-line are angulated ; the cardinal area is moderately wide with about three concen- tric lozenges outlined by the grooving; the hinge-line is straight, the teeth numerous and mostly vertical, the two series not interrupted, the posterior distal teeth tending to become irregular in the adult. Lon. of shell 55, of hinge-line 41, alt. 40, diam. 40 mm. ; large specimens reach a length of 68 mm. This shell is usually named A. consobrina Sby. in collections, but when compared with the excellent figure of the St. Domingo species given by Sowerby, it is evident the two cannot be united. Sowerby's species is more elongated, with a much straighter base, the beaks smaller and lower, and the height of the shell proportionately much less than in A. halidonata. FREE INSTITUTE OF SCIENCE 647 TERTIARY FAUNA OF FLORIDA T' Moreover, the name consobrina had been used by d'Orbigny six years earlier for a French fossil species, and was therefore not available for the West Indian fossil. Sowerby's diagnosis is not distinctive and would apply equally well to several species. A. incqiiilatcralis Guppy, from Bowden, is more like his figure than is the present species. There are in the Oligocene rocks of Gatun and other localities on the Isthmus of Darien, near Panama, several species of Area of which I have imperfect specimens, some of which are nearly allied and may prove identical with A. lialidonata. The A. consobrina of Guppy's papers is the present species, which was erroneously referred to A. floridana Conr. by Gabb. Scapharca (Scapharca) inequilateralis Guppy. .•1/rd iiu-iiitilntt-ralis Guppy, Quart. Journ. Geol. Soc. Lond., xxii., p. 293, pi. xviii, fig. 2, 1866. Oligocene of the marls of Bowden, Jamaica ; Guppy, Henderson, and Simpson. This species is closely related to A. latidcntata Ball, of the Chipola, Florida, Oligocene marls, but may be distinguished from it at once by the shorter, more delicate, and much more numerous hinge-teeth of the Jamaica shell. The latter is also thinner and more elegant in sculpture and less inflated. It somewhat resembles the young of A. hypomcla Dall and A. floridana, Scapharca (Scapharca) actinophora n. s. PLATE 33, FIGURE 26. Shell subequivalve, ovate, moderately inflated, attenuated behind ; beaks low, mesially impressed, much bent forward, situated in the anterior fourth of the length ; left valve slightly larger, with about forty squarish, uniform, entire radial ribs, with narrower channelled interspaces, the ribs slightly flatter and wider clistally ; transverse sculpture of fine, low, equidistant, sub- equal, rather close-set elevated lines which are concavely arched as they pass over the ribs ; sculpture nearly identical on both valves ; hinge-line long, straight, anterior end nearly a right angle, the valve margin evenly rounded to the arcuate base; posterior end narrower, produced; cardinal area lanceolate, wider in front, with six or seven concentric grooves, angular near the beaks ; teeth numerous, vertical, larger distally in two series, about thirty-five anterior and fifty-two posterior, separated by a short vacant gap ; inner margins of the valves deeply fluted. Lon. 46, alt. 27, diam. 26 mm. TRANSACTIONS OF WAGNER 648 TERTIARY FAUNA OH FLORIDA This species is easily recognized by its numerous oblique ribs and com- pressed posterior end. Scapharca (Scapharca) acompsa n. s. PLATE 33, FIGURK 15. Oligocene of the Chipola River, Florida, marl. Shell rectangular, elongate, rather compressed, with low prosoccelotis beaks, situated at about the anterior fourth of the whole length ; right valve with about thirty-six flattened radial ribs, with much narrower interspaces ; the anterior (twenty-two) ribs are mesially divided by a sharp groove and feebly rippled above ; the posterior ribs are flat, smooth, and increase in width backward ; the anterior end of the shell is evenly rounded, the base straight and parallel with the hinge-line, the posterior end wider, a little produced below and with a conspicuous angle above ; cardinal area long, very narrow, with one or two grooves, and bordered behind with an elevated margin ; hinge-line straight, long, with numerous small, uninterrupted teeth very short mesially, longer and somewhat more oblique distally ; inner margin of the valves fluted, shell thin and delicate. Lon. 20, alt. 10.5, semi-diam. 4.5 mm. Only two right valves of this little species have been examined. It resembles the young of A. liypomcla but is immediately distinguishable by its more compressed and rectangular form and smooth, flat posterior ribs. • Scapharca (Scapharca) triphera n. s. PLATE 33, FIGURK 6. Pliocene marls of the Caloosahatchie River, Florida ; Dall. Shell subequivalve, of moderate size, elongate, not much inflated, sub- rectangular, with low beaks slightly prosoccelous and marked by a conspicuous wide mesial sulcation ; umbones situated at the anterior third of the length ; left valve with about thirty-eight rounded subequal ribs separated by narrower interspaces ; in the adult about a do/en of the anterior ribs may be squared off and deeply mesially sulcate near the margin, while a few of the ribs on the posterior dorsal slope are narrower, smoother, and more widely separated; transverse sculpture of elevated lines which are somewhat regularly spaced, and in crossing the ribs develop into sharp, thick transverse nodulations ; cardinal area very narrow and with an elevated margin behind, slightly wider in front of the beaks, longitudinally striate ; ends of the hinge-line angular; anterior end bluntly rounded, base parallel with the hinge-line, posterior end FREE INSTITUTE OF SCIENCE 649 TERTIARY FAUNA OF FLORIDA subtruncate, a little produced below ; hinge with numerous rather crowded subvertical teeth in an uninterrupted series ; inner margin of the valves deeply fluted. Lon. of largest valve 28, alt. 14; of younger valve 18, alt. 8.5, diam. 7 mm. The larger valves of this rare species are distorted or worn so that a younger one has been selected for figuring. The most conspicuous feature of the shell is the deep sulcation of the beaks, which gives them a bilobed appearance. Scapharca (Scapharca) donacia n. s. PLATE 33, FIGURE 13. Oligocene marl of Bowclen, Jamaica; Bland. Shell small, donaciform, moderately plump, with rather elevated proso- ccelous beaks at about the anterior third ; valves almost similarly sculptured ; left valve with about twenty-four low, strap-like, narrow radial ribs with somewhat wider interspaces ; the ribs are plain, smooth, and entire on both valves ; on the left valve the interspaces are crossed by numerous equidistant elevated lines which do not appear on the ribs ; on the right valve the inter- spaces are only marked by lines of growth ; hinge-line short, cardinal area very narrow, smooth ; anterior end larger, rounded ; posterior end produced and attenuated; hinge-teeth small, similar, slightly divergent; internal margin of the valves with deep short flutings. Lon. 6.8, alt. 4.5, diam. 3 mm. This little shell has no very marked characters, but appears to be adult, and not very similar to the young of any of the species associated with it. Scapharca (Scapharca) auriculata Lamarck. Air,i auriculata Lam., An. s. Vert., vi., p. 43, 1819 ; Reeve, Conch. Icon., Area, pi. vi., fig. 35, 1844. ? Oligocene of Bowden, Jamaica, Henderson ; Pliocene of Limon, Costa Rica, Gabb; Pleistocene of the Antilles, various collectors. Recent, from Key West to Martinique, in fifteen to forty fathoms. The fossil from Bowden seems to be this species, though somewhat worn ; that from Port Limon is certainly the same as the recent shell. Section Ar^iini dray. Scapharca (Argina) tolepia n. s. PLATE 33, FIGURES 7, 8. .h'i,i />,•] -is Solander MSS.,yfr/V Dillwyn, 1817. Area caint>fchcnsis Dillwyn, Descr. Cat. Rec. Sh., I, p. 288, 1817 (Syn. partim. cxclus.), Jamaica and Carolina; not of Wood, Ind. Test., p. 46, pi. 9, fig. 28, 1825. Area fiexaia Say, Journ. Acad. Nat. Sci. I'hila., ii., p. 268, 1822. Area sea film Ravcnel, Cat., p. 5, 1834, fide Stimpson. Area aincrieana (dray) Wood, Index Test. Suppl., pi. 2, Area, fig. i, 1828 ; ibid., ed. Hanley, p. 205, 1856; Tryon, Am. Mar. Conch., p. 179, pi. 37, fig. 470, 1874. Area iimerieaiia Rve., Conch. Icon., Area, fig. 21, 1844 ; Holmes, Post-PL Fos. S. Car., p. 19, pi. 4, fig. 2, 1858. Area pexata C.reene, .Mass. Cat., 1833 ; Gould, Rep. Inv. Mass., p. 95, fig. 60, 1841 ; Reeve, Conch. Icon., Area, fig. 22, 1844; De Kay, Nat. Hist. N. Y., Moll., p. 176, pi. 12, tig. 311, 1843; Stimpson, Shells of N. Engl., p. 8, 1851. ea>ii/>ee/iensis Ravcnel, Cat. Coll., p. 5, 1834 ; Arango, Moll. Cubana, p. 262, 1880. FREE INSTITUTE OF SCIENCE 651 TERTIARY FAUNA OF FLORIDA .-li-i-ii l/oliiii'sii Stimpson, S. I. Checklist, p. 2, 1860 ; Tryon, Am. Mar. Conch., p. 179, pi. 37, fig. 471, 1874. Not Area nincrit-iina Orb., Moll. Cuba, ii., p. 317, pi. 28, fiijs. i, 2, 1853. This very interesting species, of which the synonymy might be much extended, affords an excellent illustration of the effects of environment upon the recent form. Its northern limit is at Cape Cod, where the shell is often large, always coarse, and with a dense hirsute periostracum. Like many of the Scapliarcas, it varies in outline from quite round to ovate quadrate ; the sculpture of the two valves is discrepant, that of the left valve showing ribs which are narrower, flatter, and less prominent than those of the other valve and often impressed in the middle longitudinally, or even divided by a mesial groove more or less extended from the margin. The ribs of the other side are not grooved, and the literature is so at variance with itself and the facts, in attempts to discriminate the several varieties, that I can only suggest as an explanation that the writers in some cases were unaware of the discrepancy between the valves and compared opposite sides. As we proceed southward, in this species, as in many other shells, we find the shell becoming less earthy and more porcellanous, the sculpture more neat, the periostracum less pro- fuse, and the general size less. South of Cape Hatteras the chalky, thin type, common in the north, is seldom if ever found. In the Gulf of Mexico and the Antilles the shell is still smaller than in the Carolinas, and, with its de- crease in size, the sulcation of the ribs becomes more generally obsolete. A somewhat similar series of differences is observable in the Pleistocene fossils, though less pronounced. Gmclin's description was inadequate, and only identifiable by his reference to Lister. The species was elucidated by Dillwyn, who noted its resemblance to Caniimii (cihilc), but whose reference to a figure in the Encyclopedic Meth- odique should be expunged from the synonymy. The typical A. cauipechcnsis is the rounded southern form which Stimpson afterwards called A. Holincsii, as he himself recognized. Say's description of A. pcxata included all the varieties of our eastern coast, but Gould first de- scribed the shell so as to make this name apply more particularly to the somewhat elongated, earthy northern variety. Gray's A. nmcricana was founded on a very elongated, more porcellanous form, such as is common in South Carolina waters. The study of a large series of recent specimens, ranging from Jamaica to Cape Cod, obliges me to recognize that no sharp line of discrimination can be drawn between the several varieties. The number TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA of ribs varies from twenty-six in the roundest, A. Holincsii, to thirty-five in the most elongated, A. amcricana ; but the short, round ones often have as many ribs as the elongated specimens. The cardinal area is extremely narrow and depressed, and the portion in front of the beaks is very small. The ante- rior granular series of teeth is much shorter than in A. tolcpia, and does not extend much in front of the beaks. The species does not descend below the uppermost Miocene, if, indeed, any of the specimens are so old. I have only identified it with certainty from the Pleistocene of Georgia, of Simmons Bluff, South Carolina, of New Jersey, and southern New England. Section JlafJiynrca Kobelt. Scapharca (Bathyarca) Spenceri n. s. PLATE 32, FIGURES 16, 24. Pliocene of Tehuantepec ; Dr. J. W. Spencer. Shell large for the section, inflated, ovate, with prominent prosocoelous beaks; left valve with fine, rounded, concentric elevated lines, close set, and with very narrow interspaces, which show fine, close radial striae, some of which on the anterior end of the shell are more prominent ; right valve with fine, close-set radial ribs, coarser on the middle of the shell, separated by narrower, sharp, channelled grooves ; transverse sculpture of evenly spaced, low, sharp elevated lines which cross the ribs without becoming much thickened ; cardinal area very narrow behind, wider but not distinctly limited in front, the cardinal margin elevated anteriorly, with seven or eight con- centric grooves mostly behind the umbones ; ends of the hinge angular behind ; the teeth in two series hardly separated, eight to twelve in front, ten to fourteen behind, not crowded, smaller mesially, larger and more oblique distally, the anterior series somewhat irregular; inner margin of the valves with fine crenulations, stronger in the left valve, the outer edge almost or quite entire. Lon. 18, alt. 15, diam. 14 mm. This is the largest species of the section, and was collected by Dr. J. W. Spencer about seventy kilometres west of the eastern terminus of the Tehu- antepec Railway from a cutting, together with a number of otiier species, all of which indicated that they were deposited in deep water, probably between one hundred and fifty and four hundred fathoms in depth, judging by analo- gous recent species The matrix is a fine, soft, grayish mud like that of deep- water deposits of the same kind, and its presence with the fossils points to a Post-Pliocene elevation of this part of the land of at least one thousand FREE INSTITUTE OF SCIENCE 653 TERTIARY FAUNA OF FLORIDA feet. For the formation in which it occurs, and which is clearly distinct from any yet described from middle America, Spencer has proposed the name of the Coatzocoalcos formation, from the Coatzocoalcos River, which drains the coastal plain immediately to the eastward. The species is named in honor of Dr. Spencer, who collected it. Scapharca (Bathyarca) Hendersoni n. s. PLATE 33, FIGURE 9. Oligocene of the Bowden beds, Bowden, Jamaica, where it was collected by J. B. Henderson, Jr., and Mr. Charles T. Simpson. Shell very small, much inflated, the hinge-line as long as the shell, which is of a rounded triangular form, with rather prominent prosoccelous beaks ; left valve with fine, elevated, rounded concentric lines, crossed by closer, less promi- nent, and finer radial lines ; in the right valve, as usual in this section of the genus, the radial sculpture predominates over the concentric, the latter though present being inconspicuous ; cardinal area moderately wide, the beaks being nearly medial, the surface of the area longitudinally striated ; hinge with about five nearly vertical anterior teeth separated by a wide unarmed gap from six or seven smaller, more oblique posterior teeth ; margin of the valves thin, entire, or microscopically crenulated ; the inner edges of the adductor scars slightly raised above the inner surface of the valve. Lon. 2, alt. 2, diam. 2 mm. This minute little species is obviously adult, and about ten valves were obtained. It resembles A. pcctunciiloides Scacchi and A. glomcrula Dall, of the recent fauna, but is smaller, more inflated, and more triangular than either of them. It is named in honor of Mr. Henderson, during whose explorations in Jamaica it was collected. Another species of the same group with more conspicuous radial sculpture and a marked depression radiating mesially from the beaks was obtained by Professor R. T. Hill from the Oligocene of Monkey Hill, on the line of the Panama Railway, but the two valves obtained are hardly perfect enough for description. Section Anadara Clray. Scapharca (Anadara) rustica Tuomcy and Holmes. Pi, ATE 31, FIGURES 6, 9. nistii-a Tuomey and Holmes, Pleioc. Kos. S. Car., p. 29, pi. n, figs. 6-10, 1857. Nut ./. nislii-tj C'ontejcan, 1859. Ann Conr., Am. Journ. Conch., v., p. 39, pi. 2, fig. 4, 1869. St'iifi/iiti't'ii subrostrata Conr.. 1'roc. Acad. Nat. Sci. Phila. for 1862, p. 580, 1863. Miocene of Maryland in Talbot and Calvert Counties, at Calvert Cliffs, Skipton, Centreville, Plum Point, and other localities; Conrad, Cope, Burns, and Harris. A single valve, stated to be from the Miocene of North Carolina, is in the National Museum. This species appears to be rather common. The cardinal area is grooved longitudinally with numerous rather irregular concentric grooves. This is not the A. subrostrata of Sowerby (1847) or °f Smith, Quart. Journ. Geol. Soc. Loud., 3, pp. 413, 418, figs. 8, 9. A. callipli'tira Conrad is probably founded on an unusually short specimen of this species. Scapharca (Anadara) aresta n. s. PLATE 33, KICUKK 2. Chesapeake Miocene of Alum Bluff, Calhoun County, Florida; Ball and Burns. TRANSACTIONS OF WAGNER 656 TERTIARY FAUNA OF FLORIDA Shell of moderate size and thickness, arcuate below, straight above, with small but prominent prosoccelous beaks ; left valve with twenty-seven square- topped, narrow, entire radial ribs, separated by wider interspaces ; the ribs on the middle of the shell are somewhat narrower than the others; all arc crossed by evenly spaced, moderately prominent elevated lines, festooned in the inter- spaces, and forming small, square ripples on the ribs; both valves similarly sculptured ; cardinal area narrow, with elevated margins behind, wider and short in front of the beaks; the portion in front of the beaks is longitudinally striated, behind the beaks there are three or four concentric, lozenge-shaped groovings ; a single transverse groove usually passes between the beaks ; hinge-line straight ; teeth in two nearly equal series, overlapping a little proximally, the teeth rather crowded and nearly vertical ; base of the valves arcuate, rounded into the anterior end, posterior end a little produced ; in- ternal margins of the valves fluted. Lon. 41, alt. 28, diam. 26 mm. This very neat and distinct species appears to be the most common Ark in the upper or Miocene bed at Alum Bluff. Scapharca (Anadara) campsa n. s. PLATE 32, FIGURE 21. Chesapeake Miocene or upper bed at Alum Bluff, Florida; Dall and Burns. Shell of moderate size, solid, and heavy, with a straight and angulatc upper margin, obliquely rounded anterior, produced posterior, and arcuate basal margin ; beaks low, much incurved, mesially impressed, and rather anterior; left valve with about twenty-two narrow ribs separated by wider interspaces, crossed by little elevated, regularly spaced incremental lines; the ribs are not nodulous, the anterior ones are flattish or rarely have a shallow sulcus mesially near the margin; they are subequal, but in specimens in which the mesial depression of the valve is especially strong, the ribs included in it are narrower and closer together than usual ; hinge-line nearly as long as the shell, angular, but not auriculate distally ; the beaks are within the anterior third; cardinal area wider in front, narrow behind, longitudinally striated with a few grooves which circumscribe a " stemmed" arrow-head figure, few of them reaching as far forward as the beaks; teeth in two adjacent series, the anterior shorter with a pronounced thickening of the shell below it, over the vertical face of which the teeth extend rather irregularly or are supple- mented by denticular wrinkles; posterior series longer, numerous, vertical, FREE INSTITUTE OF SCIENCE 657 TERTIARY FAUNA OF FLORIDA distally much wider, and more or less oblique ; interior margin of the valves with strong, short flutings. Lon. 47, alt. 28, diam. 27 mm. This is quite a peculiar species, the teeth of which recall Argina, while all the other characters of the shell indicate its section to be Anadani, another instance, if one were needed, to illustrate the mutability of the dental forms in this family. It cannot be confounded with any of our other species. Scapharca (Anadara) clisea n. s. PLATE 33, FIGURE 25. Chesapeake Miocene of Maryland, at St. Mary's River and Crisfield ; of Nomini Cliffs, Virginia, Harris; and of Walton County, Florida, Johnson. Shell large, heavy, inflated, short, with small, high, somewhat prosocce- lous beaks, the two halves of the wide cardinal area inclined to one another in the adult at an angle of about forty-five degrees ; left valve with about thirty strong, flattened subequal radial ribs with narrower interspaces ; in the young the ribs are furnished with small transverse nodulations, which gradually become obscure in the adult; the only transverse sculpture is of the ordinary incremental lines; the ribs in the adult are flat topped and rarely show any tendency to mesial sulcation, and when present it appears only on a few of the anterior ribs near the margin ; the anterior end is obliquely rounded to the base, the posterior end a little produced basally; the cardinal area is exceptionally wide, with a single impressed line joining the beaks and six or seven concentric lozenges defined by sharp grooves ; a deep groove also bounds the area ; hinge-line straight with numerous small vertical teeth, becoming much larger distally and tending to break up into granules at both ends of the series in the senile shell. Lon. 51, alt. 53, diam. 53 mm. This shell is apparently related to A. ralliplcnm and A. stanriiica Conrad, and a larger scries of specimens may oblige us to unite all three as varieties of a single species. At present, however, the differences seem too great to admit of this course. In A. callipUiira the ribs are granulated and triply suleate, while in the present form they are simple. . /. clisea has no posterior truncation like that figured by Conrad in A. calliplcitra. A. staminca is more squarely compressed before and behind, with a tendency to incurvation of the posterior basal margin; it is a smaller shell with more posterior beaks, and less roundly inflated. We have a large series of this species from many localities, and these differences characterize them all. The forms are easily differentiated, so far as our present knowledge goes, and therefore are better TRANSACTIONS OF WAGNER 658 TERTIARY FAUNA OF FLORIDA kept apart. In all the pairs of A. slaminca in the collection the right valve is distinctly smaller than and fits into the other, while in A. clisea the margins meet evenly. It now remains to enumerate the other Tertiary species of Area not hitherto mentioned, but which have been referred to American beds by various authors. Noinina inida. A. diplenra Conrad, Bull. Nat. Inst., 1842, mentioned by name as from the Miocene of Maryland, appears never to have been described. A. graniilifera Conrad appears by name only in the list of species furnished by Conrad for the appendix to Morton's Synopsis. Unidentifiable. A. canccllata Tuomey, briefly described and unfigured, from the Eocene of North Carolina, in 1854, is not A. canccllata Gmelin, 1792, or Phillips, 1829, and should be expunged from our lists. A. ma.rillata Conrad was based on an unrecognizable internal cast from the Miocene of Maryland, and, though briefly described in 1830, has never been figured. Eocene. Area (Fossiilarca /) inornata Meyer, 1886, from Claiborne, Alabama, is very minute and has not been seen by me. A. gigantca Conrad is probably identical with Ciicu/lcsa onoelicla Rogers. Noetia pn/e/ira Gabb, from the Eocene of Texas, 1860, is Trinacria dccisa. There is an A. pulchra of Sowerby, dating from 1824. Oliffocenc. A. oronlcnsis Gabb, 1875, is abundant in the black shales of Gatun on the Panama Isthmus. The following species described or men- tioned by Gabb from the Oligoccne of St. Domingo have not been figured : A. iiinltilincata Gabb, A. palrieia Sowerby, A. pcnnclli Gabb. Area trinitaria Guppy, 1866, from the Manzanilla beds of Trinidad, appears to be a good species of the subgenus Noetia. Miocene. " Anomalocardia" trigintinaria Conrad, 1862, from the Miocene of South Carolina, seems to be an Anadara from the brief description, but has never been figured. The following nominal species from the Pacific coast have been so wretchedly figured and described that further study is necessary to identify or discriminate them ; they are supposed to be from the Miocene : Area trilinealu Conrad, A. canalis and devincta Conrad, all of which by Gabb are united specifically with A. niicrodonta Conrad, the most common of the Pacific Miocene species; A. congesta Conrad, and A. obtspoaua Conrad. FREE INSTITUTE OF SCIENCE 659 TERTIARY FAUNA OF FLORIDA Area lima/iila Einmons, 1858, Geol. N. Car., is a typographical error for A. linnila Conrad. A. lintca Conrad (in App. Kerr's Geol. N. Car., 1875) is not A. lintca Conrad, 1852 (Rep. Dead Sea Expedition under Lieut. Lynch). Pliocene and later. A. Deshaycsii Hanley is reported by Gabb from the Pliocene of Costa Rica. Nelson has described and figured an A. Larkini from the Pliocene (?) of Peru. Gabb describes and figures A. sulcicosta from the Pliocene of California (1866), but the name had previously been used by Nyst in 1836 for a Belgian fossil, and Gabb's species may take the specific name of seliizotoma. Area vclata Sowerby (Indopacific) is reported by Gabb from the Pleistocene of St. Domingo, but his shell is probably a distorted specimen of Area Candida or llelblingi. The following is a list of the recent species of Area belonging to the southern coast of the United States, and any of which might be expected to occur in our later Tertiary or Pleistocene beds : Area oeeidiiitalis Phil., A. umbonata Lam.; Barbatia barbata Linne, B. (Calloarca) Candida Gmel., B. (C.) nodulosa Mull., B. (Aear) rcticidata Gmel., luirbatia (Fossularcd) Adauisi (Shuttlew.) Smith; B. (Citcullarid) aspcrnla Dall, B. (Cucitllaria) sagrinata Dall, />. (Cucullaria) profnndicola Verrill ; Noetia ponderosa Say, Noetia bisulcata Lam. ; Scapharca sccticostata Rve., S. trans- I'crsa Say, 5. Desliaycsii Ilanley, S. anricitlala Lam., 5. (C/t/iearca) incoiigriia Say, S. (Cnncarca) Clieiniiitzii Phil., S. (Argimf) eauipec/ieiisis Dillwyn with varieties pcxata Say and americana Gray, S. (Kathyarea] pcclnncidoides Scacchi, 5. (Batliyarca) polycyina Dall, S. (Bathyarca) glomemla Dall. Superfamily PTERIACEA. FAMILY PINNID^E. The ancient genus Pinna of Linnaeus, as represented in our Tertiaries, is divided into two genera: 1. Pinna proper; with the fibrous layer of the valves mesially sulcate longi- tudinally while the inner nacreous layer is bilobed deeply by the same (closed) sulci. The type of the genus is P. nidis L., the red Pinna of the West Indies. P. flabellinn Lam. and if. carnea Gmelin belong to it. 2. Atritia Gray; has the valves unsulcate or without the median carina, and the internal nacreous layer is entire. The type is P. nigra Ch., and it is represented in our recent fauna by P. rigida Dillwyn (P. tintricata auct.) and /'. scrrata Sby. 7 TRANSACTIONS OF WAGNER 660 TERTIARY FAUNA OF FLORIDA The fossil Fionas are very difficult to handle, as the fibrous layer is often entirely lost, the fragile shell is almost invariably crushed and fragmentary, while internal casts are defective in the external ornamentation. For this reason the literature says very little in regard to the genus in our Tertiaries, and only one species has been formally described. Genus PINNA (L.) Lamarck. Pinna quadrata n. s. PLATK 29, IMGUKK 7. Shell straight, thin, acute anteriorly with the valves mesially carinate, the dorsal and ventral areas making about the same angle at the carina as the valves do at the hinge-line ; byssal gape long, extending well towards the beaks, narrow behind ; sculpture of some five longitudinal ribs on the dorsal areas and two or three below the carina, the surface near the ventral edges almost smooth. Lon. of type 56, vert. diam. 26, carinal cliam. 25, apical diam. 6.5 mm. A single internal cast was collected by Mr. Willcox at Richard's quarry, Ocala, Florida, in the Nummulitic or Ocala horizon of the Vicksburgian Oligocene. Specimens nearly twice as large as the above-mentioned were found by L. C. Johnson at Johnson's lime sink, Levy County, and Arredondo, Alachua County, Florida, in the Vicksburg limestone. They are remarkable for their rapid increase in diameter. Pinna caloosaensis n. s. PLATE 26, FICUKE 4. Shell long, slender, straight, narrow, thick, with the valves moderately rounded ; carina not conspicuous in the fossils, but the sulcus very long, deep, and sharp, represented on the interior by a large rounded rib; dorsal area sculptured with about three feeble irregularly longitudinal ridges; ventral area with about the same number, but stronger and sharper. Lon. of type 1 20, max. dorso ventral height 40, min. do. 10, convexity of the valve at the sulcus behind 12 mm. A single broken valve without the fibrous layer and the apical part of another was obtained from the Pliocene marl of the Caloosahatchie. This species is not unlike P. rudis in form, but is proportionally much thicker and the sulcus is much larger than in the recent shell, which has no such strong, rounded internal rib. FREE INSTITUTE OF SCIENCE 66 1 TERTIARY FAUNA OF FLORIDA Pinna carnea Gmclin. Pinna liaiiit iif/in/>i/is Chemn., Conch. Cab., viii., p. 212, pi. 87, fig. 769, 1785. I'inna pfriiula Chcmn., <>/>. fit., viii., pp. 211, 242, pi. 92, fig. 785, 1785 ; Arango, Moll. Cuba, p. 264, 1878; Orbigny, Moll. Cuba, ii., p. 325, 1853; not of Reeve. Pinna carnea (iniclin, Syst. Nat., p. 3365, 1792; Solander, Portland Cat., 1796; Des- haycs, in Lam. An. s. Vert., ed. ii., vol. vii., p. 61, 1836. Pinna d,-i;cn,ra Link, Beschr. Rostock SainniL, p. 159, 1807. Pinna Jhilh-llnin (Lam.), Kccve, Conch. Icon., Pinna., pi. x., fig. 18, 1858. /'tuna 7'aricnsa Lamarck, An. s. Vert., vi., p. 133, 1819; Orbigny, Moll. Cuba, ii., p. 325, i«53- / /'//i//ii Intllatii (Swains.) Reeve, Conch. Icon., Pinna, pi. ix., fig. 16, 1858. Post Pliocene of the Florida Keys; recent in the West Indies as far south as Trinidad and north to Cape Hatteras, also in the Red Sea. As Chemnitz was not systematically binomial in nomenclature, his acci- dentally binomial name cannot be accepted, though the earliest. This species seems to be distinct from P. rudis, though it is often spinose or strongly ribbed ; further study on this point is desirable. The typical P. nidis is not known from Florida, though said to be abundant on the Bahamas. The /-*. carnea varies from pale salmon color to a brownish white, and may be smooth, or sparsely muricate; it is always thin, straight, and obliquely trun- cate. /'. nidis is the only other true Pinna known from the east American subtropical region ; the true P. ninricata (L.) Rve. is probably an Oriental species, the ninricata of American authors belonging to the genus Atrina. Pinna rudis (I.innc) Dillwyn. Pinna nii/is L., Syst. Nat., ed. xii., No. 1159, 1766, ?x parts ; Chemn. Conch. Cab., viii., p. 218, pi. 88, fig. 773, 1785 ; Dillwyn, Cat., p. 322, 1817; Hanley, Shells of Lin., p. 148, 1855 ; Reeve, Conch. Icon., Pinna, pi. x., fig. 19, 1858 ; Gabb, Journ. Acad. Nat. Sci. Phila., 2cl Scr., viii., p. 378, 1881. /'//!>/,! pi-rnu/a Reeve, Conch. Icon., Pinna, pi. 12, fig. 22, 1858 ; not of Chemnitz. Pliocene of Costa Rica, Gabb ; recent in the West Indies, Bahamas, Bermuda, etc., Reeve, Jones, et al. This species is included on the authority of Gabb; I have seen no Florida specimens unless P. carnea is a degenerate form of it. It is not the P. rudis of authors from the Mediterranean and vicinity; the latter is a form of P. nobilis. Genus ATRINA Gray. The condition of the material is such that only provisional descriptions TRANSACTIONS OF WAGNER 662 TERTIARY FAUNA OF FLORIDA can be given of several of the following species, though their distinctness appears beyond doubt. Atrina jacksoniana n. s. Lesueur, Walnut Hills Fossils, pi. 5, fig. 5, 1829. In the Jacksonian Eocene of Green's marl bed, at Jackson, Mississippi, and Garland's Creek, near Shubuta, Clarke County, Mississippi, Burns; and at Creole Bluff, Grant Parish, Louisiana, Vaughan and L. C. Johnson. Shell thin, fragile, rapidly widening, somewhat compressed along the ventral border ; sculpture of near the beaks numerous feeble, more or less wavy, longitudinal elevated lines, which become less distinct vcntrally, and are obsolete over the greater portion of the shell, which appears from the numerous fragments to have been nearly smooth posteriorly, or with a few feeble concentric wavelets, most prominent vcntrally. A fragment (including the beaks), forty-five millimetres long, has a dorso-ventral maximum diameter of thirty-four, and a transverse diameter of about twenty millimetres. The valves are evenly arched, and become more convex behind. The material is abundant but very fragmentary, yet sufficient to establish the identity of the species at these localities and its distinctness from the others mentioned. Atrina argentea Conrad. rin/iii argciilca Conr., Proc. Acad. Nat. Sci. 1'hila., iii., pp. 295-6, 1848; Journ. A< ,ul. Nat. Sci., 2d Ser., i., p. 126, pi. 13, fig. 31, 1848. Vicksburgian Oligocene of Vicksburg, Mississippi, where it is abundant in the form of impressions in a brownish clay ; Conrad and Worthen. It is quite certain from the appearance of the casts that the surface of the valves originally possessed a certain number of small, feeble, spinose pro- cesses along the principal radial ribs. The specimens examined average about eighty millimetres in length. Atrina (argentea var. ?) chipolana n. s. ? Upper Oligocene of the Chipola marl, Calhoun County, and of the Oak Grove sands, Santa Rosa County, Florida; Burns. This form is only represented by fragments. It would appear to attain about the size of A. argentea, but to be somewhat more convex and arcuate. The chief distinction is in the sculpture; the dorsal areas of the valves of both have about five equidistant radial riblets ; the ventral areas in argentea have FREE INSTITUTE OF SCIENCE 663 TERTIARY FAUNA OF FLORIDA a few radial ribs near the middle of the valve, below which the sculpture becomes obsolete; in chipolana the ventral areas are sculptured with distinct oblique, concentric waves, with about equal interspaces; the upper ends of these waves terminate abruptly where they meet the longitudinal riblets, so that the sculpture of the ventral is strongly contrasted with that of the dorsal areas. This form also appears to increase in width more rapidly than the argcntca. On the whole, the two appear specifically distinct, but a complete description must be deferred until better material enables the characters to be fully elucidated. Atrina Harrisii n. s. PLATE 29, FIGURE n. Types collected by G. D. Harris (in honor of whom the species is named) from the Miocene at Jones's Wharf on the Patuxent River, Maryland ; other specimens were found by him near Plum Point, Maryland, and a frag- ment at Magnolia, Duplin County, North Carolina, by Burns. Shell rather thick (the fibrous layer lost in the specimens), ovately rounded behind, moderately convex ; hinge-line straight, ventral margin slightly incurved ; the surface of the pearly layer shows the dorsal region with numerous fine longitudinal elevated lines, below which the shell is at first nearly smooth, then the ventral region is sculptured with numerous close-set concentric riblets. Length of portion preserved about 150, max. width 60, diam. 32 mm. This species appears to have been not unlike A. serrata Sowerby, but was a much heavier shell with a blunter anterior end. Atrina rigida Dilhvyn. rinna tcnuis strhita nnincala Lister, Conch., t. 370, f. 310; Sloane, Hist. Jamaica, p. 254. I'inini nobilis Chemn., Conch. Cab., vii., p. 224, ex ptirlc, pi. 88, fig. 775, non Linne. /'/ii/iii /»'< -/iiiiitii Iiorn, Test. Mus. Vinci., p. 132, non Linn6. J'inna ri^i,tii (Solander MSS.) Uillwyn, Cat., p. 327, 1817; Reeve, Conch. Iron., I'iitihi, pi. v., i\£. 7, 1858. I'iniiii scniiiiiiihi Lam., An. s. Vert., vi., p. 131, 1819; not Reeve, Conch. Iron., I'inna, pi. ii., fitf. -. 1858 (= sfi-rata Shy.). rin 11,1 ,i//,r Shy., P. 7. S., 1835, p. 84; Reeve, Conch. Icon., vi., fitf. u. suli-'ii-ii/is Reeve-, Conch. Icon., J'inini, xvii., li^. 32, 1858. ii' OH'i^iiyi Hanley, P. /. S., 1858, p. 227 ; Reeve, of>. fit., xxvi., fij,r. 49. '858- ouvtiiifiisis Hanley, P. /.. S., 1858, p. 225 ; Reeve, <>/>. iii Lain., I'rodr. Nouv. Class., p. 82, 1799; Systcme d'mi Nonv. Class, des Yers, ]>. 134, 1801 ; Roissy, Conch., vi., p. 105, 1805 ; not of Kct/.ius, 1788, p. 20. /xi>i;i>iiii»t (sp.) r.dltcn, Mus. Holt., p. 168, 1798; cd. ii., |). 117, 1819; (type (>.i//-t\i is(>t;>ti>»ii>it (linelin.) /w<; ;>iiuiii>n Link, Hesclir. Rostock Samml., p. 155, 1807; Dcsh. Knc. Moth., Yers., ii., p. 322, 1830; H. and A. Ads., Gen. Rec. Moll., ii., p. 526, 1857. /',;/,i//i»i Solaiulfr (MSS., 1786), ////,• Uilhvyn, Cat. Rer. Sh., p. 282, 1817. Siiliini Muhlfcldt, F.ntvv., |>. 65, 1811 ; type llstn-ti t-/ilii(>piiiiii L. llipfii>cli->iit iiin.vif/iiltt Lam., An. s. Vert., vi., i., p. 142 (syn. excl.), 1819; eel. Deshayes, vii., p. 78, 1836. r,rniiti Mock, Smithsonian Checkl. Mio. Fos., p. 6. /'•/•/in /t'/'/ii Whitficld, Crust. Moll. Mio. N. J., p. 36, pi. 5, figs. 12-13, 1895. Lower Miocene of New Jersey at Shiloh and Jericho ; of Maryland near Kaston, Leonardstown, and on the Patuxcnt ; Burns and Palmer. The National Museum has an internal cast which measures twenty-seven centimetres in length, the shell of which could hardly have been less than fifteen inches long. Remarkably perfect specimens of this almost invariably imperfect shell were collected by Mr. W. Palmer at Leonardstown. The identity of the American shell described by Lamarck shortly before Say with the Pcrna Soldani Dcsh. of the Italian tertiaries (figured by Knorr, Sowerby [as inaxillata\ in his Genera, Goldfuss ct al.) has been disputed. They are certainly very similar, but in any case Lamarck says his shell came from Virginia, and the specific name torta had been previously applied by Gmelin to a variety of fifc/ina mytiloidcs Gmelin, so that it was unavailable for use a second time by Say. It seems that Collini in his Voy. Min. (p. 10, pi. I, fig. i), printed at Mannheim in 1776, had named the European shell Qstreum polyleptoginglymnm ; but, as I have not seen the work, I cannot say whether the binomial system of nomenclature is used in it or not. It is most convenient at present to regard the American as distinct from the European shell. Orbigny, regarding the European form as the true maxillata, renamed the American shell P. Conradi. TRANSACTIONS OF WAGNER 668 TERTIARY FAUNA OF FLORIDA Several species of Perna occur in the literature which do not belong to the genus as here understood, but to Modiolns. The only other species of Melina reported from our Tertiary are the unfigured M. montana Conr. (Pac. R. R. Reps., vii., p. 195, 1857), from San Buenaventura, California, 'of which nothing seems to have been seen since it was described by Conrad, and the Perna cornclliana Harris, from the Midway stage of Alabama, near Clayton. The remains of this species are quite imperfect, and it is not practicable to make comparisons with M. maxillata. FAMILY PTERIID/E. Genus PTEBIA Scopoli. I'ti-fia Scopoli, Intr. ad Hist. Nat., p. 397, 1777 ; (sole ex. Mytilns Iiirunilo L.) Avicula Olivi, Zool. Adriat., p. 125, 1792. Margaritifera Humphrey (/-.r part,-'), Mus. Calon., p. 44, 1797 (iipud Da Costa, 1776, non binom.). riiiflitila Boltcn, Mus. Boltenianum, p. 167, 1798. Avicula Lam., Prodr., p. 82, 1799. ('nii»iitm Link, Beschr. Rostock Sainml., p. 155, 1807. Margaritiphora Meg. v. Muhlf. , KnUv., p. 66, 1811. Lam., Kxtr. d'un Cours, p. 104, 1812 ; An. s. Vert., vi., I, p. 150, 1819. Leach, Zool. Misc., i., p. 107. 1814; S\vainson, Zool. 111., 2cl Ser. , ii., pi. 55, 1831 ; not of Leach, 1819, or of Lea, 1838. /' •rfiiinati-r Schum., Kssai, p. 107, -\- Avicula, p. 136, 1817. Anonica Oken, Handb. d. Zool., 1815 ; Naturg. fiir Schulen, p. 652, 1821. The present group was called Margaritifera by J. Woodward in 1728, a name long antedating Klein's Avicula, but not introduced into binomial no- menclature until after the publication of Plena by Scopoli. The Tertiary and recent forms include the following subgenera : Pteria s. s. Type Mytilus hirundo Linne. Margaritifera Humphrey. Type M. inargariferus Linne. Eleetroma Stolic/ka. Type Avicula smaragdina Reeve. Of these the latter may be represented in the recent fauna of the Antilles by Avicula Candcaiia Orb., which seems to owe its characters to commensalism with sponges ; Margaritifera is represented by the Antillean pearl-oyster, M. radiata Leach, but, curiously enough, neither is known as an American Tertiary fossil. Of typical Pteria there are but few in our Tertiary, and these are often FREE INSTITUTE OF SCIENCE 669 TERTIARY FAUNA OF FLORIDA represented by very imperfect material. In the Eocene of New Jersey, Con- rad has found an unrecognizable internal cast to which he has given the name of P. annosa. It is regarded as a Gastropod fragment. A well-established species is P. limula Conrad (+ claiborncnsis Lea, and trigona Conr. non Lam.) from the Claiborne sands. The Oligocene of Vicksburg has furnished the P. argcntca Conr., that of St. Domingo and Bowden, Jamaica, the P. inornata of Gabb, the Miocene of Virginia, the P. nntltangnla of H. C. Lea. An unnamed species has been observed in the Midway stage of the Eocene of Georgia by Professor G. D. Harris. De Gregorio has named an unrecog- nizable fragment from Claiborne Avicnla cardiacrassa, but there is nothing to indicate any distinctive specific characters in it. Cossmann, after the ex- amination of a full series, unites it to A. claiborncnsis. Pteria argentea Conrad. .t<>ii-itlii ai-^t-iiti-tt Conr., (ourn. Acad. Nat. Sci., 2cl Ser., i., p. 126, pi. 12, fifj. 10, 1848; 1'roc. Acad. Nat. Sci. I'hila., iii., p. 295, 1847. Lower Oligocene of Vicksburg, Mississippi ; Conrad. Pteria (argentea var. ?) chipolana Uall. Upper Oligocene of the Chipola beds on the Chipola River, the lower bed at Alum Bluff, etc., Calhoun County, Florida; Burns and Dall. Small, with a straight hinge-line and narrow, deep ligamentary sulcus, the right valve with a small, well-marked cardinal tooth fitting into a small pit in the opposite valve; anterior wing short, small, with a narrow byssal sinus marked on the auricle by a short groove, external surface smooth, the posterior wing feebly set off; valves rather compressed, none of the valves exceeding twenty-five millimetres in length. It is probable that this represents a species distinct from that of Vicks- burg, but the material in my possession is insufficient to determine the question, but the type of /'. argentea shows little trace of a byssal sinus and is more inequilateral than our shell. Pteria multangula 11. ('. Lea. .l~,'i<-iifii niiilliiii^nlii 11. C. Lea, Trans. Am. Phil. Soc., ix., p. 245, pi. 35, fijj. 31, 1845. Miocene of Petersburg, Virginia, Lea ; and of the upper bed at Alum l>luff, Florida, Burns. TRANSACTIONS OF WAGNER 670 TERTIARY KAUNA OF FLORIDA This species, from the fragments, should reach a considerable six.c. Lea's type was a very small shell. The beaks are less prominent than in /'. argcntca, the byssal sinus is obsolete or feeble, the right valve has a marked semilunar pit apparently to receive a tooth from the opposite valve ; the surface appears to be more or less lamellose in the adult. Pteria colymbus liolten. I'iiicttidit c<>/yiii/iit!i liolten, Mus. Boltenian., p. 167, 1798 ; Chemn., Conch. Cab., viii., p. 141, pi. 81, fig. 723, 1785 ; Morch, Cat. Yoldi, ii., p. 53, 1851. Avifitlii titliintiea Lam. (ex partc). An. s. Vert., vi., i, p. 148, 1819. Avicnln liinnnto Ciinelin, Syst. Nat., p. 3357, 1792, fx parte, non Rolten. Avifiila a/uco Phil., Zeitschr. f. Mai., vi., p. 20, 1850. Aviciiln clitoris 1'hil., Zeitschr. f. Mai., viii., p. 54, 1853. Avicula iiiacroptcrci I!eau, Journ. de Conchyl., ii., p. 426, 1851 ; Kix'bs, Cat., )). 132, 1864, not of Reeve. Aviculct coniiiiitnh Krcbs, Cat., p. 131, 1864, not of Lam. Avicula hetcntptcra Krcbs, Cat., p. 131, 1864, not of Reeve. Avicula pteria Krebs, Cat., p. 131, 1864, not of Scopoli. Avicula a/lanlica Holmes, P.-P1. Fos. S. Car., p. 14, pi. 3, fig. I, 1858. Avicula liiniiulo Say el a/., non Bolten. Pliocene of the Caloosahatchie beds, south Florida, Dall ; Post Pliocene of Abbapoola and John's Island, South Carolina, Holmes ; recent on the southeastern coast of the United States and in the West Indies in shallow water. Pteria hirundo liolten. Mytilus liirutidfl Linne, Syst. Nat., xii., p. 1159, 1766, ex partc. I'incltiila Jiiruiuio Bolten, Mus. Boltenian., p. 167, 1798 ; Chemn., Conch. Cab., viii., p. 142, pi. 81, fig. 725. Avicula tiirentina Lam., An. s. Vert., vi., I, p. 148, 1819. Mediterranean. Pteria hirundo var. vitrea Reeve. ? Avicula strix Phil., Zeitschr. f. Mai., vi., p. 22, 1850; (on Sargasso.) Avicida vitiva Reeve, Conch. Icon., Avicula, pi. 18, fig. 68, 1857 ; (West Indies.) Avieula /iiniiitf<> var. nitiila Verrill, List I-'ish Com. Moll., p. 281, 1884. Post Pliocene of the West Indies and Costa Rica ; recent, on the south- eastern coast of the United States and in the West Indies in rather deep water. FREE INSTITUTE OF SCIENCE 671 TERTIARY FAUNA OF FLORIDA Superfamily OSTRACEA. FAMILY OSTREID^. Genus OSTREA (L.) Lamarck. Type Ostrca c dulis Linne. The genus Ostrca, as restricted by Lamarck and represented in our Tcrtiaries, comprises several conchological groups. The typical Ostrca, which is monoecious, producing large embryos which are incubated for a considerable period in the parental gill-lamina;, is not known to occur in America. Our common oysters belong to a group characterized by being dicrcious and discharging the seminal products directly into the water, which must take the name of Crassostrea Sacco.* This is typified by Ostrca vir- ginica Gmel. and represented in the present European fauna by Ostrea angit- lata Lam., known there as the Portuguese oyster. It being impracticable to determine the affinities of the fossil oysters with relation to these two sub- genera, they will be considered here under the common generic name. It is not improbable that all the American oysters belong to the subgenus Crass- ostrea. Conchologically, the ostrean element of the American invertebrate fauna presents three types which exist in the present fauna and may be traced throughout the Tertiary, their outlines becoming less sharp as we recede in time. In the Kocene a fourth group may be added which seems to have left no descendants. Subgenus Crassostrea (Sacco, emend.) Dall (+ Gigantostrca Sacco, 1897). Valves discrepant, the upper valve smoother, the lower valve coarsely and irregularly plicate, with the distal margins little if at all crenulated, the hinge- margin not alate, the apices straight or oblique but not spirally twisted. Type 0. virgiiiica Gmel. Eocene to recent. Section Cynibitlostrca Sacco, 1897 (Cubitostrea Sacco, 1897). Shell with the plications of the lower valve regular and fine, species usually of small size. Type O. cyinlntla Lamarck. Eocene. It is a curious commentary on the distance from nature attained by a certain school of systematists, that their classifications enable them to put * This name has been published since the present revision was completed, and is therefore sub- stituted for the M.S. name I had used. It is to foe regretted that the diagnosis offered by the author of Crassostrea has no systematic value and is even opposed to the facts. TRANSACTIONS OF WAGNER 672 TERTIARY FAUNA OF FLORIDA two oysters bred of the same parent in different subgenera, according to their growth in quiet water on a pebble, or in running water on a twig. Subgenus Loplia Bolten, 1798 (Rastellum [Llhwyd, 1699] Fischer, 1886; Alcctryonia Fischer de Waldheim, 1807; Dcndostrca Swainson, 1840). Valves similarly sculptured, sharply radially plicated, with their margins similarly crenulated, without alae; their apices not spiral, the shell frequently arcuate. Type Ostrea crista-galli Linne. Eocene to recent. Subgenus Ostreola Monterosato, 1884. Valves with small, close radial riblets, less conspicuous on the upper valve, but ending on the margins with small crenuhe, otherwise as in Crassostrea. Type Ostrea stcntina Pay- reaudeau ; ex. 0. cqiicstris Say. Eocene to recent. Subgenus Gryph&osirea Conrad, 1865. Valves discrepant, the lower valve smooth or concentrically striate, larger, with incurved apex; hinge-line with a posterior and sometimes an anterior wing ; upper valve with distant elevated concentric laminae, flatfish or concave, with short apex ; the margins of the valves entire. Type Ostrea subcvcrsa Conrad = 0. cvcrsa (Mellv. ?) Conrad, + ? 0. vomer Morton. Eocene. As we recede in time the lines of demarcation between these groups gradually fade, and yet, even in the Cretaceous, species are found which illustrate them. The oldest type is that of Crassostrca. The group called Grypltcea is connected by slow gradations with Ostrea, but of the species which best illustrate GrypJuca none is known from Tertiary or recent faunas. Exogyra is a clearly distinct genus when confined to species with the typical characters. The subgenus GrypJiceostrea Conrad was founded on an Eocene shell closely resembling a French Eocene species (cf. Smithsonian Checklist Inv. Fos. ; Eocene, by T. A. Conrad, p. 33, 1866) and hardly distinct from the Cretaceous Ostrea vomer Morton. Subgenus GRYPH^A Lamarck. Gryphaa Lam., Syst., An. s. Vert., p. 398, 1801, ex pnrtc. Gryphaa Bosc, Hist. Nat. Coq., ii., p. 307, pi. 15, fig. I, 1802 ; Roissy, Hist. Nat. Moll., vi., p. 202, 1805 ; Cuvier, Regne An., ii., p. 459 ; Woodward, Man., p. 255, 1851. Gryphaa. (sp.) Lam., Hist. An. s. Vert., vi., p. 197, 1819 ; Fischer, Man. de Conchyl., p. 927, 1886. Gryphaa A. Blainville, Man. de Mai., p. 522, 1825. Pycnodonta F. de Waldh., Bull. Mosc., viii., 1835. (G. vcsicularis Lam.) Type Gryphcca arena/a Lam., Enc. Meth., pi. 189, figs. I, 2; not Gryphaa Sacco, Moll. Terz. Piem., xxiii., p. 21, 1897. FREE INSTITUTE OF- SCIENCE TERTIARY FAUNA OF FLORIDA 67; Although there are no true Gryphrcas in our Tertiary, the general con- fusion in the literature in regard to the type of this group, and its bearing on the nomenclature of the genus Ostrca seem to make it desirable to clear up the synonymy. Grypluza was described as a genus by Lamarck in 1801, no type being selected, but a number of species cited, part of which had been figured in other works, to which figures Lamarck applied names ; others were unde- scribed, and these names were, of course, IIOIIIIIM niit/a until such time as they might be habilitated. The figures to which Lamarck gave names were to be found in the Encyclopedic Methodique of Bruguiere, pi. 189; Bourget, Mem. hist. nat. petr., pi. 14, 15 ; anil Knorr, Naturg. Vcrst, ii., part I, pi. 20, 60, and 62. The first two columns of the following table show the original nomenclature of Lamarck and the figures upon which it was based. The names opposite the first in the third column show the equivalent names, and the fourth column references for the same fossils, used by Lamarck in 1819 when the manuscript species of the first list were first described. Only one reference is given in the second column for each of the first list of names, and preference has been given to the plate of the Encyclopedic, which has by far the most recognizable figures. Lamarck, 1801. Authority. Lamarck, 1819. No. Page. MS i 198 (j v///>f>; '/'/I ultifa Lam .... Knc f 34 (/ / ^ /it in l>ii Lam (/ t'vmhnla Lam K n pi °o f 7 (r t\'iiilni(in Lam •i 108 (/. arcnala Lam (f. africana Lam (/. carinahi Lam Knc., f. i, 2. Knc., f. 5, 6. B. 15, f. 89, 90. 1! 14 f 84 85 (/". arciMtti Lam G. x,-<-niiifii Lam (/'. filictitii Lam 4, 198 5- 199 8, 199 MS MS As Lamarck selected no type, the type must be sought from the first reviser. This was Bosc, in the following year, who cites the described species and figures as an example the G. aratata, which he refers to the Anoinia gryplius of Linne. The next author to treat the group was Roissy, who cites as examples G. snborbiculata and 6". arciiata, and figures the latter to illustrate the genus. TRANSACTIONS OF WAGNER 674 TERTIARY FAUNA OF FLORIDA He mentions that the G. angulata was still (1805) undescribed, and that it was not even known in what collection it then was. Cuvier follows in 1817, and gives a diagnosis of the genus and refers for illustration to plate 189 of the Encyclopedic, figures I and 2 of which were originally named by La- marck G. arcuata. It is certain that an undescribed species cannot be accepted as a type, and the type must be selected from the described species of the original list accord- ing to the rules of nomenclature. It would seem from the above notes that this type must be the G. arcuata or, if they are identical, the G. gryphus (L.), from which the genus derived its name. In 1819 Lamarck describes the genus again and gives a longer list of species, in which for the first time G. angulata is described. In this list, as the third column of the above table shows, nearly every one of the species of the original list had its name changed, for what reason is unknown ; while the reference to Encyclopedic, plate 189, figures i and 2, is transferred from G. arcuata to G. cymbium, perhaps by a copyist's error. To G. arcuata is added as a synonym G. incurva Sowerby, from the Min. Conch., ii., p. 21, pi. 112, fig. I, 1818. In his remarks Lamarck states that the group has long been known under the name of Gryphites, which is the name Linne applied to his Aiioinia gryplius in the Museum Tessinianum, 1753. In 1825, in the first section of his Grypluea, Blainville cites as examples Lamarck's G. cymbium (Enc. Meth., pi. 189, figs. I, 2) and G. arcuata Lam., which he figures to illustrate the genus. Woodward in 1851 cites G. incurva Sby. In spite of all this, we find in Gray, Fischer, Tryon, Stoliczska, and Sacco the assumption that G. angulata is Lamarck's type, an opinion entirely with- out proper foundation. Hanley and Salter, from an examination of Linne's type, refer it to the G. obliquata Sby. The relations of this to the G. arcuata I am unable to determine, and therefore retain the specific name of Lamarck. It is perhaps fortunate that G. angulata is not the type of Gryplicea, as anatomical and embryological investigation has shown that this species is simply an oyster of the same type as 0. virginica, and has only a slightly twisted beak to connect it with the fossils properly called Gryphcea. This fact was recognized by Sowerby as soon as he became acquainted with the species, and is now beyond question. The characters of this group can hardly be held to be generic, unless by FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OK FLORIDA those who are disposed to make a genus of every well-defined species. In allowing it even a subgcncric place I feel that I am giving it more than its just rank, in view of its very feeble distinctive characters. Origin of the Mutations of Ostrea. The oysters are a proverbially difficult group, owing partly to their adherent situs and partly to the fact that they have not hitherto been studied with regard to the direct influence of the environment on individual specimens. That this is very great I have convinced myself from a prolonged study of a multitude of specimens of 0. virginica of which the provenance was known, and of many hundred specimens of our Tertiary species, which usually show from the character of the scar of attachment something of the circumstances in which they grew. The conclusions to which I have been led by this study may be regarded as in part provisional, but in the main highly probable, and as furnishing a first contribution to the sort of study which is essential if we would understand the processes of nature through which these animals acquire their most conspicuous external characters. They may be regarded as especially applicable to the Crassostrea group. Leaving out of account the nepionic characters, the characteristics of the adult shell may be summarized and derived as follows : The most permanent characters of the shell, and the best, if not infallible, guide to specific recog- nition among the puzzling mutations a large series presents, are the form of the hinge-margin, the minute sculpture of the superficial layer of the shell ("Urn denuded in otherwise perfect fossils), and the sculpture of the valve- margins near the hinge and on each side of it. While not invariable in all specimens, these characters, taken together, will usually enable one to refer the individual to its proper place. The characteristics due to situs may be partially summarized as follows : When a specimen grows in still water it tends to assume a more rounded or broader form, like a solitary tree compared with its relatives in a crowded grove. When it grows in a tideway or strong current the valves become narrow and elongated, usually also quite straight. Specimens which have hern removed from one situs to the other will immediately alter their mode of growth, so that these facts may be taken as established. When specimens arc crowded together on a reef, the elongated form is necessitated by the struggle for existence, but, instead of the shells being straight, they will be irregular, and more or less compressed laterally. When the reef is dry at 8 TRANSACTIONS OF WAGNER 676 TERTIARY FAUNA OK FLORIDA low stages of the tide, the lower shell tends to become deeper, probably from the need of retaining more water during the dry period. Such oysters are the so-called " raccoon oysters," a name which they get from the visits of that animal at low water to feed upon them. The so-called " raccoon oysters" figured in Dr. C. A. White's Review of the Ostrtidce (Ann. Rep. U. S. Geol. Survey, 1883, pi. 81-2) are not the reef oysters which first acquired this name, but deep-water specimens which had grown in a place where they were subjected to current action. When an oyster grows in clean water on a pebble or shell, which raises it slightly above the bottom level, the lower valve is usually deep and more or less sharply radially ribbed, acquiring thus a strength which is not needed when the attachment is to a perfectly flat surface which acts as a shield on that side of the shell. Perhaps for the same reason oysters which lie on a muddy bottom with only part of the valves above the surface of the ooze are less commonly ribbed. When the oyster grows to a twig, vertical mangrove root, or stem of a Gorgonian, it manifests a tendency to spread laterally near the hinge, to turn in such a way as to bring the distal margin of the valves uppermost, and the attached valve is usually rather deep, the cavity often extending under and beyond the hinge- margin ; while the same species on a flattish surface will spread out in oval form with little depth and no cavity under the hinge. The average life of the ordinary O. virginica when " planted" for sale is about four or five years. In prehistoric times when the reefs were un- ' disturbed the favored individual might attain a much greater age ; in which case the lower valve especially took on excessive thickness, and the cavity of the shell often became considerably elongated and somewhat hourglass- shaped, as in 0. contracta Conr., whose characters in 'typical specimens arc distinctly senile, while younger specimens of the same species have the normal form. In the hinge of the oyster the resilium occupies the central ridge, while the ligament covers the edge of the depressions on each side of that ridge. The form and relative position of the muscular scar of the adductor is within certain limits a useful character, but its depression below the general interior surface of the valve or its occasional elevation above it, as in riicatnla, is of no systematic value, being merely a corollary of the rate of growth from the various secreting surfaces. The habit of rapid growth, causing a vesicular character of the shell substance, is more pronounced in some species than in others, and in some specimens of a species than in others ; it is rarely the FREE INSTITUTE OF SCIENCE 677 TERTIARY FAUNA OK FLORIDA case that this habit (as in 0. percrassa Conr.) has attained a constancy entitling it to systematic significance. Having thus pointed out some of the features which are liable to mislead the student in estimating specific values, we may proceed to consider the species of our Tertiary. Ostrea crenulimarginata Gabb. (>. i-i-cnitliinarifiiiata Gabb, Journ. Acad. Nat. Sci. Phila., 2d Sen, iv., p. 398, pi. 68, figs. 40, 41, 1860. .' (>. licnticiilifcra Conr., Journ. Acad. Nat. Sci. Phila., 2d Ser., iii., p. 330, pi. 34, fig. 18, 1858. (>. prtecompressirostra Harris, Rep. Ark. Geol. Surv., ii., p. 39, 1894. (). tiimidnla Aldr., Rep. Geol. Surv. Ala., p. 242, pi. 14, figs. I, 2, pi. 15, figs. I, 2, 1894. Midway stage of the southern Eocene, from the well at Little Rock, Arkansas; Prairie Creek, Wilcox County, Alabama; and the Chattahoochie River, near the mouth of Pataula Creek, Alabama. Conrad's species is described from a specimen too young to show its specific characters ; otherwise it is probably identical with that of Gabb. Ostrea pulaskensis Harris. 0. pulaskensis Harris, Rep. Ark. Geol. Surv., ii., p. 40, pi. I, fig. 3, 1894. Midway horizon, at various points in Arkansas. This species is represented in the collection by rather poorly preserved and young material which leaves a suspicion that it is extremely closely allied to 0. tliirsic Gabb, though not sufficient to show their identity. The valves recall the lower valve of 0. subevcrsa, but have no auriculation. Ostrea sellseformis Conrad. O. scllicfonnis Conr., Fos. Tert. Form., p. 27, pi. 13, fig. 2, 1832 (upper valve). O. radians Conr., loc. fit., fig. I (lower valve). O. divaricata Lea, Contr. Geol., p. 91, pi. 3, fig. 70, 1833. 0. si-Hii/ittiii/a Lea, op. cit., p. 90, pi. 3, fig. 69, fide Conrad. O./it/fij'dnnis Conr., Am. Journ. Conch., i., p. 140, pi. xi., fig. I, 1865 ; Proc. Acad. Nat. Sci. Phila. for 1863, p. 291. ('. tini;na-fftis \Vhitficld, Lam. Kar. Clays, p. 223, pi. 29, fig. I, 1885. (). i£/itiif<>iii>i. piiii't'i'iii! Lea, op. (//. , p. 92, pi. 3, fig. 73, 1833. (Misprinted pincera, princt-rna, and pinccinii in various works.) (>. c>rUi,,-a Morton (fx part,-}, Syn. Org. Rem., p. 52, pi. 19, fig. 3, 1834. (). ln-iu-!isis (Conr. MS.), Harris, Bull. Pal., i., pp. 3, II, 1895. .' (>. sciniliinata Lea, Contr. Geol., p. 90, pi. 3, fig. 69, 1833. Eocene of Claiborne and Gosport, Alabama ; Oligocene of Vicksburg, Mississippi, and perhaps of Florida and California. The reason why the name sciniltinata was not originally adopted for the synonymous oysters of Lea was partly on account of a suspicion that the type of sciniliinata was a worn, immature specimen of sellceformis , and partly because the name is less appropriate. There is no reason why the original decision should be changed at present. The 0. alabainieiisis, when its outer layer is preserved, shows, as noted by Cossmann, fine radial grooving, which is usually lost with the thin dehis- cent coating referred to. The species which is here termed 0. mauricicnsis would form a direct continuation of the line of the alabamiensis, and it is not impossible that they should be specifically united, but I have never been able to obtain an absolutely complete specimen of Gabb's shell, so as to see if the prismatic layer agreed. From mauriciemis to virginica the gap is hardly noticeable. The Californian oyster which has been called 0. Tayloriana Gabb is suspiciously close to the present series. Ostrea compressirostra Say. (>. t;iiiipi;-^ii-ii.tti-ij Say, Journ. Acad. Nat. Sci. Phila., iv., p. 132, pi. viii., fig. 2, 1824. (.',1-yplni-a iinitahi/is Morton, Journ. Acad. Nat. Sci. Phila., vi., p. 81, pi. iv., fig. 3, 1828; Synops. Org. Rem., p. 53, pi. iv., fig. 3, 1834. <>. siinuixa Rogers, Trans. Am. Phil. Soc., N. S., v., p. 340, 1831, and vi., pi. xxvii., fig. i, 1839. (). disparilis Conr., Medial Tert., p. 51, pi. 26, 1840. O. 'J'ttt»n,-vi Conr., I 'roc. Acad. Nat. Sci., ix., p. 184, 1865 (not of Coquand, 1869, Mon. Ostr., p. 68). .' O, piiiiilifiirniis Aklr., Journ. Cin. Soc. Nat. Hist., p. 79, 1887, as of C.abb, Proc. Acad. Nat. Sci. Phila. for 1861, p. 328, 1862. <>. Kt<-/ri,t Tuomey and Holmes, Pleioc. Kos. S. C., p. 21, pi. 6, fig. i, 1855 ; Conr., I'roc. Acad. Nat. Sci. Phila. for 1863, p. 582. O. /i,-//,i7;i,-t/i,i Conr., Hull. Nat. Inst., ii., p. 172, 1842, not of Lamarck. Eocene : of Piscataway Creek, Upper Marlboro, and Leland, Prince George County, Maryland; lower bed Aqtiia Creek, of Evergreen, Glost. r City, City Point, and Coggins Point, Virginia; also on the Eastern Shore of TRANSACTIONS OF WAGNER 680 TERTIARY FAUNA OF FLORIDA Virginia, Fort Washington, Virginia, in the North Carolina Kocenc, and that of Bell's Landing, Alabama ; a variety alepidota, without raised lamellae externally but with radial grooves, is noted from Aquia Creek and the South Carolina Eocene. Oligocene: of the lower bed at Alum Bluff, Florida. Miocene : of the upper bed at Alum Bluff, Florida ; of Grove, St. Thomas, Cooper River, and Darlington, South Carolina; Snow Hill and Duplin County, North Carolina; Grove Wharf, James River, and the Nansemond River, near Suffolk, Virginia, and Imlaytown, New Jersey. Pliocene : of Peace Creek, near Arcadia, Florida ? This well-known shell, though not exceptionally variable, has had many names. A specimen of Gryphcza mutabilis Mort, given by Dr. Morton to Dr. Lea and agreeing precisely with Morton's figure and description, is simply a somewhat worn, smoothish specimen of this species. There is little or no uncertainty about the other synonymes. It is first distinctly noted in the upper bed at Bell's Landing, Alabama, in the Chickasawan series, whence it occurs through the Eocene, Oligocene, Lower and Upper Miocene, and even, if one or two rather poor specimens can be referred to it, in the Pliocene sands of south Florida. These last may be Miocene redeposited. The specimens from Virginia which grew under advantageous circumstances are often widely alate with much elevated, elegantly fluted concentric lamellae. The average specimen, however, has uch less prominent alas and imbrications. Comparatively smooth specimens ^\ are very close to 0. trigonalis. Ostrea thirsae Gabb. Gryphcfa thirsa Gabb, Proc. Acad. Nat. Sci. Phila. for 1861, p. 329. Ostrea thirsce Heilprin, Ann. Rep. U. S. Geol. Surv. for 1883, p. 311, pi. 63, figs. 4, 5, 6, 1884. Eocene of the lower Chickasawan series at Nanafalia Bluff, Tombigbee River, and at Eufaula, Alabama. This appears to be a well-marked species, smooth with hardly any tendency to plication, almost nautiloid in form, and belonging to the same group as the next species. Ostrea Johnsoni Alclrich. O. Johnsoni Aldr., Geol. Surv. Ala., Bull, p. 41, pi. 6, fig. 6, 1886. Lower Claibornian Eocene of the Monroe County, Alabama, calcareous HREE INSTITUTE OF SCIENCE 68 1 TERTIARY FAUNA OF FLORIDA sand bed ; Claiborne, Lisbon, and Newton, Alabama, and at Caton's Bluff, Conccuh River, Alabama. This is an excellent species with a few strong plications, making the valves claw-like; otherwise close to 0. tliirsce. Ostrea (G-ryphseostrea) subeversa Conrad. (',>-\'plui-i>sti-,-<> subrt'crsa Conr., Am. Journ. Conch., I, p. 15, 1865; Checkl. Inv. Fos. Eocene, p. 33, 1866. Grvpltostrca t-Ti-rsa (Deshaycs) Conr., Checkl. Inv. Fos. Kocene, p. 3, 1866. th/n;i ,"!',-rsti (Mellv.) Heilprin, Ann. Rep. U. S. Geol. Surv. for 1883, p. 310, pi. 64, figs. 5-8, 1884. ? Gryphtea vonifr Morton, Synops. Org. Rem., p. 54, pi. ix., fig. 5, 1834; not in Joura. Acacl. Nat. Sci. Phila., vi., pi. v., figs 1-3, 1828. Cf. Ostrea latt-ralis Xilsson, Petr. Suec., p. 29, pi. 7, figs. 7, 10, 1827, and Gryphcea can- alifiilata Sby., Min. Conch., pi. 26, fig. I, 1812 (as C/iama). ? Cretaceous of the lower Greensand and upward in New Jersey, espe- cially near New Egypt. Eocene of Upper Marlboro', Maryland, Conrad ; Jacksonian Eocene of Fail Post-Office, and the Zcuglodon bed at Cocoa Post-Office, Choctaw County, Alabama. This species is worth more thorough study by some one familiar with the Cretaceous forms of both Europe and America. Its relations are merely indicated by the above synonymy. Ostrea trigonalis Conrad. (h/mi tiigniu/is Conr., Proc. Acacl. Nat. Sci. Phila., vii., p. 259, 1855; Wailes, Geol. Miss., p. 289, pi. xiv., fig. 10 (bad), 1854; Lesueur, Walnut Hills Fos., pi. 4, fig. '7. pl- 5. fig- ', l829- f O. Attwooilii, C,al)b, Pal. Cal., ii., pp. 33, 106, pl. 10, fig. 58, pl. II, fig. 58 />, 1869. t (i. sn/'j,rta Conr., Pac. K. R. Rep., vii., pt. i, p. 193, pl. 2, fig. 3, 1857. (Young shell.) Upper (Jacksonian) Eocene of Jackson, Mississippi ; Fail Post-Office and Cocoa Post-Office, Choctaw County, Alabama; Turks Cave, Alabama; Hinds County, Mississippi ; Creole Bluff, Grant Parish, Louisiana. Lower Oligoccne (Vicksburgian) of Vicksburg, Mississippi ; Upper Oli- gocene of White Beach, Little Sarasota Bay, Florida, and Oak Grove, Santa Rosa County, Florida. Miocene of Greensboro', Choptank River, Maryland ; Edgecombe County, North Carolina. TRANSACTIONS OF WAGNER 682 TERTIARY FAUNA OF FLORIDA Pliocene of Peace Creek, near Arcadia, and Alligator Creek, Florida. The original figure of Conrad is very poor. The species is widespread and recognized by its flat upper valve, few-ribbed lower valve, straight hinge- line, flat hinge-area, with excavated central channel and the peculiar vermicular sculpture of the submargin on each side near the hinge-line. It is not im- probable that O. pcrcrassa Conrad is a peculiar local race of this species and that 0. Mortoni Gabb and 0. vicksfatrgensis Conrad are young pebble-grown shells of the same species as the large, well-grown specimens which I regard as normal trigonalis. The differences are, however, so marked that it is probably best to keep them separate for the present, until more is known. 0. subtrigonalis of Evans and Shumard is a Cretaceous species. Varieties of 0. coinpressirostra approach very closely to this species. Ostrea vicksburgensis Conrad. O. vicksburgensis Conrad, Proc. Acad. Nat. Sci. Phila., iii., p. 296, 1848 ; Journ. Arad. Nat. Sci., 2d Ser., i., p. 126. pi. 13, figs. 5, 37, 1848. O. panda Morton, Syn. Org. Rem., p. 51 (ex pcerte), pi. 19, fig. 10, 1834. O. Mortoni Gabb, Proc. Acad. Nat. Sci. Phila., p. 329, 1861. Jacksonian Eocene of Fail Post-Office and Cocoa Post-Office, Choctaw County, Alabama; Eocene of South Carolina and Clarksville, Alabama; Vicksburgian Oligocene of Vicksburg, Mississippi ; Burns and Johnson. As previously noted, this species is probably an offshoot of 0. trigonalis. The Vicksburg type differs from the Jacksonian only in having the ribs less imbricated and more rounded, a distinction which is not constant. Ostrea falco Dall. PLATE 30, FIGURES 4, n. O. falco Dall, Proc. U. S. Nat. Mus., xviii., p. 22, 1895. Jacksonian Eocene of Cocoa Post-Office, Choctaw County, Alabama, in the Zeuglodon bed ; Burns and Schuchert. This remarkably distinct species is well characterized by its cellular lower valve, radiately striate, flat, arcuate, and hooked upper valve, and the strong denticulations of the submargin. Held horizontally, the profile of the upper valve is remarkably like that of the head of a raptorial bird, and this form is exceptionally constant. Ostrea podagrina Dall. PLATK 30, KICUKES 5, t>. O. podagrina Dall, Proc. U. S. Nat. Mus., xviii., p. 22, 1895. FREE INSTITUTE OF SCIENCE 683 TERTIARY FAUNA OF FLORIDA Upper Eocene of the west bank of the Suwanee River, near the Sulphur Spring, Florida; Eldridge. This singular species differs from 0. pcrcrassa and heavy specimens of (). trigonalis in its few strong plications and the rounded lateral portions of the hinge-area, which in the above-mentioned species are conspicuously flat. Ostrea percrassa Conrad. <>. fit'fi'nis.tii Conr., Fos. Mcd. Tert., p. 50, pi. 25, fig. I, 1840; I'roc. Acad. Nat. Sci. 1'hihi., xiv., ]>. 582. ? Eocene of Wood's Bluff, Alabama, and near Lawrence, Mississippi; L. C. Johnson (var. syhi&rupis Harr.). Miocene of Stow Creek, Cumberland County, New Jersey, Conrad; of Shiloh and Jericho, New Jersey, Burns ; of Magnesia Spring, Alachua County, Florida, Burns. This species in its typical form is of a porous and vesicular texture, giving the extremely thick shell a surprisingly light weight. Specimens from the southern Eocene cited above have the same form and characteristics, but the usual dense and heavy shell of other oysters. These latter might be taken for exceptionally thick and senile specimens of O. trigonalis, which in that case would figure as the original stock of 0. percrassa. This completes the list of positively Eocene species ; the 0. panzana Conrad (P. R. R. Rep., vii., pt. I, p. 193, pi. 2, fig. 4, 1857 + 0. pansa Conr. (err. typ.), 1 866), which was doubtfully referred to the Eocene by Conrad, is a perfectly unidentifiable species described from a worn and extremely obscure type now in the National Collection, but which probably belongs to a horizon later than the Eocene. Ostrea georgiana Conrad. (>. i;'i't>ri;'ia>iii Conr., Journ. Arad. Nat. Sci. I'liila., 1st Scr., vii., p. 156, 1834 ; Dana, Man. Ociil., 1st ed., p. 519, fig. 811, 1863. O. <-(>tilr. titan Conr., I'roc. Arad. Nat. Sci. 1'hila., vi., p. 199, icS,4 ; I'ac ific R. R. Rep., vi., p. 72, pi. i\., fig. 17 a, pi. v., fig. 17 a, 1857. Oligocene of the lower bed at Vicksburg, Mississippi, and Choctaw Bluff on the Alabama River, Alabama ; also at Clarksville, Alabama, and Shell Bluff, Savannah River, Georgia; Miocene of Oyster Point, upper Rio Grande, near Roma, Mexico; Martinez, California; Roberts Ferry, near New Berne, North Carolina. TRANSACTIONS OF WAGNER 684 TERTIARY FAUNA OF FLORIDA - The different names under which this gigantic oyster has been known are seen to be founded chiefly on geographical reasons as soon as the types are compared. The characters of the shell are all explainable by the effect of age and situs, so far as they differ from one another. The figuring of a typical specimen in Dana's Manual has generally been overlooked. The typical 0. georgiana are the enormous senile specimens with shells ranging to two feet long and three or four inches thick. The young and really more normal specimens have been overlooked, though much more abundant, or referred to other species, chiefly 0. virginica, from which they differ by their more elongated, usually straight, deeply excavated cardinal area and the absence of ribbing on the lower valve in most specimens. Ostrea georgiana, forma normalis. O. wauricensis Gabb (ex parte), Journ. Acad. Nat. Sci. Phila., 2cl Ser., iv., p. 376, pi. 67, fig. 26, 1860. O. Bourgeoisie Remond, Proc. Cal. Acad. Sci., p. 13, 1863 ; Gabb, Pal. Cal., ii., p. 33, pi. 1 1, fig. 57, 1869. O. Tayloriana Gabb, Pal. Cal., ii., p. 34, pi. 12, fig. 60, 1869. Oligocene of Shell Bluff, Savannah River, Georgia; of Martin Station, Florida ; White Sulphur Spring, Suwanee River, Hamilton County, Florida ; six miles southwest of Gainesville, Alachua County, Florida; La Penotiere's hammock, near Orient, Tampa, Florida; Nigger Sink, Newnansville; Devil's Millhopper, near Hawthorne; Sullivan's old field, Levy County; Johnson's Sink, Levy County; Magg's Springs, Alachua County; silex beds of Ballast Point, Tampa Bay; Rock Bluff, Appalachicola River, Calhoun County; red clay (so called Lafayette formation) over the Oak Grove marl, Santa Rosa County, Florida, and lower bed at House Creek, Georgia. Lower Miocene marl of Shiloh and Jericho, Cumberland County, New Jersey, and near Wilmington, North Carolina; Miocene of California and New Mexico. It is not unlikely that to the above synonymy should be added 0. vclcn- iana Conrad (a typographical error for helcniana) of the Mexican Boundary Report, 1857, and the unrecognizable 0. panzana and 0. robitsta Conrad, 1857. The 0. Tryoni Gabb (1881), from the Miocene of Costa Rica, appears to be a well-characterized species. The young 0. georgiana Conrad is the characteristic fossil of the Upper Oligocene of the Gulf States often found in northern Florida scattered over FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA l ^ the surface of the Vicksburg limestone from which the Upper Oligocene marl has been dissolved away. It is the " leit fossil" of the Grand Gulf beds, though not confined to them, and occurs in the single meagcrly fossiliferous bed below the Altamaha grits. The specimens are usually in poor condition superficially, having the exterior and often the interior vermiculately eroded. It occurs but rarely in the true Miocene, where it seems to become modified into the early type of 0. virginica, which is not improbably its direct de- scendant. In old Post-Pliocene beds or oyster reefs it is not uncommon to find enormously thickened senile specimens of 0. virginica which present many of the features of the Oligocene 0. georgiana. /• Ostrea haitensis Sowerby. <). Jmiti-iisis Sby., Ouart. Journ. Geol. Soc., vi., p. 53, 1850. (). /iiiv/i'iisi.\ •('•;ibb, Trans. Am. I'hil. Soc., 1873, p. 257. O. Veatiliii (i;ibb, l';il. CaL, ii., p. 34, pi. II, fig. 59, pi. 17, fig. 21, 1869. O. llei-rmanni Conr., Proc. Acad. Nat. Sci. 1'hila., v., p. 267, 1853; Pac. R. R. Rep., v., p. 326, 1855. 0, ;'<-. virgiiiifii var. falifornica Marcou, Geol. N. Am., 1858. Oligocene of Haiti, of the Bowden marl of Jamaica, of the Chipola beds of Calhoun County, Florida, and of the Oak Grove marl, Santa Rosa County, Florida. Miocene (?) of Carrizo Creek, Colorado Desert, California, and of various other localities in California. Gabb recognized the identity of his 0. Veatchii with the St. Domingo species, and a comparison of Carrizo Creek specimens adds the unfigured 0. llccrinanni to the list of synonyms. The O. vespertina was described from young shells from the types in the National Museum, and there can be no question of their identity. It is to be discriminated from its associated 0. Atfa'oodi, which has a smooth upper valve, by the fact that both valves are similarly plicated. Ostrea megodon Hanley. O. nit'g<>t/t>n Hanley, P. /. S., 1845, p. 106 ; Reeve, Conch. Icon., Ostrea, pi. xii., fig. 24 d-/>, 1871. <>. >;.). TRANSACTIONS OF WAGNER 686 TERTIARY FAUNA OF FLORIDA Oligocene of St. Domingo and of the Bowden marl, Jamaica; Mio- cene (?) of Cerros Island, off Lower California ; Post Pliocene of Lower Cali- fornia. Recent in the Gulf of California at Acapulco and southward. This is one of the types which were exterminated on the east coast of America by the disturbances which united the two continents and cut off access to both oceans, and which survived to the present fauna on the western side of the continent as united. It appears to be rare in the Oligocene, but the type is much older and is represented in the Cretaceous by O. falcata Morton. Ostrea carolinensis Conrad. O. carolinensis Conr., Fos. Tert. Form., p. 27, pi. 14, fig. i, 1832. Eocene of South Carolina ? Miocene of the Santee Canal, South Carolina, Ravenel ; and of the Choptank River, Maryland, Burns and Harris. The original reference of this species to the Eocene is probably erro- neous. The species, represented by some of the original Santee specimens in the National Collection, has only been definitely recognized from the Lower Miocene. It appears to be a sufficiently distinct species, nearly related to 0. tri- gonalis. Ostrea sculpturata Conrad. O. sculpturata Conr., Medial Tert., p. 50, pi. 25, fig. 3, 1840. O. virgin in/in Conr., Fos. Tert. Form., p. 28, pi. 14, fig. 2, 1832 ; not of Lamarck. O. subfalcata Conr., Medial Tert., p. 50, pi. 25, fig. 2, 1840. O. virginianti Tuomey and Holmes, Pleioc. Fos. S. Car., p. 20, pi. 5, figs. 7-9 (fig. 6 excl.). O. fn-rlirata Conr., Kerr, (icol. Rep. N. Car., App., p. 18, 1875. O, meridional:* Heilprin, Trans. Wagner Free Inst. Sci., i., p. 100, pi. 14, fig. 35, 35 a, 1887. Miocene of Coggins Point, Petersburg, Nansemond River near Suffolk, York River near Yorktown, and the north end of the Dismal Swamp, Vir- ginia; of Wilmington, Snow Hill, the Natural Well of Duplin County, Mag- nolia, Duplin County, and the Ncuse River ten miles above New Berne, • North Carolina; of Darlington, South Carolina, and De Leon Springs, Florida. Pliocene of the Waccamaw beds, South Carolina, and the marls of the Caloosahatchie, Shell Creek, and Alligator Creek, Florid, i. FREE INSTITUTE OF SCIENCE 687 TERTIARY FAUNA OF FLORIDA Ostrea virginica C.melin. l>. -,'ii-^iniitna of Lister and other nonbinomial writers. O. I'ir^iiiica (Imclin, Syst. Nat., ]). 3336, 1792 ; Dillwyn, Dcscr. Cat., i., p. 277, 1817 ; Lam., An. s. Vert., vi., p. 207, 1819. O. cthilis Akcrly, Am. Monthly Mag., ii., p. 296, 1818 ; not Linnc. O. virgin iii Hit Shy., Genera, Ostrt'it, I. 2, 1822. O. bflri-alis Lam., An. s. Vert., vi., p. 204, 1819. O. ciiittiiti-iisis Lam., of>. fit., p. 207, 1819. O. frion^iiliins Holmes, Proc. Elliott Soc., i., ]). 29, 1856. O.fitndata Holmes, Post-PL Fos. S. Car., p. u, pi. 2, fig. 10, 1858. .' O. si'iiiicvlindi-ifii Say, Journ. Acad. Nat. Sci. Phila., 1st Ser., ii., p. 258, 1822. Miocene of Cumberland County, New Jersey? Pliocene of the Caloosahatchie and Myakka Rivers, Florida ; Post Pliocene of the Atlantic and Gulf coasts from Prince Edward's Island to Florida, Texas, and California. Recent from Prince Edward's Island south to Florida and west to Mexico, and on the west coast of Mexico near the head of the Gulf of California. This well-known species occurs positively in the Pliocene of Florida, but the Miocene citations require revision. Specimens from the New Jersey marls received from Professor Whitfield under this name were cither 0. georgiana mut. mauricensis or the young of 0. percrassa. Most of the southern species thus named are bfetter placed elsewhere. Say does not appear to have pub- lished any Ostrea fundata, though the name has been used on his authority by Ravenel and Holmes. The long current-bred specimens, by confusion with those which have become elongated by mutual compression, have received the varietal name of procyon from Holmes. The same shell appears to be the 0. rhizophora of Guilding and Reeve, though not 0. rhizophora of Dillwyn. The 0. linida Cpr. (1863) and 0. palmula Cpr. (1857) with its variety conchaphila Cpr. (1857) are known from the Post Pliocene of the Pacific coast. I have not yet seen 0. folium Linne or 0. cqucstris Say, in the fossil state, on the east American coast. 0. solea Conrad appears to be a mere list-name, never figured or tie- scribed. 0. Titomcyi Coquand (Mon. Ostrea Terr. Cret., p. 68, 1869) was proposed for the preoccupied name of crennlata Tuomey, but Conrad had already used the specific name of Tnomeyi (1865) for a fossil oyster from Mississippi, so if the Coquandian fossil is a good species it will require a new name. TRANSACTIONS OF WAGNER ,688 TERTIARY FAUNA OK FLORIDA 0. panda for mis Gabb, 1862, an unfigured, supposedly Cretaceous, species, is regarded as unidentifiable by Dr. C. A. White, but is considered by Aldrich to be Jacksonian and identical with 0. Titomeyi Conrad. It is, perhaps, from Aldrich's remarks, a form of trigonalis. Gryphcea athyroidca Guppy (1866), from the Tertiary of Trinidad, appears to be a true Ostrca and distinct from any of the continental species. I have not attempted to make comparisons with the European species, as that would require a series of the latter, which is not accessible, but a casual inspection of the figures does not give the impression that there are many of them which might be identical with American forms. Superfamily NAIADACEA. FAMILY UNIONID^. Genus UNIO Retzius. Unio (Unio) caloosaensis n. s. PLATE 25, FIC.URES 6, 12 a. Pliocene marls of the Caloosahatchie River, Florida ; Ball. Shell oblong-ovate, rounded in front, somewhat pointed at the ventral angle behind, umbonal region only moderately prominent, sculptured with numerous fine concentric wrinkles and seven or eight wavy, sharply elevated, narrow, concentric ripples ; the latter are most prominent on the line of the posterior angle of the valves, on each side of which the ripple recedes, per- ceptibly making a small sinus, more conspicuous than any o/ the small fluctua- tions of the rest of the ripple; sides moderately compressed; ventral margin gently arcuate, straight, or slightly incurved just in front of the posterior angle which forms the ventral boundary of the posterior dorsal area ; posterior end rounded above, slightly rostrate ventrally ; valves solid, nearly smooth, or with more or less irregular incremental sculpture and faint traces in some specimens of obscure radial lines near the posterior ventral angle ; interior with strongly impressed pallial line and muscular impressions ; " cardinal" teeth short, the ventral one usually stouter in the right and the dorsal in the left valve ; laterals low, solid. Lon. 57, diam. 20, alt. 32 mm. This species, though usually defective, is not uncommon in the marls and sometimes with the valves in their natural position. The species belongs to the group of Unio Biickleyiot the recent fauna, which is abundantly represented in the Floridian lakes. Having submitted it to Mr. Charles T. Simpson, who FREE INSTITUTE OF SCIENCE 689 TERTIARY FAUNA OF FLORIDA has made a specialty of these mollusks, he has expressed the opinion that it is undescribed. It is somewhat singular that this is the only Tertiary species of I'nio known from east of the Mississippi in the United States. There are a number of Post-Pliocene species, including those from the New Jersey clays, which were long regarded as Cretaceous. Superfamily PECTINACEA. FAMILY PKCTINIDyE. Genus PECTEN Miiller. /',;•/,•>! (Klc-in, 1753) Miiller, Prodr. Zool. Dan., p. 248, 1776; Da Costa, Brit. Conch., p. 140, 1778; Ilolten, Mus. licit., ]). 165, 1798; Lamarck, Prodr. d'un Nouv. Class. Coq., p. 88, 1799. Type Os/iva iiia.viina Linne. The name Pcctcii is very ancient, and appears in the prelinnean literature colloquially. Although Linnc himself did not formally adopt it as a genus, he has used the term casually in some of his minor papers. It was first introduced into binomial literature by Miiller. An excellent discussion of the characters of the group by Verrill appears in the Trans. Conn. Acad. Sci., vol. x., pp. 41-57, 1897. The genus has been repeatedly subdivided and the number of groups which have been named, chiefly on the shell characters of recent species, is very large. As might be expected, when the fossil forms arc taken into consideration, the groups merge into one another by insensible gradations, and so far as I have been able to examine the anatomy the same is true of it also, while the minor differences of the gross anatomy do not appear to be at all strictly correlated with the superficial modifications of the shell. Like Conns, as demonstrated by Bergh, the Pectens seem to form a natural genus with a profusion of minor modifications, which maybe separated for convenience into sections and subgenera, but possesses within certain general limits very uniform characters. The value of the named groups will differ with the personal equation of those who deal with them, but it appears impossible, when the fossils arc included, to draw lines of generic demarca- tion which shall be clear-cut yet not in violation of nature. In various geological horizons, as well as in the existing fauna, certain species of Pcctcn assume a sessile habit, involving an irregular subsequent growth of the valves after attachment to other objects, as in Hiiuiites. These species have no necessary genetic connection with one another except what they gain from their relations to the Pectinida as a group, and must be regarded as purely sporadic adjustments of individual forms to a particular environment. TRANSACTIONS OF WAGNER 600 TERTIARY FAUNA OF FLORIDA The shell of Pccten comprises two general!}' more or less discrepant valves, united along a long, straight hinge-line by an inconspicuous ligament and a central strong resilium. A single rounded adductor leaves its impression pretty high up, a little before the mesial line of the valves, and the pedal retractors are usually attached to the left valve above it, being often obsolete on the right side. The ends of the resilium are received by subtriangular or oval pits in the umbonal region. These pits may be shallow or deep ; their basal margin sometimes projects slightly into the cavity of the valves; their apex is always nearly coincident with the umbonal point of the valve. In a few species, in the right valve, the lateral margins of the pit are raised into tooth-like processes, which fit into corresponding depressions in the opposite valve (e.g., P. Swiftii Bernh.), but these are not homologous with the so-called teeth of Plicatitla and Spondyhts. Outside of these, radiating fan-like from the apex of the valve, are frequently found one to three pairs of more or less prominent lamina;, which I call the cardinal crura, and further away and below, on the ridges which mark the lower boundary of the ears, will some- times be found another pair, only distally conspicuous, which I have named the auricular crura. The cardinal crura are most conspicuous in heavy shells, especially such as Pecten proper and Lyropccten, and serve to adjust the closing of the valves, as does the hinge armature of the Teleodonts. In a few species the crura are sufficiently prominent to actually interlock with the valves half open ; in many others hardly any trace of them is visible. Almost all species possess in the nepionic stage a well-marked provinculum, formed by an elongated area on each side of the pit, covered by long, narrow, close-set taxodont teeth, separated by narrow grooved interspaces. In most species the provinculum is evanescent or represented in the adult only by faint vertical stria:, which cross the cardinal crura. In a few small, thin-shelled, mostly deep-water species, the provinculum is persistent and functional (c. g., P. thal- assimun Dall), forming an interlocking hinge. In Pccten proper, Clilamys, and some other groups, the upper cardinal margin of the right valve is bent over that of the left valve. There are occasional species in which the adult valves have each a flat area along the whole cardinal margin, covered by the ligament and forming a V-shaped groove between the upper margins of the valves, as in P. Swiftii. The disk of the valve is usually rounded or oblique below and at the sides, but above continued on each side in a straight line to the umbo. The shell adjacent to these straight lines is frequently slightly different in sculpture from the rest of the disk, forming narrow areas, which were called FREE INSTITUTE OF SCIENCE 691 TERTIARY FAUNA OF FLORIDA by Conrad the " submargins." Above the submargins the auricles, or ears, project, usually differentiated by a linear depression ending in a sinus below. This sinus is sometimes absent in the posterior ears, as it is in the very young stages of tlie shell, but it is not an important systematic character, since the same species (<•. ti>isns Dall. Section Nodipcctcn Dall, 1898. Type /'. nodosiis L. Shell like Lyropcctcu, but the ribs intermittently nodose, with more or less prominent hollow nodes or bullae ; radial striation pronounced ; ears unequal, the posterior smaller, the valves often more or less oblique ; imbricate surface layer sometimes very marked. Section Chlainys s. s. Type P. islandicus Miiller. •v^ Ribs small and numerous, imbricate or spinose; valves subequal, similar, oblique, or with unequal cars, the posterior smaller; Camptoncctes striation aiul imbricate surface layer usually present ; shell usually solid and opaque; byssal notch and ctenolium present. Section .1;.tjiiipectcn Fischer, 1887. Type P. opcrcttlaris L. Shell thin, orbicular, with subequal inflated valves, usually equilateral, with uniform, well-marked radial, not dichotomous, ribs and finely imbricate radial striation; ears subequal ; valves internally lirate on the edges of the TRANSACTIONS OF WAGNER 696 TERTIARY FAUNA OF FLORIDA grooves corresponding to the external ribs ; Camptonectcs striation present, but usually obscured by the radial sculpture; ctenolium and byssal notch obvious. Section Plagioctcnium Dall, 1898. Type P. ventricosits Sby. Resembling sEqitipectcn but without radial striation ; the concentric sculpture in looped lamellae; the ribs strong, frequently smooth above; the submargins impressed below the subequal auricles; the valves well inflated with a tendency to oblique growth in the adult. To this very natural group belong nearly all the shallow-water Pcctens of our own coasts, such as P. irradians Lam., P. gibbits L., P. dislocatns Say, P. ventricosus Sby., P. nucleus L., P. pnrpitralns Lam., P. cborcus Conrad, P. comparilis T. and H., and numerous other fossil species. Section Pallium Schum., 1817. Type P. plica Lam. Shell with the disk high and narrow above, ears small ; valves moderately inflated, nearly similar, the basal margin in the adult contracted, so that the edges meet each other nearly vertically ; ribs few, large, widening distally, entire; surface radiately imbricately striate, frequently with Camptonectes striation and imbricate external layer; the cardinal crura usually well developed, often irregular. The developed cardinal crura are a function of the short hinge-line and of little systematic importance ; their regularity is usually exaggerated in the figures. Pectcn pallium L. is more appropriately placed in the Chlauiys section. In the typical species of this group the most peculiar features arc the perfectly closed valves, the margins meeting all around the shell, the absence of a byssal notch or fascicle, and the obvious tendency of the irregular cardinal crura to be discrepant on the two sides of the rcsilial pit. Some specimens have very regular lamina? like those of most laminate species, in others the anterior laminae show a tendency to break up into nearly vertical narrow folds. These features are apparently confined to the less normal specimens of this species and should hardly form the basis for systematic rank. Pectcn pana- mcnsis Dall, which has in most respects an unusually close resemblance to /'. plica, differs by having the cardinal laminae obsolete and in the presence of a byssal sinus and ctenolium. In fact, the interchange of characters is so multi- farious that one must, to be consistent, either propose a genus for every two or three species of Pectcn or include all the species in one generic group. Locard, who adopts the former method, has proposed the name Felipcs for a FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA closely allied group with /'. pcsfdis L. as the type; and Bucquoy, Dautzen- bcrg, and Dollfus (1889) propose l\-plinn, with /'. clavatus Poli as type, which would include such species as /'. panamensis ; and Sacco adds Flexopecten (1897) for P.flexuasus Poli, which differs by having larger ears. Snbgenus Pscitdmiiiisiiun H. and A. Adams, 1858. Type Pecten exoticiis Chemn., = /'. pseudamusium (Klein) Sby. Shells small, thin, more or less translucent; the sculpture, if any, feeble; inner face of the disk without lirae ; disk with or without Camptonectes stria- tion, frequently with concentric imbrication. Section Pseudamusium s. s. Type P. psevdamttstum Sby. (== exoticiis Chemn., etc.). Sculpture discrepant on the two valves, the right valve having the con- centric, and the left valve the radial elements most pronounced ; valves usually flatfish or compressed. The type is a shallow-water species and shows bright colors ; the species from deep water are frequently pale or whitish. The latter have been separated as Cyclopccten by Verrill. Section Camptonectes (Agassiz MS.) Meek, 1864. Type P. lens Sby. Shell similarly sculptured on both valves, more or less inflated; smooth, con- centrically more or less undulated, divaricately striate, or delicately imbricated. The minute features of surface sculpture are so interchangeable and so variable that I cannot regard them as having sectional, much less generic, value, at least in the sense in which the term is used in this work.* Though Cainptotiectes was originally based on the character of the divaricate stria:, the species in which this character is obsolete must be included, unless violence is to be done to what seems close relationship. Syncydonema Meek, if correctly made out by that careful author, has a com- pletely closed shell without a byssal notch, the ears subequal, the left valve smooth, the right concentrically striated. * Professor Verrill proposes forllic smooth form Pi'dinclhr ; for the undulated form Hyalopecten ; the divaricately sculptured shells would then he typical Camptonectes; the imbricated ones like P. vitrcus [(Gmelin, 1792) Dillwyn, 1817 (-)- aculeatus JelTr., 1843, -f abyssorum Loven, ; gcni.'llaro-filii 1'iiondi) not P. vilrftis Gray, 1824 ( I', gronlandicus Sby., 1843) ; P. vitreus Risso, 1826 ; P. -jilrcus Kiii<;, 1831 (— /'. corneiis Sby., 1843), nor P. vitrms Sby., 1843] would be Palliolum Monts. (restr.), 1884. Eburneopecten Conrad, 1865, based on P. sdnlil/iilus Conr., is an exact synonyme of Camptoncctes. Lissochlamis Sacco (1897) is founded on P. e.rcisus Bronn (non Pusch), a species unknown to me. TRANSACTIONS OF WAGNER 698 TKRTIARY FAUNA OF FLORIDA Until more is known, this section would best be retained. It is doubtful how important the characters of lintoliitin Meek (1864) may prove to be. Lissopectcn Verrill (1897) based on /'. hyalinns Poli seems to me merely a somewhat degenerate SEqnipcctcn. Leptopcctcn of the same author is based on the kelp-inhabiting variety of P. (Ctilamys) latiaiiritns Conrad; its peculi- arities result directly from its special situs ; the shells intergrade perfectly with the other chlamydoid forms. Subgenus Aunts/inn Bolten, 1798. Type P. pleuroncctcs L. Valves flattish, internally lirate, externally usually smooth or faintly striated; ears subequal ; the ctenolium absent and the byssal notch obsolete. Plenronectia Swainson, 1840, is synonymous. Section Anutshtm s. s. Type P. pleuroncctcs L. Valves about equally convex, gaping at the sides, nearly similar in sculp- ture, the recent forms having the left valve darkly colored and the right valve pale or albescent. Amusimn Lyoni Gabb in the youthful condition has a sculptured left valve like Propcainiismni, Section Propeamusium Gregorio, 1883. Type /'. inequiscttlptus Tiberi (=: fenestratns Forbes). Right valve impressed about the distal margin, which is not fully calcified, partially concave, the sides partially closed, away from the ears; the lira? shorter; the external sculpture chiefly concentric, while on the left valve, if present, it is radial ; the recent forms usually glassy or pale colored in both valves. On anatomical grounds Professor Verrill separates, as Paraiinisiiim, Ainn- stum Dalli Smith ; but there are no distinctive conchological characters. In the Bulletin of the Zoological Museum of the University of Turin, No. 298, pp. 101-2, June II, 1897, Sacco has given a list of subdivisions of Pectcii, without definition, but referring to the species he regards as types, or includes under the several subgenera. Among those not above mentioned are the following : Under the genus Amnsinin, of which /\ cristatus Bronn is regarded as typical, Parviamnssinm Sacco (1897) is typified by P. duodcciinla- mellatus Bronn, and Variauiussium Sacco (1897) by P. canccllatns " Schmidt" (? Goldfuss, not Bean and Phillips or McCoy), while P. fenestratns Forbes is included. This section is therefore a synonyme of Pivpcamnshiin de Gre- gorio, 1883. FREE INSTITUTE OF SCIENCE 609 TERTIARY FAUNA OF FLORIDA Pec ten burdigalsnsis Lam. (regarded by Dcshayes as a variety of the species cnstatns Bronn, referred to Aiiiiisinm by Sacco) is made type of a sub- genus of typical Pcctcti called Anmssiopectcn by Sacco, and the subgcncra Oopecten Sacco, based on Pectin rotundatns Lam., and Flabellipecten Sacco, on /'. fJal'illiforuns Brocchi, are also referred to typical Pcctcn. If differential descriptions of new groups were imperative, probably some of the above might never have seen the light, but, with present methods, the flood of new names is likely to continue unchecked by any considerations drawn from a serious study of nature. Subgenus Hinnitcs Defrance, 1821. Type //. Cortczi Defr. Shell (up to advanced youth) a typical Chlamys, later becoming sessile and irregular, in which stage the resilial pit is elongated and the cardinal margin develops an obscure area. Hinnita Gray is synonymous. There are several groups of Pcctiiiidic in Paleozoic and Mesozoic horizons, as well as one or two exotic recent types, which do not need to be considered here. FOSSIL PECTENS OF THE PACIFIC COAST. Since it became absolutely necessary to review the Pacific coast and Antillcan Pcctinidce in order to settle the status of those of the Atlantic coast, and as this review has necessitated a good deal of hard work, and the results may be useful to the student, a synopsis of them is offered here. "ft Pecten (Patinopecten) propatulus Conrad. /'•<•/<•;/ pntpalulits Conrad, Cecil. \Vilkes Kxpl. Kxped., App. I, p. 726, pi. 18, figs. 13, 13 a, 1849. J't-ctrn caiirinus of various authors, but not of Gould. Astoria Miocene of the Columbia River; Dana. The types of this species are in the National Museum. It has been regarded as identical with P. caurinus Gould by Carpenter, Cooper, and others, but, as pointed out by Meek (Miocene Checklist, S. I. Misc. Coll., p. 26, 1864), while the recent shell has from twenty to twenty-six ribs and a minutely con- centrically striated surface, the P. propalnlits rarely has more than sixteen ribs, and when perfect has the surface microscopically tessellated. The latter is also a generally smaller and more convex species. ^ Pecten (Patinopecten) Meekii Conrad. /'•(A-;/ .)/(•<•/•// Com ., I'ac. K. K. Ui'p., vii., p. 190, pi. I, fig. I, 1857. Miocene of San Rafael, California; Conrad. TRANSACTIONS OF WAGNER 7OO TERTIARY FAUNA OF FLORIDA The type specimen of this species is also in the National Museum, and it is much closer to P. cauriinis than the last species. It has twenty ribs and, except that it is somewhat more convex, closely resembles P. cauriinis in every respect when of the same size. The latter, however, has not yet been found in the succeeding Pliocene deposits, though present in the fauna of Puget Sound. Conrad's figure is a mere caricature. vyC Pecten (Patinopecten) coosensis Shumard. PLATE 26, FIGURE 2. Pecten coosensis Shumard, Trans. St. Louis Acad. Sci., L, pt. 2, p. 122, 1858. P. coosacmis Meek (err. typ.), S. I. Mioc. Checkl., p. 3, 1864. Miocene of the Empire beds (Astoria horizon) at Coos Bay, Oregon ; Shumard and Dall. This species is large, compressed, with twenty-nine to thirty-one squarish prominent ribs, and on the upper valve much wider interspaces crossed by fine incremental lines. The ribs are sometimes longitudinally grooved towards the base. Specimens are in the National Museum and measure in alt. 120, lat. 113, and diam. 27 mm. This fine species is very abundant in the locality indicated. It is nearest to the Pliocene P. cxpcinsiis Dall, in which the ribs are dichotomous. •sL Pecten (Chlamys) altiplicatus Conrad. /'i-f/i-ii altiplicatus Conr., Pac. R. R. Rep., vii., p. 191, pi. 3, fi^. 2, 1857. I'fftcit altiplectits Conr. (err. typ.), I'roc. Acad. Nat. Sci. Pbila. for 1856, p. 313, 1857. J'i-( /i->i licriceus Carpenter, Cooper ; not of C.ould. Miocene of the San Rafael hills near Santa Barbara, California ; W. P. Blake. This species, which is wretchedly figured by Conrad, is represented by the type in the National Museum. It has ten or eleven high, sharp spinulosc ribs alternated with an equal number of low, small imbricate riblcts, the inter- spaces sculptured with elevated radial scabrous threads. The beak and cars are defective, but the typical specimen is characteristic enough to show that it is entirely distinct from the recent Pecten licricms Gould, with which it has often been doubtfully united. P. catillifonnis Conrad (pp. cit., v., p. 329, pi. 9, fig. 83, 1856), which resembles in the figure a flattened valve of P. Hcennanni seen from within, and /-*. iicvadainis Conrad (pp. cit., p. 329, pi. 8, fig. 77) were described from drawings made by Professor W. P. Blake from internal or external casts in the FREE INSTITUTE OF SCIENCE 7O I TERTIARY FAUNA OF FLORIDA sandstones of Ocoya Creek. No types of them exist, and the figures are so bad that it is to be feared they will remain for a long time unrecognized. Section Lyropccli-n Conrad. I.yropi-fli-n Conr., I 'roc. Acacl. Nat. Sci. Phila. for 1862, p. 291 ; Meek, Smithsonian Checkl. Mio. Fos., pp. 5, 27, 1864. Type Pallium cstrellanum Conr., Pac. R. R. Rep., vi., (".col., p. 71, pi. iii., fig. 15, 1856; Proc. Acacl. Nat. Sci. Phila., viii., p. 313, 1857; l.iivpfflt'it cstn-llaniini Cooper, I!ull. State Mining Bur. Cala., No. 4, pi. 6, figs. 65-67, 1884 (text excl.). Not /'. cslrcllanum Conr. of Pac. R. R. Rep., vii., p. 191, pi. 3, lij^. 3-4, — F. volaformis Conr., P^K Acad. Nat. Sci. for 1862, p. 291. I.iropct •/<•;/ C.abl), Pal. Cal., ii., p. 105, 1869. Not I.vrof>,-ctcn Conrad, Am. Journ. Conch., iii., p. 6, 1867. Type P. crassicardo Conr., Proc. Acad. Nat. Sci. Phila. for 1862, p. 291. Not Lirofit-ctt'ii Fischer, Man,- de. Conchyl., p. 944, 1887. Type P. nodosus Linne. Not Lyrflfci-fi-n Yen-ill, Trans. Conn. Acad. Sci., x., p. 63, 1897. Type P. /tv/tosi/s Linn6 (following Fischer). Not Lvriofn'i It-n Hall, 1883, = section of Aviculopecten. Among the types of the Pacific Railway explorations is a fossil Pecten with a label " Estrella Valley" in Conrad's handwriting. The ears have been broken off, but in other respects it agrees well with the description and figure of Pallium cstrcllanum. The ribs are worn flat, and the undulations mentioned in the description are due to erosion. It is the only specimen agreeing at all closely with the requirements, and I have no doubt it is one of the specimens from which Conrad's description was prepared. Better preserved fragments show the intercalary line clearly, and also that the ribs were imbricated, as in /'. ftfl'crsonius, by minute elevated scales. It is, in short, a Pecten belonging to the same group as P. Jcffcrsonim, Madisoiriiis, crassicardo, etc. Curiously enough, the same specimen served as the subject for Conrad's P. Hcermanni (I'm. . Acad. Nat. Sci. Phila., vii., p. 267, 1855), described in a line and a half and never figured. The two were identified by Conrad as the same species on the National Museum labels. In the confusion that surrounds the specific name estrellanum (three species of Pecten from the same region having been so named by Conrad), it is probably better to revert to the earlier name of Heermaniii. A fair figure, cited above, has been given by Cooper. The type of the second form, named estrellanum, is lost. It appears to have been a shell resembling Pecten dcntatus Sby. in outline, but the sculpture and number of ribs agree with the original cstnilanns. Conrad renamed it L. TO/I, 'tUnnis, but the difference of shape may be due to crushing, as the fossils TRANSACTIONS OF WAGNER 702 TERTIARY FAUNA OF FLORIDA of this horizon are all more or less distorted, and the shell may be the same, as he originally thought it to be. The dentition of the hinge is similar to that of many Pectens, such as P. Stviftii Bernhardi, P. vcntricosns Sby., and P. purpuratus Lam. The third species referred by Conrad to this group is P. magnolia Conr. (Pac. R. R. Rep., vii., p. 191, pi. I, fig. 2, 1857), of which the very imperfect fragments which served as types are in the National Museum. The figure is a very erroneous diagram compounded from the characters of these fragments. A better specimen of the same species was later described by Conrad under the name of L. crassicardo (Proc. Acad. Nat. Sci. Phila. for 1862, p. 291) but has not been figured. The types are in the Academy's collection. Both valves are convex and have the hinge-teeth moderately developed. The shell has from eleven to fourteen ribs and much resembles P. Jcffersonius, except in the greater development of the hinge-teeth and the radial ribbing of the ears. It grows even larger than the average Jeffcrsonius and belongs to the Miocene of the Santa Inez Mountains, Santa Barbara County, California. According to Gabb (Pal. Cal., ii., p. 105) a broken specimen of this species served as the original for the figure of Spondylus estrellanus Conr. (Pac. R. R. Rep., vii., pi. I, fig. 3, 1857), an opinion which the figure, poor as it is, offers much to confirm. The genus established by Conrad was based on the heavy cardinal laminae which compose a distinctly dentiferous hinge; this feature, however, varies in the different species and is insufficient as a basis for a group of such value in view of its inconstancy. The group name, whatever rank is assigned to it, must depend upon the type. This, as already pointed out, belongs among those species which unite with sculpture similar to that of P. maxiinus the character of having both valves more or less convex, instead of having the right valve flattened or even subconcave. Such shells are more or less inter- mediate between ALqmpectcn Fischer and Pcctcn proper. In 1867 Conrad, with the forgetful ness which marked his later work, produced the genus Lyropcctcn again, as if it was not already described, and offers as a type L. crassicardo, one of his original species but not that origi- nally indicated as the type. L. crassicardo, however, is a true member of the group. But to this species he adds Pecten nodosus and its allies, which are not entitled to be admitted. Fischer, in citing Conrad, ignores the original description and mentions P. nodosus as the type, which it never was, and thus subsequent writers were led into error. The modification of the original FREE INSTITUTE OF SCIENCE 703 TERTIARY FAUNA OF FLORIDA1-/ orthography by G;ibb and Fischer is unnecessary and contrary to the rules of nomenclature followed in this volume. Notwithstanding the fact that the real type is intermediate in form between the /'. vcntricosns group and that of I'. Jcffersonius, the balance of characters is decidedly in favor of the latter, and, thus restricted, it forms a fairly natural and recognizable assembly which will contain, besides the type, such forms as /•*. crassicardo Conr., ly. Jcffersonius Say, /'. Madisonius Say, P. edgecombensis Conr., l\ septenarius Say, — all large species, with conspicuous ribbing, radially squamose-striate surface, convex and nearly equilateral valves, and more or less developed cardinal lamina:. The group is chiefly Miocene. In Pecten Clintoniits we have a species which appears to differ remarkably from such forms as Jcff'crsonins, and yet the most essential distinction is the absence of ribbing. If we were to imagine a specimen of P. Jcffersonius with the ribs flattened out, the distinction between it and P. Clintomus would be almost imperceptible. In recent Pectens the group is only represented by such forms as P. fuscopnrpiirens Conrad, which never attain a large size but resemble in their sculpture the young shell of /'. Madisoitiiis and its allies. They can hardly be accommodated in the group as here restricted. Pecten (Plagioctenium) deserti Conrad. 1',; t,-n ii,-s,'rti Conr., 1'ac. 1\. R. Rep., v., p. 329, pi. 8, fig. 77, 1856; Descr. Fos. and Shells, House Reps. Doc. 129, p. 15, July, 1855. /'t't'tt'ii (/is, us Cooper, Cal. State Min. Ikir. Dull., No. 4, p. 57, pi. 4, tigs. 55, 56, 1894 ; not /'. disfits Conrad, 1857. Miocene (?) of Carrizo Creek, Colorado Desert. This appears to be a well-defined species resembling P. turgidns Lamarck, having twenty-three close-set, smooth, rounded, prominent ribs, and both valves moderately convex ; the specimens are usually crushed. This has been confounded by Cooper with /'. discus Conrad, his remarks showing that Dr. Cooper is unacquainted with the true /'. discus. Pecten (? Plagioctenium) pabloensis Conrad. /',;/,/! /in/'/i v//.v/\ Conr., Par. K. K. Reps., vi., p. 71, pi. 3, fig. 14, 1857. Miocene of San Pablo Bay, California ; Merriam. This species is represented by a better figure than some of the others, and has been collected from the original locality by Dr. John C. Merriam, of the University of California. It has been erroneously referred to the TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA young of P. estrdlanum (= Heermanni Conr.) by Dr. Cooper. It is small, with feeble sculpture like a young, pressed-out Pecten propatulus, with eighteen to twenty major ribs alternated with smaller intercalary riblets. The ears are discrepant, the right anterior one radially ribbed. The .shell measured about thirty millimetres in height and length. Pecten (Pecten) bellus Conrad. Jttnini hclla Conrad, I'ac. R. R. Rep., vi., p. 71, pi. 3, rig. 16, 1857. Not Janira bclla Gabb, Pal. Cal., ii., p. 105, pi. 16, fig. 20, 1868. Not I'ccti-n hcllns Shy. (iibi ?), nor />. bellis McCoy. Tertiary of Santa Barbara, California. Neither the description nor the figure are sufficient to positively identify this shell, of which no authentic specimen is known. Such information as is given does not agree with either of the recognized species. Pecten (Chlamys) fucanus n. s. PLATE 26, FIGUKK 7. Found in concretions from the Miocene sandstones of Clallam Bay, twenty-five miles eastward from Cape Flattery, on the south shore of Fuca Strait, Washington, by Mr. J. S. Diller, of the United States Geological Survey. Another specimen was received from J. G. Swan, collected in the same vicinity. This is a rather large species of the type of P. Hindsii var. strategics, both valves moderately convex and with a fine subsidiary surface tessellation ; sixteen squarish ribs, of which the median one in the left valve is stronger than the rest and surmounted by prominent imbricated scales; the others are simply radially striated, as are the interspaces, which carry a mesial elevated thread ; the submargins arc radially threaded, as are the subequal ears, which also bear marked concentric lamella;; the rcsilial pit is of moderate sixe and the cardinal edge is deeply grooved parallel to and just below the margin; the interior reflects the external ribbing. Alt. 85, lat. So, convexity of left valve 16 mm. Types in the National Museum. This interesting form is represented by very perfect internal and external casts of the left valve and other less perfect examples. It is doubtless the precursor of the recent P. hcriceus group. Pecten (Chlamys ?) discus Conrad. 1'i-ftcn discus Conrad, Pac. R. R. Re])., vii., p. 190, pi. 3, rig. I, 1857; not of Cooper, Cal. State Min. IJur. Hull., No. 4, p. 57, pi. 4, rigs. 55, 56, 1894. FREE INSTITUTE OF SCIENCE 705 TERTIARY FAUNA OF FLORIDA From the fine-grained Miocene shales of Santa Barbara County, Cali- fornia. This is ,i beautiful thin, flat species, resembling a young Patiiiopcctcn, but more oblique and oval, the left valve showing nine or more low, wide, smooth ribs in the middle of the disk, with wider smooth interspaces, ami the sculp- ture obsolete towards the ends and base of the valve ; the right valve has narrower, sharper, smaller, and more numerous riblets; the left valve meas- ures about forty-seven millimetres in height and width, and the shell was apparently about ten millimetres in diameter; the ears are plain and unequal. Conrad's figure is very poor and gives little idea of the shell. This may belong to the section ^Eqtiipccten. Species which may be of Miocene or Pliocene age and were collected on Cerros Island, Lower California, were described by Gabb (Pal. Cal., ii., p. 32, 1866). /'. fciToseiisis Gabb (pp. cit., p. 32, pi. 9, figs. 55, 55 a) has eighteen to twenty flatfish, entire ribs, with about equal interspaces. It is of the type of/'. cborfiis Conr., but much larger. /'. / \\itchii Gabb (op. cit., p. 32, pi. 10, fig. 56) is i if the general type of P. itihii'sns, and has about fourteen feebly nodose broad ribs, striated, reticulated, and minutely squamo.se. The little, smooth P. I'cck- liiniti Gabb with Camptonectes striation (Pal. Cal., ii., p. 59, pi. 16, figs. 19, 19 a, 1866) and the concentrically undulated /'. pcdroantts (Trask) Gabb (Plagiostoma pcdn>i\na Trask, Proc. Cal. Acad. Sci., i., p. 86, pi. iii., fig. I, 1856 ; + /'. annnlatiis Trask, loc. cit., fig. 2, and /'. truncata Trask, fig. 3 ; Gabb, Pal. Cal., ii., p. 60, 1866) comprise the remaining species of the Pacific coast, which are supposed to be of Miocene age. Some of them may also prove of Pliocene age. The following undetermined forms have been observed in the collection of the State University at Berkeley, California: l\cten sp. A species in the State University collection at Berkeley, Cali- fornia, which had been marked /'. pablocnsis by Dr. Cooper is evidently distinct; it has fifteen primary ribs on the left valve, many of them unevenly divided near the basal margin by a shallow sulcus ; in the interspaces are low, rounded riblets, extending about half way up the disk; right valve some- what more convex; the ears subequal and vertically striated. Alt. 85, lat. 90 mm. Found in the Miocene of Foxin's Ranch, California. Pcctcii Ifccnitiiiiiii Conr. var. ? A large species from Santa Inez Canon, Santa Barbara County, California, is biconvex, with sixteen large, nearly smooth ribs in the right valve, with subequal interspaces, in the middle of each of which is a single small raised thread; ears .subequal, the posterior TRANSACTIONS OF WAGNER 7O6 TERTIARY FAUNA OF FLORIDA radially and the others concentrically threaded ; the left valve somewhat less convex. Alt. 145, lat. 147, extreme length of hinge-line 80 mm. Pecten sp. San Pablo formation, Mount Diablo, Contra Costa County, California, has fourteen to sixteen ribs, strong and simple, with narrower chan- nelled interspaces, which, as well as the ribs in some cases, are radially striated; ears subequal, somewhat impressed, with a few rather coarse radial riblets and concentric striation. Alt. 127, lat. 137, hinge-line 70 mm. Pecten sp. A small species recalling P. descrti was collected near Mount Diablo ; it is rounded, moderately convex, with eighteen to twenty slightly nodulous subequal ribs, with channelled equal interspaces crossed by fine looped concentric sculpture ; the shell is like a small teqttisulcatus in general form, with small subequal ears. Alt. 28, lat. 28, hinge-line 18 mm. Pecten sp. indet. The flat valve of a species, in poor condition, but re- calling P. dcntatus Sby., has been received from Miocene beds near San Diego. The following are of Pliocene age : Pecten (Patinopecten) expansus Dall. PLATE 26, FIGURE i. Paten expansus Dall, Proc. U. S. Nat. Mus., i., p. 14, 1878. Pliocene of Pacific Beach (lower horizon), near San Diego, California ; Hemphill, Dall, and Hamlin. Shell large, flattish, with, on the right valve, twenty-five to thirty flat dichotomous ribs, which differentiate it from the other species of this group. Pecten (Pecten) Stearnsii Dall. PLATE 26, FIGURE 5. /'<•( It-it Stt-arnsii Dall, op. fit., p. 15, 1878. Found with P. expansus. This is the Pliocene precursor of Pecten diegcnsis Dall, from which it differs by having five or six more ribs, which, in the adult, have a conspicuous median sulcus. Pecten laqtieatus Sby., a Japanese species, has been erroneously cited by Reeve from California. Pecten (Pecten) Hemphillii Dall. t'fftfii Hcmp/iHHi Dall, op. fit., p. 15, 1878. ini hi-lla ('.abb (non Conrad), Pal. Cal., ii., pi. 16, fig. 20, 1869; not /'. l>,-lla Sby., nor /'. /v///.v McCoy. FREE INSTITUTE OF SCIENCE TKRTIARY FAUNA OK FLORIDA Found with I', expa/isiis. This shell is probably identical with the Janira bclla of Gabb, but it differs from the original /. bclla Conrad by its entire ribs, rounded above instead of square, with extremely fine concentric lamellation. Pecten (Pecten) compactus n. s. I'I.ATK 34, FIGURE 5. Pliocene of Ventura County, California, at an elevation of two hundred feet and eight miles inland from the sea; U. S. Nat. Mus., No. 61,246. Shell having a general resemblance to Pecten dentatns Sby. and P. Ponlsoni Morton, being slightly larger than the latter and sculptured more like the former. Right valve with twenty flat-topped, entire, smooth, squarish ribs, separated by much narrower channelled interspaces, crossed by faint incremental lines; submargins smooth except for incremental lines; posterior ear with six or seven faint minute radials crossed by elevated lines of growth ; byssal ear small, with three or four conspicuous subimbricate radials and a rather small notch and ctenolium ; internal basal margin fluted ; hinge-teeth rather strong. Alt. 27, lat. 27, diam. of left valve 8 mm. Pecten (Plagioctenium) subventricosus n. s. PLATE 29, FIGURE 8. Pliocene of Ventura County, California, Bowers; and of Pacific Beach at San Diego, Stearns and Hemphill. Shell of the type of /•*. vcntricosm Sby., from which it differs by being smaller and less tumid, less expanded laterally, with the ribs rounded, instead of flattened, above, and with narrower interspaces ; the tops of the ribs smooth, the sides with a dense fringe of concentric lamella;, much as in com- parilis T. and M. Alt. and lat. 65, diam. 24 mm. I Pecten (Chlamys) opuntia n. s. PLATE 29, FIGURE 6. Pliocene of San Diego, California; Hemphill and Ilamlin. Allied to P. licriccits var. navarclius Dall, from which it differs by its smaller and not fasciculated radial ribs, more elongated anterior ear, more densely radially costate posterior ear, small size when adult, and by a tendency to be suddenly contracted at the basal margin on the completion of growth, somewhat as in P. pcsfdis. Alt. 35, lat. 32.5 mm. 10 TRANSACTIONS OF WAGNER 708 TERTIARY FAUNA OF FLORIDA Pecten (Chlamys) Parmeleei n. s. PLATE 37, FIGURUS 14, 14 a. Pliocene of San Diego, California ; Parmelee. This species is close to P. Swiftii Bernhardi of Japan (J. de Conchyl., vii., plates I and 2, 1858) but smaller, and differs by the smooth top surface of the ribs, which in P. Szviftii are more or less striated or coarsely threaded, and by the not alternated radial riblets on the right posterior ear ; also, especially, by the profuse coalescent microscopically checkered squamation, which makes a complete external coating to the valve. Alt. 45, lat. 38 mm. The Pecten fauna changes almost completely with the Pleistocene, all the species being known as recent and generally of the same climatic groups as those at present living in the most adjacent waters. The following species have been noted : Pecten (Chlamys) islandicus Miiller. Pecten islandicus Mull., Prodr. Zool. Danica, p. 248, 1776. Pecten cinnabarina Born, 1778, -f- P. rubidus Martyn, 1784, + Ostrea dcniissa Solander, r797. + Pecten Pealeii Conrad, 1831, + P. Fabricii Philippi, 1844. Bowlder clays of the northwest coast, also living in Bering Sea ; Ball. Ribs numerous, subequal, rounded, small, scaly on both valves, with" channelled minutely reticulate interspaces. Pecten (Chlamys) hericeus Gould. I'cili-n hericeus Gould, Proc. Bost. Soc. Nat. Hist., p. 236, 1850. Pecten hastatus Cpr., 1863 ; not of Sowerby, 1843. f = Pecten rastellinum Val., Voy. Venus, pi. 19, fig. 4, 1835. Pleistocene of San Diego, California ; Hemphill. Middle ribs of the fasciculi on the left valve high, spiny, the rest merely scaly. This is entirely distinct from the true P. liastatns Sby., with which Carpenter confused it. The latter is a smaller, quite rare shell, with entirely different sculpture, and has not yet been found in the fossil state. I have taken the name of Gould, as the oldest, for the specific designa- tion of a group of forms of which the original hericeus is only a special development, the prevalent and normal form of the species being the follow- ing shell : Pecten hericeus var. navarchus Dall. /'<•(/,•>! niliidnx Hinds, Zool. Sulph. Voy., p. 61, pi. 17, fig. 5, 1844; not /'. rukidiis Martyn, 1784. FREE INSTITUTE OF SCIENCE 709 TERTIARY FAUNA OK FLORIDA Bowlder clay of Comox, Vancouver Island, Newcombe; Pleistocene of San Pedro, Dall and Stearns ; of San Diego, California, at Pacific Beach, Humlin. Smaller than P. islandicus ; ribs small, obscurely fasciculated, dichoto- mous, and imbricated on both valves. Living from the Aleutian Islands south- ward to Lower California. Pecten hericeus var. Hindsii Carpenter. I'cctcn (? var.) Hindsii Cpr. , Suppl. Rep. Brit. Assoc., p. 645, 1863. Pleistocene of Sucia Island, Fuca Strait, Newcombe ; recent from Bering Sea to Monterey, California. Ribs on the right valve smooth, not fasciculated, sometimes wide, flattish, usually dichotomous; left valve as in var. iiavairhns. The typical specimens seem remarkably distinct from navarchus, but in a large series intergradation is obvious. Pecten hericeus var. strategus Dall. Pleistocene of Alaska and recent at Unalashka ; Dall. The fasciculi of the left valve, to the number of five to seven, with the riblets coalescent, forming large, smooth-backed, turgid ribs, with smaller imbricate intercalary threads. The large ribs sometimes break up suddenly into the usual small riblets near the base. The recent specimens are bright scarlet. Pecten (Chlamys) latiauritus Conrad. /'rA1// latitiHrilns Conrad, Juurn. Acad. Nat. Sci. Phila., vii., p. 238, pi. 18, fig. 9, 1838. /'< -i-tt-ii /uniia Phil., 1844 i /'. iiti'solimeris Sowerby, 1847. /<•<•/<•// tiimhczcnsis Orbigny, 1847, + P. aspsrsits Sby., 1843, non Lam., 1819, + P. Soiot'rliii Reeve, 1852 (non Guilding), is very closely related. Pleistocene of San Pedro Hill and San Diego at Coronado Beach ; very abundant. Also living. Hinge-line wide; the ears acutely pointed above; ribs distinct, squarish, often mesially grooved ; shell wide. This is the type, which varies widely. Pecten latiauritus var. monotimeris Conrad. /'. Hiiiiic/iiiti-ri.i Conrad, />/>. fit., p. 238, pi. 18, fig. 10, 1838. Shell more oblique, inflated, and markedly shorter, with smaller ears. Found with the last, with which many specimens intergrade. TRANSACTIONS OF WAGNER 710 TERTIARY FAUNA OF FLORIDA Pecten latiauritus var. fuoicolus Dall. Witli tlic last, and living on fuci, south to Cape St. Lucas. Shell moderately compressed, smooth, concentric, sculpture obsolete ; ribs low, rounded, wide, entire; hinge-line shorter than in the type, and without any sinus between sus Sby., P. Z. S., 1835, p. 109. Pecten intermedius Conrad, Am. Journ. Conch., Hi., p. 7, 1867. Pleistocene of Cerros Island and other points on the Lower Californian coast. Living in the adjacent waters. There seems to be little reason for separating this form from the P. nodosus of the Antilles. Both vary through a strictly analogous series of mutations. Pecten (Pecten) diegensis Dall. Pecten floridus Hinds, Zool. Sulph. Voy., p. 60, pi. 17, fig. 6, 1844 ; not Ostrea ( Pec ten) florida Gmelin, 1792. Pleistocene of San Diego ; Hemphill. Living on the adjacent shores from Monterey, California, southward. Pecten (Plagioctenium) veritricosus Sowerby. Pecten vi-ntricosii.t Sby., Thes. Conch., /Jv/,7/, p. 51, pi. 12, fi^s. 18, 19, 1843. Peeten tiiinitiii* Sby., P. Z. S., 1835, p. 109; not /'. ttiinidi/s Tun, 1822, nor of Zieten, 1830. Pet ten circiileirh Sby., /M parte, 1835; ; /'. ///, ,M >H>., 1847. ? = Pecten poinatia Val., Voy. Venus, pi. 19, tijj. 3, 1835. FREE INSTITUTE OF SCIENCE 711 TERTIARY FAUNA OF FLORIDA Pleistocene of San Pedro, San Diego, and Lower California; Hemphill, Stearns,. and Orcutt. Living from Santa Barbara southward. This species is the Pacific coast analogue of P. dislocatns Say. Pecten (ventricosus v.ir. ? ) aequisulcatus Cpr. l\-ctfii ti'i/nisiiffiidis n. s. ? Carpenter, Suppl. Rep. Brit. As., 1863, p. 645 ; Ann. Mag. Nat. Hist. Mar., 1865, p. 179. Found with the preceding. This form bears to ventricosus precisely the relation which P. irradians Lamarck, on the Atlantic coast, bears to P. dislocatns Say. Pecten (Propeamusium) alaskensis Pall. /<•<•/<•// ahiski'iisis Pall, Am. Journ. Conch., vii., p. 155, pi. 16, fig. 4, 1871. Pleistocene of Vancouver Island, near Esquimalt, and at various points in Alaska. Living from Bering Sea to Panama Bay, usually in deep water. This species has twenty to twenty-two internal rib-like lirae. There is a small species of Propeamusium resembling /'. squamnla Lam. in the Arago beds of Oregon, but the exterior is not yet known. It is prob- able that a fair number of additions to this list may be made when the different horizons of the Pacific coast are sufficiently explored. l\ftcu pyxidatns, which has been listed from the Pacific coast, is apparently a Chinese species. P. subcrcnatiis Carpenter and P. Toivnsendi Gould seem to be list-names, cited in Carpenter's supplementary report to the British Asso- ciation in 1865, but never characterized and now unidentifiable. Subgenus HINNITES Defrance. fliitiiitrs Pefr., Did. Sri. Nat., xxi., p. 169, 1821. Type //. C<»-/fsi Pefr. llinnita Ferussac, Tabl. Syst. , p. xl., 1822. IliiniHS Wood, Ann. Mag. Nat. Hist., xxxvii., p. 253, 1841. J>C^ Hinnites crassus Conrad. Iliiiuit, .v crtissii Conr., Pac. R. R. Rep., vii., p. 190, pi. 2, figs, i, 2, 1857. ? ffinmtes giganteus Csvf, Ann. 1'liil., p. 103, 1826. Cf. I\rt,-n cMihitits Val., Voy. Venus, pi. 18, fig. 2, 1835. Miocene of Santa Margarita, Salinas Valley, California. It should be mentioned that Hinnites gigantcus Gray (Ann. Phil., 1826, + H. PonlsoniConv., 1834) is not uncommon in the Pleistocene, and the young shells, which sometimes reach the length of thirty millimetres before becoming TRANSACTIONS OF WAGNER 712 TERTIARY FAUNA OF FLORIDA attached to other bodies, are in fact Pectens, and very liable to be taken for an undescribed species of that genus. They are variable in the amount of spinose sculpture, and the more spiny ones often closely resemble the young of the true Pec ten liastatus Sby. In the recent specimens a character by which they can usually be discriminated is a suffusion of purple color on the hinge- line near the cartilage-pits. FOSSIL FECTENS OF THE ANTILLEAN AND CENTRAL AMERICAN REGION. Nearly all of these species are Oligocene ; a few are referable to the Pliocene; but the typical Miocene or Chesapeake fauna has not been identi- fied anywhere south of Florida. The first species described from this region appear in the paper by Sowerby on the Bowden fauna in 1849. As a number of these were very briefly described and never figured, I sent a series of the Bowden Pectens in the National Museum to Mr. Clement Reid, of the British Geological Survey, who very kindly compared them with Sowerby 's types and furnished me with valuable annotations upon them. In the small scries available for study the range of variation necessarily remains doubtful in some cases, though I have had the advantage of comparing with the series of types in the Guppy collection of Antillean fossils now the property of the United States National Museum. It appears from Mr. Reid's examination that the type specimens arc not segregated in the Sowerby-Heniker collection, that the fossils are loose in trays, and these trays sometimes contain more than one species. The confu- sion has probably occurred since Sowerby's time, as he was a very careful worker. Under these circumstances the reviser can only take the form which is best in accordance with the original diagnosis and restrict Sowerby's name to it. Pecten (Pecten) soror Gabb. Janira soror Gabb, Trans. Am. Phil. Soc., xv., p. 257, 1873. Oligocene of St. Domingo, Gabb ; of Jamaica and Cumana, Guppy. A large species with twenty rounded, strong ribs, separated by flattish interspaces, with fine concentric elevated lines, the flat valve also strongly ribbed, the right valve very convex, and the shell a little inequilateral. Pecten (Pecten) eugrammatus n. s. I'I.ATE 34, FIGURE 22. Oligocene of Haiti and St. Domingo, Guppy. FREE INSTITUTE OF SCIENCE 71 T. TERTIARY FAUNA OF FLORIDA Shell suborbicular, convex, with twenty-one high, sharp ribs separated by V-shaped narrower interspaces, the ribs with a sharp but shallow mesial sulcus and the outer edges of the sulcus sharp and flaring ; submargins smooth, ears radially threaded, inner margin deeply fluted; surface with fine, low, sharp concentric lamella; when perfect; notch small, narrow, sharp, with no ctcno- lium ; cardinal crura well developed, sharply cross-striated ; ears small. Alt. 23, lat. 24, cliam. 8 mm. This species may possibly belong to sEquipccten, but its aspect is that of Pec ten. I have not seen the left valve. There is an unnamed valve of this species in the Heniker collection. Pecten (Euvola) bowdenensis n. s. PLATE 29, FIGURE I. Oligocene of the Bowden beds, Jamaica ; Henderson and Simpson. Shell resembling P. zicsac L. in the right valve, with about twenty-three obsolete smooth ribs separated by impressed lines; right valve very convex ; ears subequal, smooth, notch narrow, deep; left valve with seventeen low, rounded ribs separated by wider, squarely impressed interspaces ; submargins wide, smooth ; disk moderately concave ; ears subequal, smooth, concavely arched ; interior margin of the base with paired lirae, the pairs separated by deeper channels; cardinal crura obvious. Alt. 43, lat. 44.5 mm. The sculpture of the left valve definitely separates this species from the young of P. ziczac, /'. incdiits, and allied forms known from this region. Pecten (Euvola) limonensis Dull. /,i>i/nr /«-7'/V'?/i' r.abb, Joiirn. Acad. Nat. Sci. Phila., 2cl Scr., viii., p. 379, 1881 ; not I'x\'i;niuiiii Shy.. (Hiart. Journ. Gcol. Sor., vi., p. 52, \f<^}. Rcften aitgwticostatus GaJab, ('.col. St. Dom., p. 256, 1873. l\-ctfii <-.iw.v/V;w///.< C.uppy, ('.col. Journ., xxii., p. 294, 1866. Oligocene of St. Domingo, Gabb ; and Jamaica at Bowden, Henderson and Simpson. Shell small, suborbicular, with nineteen to twenty-one sharply keeled ribs separated by V-shaped interspaces, with little-elevated, sharp, thin, con- TRANSACTIONS OF WAGNER 7IA TERTIARY FAUNA OF FLORIDA centric linear imbrication; form tumid, cardinal crura well marked; left valve less convex than the other. Alt. and lat. about 15 mm. The above diagnosis is from the type of P. angnslicostatns, and agrees with Sowerby's diagnosis. The shells which are now found under the name of Sowerby in the Heniker collection are, according to Mr. Reid, a pair (A) which are orbicular, suboblique, not tumid, with a well-marked small rib in each furrow, coarsely squamose sculpture, and a height of forty-seven and a half millimetres. The other specimen (B) is a single valve with the rib in the furrow obsolete or absent, the shell oblique, surface coarsely squamose. The two are not certainly the same species, and both of them conflict in character with Sowerby's diagnosis. I cannot accept them, therefore, without further evidence, as being the originals. Specimen A recalls strongly the shell here named P. Gabbi, and may be a specimen of that species which has been acci- dentally labelled with a name not belonging to it. In case this view is not accepted, in spite of the discrepancies between the specimen and Sowerby's description, the present form will take Gabb's name. Pecten (^Equipecten) insequalis Sowerby. Pecten inaqnalis Sby., op. cit., p. 52, 1849; Guppy, Geol. Journ., xxii., p. 294, pi. 18, fig. 6, 1866. Oligocene of St. Domingo and Haiti, Gabb ; Jamaica, Bland ; Curacao, United States Fish Commission; Isthmus of Darien, Mill. This much resembles P. angjisticostatits Gabb in form and size, but the ribs are rounded and the interspaces roundly concave. It is the most common and widely distributed of the Antillean Oligocene Pectens. Pecten (.ffiquipecten) thetidis Soucrby. Pecten thetidis Sby., op. cit., p. 52, 1849. Oligocene of St. Domingo, Heniker; Bowden, Jamaica, Henderson and Simpson ; Curasao, United States Fish Commission. This is a shell much resembling the recent Florida shell which Conrad named fuscopurpureus, but the latter is larger and less solid. The specimens in the Heniker collection include two indeterminable valves: (A) four tumid, inequilateral, equivalve, with nineteen sharp ribs and sharp furrows, sculpture squamose ; (B) one orbicular compressed valve with nineteen ribs which are markedly quadrate at the margin, squamose and wrinkled, but scarcely spiny, the ribs of the disk and those of the wing forming a nearly continuous series. FREE INSTITUTE OF SCIENCE 715 TERTIARY FAUNA OF FLORIDA Mr. Reid remarks that Sowerby's description was apparently mainly drawn from I?, and that the two forms are so distinct that it is difficult to believe that Sowerby can have referred them to the same species. In the absence of a figure we may adopt B as representing the name, which would agree with usage as seen in the Guppy and other collections. The other specimens (A) seem from the remarks cited to be nearest to some varieties of oxygoiiuui or iveeqwalis. Pecten (^Equipecten) scissuratus n. s. PLATE 34, FIGURR 4. Oligocene of Ponton, St. Domingo, and ten and a half kilometres west of Colon, Isthmus of Darien ; Hill. Shell moderately compressed, with sixteen well-marked ribs ; valves nearly equilateral, the right one less flat than the other; disk suborbicular, with small subequal ears ; left valve with the ribs smooth and rounded on top, separated by subequal, slightly channelled, smooth interspaces; the ribs on each side just below the top are incised by a sharp, narrow groove, in which are closely set small imbricated scales, which seem easily detached, so that in the worn specimens the sulcus alone remains, ending in a narrow, sharp slit at the distal end of the rib; the ears are flat, with sparse radial threads; in the right valve the ribs are squarish and smooth, the sulci are absent, and the surface sculpt- ure confined to faint incremental lines; the ears have a few imbricate radii, and the notch is shallow ; the submargins are narrow and young shells have a polished surface ; the internal surface is channelled in harmony with the ex- ternal ribbing ; the auricular and cardinal crura moderately developed. Alt. 31, lat. 30, diam. about 6 mm. In young shells the sulci on the ribs are not conspicuous, and in perfect ones the scales must more or less completely hide the grooves. Pecten (Chlamys) anguillensis Guppy. /',;•/,•>! nii^iii//i-ii.ti.'i Guppy, 1'roc. Sri. Soc. Trinidad, Dec., 1867, p. 175. Oligocene of Anguilla and Antigua ; Guppy and Spencer. This is quite closely related to the recent P. antillarnm Recluz, of which it is evidently the precursor, and also resembles /'. luciilciitiis Reeve. Pecten (Chlamys) ornatus Lamarck ? var. vaginulus Dall. Oligocene of the Bowden beds, Jamaica ; Henderson and Simpson. Seven small valves of a species closely resembling P. ornatiis were TRANSACTIONS OF WAGNER 7l6 TERTIARY FAUNA OF FLORIDA \ obtained at Bowden ; the form and sculpture are practically the same, but the ribs (twenty-one to twenty-five) are single, subequal, and not fasciculated, and are separated by simple narrower interspaces not radially threaded. The young of oniatns, as far as observed, seem to always have one or more inter- stitial riblets. I therefore propose for the present form the varietal name 01 vagiintlus, which may be raised to specific rank if the difference is confirmed by the characters of adult specimens. Pecten (Chlamys) interlineatus Gabb. J'r/i-n inti-iiincatits Gabb, Geol. St. Dom., p. 256, 1873. Oligocene of St. Domingo; Gabb. Shell close to P. angnillcnsis Guppy, with about sixteen flatfish, eroded ribs, with narrower interspaces containing a single thread ; the surface sculp- tured with fine, wavy, concentric lamellae ; posterior two or three ribs under the byssal notch are corrugated on the anterior edge ; submargins narrow, the anterior smooth ; ears subequal, radially sculptured, notch deep. These notes are taken from the types of this unfigured species in the collection of the Academy of Natural Sciences, Philadelphia. This may prove to be identical with the specimen now standing as the type of P. oxygomtm Sby. in the Heniker collection. Pecten (Chlamys ?) sp. indet. l\ctcn opcrciilaris Gabb, Gcol. St. Domingo, p. 256, 1873 ; not of Linnc. Oligocene of St. Domingo; Gabb. This is a nearly smooth, ovate-oblong shell, with twenty-two nearly obsolete ribs, fading out at the submargins ; ears small, low, subequal. Alt. 70, lat. 58 mm. It is obviously not the European species with which Gabb too hastily identified it. Pecten (Chlamys) cactaceus n. s. PLATE 34, IMCIIKE 2. Tertiary of St. Domingo, Gabb; Pliocene of Tehuantepec, seventy kilo- metres west of eastern terminus of the railway, near the foot-hills of the elevated country, Spencer. Shell thin, fragile, compressed, nearly equilateral and equivalve, with ten to twelve sharp, narrow-keeled ribs, with much wider shallow interspaces, in which there are five or six fine, sharp radial threads; whole surface, when FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA ' ' perfect, covered with imbricating scales, those on the ribs triangular, apices basally directed, and similarly on a smaller scale, on the threads, between the keels and threads the imbrication is looped in an umbonal direction, sharp and rasp-like ; ears subequal, with close, sharp, concentric, elevated lines and a few subspinose radial threads ; interior grooved in harmony with the external ribs, the margins of the channels reinforced by lira; in the adult ; crura developed, notch shallow. Alt. 47, lat. 46, diam. about 8 mm. This is quite a distinct species, not particularly like any other described from this region and apparently a deep-water shell. The specimens in Gabb's collection are mixed with others identified by him as oxygonnm Sby., and their horizon is not definitely settled. Pecten (Nodipecten) nodosus Linne. /'•(V/v/ inxfi'sns Linnc (as Ox/tnt), Syst. Nat., No. 164, 1758. I't'clcn magnificus ('.abb, (leol. St. Dom., p. 256, 1873 ; from type, not of Sowerby, 1835. Oligocene of St. Domingo, Gabb (? Pliocene) ; Pliocene of Florida and the Antilles, Willcox. Living in the Antillean region. The shell named magnificiis by Gafjt) is merely one of the less nodose mutations of this wgll-lvjiown and variable species. • Pecten (Plagioctenium) excentricus ('.abb. /'•<•/<•// cxccnlricits ( '.abb, Geol. St. Dom., p. 256, 1873. Oligocene of St. Domingo; Gabb and Bland. Shell small, oblique, with about twenty-one low ribs, narrow and flattened on top, with subequal interspaces, both crossed by sharp, looped concentric lamellae; submargins smooth, ears small, with sparse radial lines; auricular crura pronounced, cardinal crura strong, with sharply incised cross-striation. This recalls a young specimen of subventricosus. Pecten (Plagioctenium) Gabbi Dall. PLATE 29, FICUKK 3. l',-i /<•>: ptinini-imis ('.abb, Journ. Acacl. Nat. Sci. Phila., 2(1 Ser., viii., p. 347, pi. 45, fif,r- 24, 1881 ; nnt of Orb., Voy. Am. Mer. 1'al., |). 135, pi. vii., figs. 5-9, 1849. Oligocene of Antigua, Spencer ; and of St. Domingo, Gabb. Shell broad, compressed, oblique, inequilateral, with nearly equal valves and about nineteen concentrically scabrous, longitudinally striated ribs, with narrower interspaces, each filled with one imbricated riblet. Alt. 48, lat. 52, diam. 13 mm. TRANSACTIONS OF WAGNER 718 TERTIARY FAUNA OF FLORIDA The Antillean species is quite distinct from that figured by Orbigny, and more nearly resembles his P. tehuclchus, which has a more inflated and rounder shell, with a much larger and less oblique posterior car. (Cf. Voy. Am. Mer., Mollusques, pi. 85, figs. 21 to 24.) Pecten (Plagioctenium) demiurgus n. s. PLATE 26, FIGURE 3. Pfcti-n fomparilis Guppy, Geol. Mag., Dec. ii., vol. i., p. 451, 1874; not of Tuomey and Holmes, 1855. (From types.) From the Caroni Series of Trinidad at Savanetta ; Guppy. This species, which is closely related to the Pacific coast P. ventricostis Sowerby, differs by its rounded and minutely squamose ribs, narrower um- bones, wider and less inflated shell, with the anterior ears more deeply inset. It has twenty ribs, smooth submargins, and a rather deep notch. Alt. 70, lat. 72, max. diam. 36 mm. The left valve is a little less inflated than the other. Pecten ritdis Gabb, as of Sowerby, from the Tertiary of Costa Rica, appears to be indeterminable. Pecten (Pseudamusium) Guppyi n. s. PLATE 34, FIGURES 12, 13. Oligocene of the Bowden marl, Jamaica, and of the Alum Bluff sand at Oak Grove, Santa Rosa County, Florida, Burns; and in the Pliocene marl of Port Limon, Costa Rica, Hill. Shell small, suborbicular, moderately convex, smooth, with the surface covered with microscopic Camptonectes striation ; ears small, the anterior slightly larger, all with very minute radiation and concentric lines ; notch narrow, small, with no ctenolium ; interior smooth, without line or developed crura; traces of the auricular crura alone perceptible; cardinal margin bearing a sharply cross-striated, very distinct provinculum; basal margins flattened, posterior margin slightly compressed. Alt. 6, lat. 6 mm. The abundance and uniformity of this little shell testify to its adult character. Occasional individuals show a thickened line internally on each side, on the lower edges of the submargins, like some recent species, and also traces of coloration in blotches. Amusium papyraceum Gabb. J'/i-iiroiicctia papyracca Gabb, Geol. St. Dom., p. 257, 1873. ? = Ann/sin in Mortoni Ravenel, 1844. Oligocene of Bowden, Jamaica, Henderson ; and of St. Domingo, Gabb. FREE INSTITUTE OF SCIENCE 7IQ TERTIARY FAUNA OF FLORIDA This species when young is more ovate, when adult orbicular. The um- bones are smooth, by which it may be instantly distinguished from P. (Aitni- sitti/t) Lyoni. Whether it can be separated from Atmisiiii/i Morloni Rav. or not will depend upon comparisons for which the material at my command is as yet insufficient. The species is still living in Antillean and Gulf waters. Alt. 50, lat. 55 mm. Amusium Lyoni Gabb. I'll -iiroiu-i tia Lyoni Gabb, Journ. Acad. Nat. Sci. Phila., 2d Ser., viii., p. 347, pi. 45, tig. '2$n-l>, 1881. J'ccttii Morlt'iti Guppy, <>/>. tit., p. 451, 1874. Oligoccnc of Anguilla, Guppy ; of Bowdcn, Jamaica, Guppy ; Pliocene of Tehuantepec, Spencer; and of Costa Rica, Gabb. This form, otherwise very similar, is immediately distinguishable from P. (A.) papyraccus by the nepionic sculpture of the umbonal region. Most of the recent Pectinidce of the Gulf and Antillean region are found associated with other recent shells in the raised beaches and reefs so numer- ous on the islands. It is not necessary to enumerate them here, but I may mention that Pecten (Envola) ziczac L. is quite abundant in the Pleistocene of Barbados. FOSSIL I'ECTENS OF THE FLORIDIAN REGION. The environs being now cleared, we may proceed to consider the species represented in the Floridian horizons and the adjacent portions of the south- eastern United States. Pecten (Pecten) Poulsoni Morton. /. Lcsticiir, Walnut Hills Kos., pi. 5, figs. 3, 4, 1829. /'<•. fit., p. "8, not of Dall. I'd- ten (Pseudamusiunt) striatus Dall, Bull. U. S. Nat. Mus., No. 37, p. 34, No. 40, 1889 (not of Miiller, fuic Yen-ill), young shell ; Verrill, op. fit., p. 96, in errata, 1897. Pleistocene of St. John, New Brunswick, and Gardiner's Island, New York ; living from Labrador southward, in increasing depths of water, to Cape Hatteras, North Carolina. The sculpture of the more northern specimens is less strong than in those from more southern habitat, and for the former Professor Verrill suggests the retention of Mighels's name taniicostatits (originally given to the young shell) in a varietal sense. This is not P. tcnuicostatus Hupe, in Gay's Chile, 1854. As previously noted, the writer sees no reason why Gmelin's name, given in error as to the true habitat of this species, but universally familiar, should not continue to be used. If, however, an exaggerated purism demands a change the next most appropriate name is that of Solander, given without description in the Portland Catalogue, described in the Banksian MSS., and cited by Humphrey as the Great Compass shell from Newfoundland, with nearly equal valves, remarks which cannot possibly apply to any other species. He not unnaturally places it after the species of Aniusium, as H. and A. Adams did in their Genera of Recent Mollusca (ii., p. 55) sixty years later. Pecten (Placopecten) virginianus Conrad. /',; /i-ii ^'ii-^iniiuuix Conr., Fos. Medial Tcrt., p. 46, pi. xxi., fig. 10, 1840. Miocene of City Point, Virginia; E. Ruffin. This is a puzzling shell, of which only the type specimen (a right valve) and one oilier valve are known. It appears like a young shell of /'. Clintonins in all essentials, except that it is more convex and has the byssal ear separated by a broad fasciole and deep notch from the submargin and is provided with a strong and conspicuous ctcnolium. The young shells of /'. Clintonms of the same size (altitude fifty-eight millimetres) as the type of virginianus have not these characters, as an examination of a large number has shown. A speci- men of the same valve from Coggins Point, Virginia, identified by Conrad as I'ii-giiiiainis, seems to me merely a young P. Clintonhis with a somewhat deeper notch than usual, but the original type specimen differs more markedly, and TRANSACTIONS OF WAGNER 728 TERTIARY FAUNA OF FLORIDA until intermediate specimens are obtained I should not feel justified in sup- pressing the species. Pecten (Placopecten ?) marylandicus Wagner. I'ecten marylandicus Wagner, Journ. Acad Nat. Sci. Phila., viii., p. 51, pi. 2, fig. I, 1838. l\\1cn tennis H. C. Lea, Trans. Am. Phil. Soc., 2cl Ser., ix., p. 246, pi. 35, fig. 33, 1845. Miocene of the Patuxent River, at Jones's Wharf, Maryland, Wagner; of Petersburg, Virginia, Lea; and the Mehcrrin River, North Carolina. I have examined the types of P. marylandicus in the Academy's collec- tion, and the type of Lea's species is in the collection of the National Museum. It is difficult to say to which section the species should be referred, as in the typical P. marylandicus the radiating threads often are gathered into fasci- cles (fifteen to seventeen) which crenulate the valve margin, while in P. tennis the threads are not fasciculated and the margin is entire. In the former the interior is fluted, in harmony with the external sculpture, while in the type of tennis the fluting is quite obsolete, though there are faint radial striations near the margin. In marylandicus the radial sculpture averages coarser than in tennis. Yet these differences march closely with those observed in a large series of P. hcriccns Gould from the northwest coast, and the other characters are so similar that I feel indisposed to assign specific rank to the differences. In the largest and finest specimens of P. marylandicus there arc fluctuated scales concentrically arranged on each side of a mesial thread, in the inter- spaces between the principal ribs. The shell attains an altitude of ninety and a width of ninety-five millimetres, and the byssal notch is deep and conspicuous. The species forms a transitional link between Placopecten and Chlamys s. s. Pecten (Nodipecten) nodosus Linnc. Ostrca nodosa L., Syst. Nat., Ed. x., p. 697, No. 164, 1758 ; Ed. xii., p. 1145, 1767. Pecten corallinus Chemn., Conch. Cab., vii., p. 306, pi. 64, figs. 609-1 1, 1784. Pecten nodosus Lam., An. s. Vert., vi., p. 170, 1819; d'Orb., Moll. Cuba, ii., p. 353, 1845. Pecten pcrnodosits Heilprin, Trans. Wagner Inst. , i., p. 131, pi. \6b, figs. 69, 69 a, 1887. Pecten nodosus Heilprin, op. cit., p. loo, 1887. /'i-cti-ii fmgosits Conr., Journ. Acad. Nat. Sci. Phila., 2d Ser., i, p. 214, pi. 39, fig. 11, 1849. Pecten inn^nif^tus Gabb, Geol. St. Dom., p. 256, 1873 ; not °f Sowcrby, P. Z. S., 1835, p. 109. Lyropeeten nodosus Verrill, Trans. Conn. Acad., x., p. 91, 1897. Pliocene of the Caloosahatchie marls, Florida, Willcox ; Pleistocene of FREE INSTITUTE OF SCIENCE 729 TERTIARY FAUNA OK FLORIDA the Antilles and the north coast of South America ; living in the Gulf of Mexico and the Antilles, and probably also (as /'. subnodosits) on the Pacific shores of middle America. (Cf. remarks under Lyropecten and P. sitbnodosus Sby., pp. 701, 710.) This species is the type of the section Nodipcctcn. It varies in the number of ribs (seven to ten) and extremely in its amount of nodulation. Some specimens have merely turgid undulations of the ribs, as in the form first described of the Pacific siibnodosiis. Others bear subglobular bulLne on the ribs at short intervals. Others begin without nodes and after half their growth is accomplished suddenly become nodulous. P. siibnodosits varies in the same way. The deeper the water, apparently, in which the individual lives, the thinner and more nodose the shell. Mr. Willcox found some remarkably fine specimens in the marls of the Caloosahatchie. Pecten (Nodipecten ?) peedeensis Tuomey and Holmes. l't-cti-n pfi-Jfi-nsis T. and H., I'leioc. Fos. S. Car., p. 30, pi. 12, figs. 1-5, 1855. Miocene of the Peedee River, Darlington District, South Carolina, and of Virginia. This fine species frequently has the younger part of the shell nodose and the distal portions of the ribs wider, feebler, and less nodose. It has eight or nine ribs and conspicuous concentric lainellation. It seems nearly inter- mediate between the Lyropecten and Nodipcctcn types, and may belong to the section Macrochlamis Sacco (Bull. Mus. Zool. Torino, xii., No. 298, p. 101, June, 1897, type P. latissimns Brocchi). Pecten (Nodipecten) condylomatus n. s. PLATE 34, FIGURES 14, 15. Oligocenc of White Beach, Osprcy, Florida, and of the Chipola River at Bailey's Ferry, Florida, Burns and Dall ; lower bed at Hawkinsville, Georgia, Burns. Shell small for the group, subequilatcral, slightly inequivalve, the right valve more convex with nine to thirteen strong, undulated, rounded, more or less nodulous, finely radially striated ribs, the undulations affecting the whole of the disk, sudden and very pronounced, giving a side view of the valve somewhat the aspect of a clenched fist ; interspaces narrower radially, finely threaded, the whole valve with fine concentric lamellation somewhat prickly or limose at the intersections ; submargins rather wide, radially finely TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA striate ; ears small, subcqual, the surface coarsely radially threaded, the byssal ear produced with a conspicuous sinus and fascicle; ctenolium well marked ; inner basal margin fluted by the ribs ; cardinal margin with two or three strong crural ridges. Alt. 40, lat. 45, diam. about 22 mm. This is an interesting species, peculiar from its small size and the abrupt- ness of its knuckle-like undulations. Some specimens, however, are but little undulated, and the mutations are much the same as occur in other species of the section. The following species, while they are related by sculpture, form, and con- chological character to the Nodipecten type, are not known to form nodules ; the ribs may be slightly tumid at intervals or periodically undulated, but there are no hollow bullse, as in the more typical forms. But these characters are precisely those of the non-nodulous varieties of the nodulous species, and so I feel justified in including them in this section. Pecten (Nodipecten) anatipes Morton. Pecten anatipes Morton, Am. Journ. Sci., xxiii., p. 293, pi. 5, fig. 4, 1833 ; Syn. Org. Rcni., p. 58, 1834. Oligocenc of Mississippi, Vicksburgian horizon, at Heidelberg and in Jasper County ; Johnson. The shell is small, with five or six ribs and narrower feebly striated inter- spaces ; cardinal crura well developed. Pecten (Nodipecten) pulchricosta Meyer and Aldrich. Pecten piileliricosta M. and A., Journ. Cin. Soc. N. H., ix., p. 45, pi. 2, figs. 23, 23 a, 1886. Jacksonian Eocene of Wahtubbee Hills, Clarke County, Mississippi; Aldrich and Burns. Shell small, thin, with eight large ribs, which near the umbo arc divided by one or two well-marked sulci, which soon become obsolete, after which the ribs are simple; the surface sculpture is of even, uniform, crowded, concentric elevated lines. The ears are subequal, the byssal notch well marked. Neither in Meyer's figure nor in the specimens do I find the ribs dividing near the basal margin, as stated in his diagnosis. Pecten (Nodipecten) Rogersi Conrad. 1'ecteti Rogers! Conrad, Journ. Acad. Nat. Sci., 1st Scr., vii., p. 151, 1834; Medial Tcrt, p. 45, pi. 21, fig. 9, 1840. FREE INSTITUTE OF SCIENCE 7 i1 TERTIARY FAUNA OF FLORIDA Miocene -of the James River, near Smithfield, Virginia, and of Maryland, near Skipton ; Conrad and Harris. Shell with four large and two smaller lateral simple ribs, internally lirate; submargins narrow, minutely scabrous, not radiated ; the rest of the disk entirely covered with fine, squared, elevated, minutely scaly radial threads ; ears subequal, finely radiated; sinus well-marked; ctcnolium and cardinal crura developed. Alt. of type 20, lat. 19 mm. This is not the Pecten (Pseudamttsium f) Rogersi Clark, Bull. U. S. Geol. Surv., No. 141, p. 85, pi. 34, figs. 2 a-b, 1896, from the Eocene of Potomac Creek. Front Royal, Virginia. For the latter the specific name of frontalis is suggested, since there is already a species named for Professor Clark. Pecten (Nodipecten) caloosaensis n. s. PLATE 29, FICI'KH 12. Caloosahatchie Pliocene marl of the Caloosahatchie River and Shell Creek; Willcox and Dall. Shell moderately large, with four principal ribs and sometimes a sub- sidiary, much smaller, rib at the inner edge of the submargins ; backs of the ribs strongly radially striated or even threaded, the interspaces smooth or with only obsolete traces of striation, equal to or wider than the ribs ; concentric sculpture usually weak, of close-set concentric elevated or incremental lines ; submargins wide, the outer margins smooth, the inner threaded like the backs of the ribs ; ears large, triangular, widest at the cardinal margin and pointed at the distal cardinal angle, their sculpture radial, not crowded; feeble, except upon the byssal ear, where the threads are strong and concentrically scabrous ; byssal notch wide, shallow, the fascicle conspicuous ; ctcnolium distinct ; in- terior reflecting the external ribs; hinge with the crura present but feeble in the young; the old specimens have them obsolete, but on the cardinal margin a relatively broad ligamentary area is formed. Alt. 83, lat. 80, diam. 30 mm. This is one of the finest and most characteristic species of the Pliocene, remarkable for its wide, acute ears, and for having the interspaces of the ribs nearly smooth, although the ribs arc striated. Pecten (Nodipecten) antillarum Recluz. /'•(/(•// niililliiritiii Rcrlux, Jmirn. de Condiyl., iv., p. 153, pi. 5, fi£. I, 1853 (May); I'cau, l 'at. Coq. (uiadelupc, p. 21 ; Anin^ii, Fauna Mai. Cubana, ii., p. 209, 1878. l\'itiii fiim/its Reeve, Conch. Icon., l\-ctfii, pi. xxxi., li;^. \y), 1853 (June); Krebs, \V. I. Mar. Shells, p. 134, 1864. TRANSACTIONS OF WAGNER 7-J2 TERTIARY FAUNA OF FLORIDA Pet-ten (P.-ii-iii/ir/iutssiinii) argenteus Marrat, Argo ExpecL, p. 7, 1876 ; not pf Reeve. (An immature specimen.) Peeten sukatus Krebs, W. I. Mar. Shells, p. 134 ; not of Lam. Pliocene and Pleistocene of the Antillean region ; living in Cuba, Guade- lupe, the Bahamas, and the Florida Keys. This species is often destitute of the nodosities, and in that condition is referable to Chlainys. The very young shell is thin and glistening, in which state it has been mistaken for the Chinese P. argcntcus Reeve. Old and worn specimens have been taken for P. sulcatus Lam. Its analogue and precursor in the Antillean Oligocene is the P. anguillcnsis Guppy. Pecten ( ^Jquipecten) perplanus Morton. J't-cten sp. Lesueur, Walnut Hills Fos., pi. 5, fig. 2, 1829. Pecten perplanus Morton, Am. Journ. Sci., xxiii., p. 293, 1833 ; Org. Rem., p. 58, pi. 5, fig. 5, and pi. 15, fig. 8, 1834. Pecten Spillmani Gabb, Journ. Acacl. Nat. Sci., 2cl Ser., iv., p. 402, pi. 68, fig. 3, 1860. Eocene of St. Stephen's, Alabama, Morton ; of the Jacksonian at Jack- son, at Turk's Cave, Cocoa Post-Office, Choctaw County, and Fair Post-Office, near Claiborne, Alabama; at Pachula Creek and Shubuta, Clarke County, Mississippi; in the Vickburgian or Lower Oligocene, near Gainesville, Alachua County, at various localities in Levy County, and in the Nummulitic horizon at Ocala, Florida, Ball, Burns, and Johnson ; Grant Parish, Louisiana, Johnson. Shell with twenty-three to twenty-five subangular ribs with sloping sides and equally wide shallow interspaces, an obsolete thread on each side of the median keel of each rib, stronger on the side away from the middle of the valve ; in large ones another thread begins near the basal margin ; whole shell covered by regularly spaced low, thin concentric lamella;, not crowded, which are slightly produced as a little linguiform process over each rib and thread, more prominent on the right valve, which has rather small, short ears, with three to five spinose or imbricate radii, and a conspicuous but not deep byssal notch ; left valve with sharper keels, feebler concentric lamellae, subequal ears, with five or six low beaded radii ; shell plump in both valves, internal margin strongly fluted ; hinge with the cardinal crura strongly developed and cross- striated. Alt. 34, lat. 35 mm. A full description is given, as I have found this shell much confused in nearly all the collections with P. Poulsoui, P. niipcms, and others. The types of P. perplanus and P. Spillmani have been compared and their identity fully FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA confirmed. /'. imperils belongs to the section Chlamys and, though with very similar sculpture, is a more elevated and less rotund species. Worn speci- mens of perplanus which have lost the scaly sculpture have a very different aspect and are often puzzling. A variety has the threads with minute crowded scales, while the tops of the ribs arc smooth, giving them a laterally fringed appearance; these specimens have twenty-two ribs only. This form was obtained at the Natural Bridge, Alachua County, Florida, and in the lower bed (Hawthorne horizon) at Hawkinsville, Georgia, by Burns. Pecten (perplanus var. ?) centrotus Oall. PLATE 34, FIGURE 21. Eocene (Vicksburgian ?) of the Ponce de Leon artesian well, St. Augus- tine, Florida, at a depth of two hundred and twenty-five feet; Willcox. Shell like the preceding, with twenty-three flat-topped smooth ribs with lateral fringes which wholly fill the interspaces but do not unite in the middle of the channel. Two or three of the ribs near the middle of the disk show six to eight distant, regularly spaced short spines projecting from their tops; the other ribs are destitute of spines. Interior sharply and deeply grooved to correspond with the external ribs. Alt. 2O, lat. 18.5 mm. The single valve obtained is somewhat defective, but its sculpture is so different from any of the other forms that it seemed best to describe it. Pecten (^Equipecten ?) choctavensis Altlrich. l\\-tt'>i tlun'tavi-nsis Aldrich, Harr. Bull. Pal., ii., p. 68, pi. 5, fij;. 7, 1895. Eocene of Wood's Bluff, Choctaw County, Alabama; Aldrich. This shell when not worn has a very flat imbricated sculpture over-all, pointed on the backs of ribs and riblets, the surface on the interspaces being quincuncially microscopically punctate. It is rather flat for an sEquipectcn, and is one of the many peripheral species uniting the different sections. Pecten (.SDquipecten) chipolanus n. s. 1'l.ATK 21). KlCURK Q. Upper Oligocene of the Chipola marls, lower bed at Alum Bluff, and the silex beds at Ballast Point, Tampa Bay, Florida ; Dall and Burns. Shell solid, rounded, plump, with fifteen to seventeen strong, rounded ribs with narrower interspaces which arc almost channelled, both ribs and chan- nels with continuous fluctuated, sometimes crowded, low concentric lamellae ; TRANSACTIONS OF WAGNER 7 >4 TERTIARY FAUNA OF FLORIDA the ribs faintly grooved distally on top; the concentric sculpture sometimes strong on three or more ribs and almost absent on the intervening ones; hinge-line wide, ears large, with conspicuous but not deep notch, with six or seven coarsely imbricated, close-set radial threads on the byssal car and more numerous threads on the others ; submargins nearly smooth ; cardinal crura strong; inner basal margin with strong, short flutings, obsolete above. Alt. 25, lat. 25, length of hinge-line 18 mm. Pecten (-33quipecten) suwaneensis n. s. Vicksburgian of Suwanee County, Florida ; Johnson. Shell with twenty-two entire, rounded ribs, with narrower, rather shallow interspaces crossed by little raised, concentric, not crowded, more or less fluc- tuated laminae continuous over ribs and spaces, with lateral grooves on the ribs near the basal margin ; submargins narrow, smooth ; ears subequal, moderate, with fine, close, concentric sculpture and four or five distant fine imbricated radii; notch distinct, rather deep. Alt. 20, lat. 20 mm. This form differs from P. Kneiskemi by its uncliannelled interspaces, con- tinuous concentric lamellae, and subequal ears; from /'. cliipolntnts by feebler and more numerous ribs, shorter ears, and less conspicuous sculpture. It is flatter, thinner, and smaller than the weakest specimens of /'. pet-plaints, and while its characters are not marked, docs not seem to be linkable with any of the others of its section. P. nnfcnis, which is the nearest to it among the species of Chlamys, has a more solid shell, more sharply keeled ribs, and differently sculptured ears, while its form is decidedly more ovoid. Pecten (.^Equipecten) glyptus Veirill. 1'cctfn glyptus Verrill, Trans. Conn. Acad., v., p. 580, 1881; Dall, Proc. U.S. Nat. Mus., xii., p. 248, pi. 8, fi>s. 2 and 3, 1889. /'iYti-n 7Vjw//I)all, Bull. Mus. Gomp. Zoo]., \\iii., p. 438, 1887. Chlamys (/Eqvip&cttri) glypta Verrill, Trans. Conn. Acad., x., p. 76, 1897 ; in part. This species is cited here as the only true living representative on our coast of the section sEquipecten, and it is rather more inequilateral than typical species of that group. It has been found from the vicinity of Cape Ilatteras to the continental bench off Martha's Vineyard. Professor Verrill's specimens were very imperfect, and some worn fragments of another species, P. plirygiittn Dall, were confused with those belonging to P. glyptus in Pro- fessor Verrill's cited paper. Of his figures on plate xvi., 7, 10, and per- FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA haps 1 1 represent badly worn P. plirygiitin, while figs. 8 and 9 are taken from the worn type of /'. glyptus. Perfect specimens of the latter are in the National Museum and were figured as above cited in its Proceedings. It is not yet known in the fossil state. Pecten (Chlamys) islaiidicus Miillcr. I'l-i/iit is/iiiii/ifiis Miillcr, 1'roclr. X.ool. Dan., p. 248, 1776. Os/i'i'ti ctnnabarina Horn, Test. Mus. Vinci., p. 103, 1780. I',; ti-n nihiiius Martyn, Univ. Conch., No. 153, pi. 53, fig. I, 1784. Os/iTti t/f/iiissii Solander, Mus. Calonn., p. 52, 1797. I'ccli-n l\-ali-ii Conr. , Am. Mar. Conch., I, p. 12, pi. 2, fig. 2, 1831. /'•(•//•;/ l-\il>riiii 1'liil., Abb. uiul ]!eschr., iv., p. 3, pi. i, fig. 5, 1844. Chlaiiivs i<'*/cl/itta \'crr. and ISush, Trans. Conn. Acad., x., p. 75, 1897. (Very yninr. shell.) Pleistocene of New England and New Brunswick and northward in the bowlder clays, also on the North Pacific coasts in deposits of the same age ; living from the Arctic waters southward to Chesapeake Bay. The minute shell described by Professor Verrill under the name of cos- tcllata is less than five millimetres long and has not assumed the adult char- acteristics. From an examination of the type I see no reason to doubt that it is a very young specimen of the present species. This shell is the type of the subgenus Clilamys. Pecten (Chlamys) Kneiskerni Conrad. J'fctt-n k'lu-iskcrni Conr., Am. Jotirn. Conch., v., p. 40, pi. I, fig. 18, 1869. I'l'iU-n Knciski-rni WhittieUl, Lam., N. J., p. 224, pi. 29, fig. 5, 1885 ; in part. Eocene marl of Shark River, New Jersey, Conrad ; Jacksonian Eocene of Claiborne, Alabama, and Enterprise, Mississippi, Johnson; Oligocene of the Chipola beds, Monroe County, Florida (?), Burns. In Professor Whitfield's attempt to identify the cast of an immature shell named as above by Conrad, the former has evidently brought together the young, uncharacteristic shells of several species of Clilamys. Conrad's shell was described as having thirteen ribs and none on the submargins ; Whitfield gives the species fifteen to fifty ribs and radiated submargins. This is a range altogether too great for a single species. Probably some of Professor Whit- field's specimens were young choctaveusis, which has an unusually large number of ribs. I have supposed a shell from the Jacksonian might represent the unidentifiable species of Conrad. This has twenty-live ribs, divaricating TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA near the base with rather sparse concentric imbrications ; ribs wider than the interspaces, entire in the young ; valves rounded ; ears rather small with concentric imbricated radii and rather deep byssal sulcus. Another form, which apparently has not yet taken on its adult character- istics, has been described from the same beds by Whitfield under the name of P. Rigbyi. It is said to have from twenty-two to twenty-six ribs with strong, close concentric scales. It differs from Kndskerni, according to Whitfield, by its wider and stronger ribs with closer and more prominent imbrication. (Whitfield, op. at., p. 226, pi. 29, fig. 6, 1885.) Pecten (Chlamys) membranosus Morton. I'atcn ineiiibranosus Morton, Org. Rem., p. 59, pi. 10, fig. 4, 1834. Pecten carolinensis Conr., Kerr, Rep. Geol. N. Car., App., p. 18, pi. 3, tig. 2, 1875 ; not Lyropecten carolinensis Conr., 1875. Eocene of Jones County, Haldeman; of Rocky Point and Wilmington, North Carolina, Stanton ; Eutaw Springs, South Carolina, Conrad. This somewhat resembles the recent P. ornattts Lam., but is shorter and more orbicular. There is no question of the identity of Mr. Conrad's P. carolinensis with Morton's species ; I have compared the types. Pecten (Chlamys) wahtubbeanus n. s. PLATE 34, FIGURE 9. Claibornian and Jacksonian Eocene of Louisiana, Alabama, and Mis- sissippi ; abundant at Wahtubbee ; Burns. Shell small, flattish, with small, unequal ears and rounded disk; fourteen or fifteen ribs carrying basally three densely finely imbricated, rounded threads, the interspaces narrower with two crenulate threads ; submargins with close, fine, imbricate threads ; ears prominent, with a deep, wide byssal notch, radi- ately imbricate with coarse, elevated radial threads ; interior with shallow sulci, the cardinal crura developed but no lirae on the disk. Alt. 22, lat. 22 mm. This species differs from the Claibornian P. Deshayesii Lea by its threaded and less individualized ribs, its similarly sculptured valves, more conspicuous notch, and concentric sculpture and smaller size when adult. /'. fohnsoni Clark, from the Maryland Eocene, has more numerous ribs with simpler sculpture, and which increase by intercalation instead of dichotomy. A shell which I suppose to be the same as Clark's was obtained from the Jacksonian of Clarke County, Mississippi, by Johnson. FREE INSTITUTE OF SCIENCE 7^7 TERTIARY FAUNA OF FLORIDA '**' rccten Johnsoni Clark (Bull. U. S. Geol. Surv., No. 141, p. 85, fig. 3 a, 3 /;, 1896), from the Eocene of Maryland, is a young shell, not fully exhibiting the adult characters, and of which the type specimen seems worn. It belongs in this vicinity, but has twenty ribs, with single short intercalary threads, crossed only by fine lines of growth. The specimens were obtained from Potomac Creek, Va. Pecten (wahtubbeanus var. ?) Willcoxii n. s. PLATE 29, FIGURE 4. Eocene of Clarke County, Mississippi, and of the Wahttibbee hills (Claibornian) ; Johnson and Burns. Shell small, broad, flattish, thin ; left valve with about sixteen narrow, rounded, elevated ribs, with somewhat sparse, regularly spaced prickles on their tops ; between the ribs are similar, but lower and smaller, non-dichoto- mous radial threads; submargins very narrow, nearly plain, with faint Cainp- tonectcs striation ; ears small, subequal, except the byssal ear, which is longer, narrow, with a deep sinus and conspicuous fascicle, and about six scabrous radii, the right posterior ear with concentric striae and only faint traces of a few radii ; the cars on the left valve similar, with five or six strong scabrous threads ; internal basal margin of left valve with short flutings in harmony with the radial sculpture ; the disk not grooved ; in the right valve the internal channels are more pronounced ; the right hinge-line has a single crural ridge parallel with the margin on each side of the pit. Alt. 23, lat. 24 mm. This form is closely related to P. wahtubbeanus, from which it differs by the isolated character of the prickles on the ribs, which are replaced in ivah- tubbeaiins by more or less continuous concentric lamellation, while the ribs of the right valve of the latter are more or less split up, but in P. Willcoxii present the appearance of a fascicle of separate threads. In worn specimens of wahtubbeanus the ribs appear rounded and plain after the removal of the scales ; in Willcoxii the division into threads is distinct. Nevertheless it is possible that a larger series may show the two forms to be merely the ex- tremes of a single species. From P. tnembranosiis the present form is easily distinguished by wider hinge-line, larger ears, thinner shell, and by its radial threads fasciculated rather than subequally level. It is named in honor of Mr. Joseph Willcox, to whom our Tertiary Paleontology is so much indebted. Pecten (Chlamys) Deshayesii I.ca. l',i I, n n,-sliity<-sii l.c;i, Ccinlr. (Ii-ol., p. 87, pi. 3, li^. C>6. 1833. 1',',/,-n I.y,-lli I.ea, «/>. !. 21, fig. 15, 1,890. / J'l-cii-n iiiiiuitits Lea, ('/. <•//., p. 88, 1833. Not /•". Dcsliaycsii^A, Coq. et Polyp. Fos., p. 288, 1845. Jacksonian of St. Stephen's Bluff, Tombigbee River, Alabama, of Clai- borne, Mississippi, and four miles west of Live Oak, Florida; Burns and Stanton. This species is positively known to occur in the Jacksonian at Claiborne and elsewhere, but I have obtained no specimens from the vast amount of marl belonging to the true Claibornian sands horizon which has come under my notice. The shell is rather variable, losing the concentric sculpture when worn. It has fifteen to twenty-one ribs; the byssal notch is inconspicuous; in the right valve the ribs are strong and rounded on top with the concentric sculp- ture chiefly evident at their sides, the interspaces sparsely imbricated with one or two interstitial divaricate threads near the base; ears flattish, slightly scaly, with radial grooves, notch very shallow; left valve with the sculpture like that of P. wahtiibbcamis but much less dense. Altitude and latitude forty- eight millimetres. There is hardly any room for doubt that Lea's other species are merely the immature stages of this same shell. Pecten (Chlamys) cocoanus n. s. PLATE 34, FIGURE 23. Jacksonian Eocene of Red Bluff, Mississippi, and Cocoa Post-Office, Choctaw County, Alabama ; Burns. Shell small, thin, flattish, oblique, produced behind, with about twenty- five small, low, entire ribs, rounded above, and about fourteen interstitial single smaller threads, the tops of all of which are somewhat sparsely concentrically imbricated, the interspaces showing only incremental lines; ears quite unequal, small, the posterior smaller, each with five or six low, hardly scaly radii ; inside of the valve obsoletely channelled, the cardinal crura developed. Alt. 23, lat. 23 mm. This shell differs from P. iiicinbranosus by its entire and less numerous ribs, and from P. W&htubbeanus by its greater obliquity, its entire, less con- spicuous, and less densely imbricated ribs. Peoten (Chlamys) G-reggi Harris. J'l-i ten (ir/^f Hani.s, Mull. Pal., i.\., p. 45, pi. vii., figs. 4-5, 1897. FREE INSTITUTE OF SCIENCE 7 >9 TERTIARY FAUNA OF FLORIDA Lignitic or Chickasawan Eocene at Bell's, Greggs's, and Peach Tree Landings, Alabama, and Fort Gaines, Georgia. This species is well distinguished by its narrow, simple, often distally obsolete ribs, usually about twenty-four in number, with wider interspaces, thin shell, small ears, and ovate form. Pecten (Chlamys) clarkeanus Aldrich. Pcitcn I'liirkcanus Aldr., Harr., Hull. Pal., 2, p. 68, pi. 5, fig. II, 1895. Eocene of the Lisbon horizon, Sowilpa Creek, Alabama, Aldrich ; and at Black Bluff Shoals, Brazos River, Texas, Lea collection. This species resembles worn specimens of P. u'alitiibbcaiins, from which it differs by its more numerous (thirty to thirty-eight) ribs and its singular habit of intermitting the production of ribs altogether at times, so that the beak will show well-defined ribbing and a part of the disk be perfectly ribless, while later on the ribs may appear again. It should be noted, however, that only about three out of ten valves show the latter feature, the others having continuous plain ribs from beak to margin. Some of the forms included by Whitfield under P. Kneiskcrni may belong here. Pecten (Chlamys) nuperus Conrad. I'ct It'ii nupi-nts Conrad, Proc. Acad. Nat. Sci. Phila., vii., p. 259, 1854. I\-i ten niipt'nim Conrad in \Yailes, Geol. Miss., p. 289, pi. xiv., fig. II, 1854. Jacksonian Eocene of Jackson, Mississippi, Conrad and L. C. Johnson ; Montgomery, Grant Parish, Louisiana, Vaughan ; Russell's Springs, Decatur County, Georgia, Pumpelly; also in the Vicksburgian at Arredondo, Florida, Johnson. This species has been very generally confounded with P. perplanns Morton, from which to a casual glance it chiefly differs by its chlamydoid form. On more careful inspection, however, it will be observed that P. nuperus has fewer ribs (circa twenty-two), which, though somewhat similarly scabrous, are not accompanied by beaded lateral threads ; the ears are higher and larger, the submargins wider, longer, and more conspicuous, and the radii of the ears are formed by rows of sparse, fluctuated, little-elevated scales, rather than by threads. The ribs of the disk in adults are keeled, with V-shaped narrower interspaces, the whole sculptured with continuous, fluctuated, con- centric, rather close-set, little-elevated, very thin lamella, which are usually worn off more or less. In the right valve, as well as in young or worn speci- 12 TRANSACTIONS OF WAGNER 74° TERTIARY FAUNA OF FLORIDA mens, the ribs are more rounded. On the whole, the species appears to be sufficiently well discriminated. The only other described Eocene species from the Atlantic coast is P. anisopleura Conrad (Kerr, Geol. N. Car., App., p. 18, 1875), the type of which is a large, heavy shell which has lost its hinge, and was collected by Dr. Yarrow " forty miles south of Beaufort, North Carolina," which would put its locality near New River, Onslow County. It is of ovate shape, with large, squarish ears, and very irregular, large, radial, strongly but sparsely scabrous ribs, rounded above with two or three smaller riblets on each side more depressed than the centre of the rib. Alt. 85, lat. 70 mm. The shell is much bored by pholads and badly wormeaten and worn. It looks like a dilapidated valve of Hinnites or Spondylus, and its horizon is entirely uncertain. Pecten (Chlamys) alumensis n. s. PLATE 34, FIGURES 10, n. Oligocene of the Chipola horizon, in the lower bed at Alum Bluff, Chattahoochee River, Florida ; Ball. Shell small, thin, with compressed, flattish umbones and fourteen or fifteen feeble, obsolete ribs on the lower part of the disk separated by equal shallow interspaces; the whole surface marked with fine concentric lines; ears subequal, concentrically striate, not radiated, except the byssal ear, which has five scabrous riblets and a well-marked notch ; interior fluted to corre- spond with the external ribs; the cardinal crura developed. Alt. reaching 15-18 mm. in fully adult shells; figured specimen 8, lat. 7.5 mm. This small shell is sufficiently distinct in its characters to indicate its specific rank, though it may be that it attains a larger size when adult than any of the specimens obtained. One or two of the specimens have the ribs more rounded and prominent than the majority. Pecten (Chlamys) tricenarius Conrad. Pecten tricenarius Conr., Proc. Acad. Nat. Sci. Phila., i., p. 306, 1843 ; Fos. Medial Tert., p. 74, pi. 42, fig. 2. (Miocene?) Pamunkey River, Virginia; Tuomey. Of this species only the type is known, and the horizon is uncertain. It has somewhat of the outline of P. pcrplamts, but has a smaller shell and larger ears. The disk shows thirty-five rounded, nearly smooth, not dichoto- mous ribs, somewhat irregular in size, will) equal interspaces, smooth and FREE INSTITUTE OF SCIENCE 741 TERTIARY FAUNA OF FLORIDA uniform. The ears are radially threaded, the byssal ear with four riblets over a rather wide and deep notch. The submargins are short and small, with traces of Camptonectes striation but no radial sculpture. The type is in the Academy's collection. Pecten (Chlamys) decemnarius Conrad. Pcctcn liccciiiiuirins Conr., Journ. Acad. Nat. Sci. Phila., vii., p. 151, 1834; Fos. Mod. Tort., p. 49, pi. 24, fig. 2, 1840. /<•<•/<•« i/ispa/atiis Conr., Fos. Med. Tert., p. 74, pi. 42, fig. 3, 1845. Miocene of City Point, Coggins Point, and York River, Virginia, Burns and Harris; Pamunlcey River, Virginia, Conrad; also in the Ashley River phosphate rock, of South Carolina, Ball. This species is notably irregular in its sculpture, the disk being sculptured cither by numerous more or less distinctly fasciculated, small, radial threads, or the fasciculi may be replaced partially by stout, elevated, rounded ribs, with wide, radially threaded interspaces. The radial sculpture may be nearly smooth or covered with a conspicuous, dense, concentric lamellation. Three or four of the ribs may be more prominent than the others, and the smaller ones uneven in size and rugose, forming the variety dispalatits. When the fasciculi arc rib-like they are usually dichotomous. The umbonal region in typical dccfmnarins is usually feebly sculptured, but in the variety dispalatus the ribbing approaches the beaks more nearly. The type of the latter has been carefully compared, and the ears and surface agree exactly with those of the decemnarius form. Large valves of the latter attain a height and width of sixty- eight millimetres ; the type of dispalatus measures twenty-four millimetres. The cardinal crura are parallel with the hinge-line and moderately developed. The byssal notch is wide and conspicuous, the posterior ears small. In sculpture this form almost exactly parallels the recent northwest American /'. hcriceits in its mutations. Pecten (Chlamys) coccymelus n. s. PLATE 34, FIGURE I. Miocene of Plum Point, Maryland ; Clark. Shell small, ovate, inflated, strongly sculptured, with unequal ears; disk with eighteen narrow, high, compressed ribs, with wider interspaces, which near the basal margin carry one or two very small radial threads; the backs of the ribs support numerous high, evenly spaced, distally guttered, small spines ; in the interspaces only transverse sculpture of wavy incremental lines ; TRANSACTIONS OF WAGNER 742 TERTIARY FAUNA OF FLORIDA submargins small, narrow, with fine, beaded radial threads, which in the left valve also extend over the ears ; hinge-line short, the cardinal crura developed, sharply cross-striated; auricular crura present; interior of the disk fluted in harmony with the external ribs. Alt. 30, lat. 25, semidiam. 5 mm. A single left valve of this elegant species was obtained. From the young of P. Madisonius, which sometimes approach it, it is easily distinguished by its more oval and inflated form, nearly smooth interspaces, and compressed ribs. Pecten (Chlamys) Harrisii n. s. PLATE 34, FIGURE 24. Pliocene marls of the Caloosahatchie River; Dall and Willcox. Shell strong, rounded, with seventeen coarse, rounded ribs with narrower interspaces, overrun by close-set, prominent, slightly wavy, strong concentric lamellation ; near the basal margin the ribs and interspaces are marked with a few sharp radial stria? ; submargins and ears with smaller radial threads similarly lamellose ; notch narrow, deep ; ctenolium present, short ; interior of the disk strongly fluted, lirate ; cardinal crura strong, auricular crura feeble. Alt. and lat. 31, semidiam. 7 mm. A single adult right valve and numerous immature ones were obtained. The valve figured is a little irregular. The young shells are proportion- ately flatter and with wider ears. They have, as often observed in the young of P. exasperatus, in some cases three or four of the ribs more prominent than the rest, and the lamellation worn off from the tops of the ribs or in- complete there. The species is named in honor of Professor G. D. Harris, of Cornell University, whose work on the Eocene fossils of the Southern States is well known. Pecten (Chlamys) exasperatus Sowerby. '? Pecten nniscosus Gray, Wood's Ind. Test. Suppl., pi. 2, fig. 2, 1828 ; Sby., Thcsaur. Conch., Pecten, p. 66, pi. xix., fig. 225, 1843 ; Reeve, Conch. Icon., viii., pi. 16, fig. 60, 1853. " South Seas." Pecten exasperatus Sby., Thesa'ur. Conch, i., p. 54, pi. 18, figs. 183, 184, 186, 1843 ; Reeve, Conch. Icon., viii., pi. 2, figs. 7, &a-l>, 1852; Dall, Bull. U. S. Nat. Mus., No. 37, p. 34, 1889. "Mediterranean." Pecten triradiatus Reeve, Conch. Icon., viii., pi. 28, fig. 120, 1853 ; not of Miiller, Zool. Dan., ii., p. 25, 1788. Pecten cretatus Reeve, op. cit., pi. 29, figs, \2ga-b, 1853. Pecten fuscopurpurcus Conn, Journ. Acad. Nat. Sci. Phila., N. S., i., pp. 209, 280, pi. 39, fig. 10, 1849. Tampa, Fla. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA Pliocene of Costa Rica, Gabb, and of the Caloosahatchie marl at Shell Creek, Willcox; Pleistocene of Florida, South Carolina (Simmons Bluff), and of the Antilles; living from Cape Hatteras, North Carolina, to Guadelupe Island, West Indies. The figures given of iiniscosiis disclose no differences in the minor sculp- ture or the number of ribs, and there are no discrepancies in the description, compared with that of exasfcratiis. The locality originally given for the latter has not been confirmed, and that given for inuscosiis may prove erroneous. In this case, the latter name would take precedence. I have little doubt of their identity, but do not unite them because I have seen no authentic speci- mens of nniscosus. The present species is moderately tumid, and has a scabrous sculpture besides traces of the Camptonectes striation. The backs of the ribs are set, in perfect specimens, with small, sometimes clavate spines, and there are from one to four fine threads on each side of the main keel which are usually more or less prickly. The middle of the interspaces is, however, usually free from the radial sculpture. Adult specimens with the spines considerably worn are such as Conrad called fuscopurpureus. The colors of the shell are very varied, including brown, white, yellow, pink, and various shades of red, either simply unicolored or mottled. In the mottled brown ones it is common to see from three to five of the ribs uniformly white from end to end, or of a lighter color than the rest ; this forms the triradiatus type. I have examined sixty-nine adult valves, of which ten had seventeen ribs, thirty-three had eighteen ribs, twenty-three had nineteen ribs, and three had twenty ribs; the normal number, therefore, being eighteen to nineteen. The young shells are more rotund than the adults, and their ears are proportionately more con- spicuous. Guppy (Geol. Journ., xxii., p. 294) cites this species as occurring in the Oligocene of Jamaica, but the specimens he refers to present certain differences and are probably distinct. Pecten (Chlamys) ornatus Lamarck. I'-t ti-it urnatus Lain., An. s. Vert., vi., p. 176, 1819; Reeve, Conch. Iconica, xix., fig. (>K, 1853. .' <)x/>;;i .wrfi-f, 37 c, not fig. 37 a, 1852. /'•i /<•;; Soi',-rl>ii (luilding, it pin-piiratiis Conrad, Am. Mar. Conch., p. 10, pi. ii., fig. I, 1831 ; DeKay, Zool. N. Y., v., p. 174, 1843 ; not of Lamarck. Pcctcn t/is/in-a/us Holmes, Post-Pi. Fos. S. Car., p. 13, pi. ii., fig. 13, 1858. l\-ct,-n citntliiris Ciiippy, I 'aria Fauna, p. 155, 1877 ; not of Sowerby. I'l-i-tt-n gibbits Orb., Moll. Cuba, ii., p. 352, 1845 ; Krebs, W. I. Mar. Sh., p. 134, 1864; Arango, Fauna Mai. Cubana, ii., p. 270, 1878. l\;t,-n irmiUatis var. dislocatus Uall, Bull. U. S. Nat. Mus., No. 37, p. 34, No. 24, 1889. Pcctfii nucleus Hcilprin, Trans. Wagner Inst., i., p. 102, 1886. Fossil in the later Miocene of the Nansemond River, Suffolk, Virginia, Burns ; in the Pliocene of Florida, in the Caloosahatchie marls on the Caloosa- hatchie, Shell Creek, Myakka River, and Alligator Creek, Willcox and Dall ; in the Pleistocene of North Creek, Osprey, Florida, Dall, and of the Caro- linas; also in the raised coral reefs of the Antilles. The Miocene specimens are of the typical variety gibbiis ; the Caloosahatchie marls contain var. giblws and var. ainplicostatus in about equal numbers ; the Pleistocene of North Creek has var. gibbus and var. Iwrcalis, an indication of the more southerly extension of the latter during the low temperatures of that epoch. This species is at present widely distributed, and is found living from Cape Hattcras south to the Greater Antilles and Brazil, and on the continental shore to Vera Cruz and the Bay of Campeachy; also on the northwest coast of Africa, according to various authors. TRANSACTIONS OF WAGNER 746 TERTIARY FAUNA OF FLORIDA Since the original description of Linne was based on Jamaican specimens figured by Browne,* there can be no question as to the proper application of the specific name. The matter has been confused (in spite of Linne's state- ment that the ribs are smooth) by the inclusion of a distinct form with striated ribs — figured by Born and Chemnitz and identified by Hanley with P. gibbus, but more recently described by Fischer — from Guadelupe, under the name of P. Schrammi. It is true that there are occasional microscopic radial striae on the ribs of P.-dis/ocatns or gibbus, but these do not amount to the strong striation indicated by the figures of Sovverby and Fischer. The specific name gibbus, being the oldest, must be adopted for the species. Its identity was recognized by both Gould and Stimpson, and cannot be doubted by any one who has the privilege of studying a large geographical series. Several fairly recognizable varieties exist, and for convenience will retain their familiar names. The differences appear to be due partly to habitat and partly to situs. In order to test the range of variation in sculpture, I have counted the ribs on two hundred and thirty-five specimens, carefully segregating the varieties, though, necessarily, there was a marked proportion which might have been referred to either of two varieties with equal propriety. In order that the test might be as exact as practicable, the ribs on the left valve, when both were present, were selected for counting; the ridges marking the borders of the submargins were counted as ribs, the riblets of the submargins were not counted, and no specimens less than twenty millimetres in height were used. Pecten gibbus var. dislocatus Say ( = gibbus s. s.). Miocene to recent. The variety dislocatus should be called variety gibbus, since it is the typical form described by Linne, but I retain in this place the more familiar name for temporary convenience. Its range extends from Cape Hatteras to Cape St. Roque in northeastern Brazil, and probably to the Amazon, and it occurs also, if the dealers' labels can be trusted, on the west coast of Africa. A specimen said to be African is variegated with gray and white, and has twenty ribs ; of one hundred and fifty-one American and Antillean specimens three had eighteen ribs ; thirty-six, nineteen ribs ; fifty-five, twenty ribs ; thirty- two, twenty-one ribs ; ten, twenty-two ribs ; and one, twenty-three ribs. It may be said, therefore, that the normal number of ribs for this variety is from * P. Browne, Civil and Nat. Hist. Jamaica, p. 41, pi. 40, fig. 10, 1756. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA nineteen to twenty-two. It has a preference for quiet water, and generally attaches itself to hard substances, — coral, vermetus rock, and stones, — and has a wide range of coloration, usually bright. Of the fossil specimens nine had seventeen ribs ; fifteen, eighteen ribs ; seven, nineteen ribs ; four, twenty ribs ; four, twenty-one ribs ; and one, twenty-two ribs ; thus showing a slight ten- dency towards fewer ribs than in the recent specimens. Pecten gibbus var. amplicostatus Dall. Pliocene to recent. This differs from the typical gibbus by its fewer and broader ribs. It is about the same size as the type, and occurs chiefly west of the Mississippi, on the Texas coast, and south to Carthagena. It is usually white or nearly white on the right valve, and grayish with mottlings of white on the left valve. Of fourteen specimens, one had twelve; two, fourteen ; four, fifteen ; and seven, sixteen ribs. It is quite tumid and very solid, and probably inhabits coral or rocky bottom. Of the fossils one had fourteen; ten, fifteen; and sixteen, sixteen ribs. Pecten gibbus var. nucleus Born. Oslren nucleus Born, Test. Vinci., p. 107, pi. 7, fig. 2, 1780. Pecten gibbosus variegates, etc., Chemn., Conch. Cab., vii., p. 323, pi. 65, figs. 621 a-b, 1784. Ox/n-ii turgiila Grnclin, Syst. Nat., vi., p. 3327, 1792 ; Lam., An. s. Vert., vi., p. 167, 1819 ; fide Hanley. ' ih/ira ;•<•//.« Conr., Am. Journ. Sci., xxiii., p. 341, 1833 ; Fos. Med. Teit., p. 48, pi. xxiii., fig. 2, and xxiv., fig. 3, 1840. /?•(•/<•// •t'ici-naiiits Conr., Proc. Acad. Nat. Sci. Phila., i., p. 306, 1843. (Immature shell.) /'trti-n //()//';•<'(>/•// kavenel, Proc. Acad. Nat. Sci., ii., p. 96, 1844. ? Pt-ctt-n microfili'ura H. C. Lea, Trans. Am. I'hil. Soc., ix., p. 245, pi. 35, fig. 32, 1846. (Young shell.) I't'i'li'ii coinpari/is Tuomey and Holmes, Pleioc. Fos. S. Car., p. 29, pi. 11, figs. 6— 10, I«55- I't'cti-n yerkcnsis Conr. , Am. Journ. Conch., iii., p. 189-90, 1867. j','t /,•/! siniis Conr., Am. Journ. Conch., v., p. 39, pi. 2, fig. 2, 1869. Miocene of Charles County, Maryland, Cope; Ashley River phosphate rock, South Carolina, Dall. TRANSACTIONS OF WAGNER 754 TERTIARY FAUNA OF FLORIDA Shell small, thin, polished, compressed ; left valve more convex, with about twenty faint, flat, rather irregular obsolete ribs, separated by narrower, shallow sulci, the whole surface with minute Camptonectes striation ; right valve with concentric incremental lines and a few faint threads near the beaks and anterior submargin; ears small, subequal ; ctenolium present; cardinal and auricular crura developed ; interior of left valve faintly fluted, but without lirae. Alt. 19, lat. 18 mm. In some of the specimens there are a few feeble concentric undulations near the beak of the left valve. ? Section Hyalopectcn Vcrrill. Hyalopccten Verrill, Trans. Conn. Acad., x., p. 71, 1897. Type P. iindalus Verrill, op. cit., vi., p. 444, 1885 ; = P. fragilis Jeffreys, Ann. Mag. Nat. Hist., p. 424, 1876, -\- Hyalopecten dilectus Verr. and Bush, Trans. Conn. Acad., x., p. 80, 1897. This section differs from the ordinary abyssal Psendamiisium in being concentrically undulated, and from the thin, smooth, shallow-water forms like P. gronlandicus in the absence of the Camptonectes striation. These features are barely of more than specific value, as they appear to be generally inter- changeable, like other surface characters in this genus. The types of Jef- frey s's P. fragilis are in part in the United States National Museum. They agree perfectly with his description and figures (P. Z. S., 1879, p. 561, pi. xlv., fig. I [inner and outer views]). The first specimens obtained were frag- mentary, as was the case with P. niidatus Verrill. I have compared the speci- mens received from both authors with care, and consider them conspecific. P. dilectus is complete, and, except that it is a younger and smaller shell, I have been unable to detect any differences, even of a varietal nature. On the other hand, the specimen to which Professor Verrill has given the name fragilis Jeffreys is a perfectly distinct species with marked characters, as noted by Professor Verrill (op. cit., p. 81). Jeffreys in his original description describes his shell (left valve) as having " numerous fine and raised striae" which " radiate from the beak and cover the whole surface." How, then, Professor Verriil should come to regard a shell " distinctly undulated but not otherwise sculpt- ured" as the species of Jeffreys is a mystery which I cannot solve. At all events, they are perfectly distinct, and the P. fragilis Verrill, non Jeffreys, may take the specific name of eucymatus. It should be observed that the " raised striae," or threads, described by Jeffreys, are more abundant and more constant on the left valve ; on the right valve they are often nearly obsolete, FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA ' ** and on the left valve the different individuals differ in the amount of their radiation. Pecten (Hyalopecten) sp. indet. Lower Miocene of the Ashley River, South Carolina, in the so-called " phosphate rock." Valves of a species too imperfect for satisfactory description, yet showing distinctly a thin, undulated, and probably radially striate shell, of about the size of half-grown /•*. fragilis (circa eight millimetres in altitude), were found in the rock above mentioned. The shells were crushed and their undulations flattened down during fossilization, and the chief character which appears to have distinguished them from P. fragilis is that the undulations were higher and sharper and the form perhaps more ovate. Still, this group is so singular, and its discovery in a fossil state so interesting, that I feel it should be recorded. Pecten (Pseudamusium) Guppyi Dall. PLATE 34, FIGURES 12, 13. This species has already been cited (p. 718) as occurring in the Alum Bluff beds at Oak Grove, Santa Rosa County, Florida, as well as in the Oligo- cene and later formations of the Antilles and Costa Rica. Subgenus AMUSIUM (Bolten) Schumacher. .\iiuiaiiint (Rumphius, 1705) Bolten, Mus. Bolt., ist ed., p. 165, 1798 (no description); Sebum., Essai, p. 117, 1817 ; Dall, Bull. Mus. Comp. Zool., xii., No. 6, p. 207, 1886. ricuroiifctM Swainson, Malac., p. 388, 1840. Type Ostrcii plcuroncctcs Linnc. Pecten (Amusium) precursor n. s. Oligoccne of the Chipola beds at Alum Bluff and on the Chipola River and elsewhere in these beds; Burns and Dall. There are several species of Ainitsiuiii ranging from the Oligocene to the recent fauna in this region. In general they appear extremely similar, so much so that such figures as "are ordinarily given would show no differential characters. By careful and repeated study I find myself able to separate them by the umbonal sculpture, which differs in the different forms as follows : Ncpionic shell perfectly smooth externally. 1. Shell more or less ovate: P. pafyraccits Gabb. 2. Shell very large, orbicular: P. Mortoni Rav. 13 TRANSACTIONS OF WAGNER 756 TERTIARY FAUNA OK FLORIDA Nepionic left valve with obsolete radii and often feeble concentric undulations: P. precursor Dall. Nepionic left valve with distinct flattened ribs with shallow channelled inter- spaces crossed by concentric, evenly spaced, not crowded, elevated lines : P. Lyoni Gabb. Left valve of the adult with obsolete rounded ribs extending, in the adult, well over the middle of the disk : P. ocalanus Dall. P. precursor is nearly as large as P. Mortoni, but slightly rougher and more convex when adult, the young are nearly orbicular ; a distinct trace of Camptonectes striation, near the beak and submargins, may be discerned with a magnifier in a good light. Alt. no, lat. 123, diam. 20 mm. The right valve is much flatter than the other. As the material is much broken up, it seemed hardly worth while to figure it. Pecten (Amusium) ocalanus n. s. PLATE 29, FIGURE 2. Oligocene of the Vicksburgian at Natural Bridge, Alachua County; at various localities in Levy County; at Arredonda and Archer; Newnansvillc and Johnson's lime sink; and in the Nummulitic horizon at Ocala and Martin Station, Marion County, Florida; also in the Vicksburgian of Alabama; Dall, Burns, and Willcox. Shell of moderate size, nearly equivalve, quite inequilateral, moderately convex; right valve with the disk nearly smooth, posterior margin produced; ears subequal, nearly smooth, their outer angles a little raised, so that the cardinal margins form a very obtuse angle at the beak ; byssal sinus repre- sented by a marked flexure but not a distinct notch ; left valve similar, slightly more convex, with about eighteen obsolete rounded ribs, separated by narrow, shallow grooves, sharpest near the beak, radiating nearly to the basal margin but becoming less visible there and at the submargins; ears ver- tically striated, subequal ; interior of the disk with about twenty-one pairs of well-marked lirae similar in each valve ; hinge with developed cross-striated cardinal crura, auricular crura present; margins of the valves smooth, not crenulated. Alt. of figured shell 35, lat. 35 ; alt. of largest specimen 43 mm. The fossils vary from nearly smooth to obviously ribbed ; the byssal sinus is more distinct than in the other species and sometimes verges on a notch, and there is a perceptible byssal fascicle. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA Pecten (Amusium) papyraceus Gabb. This species, described from the Tertiary of St. Domingo, appears to be identical with the recent species of the Gulf of Mexico and the Antilles. I formerly referred it to P. Mortoni, to which it is closely related, but it is generally less orbicular and smaller than the typical P. Mortoni, and in default of a full and completely intergrading series it is probably better to retain Gabb's name. Pecten (Amusium) Mortoni Ravenel. Pecten J/rvWv// Rav., Proc. Acad. Nat. Sci. Phila., ii., p. 96, 1844 ; Tuomey and Holmes, I'leioc. Fos. S. Car., p. 27, pi. 10, figs. 1,2, 1855 ; Emmons, Geol. N. Car., p. 281, 1858. Miocene of Fairhaven and Drum Point, Maryland; Duplin County, North Carolina ; Cooper River and Goose Creek, South Carolina, and in the upper bed at Alum Bluff, Chattahoochee River, Florida ; Pliocene of the Caloosa- hatchie marls on the Caloosahatchie and Shell Creek, Florida ; Burns, Willcox, and Ball. Pecten (Propeamusium) alabamensis Aldrich. J't'i/i-it (I'/cunnicc/iii) iiliibanicnsis Aldr., Bull. Geol. Surv. Ala., p. 40, pi. 4, fig. 8, 1886 ; Harris, Bull. Pal., iv., p. 162, pi. 2, fig. 3, 1896. /'irfi-n u/dfiiMii-nsis Harris, Geol. Surv. Ark., Rep. for 1892, ii., p. 41. /<•<•/(•// (.•liiiHs.'iiitiii) iita/>iiiiii-iisis de Gregorio, Mon. Claib. Fauna, p. 183, pi. 21, fig. 26, 1890. Basal or Midwayan Eocene of Dale's Branch, Matthews Landing, and Nahcola, Alabama, and of Marshall's Well, Little Rock, Arkansas. This interesting little species reaches less than five millimetres in extreme height, has the right valve concentrically striated or nearly smooth, the left with sparse, partly obsolete radial threads crossed by elevated, concentric, distant lines, with a tendency to nodulation at the intersections. Internally there are about eight or ten well-developed lira; and the auricular crura. The byssal ear has sparse radii and a distinct byssal notch. Pecten (Propeamusium) squamula Lamarck ? .'/',;/<7i ii/iiiuinila Lam., Ann. du Mus., viii., p. 354, No. 3, 1806; Hist. An. s. Vert., vi., p. 183, 1819; Desh., Descr. Coq. Fos. Km. Paris, i., p. 304, pi. xlv., figs. 16-18, 1824.. .'. \mitssiinn at/iiainu/a Cossm., Ann. SIM . Roy. Mai. . 188, 1887. .•liiiiissiiiin si/iiiiiiiH/inii Harris, Bull. Pal., ix., p. 44, pi. 7, figs. 2, 3, 1897. Chickasawan (or Lignitic) Eocene of Wood's Bluff, Alabama ; Harris. TRANSACTIONS OF WAGNER 758 ' J TERTIARY FAUNA OF FLORIDA This small species is destitute of the reticulate sculpture on the left valve which characterizes P. alabainaisis, and is doubtless distinct. It has been referred by Professor Harris to Lamarck's species. On comparing the figures of Harris and of Deshayes, the latter seem to represent a species broader and more orbicular than Professor Harris's figures of the Wood's Bluff shell. I have, however, not seen specimens of either. There are several closely related recent species in the deep waters of the Atlantic off the American coast and among the West Indian islands. FAMILY SPONDYLID^. Genus SPONDYLTJS Linne. i/"^ Spondylus Linnd, Syst. Nat., Ed. x., p. 610, 1758. Type S. gicdcropus L. Mediter- ranean. The species of this genus are not numerous in the American Tertiary or the recent fauna. Spondylus dumosus Morton. Plagiostoma dumosuin Mort., Org. Rein., p. 59, pi. 16, fig. 8, and fig. in text, 1834. Spondylus dumosus Conr. , Cat. Eoc. Fos., Am. Journ. Conch., i., p. 14, 1865. Eocene of the Jacksonian horizon, St. Stephens, Clarke County, Cocoa Post-Office, Choctaw County, etc., in Alabama; Red Bluff, Wayne County, Carson's Creek near Shubuta, and Chickasawha River, Wayne County, Mis- sissippi; Winchell, Burns, and Johnson. This well-defined species is unusually uniform in its characters and may be easily discriminated from the next species by its longer and more con- spicuous submargins. It also seems never to reach so large a size. Spondylus bostrychites Guppy. Spondylus bifrons Sowerby, Ouart. Journ. Geol. Soc., vi., p. 53, 1849 ; not of Goldfuss, Petref., ii., p. 99, pi. 106, figs. 10 a-c, 1835. Spondylus bostrychites (nippy, Proc. Sci. Soc. Trinidad, p. 176, 1867; Gabb, Geol. St. Domingo, p. 257, 1873. Oligocene of St. Domingo, at Ponton ; of the Bowden marl, Jamaica ; of Anguilla; of White Beach, near Osprey, Florida, and in the Ballast Point silex beds, Tampa Bay, Florida. Variety chipolanus : Chipola beds on the Chipola River; lower bed at Alum Bluff, Chattahoochee River; Alum Bluff beds at Oak Grove, Santa Rosa County, and the Ballast Point silex beds, Tampa Bay, Florida. The type form of this species has a relatively small number of spinosc FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA ribs, the intervening ones being free from spines, longitudinally finely striate, and show when very perfect minute scales. The adult shell is rather short and rounded and less inflated than usual in the genus. The species is remark- able for its small hinge-area. In the variety chipolanns Dall there is no radial striation on the inter- spatial ribs, but rather a concentric sculpture; there are many more spinose ribs, the shell is more oval and more inflated, and, as far as the material goes, seems to attain a larger size. It may prove distinct with more perfect speci- mens, in which case the varietal name may be taken as specific. Spondylus rotundatus Heilprin. PLATE 35, FIGURES 25, 253. Sponilylus rotimdiitus Heilprin, Trans. Wagner Inst., i., pp. 99, 103, pi. 14, fig. 33, 1887. Pliocene marls of the Caloosahatchie and Shell Creek, Florida; Willcox and Dall. This fine species was represented in the original publication by a very poor figure drawn from a very imperfect lower valve, so I have had another figure prepared showing the characters. It is characterized by the presence of eight or ten primary ribs with longer spines, which arc broad, spathulate, and longitudinally ridged ; at the end, when perfect, the spine is decurved like a half-shut hand. Between the primaries are two or three smaller ribs densely clothed with similar but smaller and shorter spines whose backs are so close together as to almost conceal the whole surface. The cardinal area is of moderate size, triangular and twisted. The lower valve is similarly sculptured, but with less regularity. Traces of coloration indicate that the shell originally was of deep red or purple color. S. rotundatus is less similar to the recent most foliaceous specimens of S. ccliinatiis than is the Oligocene bostrycldtcs. Spondylus echinatus Martyn. Os/i'ti'ii t'lJiiihitii Martyn, Univ. Conch., ii., fig. 154, 1784. Spondylus armatus Humphrey, Mus. Calon., p. 54, No. 1021, 1797. S/i,>inty/iix i»iify/ns aiinin/iiii'its Boltt-n, op. cit., p. 195, 1798. Sf«»i,tv/i/s 11111,-i-ii-nnns Lam., An. s. Vert., vi., p. 188, 1819; (Knc. Mcth., pi. 195, figs. I, 2;) Reeve, Conch. Icon., pi. 4, fig. 17, 1856. TRANSACTIONS OF WAGNER 760 TERTIARY FAUNA OK FLORIDA Spondylus longitudinalis Lam., An. s. \'ert., vi., p. 191, 1819; (Chemn., vii., p. Si, pi. 45, fig. 466;) Reeve, pi. 13, fig. 46, 1856. Spondylus spat hull ferns Lam., op. cit., p. 191 ; (Enc. Mcth., pi. 191, figs. 4, 6, 7 ;) Dall, Bull. U. S. Nat. Mus., No. 37, p. 32, 1889. Spondylus crassisqitaina Lam., op. cit., p. 191, ex partc. Spondylus arachnoides Lam., op. cit., p. 188. Spondylus longispina Lam., op. cit., p. 189. Spondylus avicularis Lam., op. cit., p. 190. Spondylus gih'iis Reeve, Conch. Icon., pi. 11, fig. 38, 1856. Spondylus frinaii-iis Reeve, op. fit., fig. 39. Spondylus iftcrifiis Reeve, op. cit., fig. 40. Spondylus ramosus Reeve, op. cit., pi. 14, fig. 51. Spondylus imbiitus Reeve, op. cit., pi. 15, fig. 55. Spondylus itstitlatits Reeve, op. cit., pi. 16, fig. 58. Spondyhis iicxillum Reeve, op. cit., pi. 16, fig. 59. Spondylus mix Reeve, op. cit., pi. 18, fig. 64, 1856. Spondyhis di^itatits Reeve, op. cit., fig. 68. Spondylus cfhinatus Orbigny, Moll. Cuba, ii., p. 359, 1846. Spondylus folia-h'assicce Orbigny, op. cit., p. 358, 1846. Fossil in the Pleistocene elevated reefs of the West Indian Islands and of the continent from southeastern Florida to Brazil ; and recent over the same general region, extending as far north as Cape Hatteras, North Carolina. This species has the irregularities of sculpture due to, or usually asso- ciated with, the sessile habit, and the mutations of color characteristic of many Pectinidas. To these and to the exigencies of trade imposed by dealers upon Reeve is due the multiplication of merely nominal species indicated in the preceding synonymy. The normal or most ordinary type of sculpture comprises from four to eight radial ridges from which project spines, either narrow and almost pointed, or wide and crumpled or digitate, separated by wider interspaces with smaller, sometimes spinulose, radii, to which is added a series of still finer threads, chiefly indicated by rows of small, short scales. By the continuity and regularity of the radial lines the species is separated from the otherwise quite similar S. gcedcropus Linne of the Mediterranean. Specimens which have been cleaned with acid have usually lost the tertiary rows of minute scales, but they seem to be absent naturally from some specimens which have only two series of radials, the secondary ones but little spiny, and the spines comparatively sparse, long, and narrow on the primary ribs. This type forms the variety aincncamis. The sculpture on the fixed valve is more foliaceous FREE INSTITUTE OF SCIENCE 761 TKKTIARY FAUNA OF FLORIDA and less spiny than on the other. The spinosity varies greatly ; some indi- viduals have almost none, others are profusely spiny, and others, again, have the spines limited almost entirely to the major ribs, which vary greatly in number. There is occasionally a distinct ctenolium in adult specimens. The colors and their distribution vary as in many Pectens. I have seen from the West Indian region but one species of large folia- ceous Spondylus (with one well-marked variety), — the present species. There is one deep-water species, common to the Mediterranean, — the Spondyhis Gitssniii of Costa, which is small, with acicular spines, and colorless. The Eocene -S". aimissiopse de Gregorio is the young of Plicatnla fila- mcntosa Conrad. S. iiiomalits Whitfield, from the Miocene of New Jersey, is based on a smooth specimen of Plicatnla dcnsata Conrad. S. cstrallcnsis Conrad, 1857, afterwards altered to .V. cstrcllaiins, from the Miocene of the Kstrella valley, California, was based on a much-mutilated specimen of Lyro- pcctcn. The very imperfect type of Pcctcn anisoplcitra Conrad from North Carolina strongly resembles a Spondyhts, but is too incomplete to permit of positive determination. A species doubtfully referred to this genus is men- tioned by Ileilprin in his paper on the Eocene Mollusca of Texas (1'roc. Acad. Nat. Sci. Phila. for 1890, p. 404). Professor Harris has figured a valve of a Spondylus from the Chickasawan or Lignitic beds of Hatchetigbee Bluff, which he doubtfully refers as a variety to S. (luinosits Morton. The specimen is too imperfect to afford definite evidence, but may probably turn out to be a distinct species (cf. Bull Pal., No. 9, p. 42, pi. 6, fig. 11, 1897). Genus PLICATULA Lamarck. riicatitln Lain., Syst. An. s. Vert., p. 132, 1801. Type P. ^ibbo^i Lain., /. f. == P. raiiwsa Lam., 1819. //,ir/>,i.\- Parkinson, Orjj. Rem., 3, pi. 12, 1811 ; Brookes, Intr. Condi., p. 83, 1815. Type //. 1'tii-kiiisiniii Bron 11. <^//Yiu>iiii,i Conrad, 1'roc. Acad. Nat. Sci. Phila. for 1872, p. 216. Type O. cii>v/in<-itsis Conr. The only established species mentioned by Lamarck in the Systeme, wlicrc he described the genus, is the West Indian form, which he at first named P. g'ibbosa and wrongly identified with the Chinese Spoiidv/ns plicatits of Linne. In 1819 he arbitrarily changed the name to rainosa. Linne's still preserved type specimen and designated habitat show that his species was not TRANSACTIONS OF WAGNER 762 TERTIARY FAUNA OF FLORIDA the same as that of Lamarck. The latter, and not P. plicata, must therefore be cited as the type of the genus. The original specific name must, of course, be retained. The genus is easily separated from the Spondyli by the character of its hinge. It may attach itself by either valve ; there is no regularity in this respect within the species. An important memoir by Dcslongchamps on this group is to be found in the Trans. Soc. Linn, de Normandie, ii., 1860. Plicatula arose in the Trias and reached its maximum in the later Mesozoic. It is doubtless an offshoot from the Pcctinidce, with which the characters of the hinge, the occasional auriculation, and the presence in some species of internal lirae, appear to connect it. Plicatula fllamentosa Conrad. PKcatula. filamentosa Conrad, Fos. Tert. Form., p. 38, 1833. Plicatula Mantilli Lea, Contr. Geol., pp. 89, 90, pi. 3, fig. 68, 1833. Plicatula planata Aldrich, Journ. Nat. Hist. Soc. Cin., ix., p. 45, pi. ii., fig. 20, 1866. (Young shell.) Spondylus amussiopst- Gregorio, Claib. Mon.,p. 179, pi. 20, figs. 11-13, 1890. (Young shell.) Eocene of the Chickasawan or Lignitic at Hachetigbee, and of the Clai- borne sands at Claiborne, Alabama, also at Newton and Wahtubbee, Missis- sippi, and in corresponding beds in Louisiana, Burns, Johnson, Aldrich, Harris, and others ; and in Lee County, Texas, Singley. This species is peculiar in its characters. When young it has fine radial striation on both valves, which may sometimes be wholly or partly spiny (mut. planata), and the shell is flattish ; this sculpture changes rather suddenly by an appearance of the large plications, of which the lateral ones rarely bear a few coarse spines. The radial striation continues through life in well-de- veloped specimens, and may be recognized in unworn shells. There are sometimes well-marked auricles developed near the beaks. The interior of the young, as noted by Gregorio, presents a few strong lira; resembling those of Propcamusium ; these persist until middle age, especially distally, but on the disk are gradually buried in shelly matter. The thickened ends of the lira; are visible longer, but gradually disappear, their position in the adult being marked by small pits. Plicatula fllamentosa var. concentrica. Wahtubbee Mills, Clarke County, Mississippi ; Burns. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA This form is marked by a total disappearance of the radial stria; and the development of fine, even, regularly spaced, concentric, elevated sculpture all over the shell. I should have regarded it as a distinct species had it not been for a few intcrgrading specimens. A fossil which may be a Plicatula, but of which the hinge is not accessi- ble, is figured from the Midwayan Eocene by Harris, Bull. Pal. No. 4, p. 47, pi. 2, figs. 2, 2 a, 1896. Plicatula densata Conrad. riinitiiht ilcnsata Conrad, Proc. Acad. Nat. Sci. Phila., i., p. 311, 1843 ; Medial Tert., p. 75, pi. 43, fig. 6, 1845; Proc. Acad. Nat. Sci. Phila., xiv., p. 582, 1863. Spotnlylus inornatus Whitfield, Mioc. Pal. N. J., p. 34, pi. 5, figs. I, 2, 1895. In the Oligocene Vicksburg limestone at Archer, Florida, and the Num- mulitic horizon at Ocala, Florida, Dall and Willcox; also in the Guallava beds of Costa Rica, Hill ; in the Chipola beds on the Chipola River, and in the lower bed at Alum Bluff; in the silex beds of Ballast Point, Tampa Bay, and in the Alum Bluff sands at Oak Grove, Santa Rosa County, Florida, and the Bowden marl, Bowden, Jamaica; in the Miocene marls of Cumberland County, New Jersey, at Shiloh and Jericho. This species is distinguished from the later marginata of Say by its usually rounder form and more numerous, less prominent plications. Occa- sional specimens attached to a smooth surface by a considerable area do not develop the plications, and one such has served as the type of Whitfield's species. Plicatula gibbosa Lamarck. ifibhosa Lam., Syst. An. s. Vert., p. 132, 1801. ranwsa Lam., An. s. Vert., vi., p. 184, 1819; PHeilprin, Trans. Wagner Inst., i., p. 102, 1887. t'lislatd (lal)]). C.eol. St. l)om., p. 257, 1873. I'liiiiliila vcxillutii Ciiippy, (Icol. Mag., Dec. ii., vol. i., p. 444, pi. xvii., fig. 7, 1874. ? Oligocene of Jamaica, Guppy ; recent in the Atlantic from Cape Hat- teras, North Carolina, south to the West Indies and Rio de la Plata, Brazil. This species is contained in the Guppy collection from Jamaica, the specimens showing the dark lines belonging to the species, but I suspect that they were obtained from a later, perhaps a Pleistocene, deposit, as the explora- tions of the Bowden marl by Messrs. Henderson and Simpson have produced only .specimens of the P. densata from the Bowden horizon. TRANSACTIONS OF WAGNER 764 ' TERTIARY FAUNA OF FLORIDA Plicatula marginata Say. Plicatulii marginata Say, Joum. Acad. Nat. Sci. Phila., iv., pp. 136-7, pi. 9, fidi>dcsunis is a short step; another step, somewhat shorter, brings us to Monia. The genus Placiiiianonda Broderip was founded on a remarkable and still FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA very rare shell, the P. Cituiiiigii of west Central America. It is, in some respects, intermediate between Epliippiitui and Mania Gray, but presents additional characteristics of its own. The shell is strongly plicated with a few folds ; is attached when very young, but may be free in the adult state. In the right valve the cardinal margin is broad and strongly rugose with interlocking rugosities of both valves. Though deep, they are too irregular in form to be called teeth. In the right valve two strong elevated crests — the auricular crura — meet above at a very acute angle, and are received into sockets in the opposite valve, separated by a space bearing a strong median ridge. The ligament connects the outside of the crests with the sockets, but is continuous with a resilium occupying the upper third of the space between the crests. The adductor leaves a large subcentral, nearly circular, impression on both valves. The byssal foramen is closed at an early age, leaving a round scar between that of the adductor and the end of the anterior crest, which scar is joined to the beak by a linear, solidly cemented suture. The byssal muscle persists as an accessory adductor in function. There is no perforation of the shell nor any necessary connection with external objects, in the adult state, any more than in Epliippiiini or Carolia. None of the other genera of the group exhibit the interlocking rugose cardinal area. The species by which the genus Placunanoinia is usually judged belong to a group, properly separated by Gray in 1849 (?• Z. S., p. 121) under the name of Mania, with P. inacroscliisma Deshayes as the type. In Monia there is a very large, partly shelly, partly corneous, byssal plug, embraced by the right valve (but with the suture always unsoldered, though close fitting), by which the animal is attached at all stages of its existence, unless in the larval condition. There is no cardinal area, no interlocking teeth or rugosities, or paired, elevated internal crests or median internal resilium connecting the valves below the choiulrophoric arch. In Monia inacroscliisma as compared with Placenta we have a condition more like that of Ephippiiiui, but with a large notch and byssal plug, while the chondrophoric margin is arched and not angulated, being represented by a single pedunculated wide mass with a resilium under the arch. That por- tion of the ligament attached to the chondrophore has become so large and massive that it has supplanted entirely the remnant on the cardinal margin, and the latter, at least in adults, is non-existent. In the left valve the margins of the ligamentary scar are sometimes moderately thickened, but the process 14 TRANSACTIONS OF WAGNER 772 TERTIARY FAUNA OF FLORIDA has not been carried so far as to form crura. Coincidently with the existence of the enormous plug in this group, the byssal muscle has been enlarged until it exceeds in section the size of the adductor, above which it is inserted on the surface of the left valve. In Aiiomia proper and sEnignia, the other features not being greatly modified, we have the byssal muscle divided into several bundles, each producing its separate scar on the upper valve. In the form of Carolia, which we are about to describe, we have combined with the single chondrophore of Mania the obsolescent notch and plug, to- gether with the simple adductor scar of Ephippium. The sensible but narrow cardinal area of the latter is represented by a broad and conspicuous margin. The lateral edges of the ligamentary scar in the left valve form narrow elevated crura, while the exterior is free from the radiating stria: common to all the other forms and resembles that of the smooth Anomias. If these differences be taken as sufficient for establishing a section of the subgenus, the name Wakullina will be used, from Wakulla County, Florida, in which the type specimens were collected. The synonymy of this group is in an unsatisfactory condition. The genus Placenta was first named by Da Costa in his Conchology (p. 271, 1776), though, unfortunately, this author not having consistently adopted in this work the Linnean nomenclature, it is not entitled to be cited in synonymy. The name Placenta had been used by Klein in 1734 to designate an Echino- derm, but this author is absolutely without a binomial nomenclature and not entitled to any consideration in discussing systematic questions. Da Costa's name became current among students and was adopted in proper binomial form by Retzius in his well-known dissertation on new genera of shells, pub- lished by his pupil, Phillipson, at Lund in 1788. Meanwhile Linne had referred the species to Anoinia under the name of Anomia placenta. In an unpublished description of the shells in the ducal cabinet of Portland, Dr. Solander had proposed the name Placnna for the same type, and this was used by Bruguiere on the plates of the unfinished Encyc. Methodique (174, 175, 1792), though with the genuine Plaaina he united certain species of Plicatnla. Solander's name was also quoted by Humphrey in his Catalogue of the Museum of Calonne (p. 45, 1797), which contained a number of specimens derived from the Portland cabinet. A year or two later Bolten revived the hitherto nonbinomial name of EpJiippitnn employed by Chemnitz to designate (Conch. Cab., viii., p. 1 16, 1785) the saddle- oyster, — he included that as well as Anoinia placenta in his genus FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA (Mus. Boltenianum, p. 166, 1798), — while in 1799 Lamarck (Prodrome, p. 82) adopted Solander's name with the original type. In 1817 Schumacher used Retzius's name and correctly placed Placnna in its synonymy. Since that time, however, as was natural, the name adopted by Lamarck has had the wider currency, perhaps partly on account of the erroneous statement by Herrmannsen (Ind. Gen. Mai., ii., p. 277) that Chemnitz refers to Solander's manuscript name in the volume of the Conchylicn Cabinet published in 1785, three years before Retzius gave Da Costa's name a binomial standing. A careful search of Chemnitz in the place indicated shows no reference what- ever to Solander or his name, as has already been pointed out by Deshayes. In 1848 Gray enumerated the species of Placenta Retz. (P. Z. S., 1848, p. 114) and divided the genus into two sections or subgenera, I, Placentas, s., typified by P. placenta Lin., and 2, Ephippiuin (Chemn.), after Bolten (+ Scl- laria Link, 1807), comprising the saddle-oysters. The name Epliippiiun (Hulten) antedates by four years its use in Entomology, even if we do not go back to the non-binomial Chemnitz, and though part of the species were referable to Placenta Retz., the remainder, belonging to an unnamed group, were entitled to retain Bolten's name. If Bolten's name had been entirely new the absence of a diagnosis might militate against its acceptance, but as it is really a revival of a well-known but not binomially established name, with proper references to Chemnitz's and other figures and to Gmelin's syn- onymes, while there can be no possible doubt as to the species included, it would seem that no question need arise on this account. In 1864 Deshayes referred a problematical fossil (Placuna solida Desh.) to this group under the name of Hemiplicatula, for which in 1886 Fischer proposed the emended form of Sciniplicatitla. Its true relations can only be determined by a more critical examination than it seems yet to have received. In 1867 Conrad described a genus Paranoinia, from the Ripley group (Upper Cretaceous) of Alabama, to which he referred his Placunanomia Saffordi (Journ. Acad. Nat. Sci , 2d Ser., iv., p. 290, pi. 46, fig. 2l)and the Placmia scahra of Morton. The typical species is ill preserved, and the beaks almost always wanting, but, from the examination of a large number of speci- mens, it seems probable that the genus resembles Mania in its external char- acters ; the presence of a triangular chondrophore recalls Anoinia, but there is not sufficient evidence of a permanent foramen, the muscular impressions are not preserved, and there is in the right valve, associated with the single chondrophore, a pair of low, narrow crests, recalling those of Placenta, but TRANSACTIONS OF WAGNER ' TERTIARY FAUNA OF FLORIDA obviously of different function. The genus is a puz/.le and cannot as yet be safely united with any other. Diploschiza Conrad, however, appears to be founded on a broken valve of an ordinary Anotnia. It is impracticable to attempt here a revision or discussion of the names which have been applied to exotic fossils apparently related to this group, as the material is wanting, and few of them have been intelligently studied in the light of the anatomical relations of the recent forms. In 1870 Stoliczka (Cret. Pelec. India, p. 451), misled by 'an imperfect knowledge of its synonymic status, proposed for Ephippium (Bolt.) Gray the name Placunema, which falls into synonymy. It seems to the writer that the absence of any foramen and the perma- nently byssiferous habit of Placenta generically distinguish it from all the foraminiferous Anomiidce. Its arenaceous habitat is also different from all the rest. Placnnanomia as typified by P. Cumingii seems also a good genus. The list, omitting doubtful forms and unstudied exotics, will stand about as follows : 1. Byssal scars absent or obsolete. Genus Placenta. Type P. orbicitlaris Retzius. Genus Ephippiitm. Type E. sella Gmelin. Genus Carolia. Type C. placunoidcs Cantraine. Section Wakullina. Type C.Jloridana Dull. 2. A single conspicuous byssal scar on the disk. A. Adult foramen closed ; hinge armate. Genus Placunanomia. Type P. Cumingii Broderip. B. Adult foramen small ; hinge unarmed. Genus Pododesmits. Type P. rndis Broderip. 0. Adult foramen large ; hinge unarmed. Section Monia. Type /-*. macroscliisina Dcshaycs. 3. Two byssal scars on the disk; hinge unarmed; foramen open. A. Main byssal scar largest ; foramen ample. Genus Anomia. Type A. cpliippiitm Linne. B. Adductor scar larger than those of the byssus; foramen small. ? Section Patro. Type A. clyras Gray. C. Main byssal scar distant from the two others. Section sEnigma. Type A. icnigmatica Jonas. FREE INSTITUTE OF SCIENCE TKRTIARY FAUNA OF FLORIDA In addition to the major and minor byssal scars on the disk, there is a small semilunar scar near the resiliary pit, due to a branch of the byssal muscular system. The " Placnna papynicca" of which the nepionic foramen is figured by Fischer (Man. Conch., p. 953, fig. 701), belongs to the genus Epliippiinit. The dynamic relation between the size and position of the byssal foramen and the byssal scars is sufficiently obvious. The only American fossil referred to P/iiciina, — /'. scabra Morton, — as already indicated, belongs to the Cretaceous, and is placed by Conrad in his genus Paranomia. Genus CAROLIA Cantraine. (.\intliti Cantraine, Hull. Acad. Sci. Brux., 1838, p. ill. Type C. placunoidcs Cantraine; Fischer, J. cle Conchy!., xxviii., p. 345, pi. xii., 1880 ; Man., p. 932, fig. 700, pi. xvi., fig. 7, 1886. Lower Eocene of Egypt. ll<-niipltu-itna (Sby. MS.) ('.ray, 1'. Z. S., 1849, p. 123. Type H. Rosicri Sby. Cf. KO/RTC- in Descr. de 1'Egypte, Mineralogie, pi. xi., fig. 6. Shell thin, nacreous, with radiating stria?, the right valve flattened; rcsilium rounded-triangular, internal, large, attached in the right valve to a pedunculate chondrophore seated on the anal side of the umbo and extended adorally so as to bring the 'middle of the resilium in the median line of the valve; in the left valve the resilium is attached in the cavity of the umbo, leaving a broad, fan-shaped, thickened scar of attachment, of which the anterior and posterior margins are elevated into diverging lamella.'. In the young stage the right valve is perforate for the passage of a byssus or byssal plug, which gradually atrophies, so that in the full-grown shell the sinus and perfor.ition are closed with shelly matter and so overshadowed by the heavy chondrophore as to be hardly perceptible even as a scar. It should be observed that the attachment of the resilium is wholly posterior, and not the result of the. merging of an anterior and posterior chondrophore. The scar of the adductor in each valve is single, orbicular, and nearly central, with two very minute accessory pedal or byssal muscular scars above it in the left valve. This genus has been discussed by Gray and Fischer, the latter giving some instructive figures of the gradual obliteration of the sinus and of the analogous early sinus in lipltippiitin p. C. (\\\ikulliini)Jl»ri,1a>M Dall, Proc. U. S. Nat. Mus., xviii., p. 21, 1895. From the Oligocene of Florida in the Sopchoppy limestone on the banks of Deep Creek near the Sopchoppy River, Section 13, Township 4, Range 3, Wakulla County, Florida; collected by L. C. Johnson, of the United States Geological Survey; also in the " Fuller's earth" bed by Dr. D. T. Day, at Quincy, Florida. Shell thin, not sculptured, nacreous, suborbicular, and adherent, some- what irregular ; right valve flattened or concave, especially at the umbo ; left valve convex with a moderately prominent umbo near the cardinal margin ; hinge-margin variable, but always with a transverse flattish area arched in the middle over the attachment of the internal ligament; exterior irregularly im- bricated by the seal)- nacreous layers; interior smooth, with a large subcentral nearly orbicular adductor scar; right valve with the minute scaled byssal foramen under the middle of the chondrophorc connected by a soldered linear suture with the upper anterior margin of the valve; chondrophore rounded triangular, broad, radiately rugose above, recurved as a thin lamina from the umbo in fully adult specimens (see figure), rather closely sessile and fitting into the umbonal cavity of the opposite or convex valve; left valve with the ligamentary attachment broadly triangular, marginated by a thin lamellar deposit of shell substance on each side and arched over by the elevated portion of the cardinal area. There is no trace of a scar correspond- ing to the byssal muscle of youth in adult specimens. Antero-postcrior diameter no, dorse-ventral height i IO, maximum thickness of the closed valves 9 mm. This fine shell, curiously enough, is, so far as known, the only species in the Sopchoppy limestone which retains its shell-structure, all the other mollusks, so far as observed, being represented only by their impressions in the soft limestone. It is interesting to find an Egyptian type in our southern fauna, though the only relation between them is, in the writer's opinion, that which both bear to the Anoiniidce which preceded them, and the analogous recent forms which have succeeded to them. The characters upon which Carolia is based are purely dynamic and might be expected to occur in a long succession of Ano/niiitii: of any region, the several Carolias having no genetic connection with each other, as such, any more than the Oregonian Batissa has with those of other continents now living. TRANSACTIONS OF WAGNER 778 TERTIARY FAUNA OF FLORIDA Genus PLACUNANOMIA Broderip. Plamnanomia Urod., P. Z. S., 1832, p. 28. Type P. Ciiinin^ii Brod. Placitiwiniii Swainson, Malac., p. 390, 1840; Gray., P. Z. S., 1849, p. 120. Placunanomia plicata Tuomey and Holmes. P. plicata T. and H., Pleioc. Fos. S. Car., p. 19, pi. 6, figs. 4-6, 1855. Newer Miocene of Duplin County, North Carolina, at the Natural Well, Burns ; and at Smith's on Goose Creek, South Carolina, Tuomey and Holmes ; living in Charleston Harbor, South Carolina ? Ravencl. Tuomey and Holmes state that Dr. Ravenel had in his collection a recent specimen of this species obtained from Charleston Harbor, but the absence of any confirmatory evidence for more than forty years leaves the accuracy of this determination in doubt. The fossil much resembles P. Cumingii, but is less deeply plicated, more delicate, with the rugosities of the cardinal border more feeble, and the byssal scar nearly equal in size to that of the adductor, in the right valve, while in P. Cumingii the adductor scar is conspicuously the larger of the two. If the present species be extinct, as seems likely, it is one of several instances where peculiar forms which were common to both coasts of America before the Pliocene survive the separation of the two oceans only on the Pacific side, a result which I believe to be due to the much steeper slope of the Pacific shores, which enabled many species of mollusks or their embryos to migrate seaward as the land rose and thus survive the change, while the more level margin of the Atlantic resulted in the total desiccation of a wide strip of sea-bottom in a relatively short space of time, thus exterminating a large proportion of the less active littoral fauna simultaneously over the whole of the elevated border of the coast. Conrad has briefly described (Kerr, Geol. Rep. N. Car., App., p. 19, 1875) an unfigured Miocene species from North Carolina under the name of P. fragosa. The type is lost and the generic place of the species is doubtful. Placunanomia lithobleta n. s. Rare in the Oligocene of Bowden, Jamaica; Henderson and Simpson. Shell resembling P. plicata, but flatter; not plicate, but gently waved distally ; surface radially sculptured with minute, almost microscopic, threads, which are frequently interrupted, when the termination of the proximal part of the thread is swollen, resembling a minute head or pustule; interior re- sembling P. plicata, but the hinge weaker, the amorphous irregularities con- FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA '' fined to a very small space near the umbo, and inconspicuous ; crura of the lower valve small, forming an acute angle, well elevated, the socket for their recep- tion on the opposite valve shallow. Alt. about 50, lat. 50, diam. about 8 mm. This form is distinguishable at once from the Pliocene and recent species by its peculiar surface sculpture. Genus PODODESMUS Philippi. l\iiloitfsmits Phil., \Yicgm. Arehiv., i., p. 385, 1837 ; Handb. der Conch., p. 380, 1853. Type P. dt-fipii-ns Phil. = P. nidis Brod. ? Tfdinia ('.ray, P. Z. S., 1851, p. 197 ; Cpr., Maz. Cat., p. 165, 1857. Placiiiianomia pars, Broderip, dray, Carpenter, Reeve, et al. Pododesmus rudis Broderip. P/iict/iituwmia rudis Brod., P. Z. S., 1834, p. 2; Reeve, Conch. Icon., pi. i, fig. 2, 1859. dt-cifnt-ns Phil., Wiegm. Arehiv., i., p. 387, pi. 9, fig. I, 1837. iiii i-ffiina/a lirod., /. r. / Reeve, Conch. Icon., pi. i, fig. i, 1859. /'/tifii>iii>ii»>iiti itt»n»'»ui/is Gray, P. Z. S., 1849, p. 121 ; Reeve, Conch. Icon., pi. 3, fig. 1 4 . iiit (l\nis) rudis Gray, P. Z. S., 1849, p. 120. ia llarfonli Reeve, Conch. Icon., pi. 2, figs. 8 a, 86, 1859. :' IVacHiiaiwinia (inifM/t Reeve, »f>. cit., pi. 3, fig. \oa, b, 1859. ? Chipola Oligocene of the Chipola River, Florida ; Dall. Recent from Cedar Keys, Florida, through the West Indies, and south to the mouth of the La Plata River, South America. This shell resembles Anomia aculcata externally, from which it is dis- tinguished by its .small, often obsolete, byssal foramen, and by having only two muscular impressions, — one large and conspicuous, which is the mark of the modified byssal muscle, and another below it, smaller and hardly distin- guishable on a fresh polished specimen, which is due to the adductor. It is likely that the Chipola species is distinct and could be properly characterized when adult, but the two upper valves obtained are quite young, and offer absolutely no characters by which they can be differentiated from P. rndis of the same size. I have therefore thought it best to refer the form to /'. rudis until more material is available. The relative position of the scars in the Aiti'iiiiiilic changes with age. Pododesmus scopelus n. s. PLATE 30, FIGURK 8. Uppermost Oligocene of the Alum Bluff beds, at Rock Bluff, Chatta- hoochee River, Florida ; Dall. TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA Shell large, irregular, taking the form of the object to which it adheres, the upper valve convex, with rude, irregular radial threads or unequal riblets, close-set and frequently broken up so as to appear vermicular; interior smooth, with two muscular impressions rather feebly impressed, the site of the rcsilium deeply impressed and extending behind the cardinal margin; attached valve concave, irregular, the foramen small and elongate, probably eventually closed, the chondrophore projecting partly over it in our specimens ; space between the valves very small. Alt. 44, lat. 58, diam. 7 mm. This species is one of the few characteristic fossils which are preserved at Rock Bluff, and has not occurred at Oak Grove or Alum Bluff in the same horizon, which may be explained by the fact that the bed at Rock Bluff is an old oyster reef, in which only Ostrea, Turritella, the present species, and frag- ments of Peclen and Balanus are preserved. The matrix is ill adapted to conserve fossils in their perfection, and the specimens of Pododesmus are very irregular and mostly shattered by internal .movements of the marl. Section Mania Gray. Pododesmus (Monia) macroschisma Dcshayes. Anomia macroschisma Desh., Rev. Zool. Soc. Cuvierienne, p. 359, 1839; Mag. Zool., 1841, pi. 34; Middendorf, Beitr. Mai. Ross., iii., p. 6, 1849; i'1"1-. Abbild. beschr. Conch., p. 132, pi. i, fig. 4, 1850. Placunanomia macroschisma Gray, P. Z. S., 1849, p. 121 ; Cat. Anom. Brit. Mus., p. 12, 1850 ; Cpr., Rep. Brit. As., 1863, p. 646. Placunanomia cepio Gray, P. Z. S., 1849, p. 121 ; Cat. Anom. Brit. Mus., p. II, 1850; Reeve, Conch. Icon., pi. 3, fig. 12, 1859. Placunanomia alope Gray, op. cit., p. 122, 1849; Reeve, Conch. Icon., pi. 3, fig. u. Upper Miocene of Sooke, Vancouver Island, C. F. Newcombc ; Plio- cene of San Diego, California, Hcmphill ; Pleistocene of California, Oregon, and Alaska, Dall ; recent from North Japan to Kamchatka, the Aleutian district and southeastern Alaskan coasts south to Lower California in shallow water. This species is abundant in the Pleistocene and occurs in the California!! Pliocene of the San Diego well. It is a very large, solid, and characteristic species. Carpenter referred a fossil of the Carri/.o Creek Miocene, Anomia subcostata, to this species, but the sitbcostata is a true Anomia. It is possible that Placunanomia inornata Gabb, referred by him to the Cretaceous and by Conrad to the Tejon Eocene, may belong in this section, and it even greatly resembles this species externally (cf. Pal. Cal, p. 217, pi. 32, figs. 288, 288 a, FREE INSTITUTE OF SCIENCE 78l TERTIARY FAUNA OF FLORIDA 1868). Placiinanomia fragosa Conrad, from North Carolina, from the descrip- tion may be referred to this group, but in the absence of any type or figure, or even any exact locality for the species, it is impossible to be certain. An unnamed species of the Chickasawan (Harris, Bull. Pal. No. 9, p. 42, pi. 6, fig. 10), if the scars are completely figured, should belong in this group. Genus ANOMIA (Linnd) Mullen Aiiiuiiin (pars) I.inne, Syst. Nat., Kd. x., p. 700, 1758. Anniniii Miiller, I'rotlr. Xool. Dan., pp. xx.\., 248, 1776; Retzius, Diss., p. 9, 1788. l-'.t-liinn •- Echionoderma Poll, Test. L'tr. Sicil., i., p. 34, and ii., p. 255, 1791. Ci'pn (Ihvass) Humphrey, Mils. Calon., p. 45, 1797. renesti-lla 1'xjlten, Mus. Boltenianum, p. 193, 1798 ; Ed. ii., p. 134, 1819. Aiiiiiiivit Agassi/., Monies des Moll., i., p. 23, 1839. Diploschiza Conrad, Am. Journ. Conch., ii., pp. 77, 105, 1866. Not Aitinnid Da Costa, Klein. Conch., p. 292, pi. vi., figs. 3, 10, 1776; nor of Bolten, Mus. Bolt., p. 134, 1798 (Brachiopoda). The fossil species of this group are very difficult things to study, since the lower valve is seldom preserved and the muscular impressions can seldom be made out. I shall therefore refrain from consolidating doubtful species in the absence of a sufficiency of material for thorough study. To the natural difficulties is added that due to the fact that the sculpture in this genus is very variable in perfectly normal specimens and is further complicated by the differences of form and surface due to the object upon which they are sessile. I have satisfied myself by the examination of a large number of recent speci- mens belonging to a single species from a single locality that the relative positions of the adductor and byssal scars on the left valve are not constant in the same individual at all ages, and consequently that small differences of this kind cannot safely be used as specific distinctions. The best character seems to be the more minute surface sculpture when fully developed in normal specimens. Anomia lisbonensis Aklrich. .\iitni//it i-filiififiitiitli-s Gabb, var. lishitneitsis Aldr., Bull. (leol. Surv. Ala., i., p. 41, pi. 4, Ii-. 6, 1886. Claibornian Eocene at Lisbon Bluff, Alabama, Aldrich ; and in similar horizons in Webster and Bienville Parishes and near Nachitoches and Mt. Lebanon in Louisiana, Vaughan ; near Wheelock and in Lee County, Texas, Singley and Johnson. This is a normally smooth, large species, with radiating bands of color on TRANSACTIONS OF WAGNER 782 1 TERTIARY FAUNA OF FLORIDA a lighter ground. It is clearly distinct from the species to which it was originally referred as a variety. Anomia ephippioides Gabb. Anomia ephippioides Gabb, Journ. Acad. Nat. Sci. Phila., 2d Ser., iv., p. 388, pi. 67, fig. 59, 1860. Claibornian Eocene of Texas, Gabb ; near Laredo and Wheelock, Texas, Johnson and Singley. This species was originally very imperfectly described and figured from worn specimens. The chief specific character is not alluded to. The young when in perfect condition are covered with minute pustules; as the shell approaches maturity these elongate and become close-set, rather coarse threads, separated by narrower grooves. In perfect condition it cannot be mistaken for any other American species. This sculpture, it should be clearly understood, is normal to the species and entirely independent of irregularities due to situs. Anomia Ruffini Conrad. Anomia Ruffini Conr., Proc. Acad. Nat. Sci. Phila., i., p. 323, 1843; Medial Tert. Fos., p. 74, pi. 42, fig. 6, 1845 ; S. I. Checkl. Eoc. Fos., p. 3, 1866. Anomia McGeci Clark, Bull. U. S. Geol. Surv., No. 141, p. 86, pi. 34, fig. 5 a-b, 1895. Eocene, Waterloo, Pamunkey River, New Kent County, Virginia, E. Ruffin ; Hanover County, Virginia, and various localities in Maryland, Clark and Whitfield. (Miocene of ?) Specimens collected by Ruffin, in the National Museum, from Shell Bank and Waterloo, leave little doubt that Clark's species, from the same region, is identical with that of Conrad. The characteristics of the species are its large size and the irregular fluting of the shell, especially near the margins. The muscular scars are usually difficult to make out, but the species is an Anomia and not a Pododesinus, as might be suspected from Clark's figure. The species is not found in the Caloosahatchie beds, though included by an error of identification in Heilprin's list. The other Eocene species referred to in the literature, but which I have not identified, are A nomia jugosa Conrad (Proc. Acad. Nat. Sci. Phila., i., p. 310, 1843; "'•> P- 22> pl- *> fifl- !5) fr°m the Jacksonian of South Carolina, — a species of which neither the description nor the figure affords sufficient information to enable one to identify it, — and A. navicelloides Aldrich (Nautilus, xi., p. 97, Jan., 1898) from the Wood's Bluff horizon at Choctaw Corner, Alabama, which is still unfigurecl. FREE INSTITUTE OF SCIENCE 783 TERTIARY FAUNA OF FLORIDA Anomia microgrammata n. s. PLATE 35, FIGURE n. Oligocene of the Chipola beds at the Chipola River and the lower bed at Alum Bluff, Florida ; also at Ballast Point, Tampa Bay, Dall, Burns, and Willcox ; and at Bowclcn, Jamaica, Henderson and Simpson. Shell small, irregular, characterized by a fine, almost microscopic, close- set radial striation covering the whole surface and flaring away from the medial line of the valve in a somewhat wavy manner ; the two lower scars on the left valve are subcqual and side by side, the major byssal scar larger, oppo- site the medial line between them ; the beak of the left valve is some distance within the margin, and the surface where worn appears smooth ; the striation is only visible under a lens in most cases. Alt. 17, lat. 25 mm. This species is recognizable by its fine, almost divaricate striation, which does not break into pustules near the beaks, as in the larger and more coarsely sculptured A. cpliippioidcs. The specimens from Bowden have a still finer and often partially obsolete striation. They form the variety indccisa (Guppy, MS.). Anomia floridana n. s. PLATE 35, FIGURE 7. Oligocene of Oak Grove, Santa Rosa County, Florida; Burns. Shell of moderate size, usually rather convex, the surface irregular, obso- letely microscopically radially striated, more or less irregularly feebly pustular and with obsolete, broken, feeble radial plications; the minor byssal scar is above and slightly further back (about half its own width) than the adductor scar of the same size ; the major byssal scar is rounded and much larger, situated directly above the minor one, so that the three scars are nearly in one dorso-ventral line ; the beak of the left valve is at the cardinal margin. Alt. of largest specimen 35, lat. 39 mm. This species is intermediate in size and character between A. inicrognvn- niata Dall and A. Ruffini Conrad. It is smaller and less sculptured than the latter, which also wants the microscopic striation; it is larger, less sharply striated, and has the beak and scars situated differently from the former. Many of the speeimens still retain some of the original greenish coloration. The only other Oligocene species described from the North American and Antillean regions is the . /. iimltonata Guppy, from Trinidad (Proc. U. S. Nat. Mus., xix., No. 1 1 10, p. 235, pi. 30, fig. 6, 1896), which is small, with minute pustulation but no radial striation. TRANSACTIONS OF WAGNER 784 TERTIARY FAUNA OF FLORIDA Anomia simplex Orbigny. Anoinia I'phippiiini Conrad, Medial Tert. Fos., p. 75, pi. 43, fig. 4, 1845. . \noiiiia simplex Orb., Moll. Cubana, ii., p. 367, pi. 38, figs. 31-3 (1845, Spanish edition), 1853 ; Dall, Bull. U. S. Nat. Mus., No. 37, p. 32, pi. 53, figs. I, 2, 1889. Anomia (iconics Gray, P. Z. S., 1849, P- ''6- Anoinia Conradi Orb. , Prodr. Pal., iii., p. 134, pi. 25, fig. 30, 1852; Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 582, 1863. Anomia ephippium Tuomey and Holmes, Pleioc. Fos. S. Car., p. 18, pi. 5, fig. 4, 1855 ; Holmes, P.-P1. Fos. S. Car., p. u, pi. 2, fig. 11, 1858; Emmons, Geol. N. Car., p. 277, 1858 ; Gabb, Journ. Acad. Nat. Sci. Phila., 2d Ser., viii., p. 380, 1881. Anoinia glabra Verrill, Am. Journ. Sci., 3d Ser., iii., p. 213, 1872 ; x., p. 372, 1875. Anomia clectrica Gould, Inv. Mass., p. 140, 1841 ; Binney's Gould, p. 205, fig. 499, 1870; not of Linne. Anoinia, sqnainula Gould, Inv. Mass., p. 140, 1841 ; Binney's Gould, p. 206 (young), 1870 ; non Linne. Anomia Ruffini Heilprin, Trans. Wagner Inst., i., p. 102, 1887 ; not of Conrad. f Anomia cphippiitm Gabb, Geol. St. Domingo, p. 257, 1873. ? Oligocene of St. Domingo, Gabb ; Upper Miocene of Duplin County, North Carolina, at the Natural Well, Conrad ; of York and Nansemond Rivers, Virginia, Burns ; Pliocene of the Waccamaw beds, South Carolina, Tuomey and Johnson; of the Caloosahatchie beds, Florida, Dall; of Limon, Costa Rica, Gabb ; Pleistocene of the Atlantic and Gulf coasts from the Carolinas southward, Holmes and Burns ; recent from Cape Sable, Nova Scotia, southward to Martinique. . I am unable to find any distinctive characters separating the Upper Mio- cene from the recent shells. The surface is normally smooth, and the varia- tions of position in the scars of the left valve are remarkable. In the young the lower pair of scars are usually equal and side by side; as the shell grows older their positions change, and the minor byssal scar is no longer on the same level with that of the adductor. Shells which by some accident of position are forced to grow in elongated form usually have the scars more strung out and more nearly in a single line, than the individuals which maintain a normal suborbicular growth. Anoinia aculeata Gmelin. Anomia aculeata Gmelin, Syst. Nat., vi., p. 3346, 1792; Gould, Inv. Mass., p. 139, fig. 90, 1841 ; Binney's Gould, p. 204, fig. 498, 1870; Verrill, Rep. U. S. Fish Com. for 1871-2, p. 697, pi. 32, figs. 239, 240, 240^, 1873; Dall, Bull. U. S. Nat. Mus., No. 37, p. 32, pi. 53, figs. 5-8, 1889. FREE INSTITUTE OF SCIENCE 785 TERTIARY KAUNA OF FLORIDA Upper Miocene of York River, Virginia, Harris; Pleistocene of Sankoty Head, Massachusetts, Verrill; recent from the Arctic Ocean south to Cape Fear, North Carolina, on the Atlantic coast; also on the northern coasts of Europe. The presence of this species in the Virginia Miocene is established by some beautifully preserved small valves with the characteristic sculpture obtained by Mr. Harris. The A. delnmbis Conrad (Proc. Acad. Nat. Sci. Phila. for 1862, p. 582) is a mere list-name, never described or referred to a locality. A well-defined species is the A. sitbcostata Conrad, from the Miocene of the Carrizo Creek 'beds, Colorado Desert, California. (Pac. R. R. Reps., v., p. 325, pi. 5, fig. 34, 1855.) It is strongly radially plicated. Anomia limatula Dall. PI.ATK 35, FIGURE 19. A iii >iitia liinatiild Dall, 1'roc. U. S. Nat. Mus., i., p. 15, 1878. Pliocene of Ventura County, California, eight miles inland and two hundred feet above the sea level, Bowers; of Coronado beach, San Diego, California, Hcmphill ; and of Pacific beach, near San Diego, Stearns ; Pleistocene of Spanish Bight, Coronado beach, San Diego, and of San Pedro Hill, Los Angeles County, California, Stearns. A fine, large species, which is characterized by its peculiar, finely granulose surface, devoid of all normal radial sculpture, and which still retains on its yellowish valves traces of dark purple, irregularly radial blotches. The cal- careous plug of this species is peculiar, being hollow, and the cylinder incom- plete on one side. From the Pleistocene of San Pedro Hill, California, has been obtained A. lainpc Gray, the common Anomia of the recent fauna of the coast (Gabb, Pal. Cal., ii., p. 106, 1868). This is almost invariably radially ribbed and often concentrically grooved, and has a polished surface quite unlike that of A. liniatnla. It has also been obtained by Stearns at Spanish Bight, Coronado beach, San Diego, California. Superfamily MYTILACEA. FAMILY MYTILID/K. Grnus MYTILTJS (L.) Bolti-n. Myliliis Lin., Syst. Nat., Ed. x., p. 704, 1758 ; Miillcr, Xool. Dan. 1'roilr., p. 249, 1776 ; D.i Costa, Brit. Conch., p. 214, 1778; Hi u^uuVe, Kn< yc . Meth., i., xiii., 1789; Humphrey, Mus. Calon., pp. 42, 43, 1797. TRANSACTIONS OF WAGNER 786 TERTIARY FAUNA OF FLORIDA < Mytihis + Volsclla Scopoli, Intr. Hist. Nat., pp. 396-7, 1777 ; Modeer, K. vet. Acad. Handl., xiv., pp. 179, 181, 1793. < Afytiilus + Perna Retzius, Dissert., p. 20, 1778. = Mytilus Bolten, Mus. Bolt., p. 157, 1798 ; Ed. ii., p. no, 1819. < Mytuhts Cuvier, Tabl. Elem., p. 423, 1798. = Mytihis Lamarck, Prodr. Nour. Class. Coq., p. 88, 1799. Type M. cdulis L. ; Link, ISeschr. Rostock Sarnml., p. 158, 1807. ? Arcomytiliis Agassiz, 1840. Type Mytihts pcctinatus Sby. (? = Scptifcr Recluz, 1848). The name Mytihis for the mussels is of very ancient date, and in adopt- ing it for his heterogeneous genus Linne merely followed classical usage. If we ascribe the genus to Linne we are obliged to seek the type by his method of taking the most common species, and while this might be done under stress of circumstances, it is better, if practicable, to follow the regular rule. The naturalists who followed Linne did not grasp the characters which separate the groups of the Linnea'n Mytili, and after eliminating the fresh- water species, they seemed to fall back on the dentiferous or edentulous char- acter of the hinge in their divisions of the group. Thus Scopoli divided the Linnean Mytilus into an edentulous group, for which he preserved the name without citing any examples, and Volsclla, which included species with one or more teeth. It was by some misidentification, therefore, that Mytilus inodiolus was included in Scopoli's Volsella and defined as having one tooth. Modeer followed Scopoli, and Retzius did the same, except that he proposed a genus Perna for the forms Scopoli had named Volsclla. Even Cuvier included both Mytilus and Modiola in his Mytulns. The first author who seems to have had clear and what may be termed modern views on the subject was Bolten, who divided his Mytilus into a smooth and a sulcate group and excluded nearly all the species not Mytiloid, as now understood. He did not name a type, but this deficiency was supplied by Lamarck a year later. A consideration of these facts shows that the course of some writers who would substitute Volsella or Perna for Modiolus Lamarck is unwarranted by the history of these names. The quadrinomials of Poli (Callitriche + Calli- tnclioderina, 1791) have no place in our nomenclature. The names which are entitled to adoption are all comparatively modern. The curious twisted sub- genus Stavelia Gray, which is usually placed with Mytilus, should be removed to Modiolus. Mytilastcr Monterosato has vermiculate sculpture. The Mytili occurring in the North American Tertiary are divisible by their sculpture into two sections : FREE INSTITUTE OF SCIENCE 787 TERTIARY FAUNA OF FLORIDA Genus Mytilns (L.) Bolten. Section Mytiltis s. s. Surface with chiefly concentric sculpture or smooth. Type Jf. cilnlis L. Section Horiiioinya* Morch (Cat. Yoldi, p. 53, 1853). Shell radially sculptured. Type Mytilus exustus Linne. To these may be added : Subgenus Mytiloconclia Conrad. Apical region of the shell much thickened and produced, with longitudinal grooves. Type M. incurva Conrad. The number of species of Mytilus in the Tertiary of the Eastern United States is very small, but the Pacific coast offers a larger number. Mytilus Conradinus Orbigny. Mytilus iiii'i-iixsn/iis Conr., Am. Journ. Sci., xli., p. 347, 1841 ; Fos. Medial Tert., p. 74, pi. 42, fig. 4, 1845 ; Tuomey and Holmes, Pleioc. Fos. S. Car., p. 32, pi. 14, figs, i, 2, 1855 ; Harris, Bull. Pal., 3, p. 5, 1895 ; not of Deshayes, 1830. Mytilus ( 'onradinus Orbigny, Prodr. Pal., iii., p. 127, 1852. Mytiloconclia incrassata. Conr., Proc. Acad. Nat. Sci. Phila. for 1862, p. 291, 1862. A/yti/ii'niii'iiti iiurassata Conr., op. fit., p. 579, 1863. Lower Miocene of Cumberland County, at Shiloh and Jericho, New Jersey, Conradsand Burns; Miocene of the artesian well at Galveston, Texas, between two thousand three hundred and eighty-four and two thousand eight hundred and seventy-one feet below the surface, Singley ; Upper Miocene of the Natural Well, Duplin County, North Carolina, Burns ; two and one-half miles below Governor's Run, Chesapeake Bay, Maryland, Burns ; Miocene of South Carolina, in the Darlington District and on the Waccamaw River, Tuomey and Holmes. This species does not differ from the true Mytilus except in being a little heavier than is usual in this genus. It has not the produced cardinal area of Mytiloconclia, with imperfect specimens of which it has sometimes been con- fused. Mytilus pandionis n. s. PLATE 30, FIGURES 9, 10. Oligocene of White Beach, near Osprey, Little Sarasota Bay, west Florida; Dall. * Arcomytilus Agassiz (Sowb. Min. Conch., French cd., 1840) is prior in point of time, but the type has the aspect of a Septifer anil the interior is not described or figured. 15 TRANSACTIONS OF WAGNER 788 TERTIARY FAUNA OF FLORIDA Shell large, somewhat compressed behind, wide, with the posterior cardinal angle in the anterior third ; cardinal line short, an impressed narrow area in front of the beaks nearly half as long as the shell ; surface apparently smooth (the type is an internal cast), umbones acute. Alt. 122, lat. 60, diam. 36 mm. This is the only large Mytilus of the J\I. cclitlis type in the east American Pre-Miocene Tertiary. It somewhat recalls very large specimens of M. gallo- provindalis Lam. Mytilus edulis Linne. Mytilus edulis L., Syst. Nat., Ed. x., p. 705, 1758 ; Dull, Bull. U. S. Nat. Mus., 37, p. 38, pi. 54, %. 3, pl- 71, fig- 2, 1889. Mytilus borealis Lam., An. s. Vert., vi., p. 126, 1819; DeKay, Nat. Hist. N. Y., Moll., p. 182, pl. 13, fig. 222, pl. 24, fig. 256. Mytilus pcllucidus Pennant, Brit. ZooL, iv., p. 237, pl. 66, fig. 3. Modiola pulex H. C. Lea, Am. Journ. Sci., xlii., p. 107, pl. i, fig. 3, 1842 (young shell) ; not of Lam., An. s. Vert, vi., p. 112, 1819. Mytilus mingancnsis Mighels, Proc. Bost. Soc. Nat. Hist., i., p. 188, 1844. Mytilus notatus DeKay, op. tit., p. 182, pl. 13, fig. 223, 1843. Pliocene of Great Britain (Red Crag). Post Pliocene of the American coast from Labrador south to St. John's River, Florida (Verrill), also in northern Europe and on the northwest coast of America; recent from the Arctic Seas south to Fort Macon, North Carolina; Coues. The writer has never observed this species in the Pleistocene of Florida and the Carolinas ; the statement of its occurrence there is inserted on the authority of Professor Verrill (Inv. An. Vineyard Sound, p. 693, 1873). Mytilus (Hormomya) exustus Linnc. Mytilus exustus L., Syst. Nat., Ed. x., p. 705, 1758 ; Lam., An. s. Vert., vi., p. 121, 1819? Mytilus bidcns L., Syst. Nat., Ed. xii., p. 1157, 1767. Mytilus domin^cnsis Lam., An. s. Vert., vi., p. 121, 1819; Orbigny, Moll. Ciibana, ii., p. 328, 1845. Myti/us striatulus Schroter, Einl., iii., p. 449, pl. ix., fig. 16. Pliocene of the Caloosahatchie and Shell Creek, Florida, Ball and Will- cox; Pleistocene of Simmons Bluff, South Carolina, Burns; and of the West Indies; recent from Charleston, South Carolina, south to Bahia, Brazil. This well-known species is rare in the marls, and not especially abundant in the Pleistocene. FREE INSTITUTE OF SCIENCE 789 TERTIARY FAUNA OF FLORIDA Mytilus (Hormomya) hamatus Say. / Mytilus >;-cur-,'iis Rat'., Mon. Coq. Biv. Ohio, p. 55, 1820; New Orleans. Mylilns hiiiiiiitiis Say, Journ. Acad. Nat. Sci. Phila., ii., p. 265, 1822 ; Binney's reprint of Say, pp. 91, 204, pi. 50; Dall, Bull. U. S. Nat. Mus. No. 37, p. 38, 1889. /!i;ti-/i\'ii<>iiti-s /taiiiati/s Perkins, Proc. Bost. Soc. Nat. Hist., xiii., p. 156, 1869. .' l)n-issciiit ivcurva Fischer, Journ. de Conchyl., vii., p. 130, 1858. .Mytillns slrialits Barnes, Am. Journ. Sci., vi., p. 364, 1823 ; Say, Am. Conch., v., pi. 50, 1832- Mitdiola haniatus Verrill, Am. Journ. Sci., 3d Ser., iii., p. 21 1, pi. 7, fig. 3, 1872; Inv. An. Vineyard Sound, p. 693, 1873. Mytilus itini/iiti-nsis Conrad, Journ. Acad. Nat. Sci. Phila., vii., p. 244, pi. 20, fig. 6, 1837; Tryon, Am. Mar. Conch., p. 187, fig. 513, 1874. Pliocene of the Caloosahatchie, Dall ; Pleistocene of VVailes Bluff, St. Mary's County, Maryland, Burns ; recent from Long Island Sound south to Costa Rica. On the Pacific coast, besides M. cdtdis, the Pleistocene affords the great M. calif or nia mis Conrad, which even, according to Cooper, is found in the Pliocene, and M. pcdroanns Conrad, which is perhaps identical with M. edulis. The Pliocene affords M. Middcndorfii Grewingk (Beitr. Kenntn. N. W. Kuste Am., p. 360, pi. vii., figs. 3 a-c, 1850) and M. Condom Dall (Nautilus, iv., p. 87, Dec., 1890), peculiar species with a few broad plications posteriorly, from Alaska and Oregon respectively. In the Miocene are the large M. Matliew- soni Gabb and the M. incrjcnsis of Conrad, which may prove to be the same \y- as Modiola inultiradiala Gabb ; both are radiately sculptured and of rather uncertain outline. In the Eocene (Tejon) are M. ascia Gabb and M. httiitenis Conrad, both rather obscure, smooth species, and M. (Ilorinoinya) dichotomns Cooper (Bull. Cal. State Mining Bureau, No. 4, p. 49, pi. v., fig. 64, 1894), of which the characters, even the genus, arc imperfectly known. Its relations to Scptifcr dichotomies Gabb and 5". bifurcatus Reeve, as well as Mytilus bifurcatus (Conr.) Stearns, remain to be clearly made out. Subgenus MYTILOCONCHA Conrad. Myocuncliti Conrad, Medial Tcrt., p. 52, 1840. Myli/,i,-i'iu-/in Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 2yo, 1862. i Conrad, op. fit., p. 578, 1863. Mytilus (Mytiloconcha) incurvus Conrad. incitnui Conrad, Medial Tert., No. I, p. 3 of cover, 1839; No. 2, p. 52, pi. 28, fig. I, 1840. TRANSACTIONS OF WAGNER 7QO TERTIARY FAUNA OF FLORIDA Mytilus inairvus Conrad, Proc. Acad. Nat. Sci. Phila., vii., p. 29, 1854. Mytilus (Myoconc/ia) incurvus Conrad, Medial Tert., p. 88, 1861. Mytiloconcha incuriia Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 291, 1862. MytilicoHcha incurva Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 579, 1863. Mytiloconcha incrassata Whitfield, Mio. Moll. N. J., p. 38, pi. 5, figs. 10, n, 1894; not of Conrad. Oligocene of Sopchoppy Creek, Wakulla County, Florida, Hodge ; Lower Miocene of Cumberland County, New Jersey, at Shiloh and Jericho; of Mary- land, near Skipton, on the Choptank, near Easton, Talbot County, and in Cal- vert County, Harris and Burns ; Miocene of South Carolina, Whitfield. The specimens found in New Jersey are very badly worn and young, hence Professor Whitfield's identification of them, which I believe erroneous. I have never seen a perfect specimen of this singular shell, but the external casts from the Upper Oligocene of Florida show its characters admirably. The M. incrassata Conrad is only a rather heavy Alytiliis. The hinge of the present species has two strong teeth in the left and one in the right valve, which are obsolete in senile specimens. These teeth are produced over the cardinal area as ridges, extending to the apex of the valve, with a furrow on each side of each ridge, a single furrow between the two ridges of the left valve. Apart from the furrows and ridges the area is flattened. Close to the posterior margin the groove of the ligament is continued along the edge of the area to the apex. In a specimen one hundred and twenty millimetres long the area is twenty millimetres long and about the same in greatest width. The characters are those of ordinary Mytilus, but curidusly exaggerated. Mytilus hesperiamts Lam., of the Red Crag of Britain, would seem to belong in this group. Genus MODIOLITS Lamarck. Modiolus Lam., Prodr. Nouv. Clas. Coq., p. 87, 1799. Type Mytilus inodiolns L. ; Hose, Hist. Coq., iii., p. 158, 1802; Link, Beschr. Rostock Samml., Hi., p. 146, 1807; Cuvier, Regne Anim., ii., p. 471, 1817 ; Goldfuss, Zool., p. 611, 1820; Risso, Hist., iv., p. 323, 1826; Fleming, Hist. Brit. An., p. 408, 1828; Forbes, Malac. Monensis, p. 43, 1838 ; Herrmannsen, Ind. Gen. Mai. Suppl., p. 84, 1852. Modiola Lam., Syst. des An. s. Vert., p. 113, 1801. Type M. papuana Lam. (Encyc. Moth., pi. 219, fig. i) ; Roissy, Moll., vi., p. 273, 1805 ; Lam., An. s. Vert., vi., p. 119, 1819; Fischer, Man. de Conch., p. 968, 1886; Dall, Bull. U. S. Nat. Mus., No. 37, p. 38, 1889. Amygdalum Megerle, Mag. Ges. Naturf. Fr., v., p. 69, 1811. Type A. dcndriticitm Meg. (Chemn., xi., p. 198, fig. 2016-7). FREE INSTITUTE OF SCIENCE 70 1 TERTIARY FAUNA OF FLORIDA Rrachidonlcs Swainson, Malac., p. 384, 1840. Type Moitin/u snlcata Lam. Moiliflla Monterosato, Noiu. Con. Medit., p. 12, 1884 (not of Hall, 1883). Type Modiola pulita Yerrill. Grcgariclla. Monterosato, op. cit., p. 11, 1884. Type Mytilus petagnce Scacchi. Rrachydiwtes Fischer, Man. de Conch., p. 968, 1886; Dall, Bull. U. S. Nat. Mus., No. 37, p. 38, 1889. The main conchological characters which separate this genus from Mytilus are the non-terminal umboncs, the tendency to hirsuteness in the epidermis, the absence of developed teeth at the beaks, and the habit of nestling in a mass of byssal fibres with extraneous entangled material which is more or less characteristic of all true Modioli, though less conspicuous and complete in the larger species. In some deep-water species a real nest is spun, like that of Lima, but more dense. A more efficient protective device could hardly be imagined than the byssal nest of M. polihts, which completely conceals the occupant from predacious marine carnivora. In the matter of sculpture these shells resemble Mytilus, and have a distinct tendency to a medial unsculptured area in the radially sculptured species. Although true teeth are not found in this group, the provinculum is often present and permanent, while its origin is obviously indicated by the secondary denticulations due to the impinging of the radial sculpture upon the margin. I believe hinge-teeth were thus originally initiated, while the secondary denticulations alluded to repeat in the descendants the process by which their remote ancestors acquired an interlocking hinge. The genus Modiolus, like Mytilus, may be divided into natural groups by the sculpture of the surface. Genus Modiolus Lam. Section Modiolus s. s. Surface smooth, shell inflated, edentulous, epi- dermis more or less hirsute. Type M. modiolus Linne. Section Amygdalum Megerle. Surface smooth, shell compressed, epidermis polished, not hirsute. Type M. picttts Lam. (Syn. Modiclla Mts., not Hall.) Section Grcgariclla Mts. Surface decussate with a central smooth area; shell plump, epidermis hirsute. Type M. petagnic Scacchi. (Syn. Botnlina Dall, 1889.) Section Brachydontcs Swainson. Surface more or less radially sulcate ; epidermis not hirsute. Type M. sulcatits Lam. (1819, not 1807). Scini- mvdiola and Wanitnodiola Cossmann seem to belong to this section rather than to Modiolaria. TRANSACTIONS OF WAGNER 7Q2 TERTIARY FAUNA OF FLORIDA Section Botula Morch. Surface deeply concentrically sulcate, shell in- flated, with conspicuously spiral umbones, the epidermis polished. Type M. cinnamomcus Lam. This section, if it were not for its peculiar muscular scars, might perhaps equally well be placed under Lithophaga, as has been clone by Fischer. It is intermediate, conchologically, between the boring Litliophagi and the nestlers, as regards externals. Section Arcoperna Conrad (Am. Journ. Conch., i., p. 140, pi. 10, fig. 14, 1865). Shell oval, general form like Botula, but the surface finely striated or reticulated and the margin, except over the ligament, crenulatcd. Type M. (A.) filosns Conr., /. c. Jacksonian and Parisian Eocene. This section resembles Modiolaria, except in the absence of the medial unstriated impressed area, and the more oval outline of many of the species. The umbones are swollen and conspicuous. Modiolus cretaceus Conrad. Modiola cretacea Conrad, Trans. Geol. Soc. Penna., i., p. 340, pi. 13, fig. 2, 1835. Perna cretacea Conrad, Am. Journ. Conch., i., p. 10, 1865. Jacksonian Eocene of Clarke and Choctaw Counties, Alabama, Conrad ; near Fail Post-Office, Alabama, in the Zeuglodon bed, Schuchcrt ; ? Oligo- cene of western Florida, Eldridge ; ? Upper Oligocene of Oak Grove, Santa Rosa County, Florida, Burns. This is a large species resembling M. modioliis L. A few young shells represented by internal casts and a lot of fragments from Oak Grove, col- lected by Eldridge and Burns, may belong to this species, but are insufficient for a positive decision. Modiolus pugetensis n. s. PLATE 35, FIGURE 17. Eocene of the Puget group in the State of Washington, from the old Renton coal mine, near Seattle; Willis. Shell small, short in front, arched and produced behind ; concavely im- pressed in front, with a rounded ridge extending from the beaks to the lower posterior margin ; surface polished, with concentric lines of growth. Alt. 17.7, max. lat. 9.5, diam. 5 mm. A larger specimen measures 25 mm. from end to end, but is imperfect. This is a very simple little species, but unlike any other in our Tertiary. FREE INSTITUTE OF SCIENCE 793 TERTIARY FAUNA OF FLORIDA Modiolus silicatus n. s. PLATE 27, FIGURE 28. Upper Oligocene of the silex beds at Ballast Point, Tampa Bay, Florida ; Willcox and Dall. Shell small, smooth, short, broad, moderately convex, with a few incre- mental strias ; beaks low, anterior end very short, posterior margin elevated, rounded, anterior margin slightly impressed; basal end rounded; inner margin smooth, with an unusually deep ligamental sulcus. Alt. 22, max. lat. 1 6, diam. 9 mm. This is somewhat like the Miocene M. inflatits T. and H., but a much smaller shell, with a less impressed lateral area and less sinuous anterior margin. Modiolus inflatus Tuomey and Holmes. Mytilus inflatus T. and H., Pleioc. Fos. S. Car., p. 33, pi. 14, fig. 3, 1855. /', rna inflatn Conrad, Proc. Acad. Nat. Sci. for 1862, p. 579, 1863. Mt'iUola inflala Whitfield, Mioc. Moll. N. J., p. 39, pi. 6, figs. 3, 4, 1895 (not Modiola injlatti Whitf., Lam. Rar. Clays, p. 197, pi. 26, figs. I, 2, 1885). Lower Miocene of Shiloh and Bridgeton, Cumberland County, New Jersey, Burns ; Miocene of South Carolina at Giles Bluff, Peedee River, Tuomey. This species is closely related to the recent M. tiilipus Lam. Modiolus Ducatelii Conrad. Mi>iii(>/ii tlucatelii Conrad, Medial Tert., p. 53, pi. 28, fig. 2, 1840. Miocene of Calvert Cliffs, Maryland, Professor Ducatel; of Jericho, New Jersey, Burns ; of York River, Virginia, Harris ; of the Natural Well, Duplin- County, North Carolina, Burns. This large species is rather abundant in the Maryland Miocene, but rarely perfect. The M. gigas Wagner (Trans. Wagner Inst, iv., p. IO, pi. 2, fi^r. 2, a-b, 1897) differs by its much wider posterior part and attenuated anterior end. It is also Miocene. The other valid species, belonging to the section Modiolus as restricted, found in our Tertiary except M. inlifns Lam., which occurs in the later rocks of the West Indies, arc all California!! and include M. capax Conrad, Pliocene and. Pleistocene (as well as recent); M. flabcllatits Old., Pliocene and recent; M. n-cins Conrad, Miocene and recent ; while the M. modiolns L., which is said to go back to the Miocene (?) in California, is known from Pleistocene deposits on both sides of the continent as well as the shores of Kurope. TRANSACTIONS OF WAGNER 794 TERTIARY FAUNA OF FLORIDA Modiolus (Brachydontes) grammatus n. s. PLATE 30, FIGURE 2. Oligocene of the silex beds at Ballast Point, Tampa Bay, Florida, Dall ; and (var. curtuhts Dall) of the lower bed at Alum Bluff, Chattahoochee River, Florida, Burns. Shell small, thin, slender, delicately dichotomously radially ribbed ; anterior end extremely short, barely exceeding the beaks ; posterior margin angulated ; front margin nearly straight, basal end rounded ; inner margin delicately crcnulate. Alt. 20, max. lat. 8.5, diam. 6.5 mm. This is closely related to the recent M. citrimts Bolt., but is more attenu- ated towards the beaks, and has the dorsal angulation and crenulations of the margin less pronounced. The variety, which more abundant material might show to be a distinct species, is stouter, more triangular, with coarser and more nodulous ribs and stronger crenulations of the margin. Alt. 12, max. lat. 7, diam. 6 mm. Modiolus (Brachydontes) Guppyi n. s. PLATE 35, FIGURE 16. Oligocene of the Bowden beds, Jamaica ; Henderson and Simpson. Shell small, thin, delicate, radiately numerously ribbed, the ribs but seldom dichotomous, general form as in M. grammatns, but shorter and more rounded, the surface frequently concentrically faintly undulated, inner dorsal margin sharply crenulate, the rest of the shell margin almost smooth ; basal end of valve rounded, dorsal angle obsolete. Alt. 8.5, max. lat. 4.7, diam. 2.5 mm. This differs from the last in its more delicate and less dichotomous ribbing, its more rounded, thinner, and less angular shell, and in the absence of crenulations over most of the margin, due to the feebleness of the sculpture. Modiolus (Brachydontes) demissus Dillwyn. Mytilus demissns (Solander MS.) Dillwyn, Descr. Cat. Rec. Shells, i., p. 314, 1817 ; Say, Journ. Acad. Nat. Sci. Phila., ii., p. 265, 1822 ; Wood, Ind. Test., p. 25, pi. 12, fig. 30, 1825 ; Greene, Mass. Cat., 1833 ; Ravenel, Cat., p. 7, 1837. plicatiila Lam., An. s. Vert. , vi., p. 113, 1819; ed. Desh., vii., p. 22, 1835; Totten, N. Engl. Cat., 1833 ; Gould, ist Rep. Geol. Me., p. 119, 1837 ; Inv. Mass., p. 125, fig. 81, 1841 ; DC Kay, Nat. Hist. N. Y., Moll., p. 184, pi. 24, fig. 258, 1843 ; Verrill, Inv. An. Vineyard Sound, p. 693, pi. 31, fig. 238, 1873 ; Dall, Bull. U. S. Nat. Mus., No. 37, p. 38, pi. 54, fig. i, 1889. FREE INSTITUTE OF SCIENCE 795 TERTIARY FAUNA OF FLORIDA Mytilus plicatulus Sby., Genera, Myt., pi. vii., 1822; Deshayes, Enc. Meth., ii., p. 568, pi. 220, fig. 5, 1830; Stimpson, Sh. N. Engl., p. 12, 1851. Modiohi scinii'ostatii Conr., Journ. Acad. Nat. Sci. I'hila., vii., p. 244, pi. 20, fig. 7, 1837. (Not of Dall,' Bull. 37, 1889.) Modiola semiiosta Yerrill (as of Conrad), Inv. An. Vineyard Sound, p. 693, 1873. (.') Mytilus claim Meuschen, Mus. Gronov., 1778 (Jiilf Morch, Cat. Yoldi, ii., p. 54, 1853). (/) Mytilus magfllanus Meuschen, Mus. Gevers, 1787 {fide Morch, op. fit., p. 54, 1853). Krac.Jiyilonifs clnva Morch, Cat. Yoldi, ii., p. 54, 1853. rcrna (Brachydontts) plicatula H. and A. Adams, ii., p. 517, 1857. Moi/iiifti iti'iiu'ssa Conrad, Am. Journ. Sci., 2cl Ser., ii., p. 44, 1846. Pliocene marls of the Caloosahatchie River, Florida, rare, Dall ; Post Pliocene of Massachusetts Bay ; recent from Nova Scotia to Georgia, west Florida, and Texas ; locally restricted towards the extremes of its distribution. There is no doubt of the applicability of Dillwyn's name to our common plicate mussel. The two names of Meuschen are doubtful, and probably cover a confusion of our species with the Mytilus magcllanicus of authors. I have not been able to consult Meuschen's works, but believe the names are not accompanied by any description or figure, and are identified chiefly by means of the alleged localities. At all events, until the information is fuller and more satisfactory, it seems inadvisable to use Meuschen's earlier name, while his later one is inapplicable. There are two distinguishable geographical races of this species, the form found north of New York, and figured in the Encyclopedic Methodique, which Lamarck called plicatulus and Conrad sci/ii- costatus ; and the southern form, which is more attenuated behind, has a more delicate and elegant sculpture, the ribs being minutely granulose, and the color lighter and of a less intense purple. Dillwyn's name included both, and may be specially centred on the southern form, while that of Massachu- setts Bay may be regarded as forming a variety plicatulus. In my Bulletin 37, United States National Museum, the two names were accidentally trans- posed. Modiolus (Brachydontes) citrinus linltrn. Area iiiiiifio/u.'i Limn', Syst. Nat., Ed. xii., p. 1141, 1767. Mytilits litriiius polyili-ntiiliis, etc., Chemn., Conch. Cab., viii., p. 175, pi. 84, fig. 754, 1785. Mytilus Jlavicans (Sol. MS.) Humphrey, Mus. Calon., p. 43, 1797 (no description or figure). Mytilus ( -Uriiins Bolten, Mus. Bolt., p. 157, 1798; Ed. ii., p. Ill, No. 45, 1819. Mytilus cxustiis Gmclin, Syst. Nat., vi., p. 3352, 1792; not of Limit-. TRANSACTIONS OF WAGNER 796 TERTIARY FAUNA OF FLORIDA Modiola ^tlca/a Lam., An. s. Vert., vi., p. 113, 1819 (not of Lam., Ann. du. Mus., 1807); Reeve, Conch. Icon., x., pi. 10, fig. 74, 1858. Modiola L'/ifi>nii/sii Potiez and Michaud, Gal. Moll., 1838 ; /it ft- Miircli. Brachydontfs modiolus Morch, Cat. Yoldi, ii., p. 54, 1853. Mytilns iiibilns Say, Journ. Acad. Nat. Sci. Phila., ii., p. 263, 1822 ; De Kay, Nat. Hist. N. Y., Moll., v., p. 183, 1843; Gibbes, Cat. S. Car., p. xxii., 1848 ; I'.inncy's Say, p. 90, 1858. Perna (Br achy don tes) modiola H. and A. Adams, Gen. Rec. Moll., ii., p. 517, 1857. Pleistocene of south Florida and the Antilles ; recent from South Carolina (Gibbes) south to the Antilles and Rio Grande do Sul, Brazil (Ihering). This species, which is excessively abundant where it flourishes at all, is commonly known under Lamarck's name of sulcatus. It is very similar to several of the nominal Tertiary species, and a full and good series of both will be required to determine how far the older forms can be discriminated. The absence of a really good series of the fossils of this group makes it impracticable to suggest any synonymy here, though probably some reduction in the number of species will be demanded with further study and material. The following list includes the species hitherto named. M. (B.) texaniis Gabb, Proc. Acad. Nat. Sci. Phila. for 1861, p. 371 ; Harris, op. cit. for 1895, p. 46, pi. i, fig. 2. This was originally described as Pcrna tcxana, and is from the Lower Claibornian and Midway Eocene. M. (/?.) Saffordi Gabb, Journ. Acad Nat. Sci. Phila., 2d Ser., iv., p. 395, pi. 68, fig. 30, 1860; Harris, Bull. Pal., iv., p. 49, pi. 3, figs. 4, 5, 1896. Midway Eocene. M. (£.) potouiaccnsis Clark, Bull. U. S Geol. Surv., No. 141, p. 85, pi. 34, figs. I a-\ c, 1896. Mideocene of Maryland. M. (Z>.) alabamcusis Aldrich, Bull. Pal., ii., p. 16, pi. 5, fig. 13, 1895 ; Harris, op. cit., ix., p. 47, pi. 7, fig. 9, 1897. Wood's Bluff horizon, Chickasawan Eocene. M. (B.) mississippiensis Conrad, Journ. Acad. Nat. Sci. Phila., 2d Ser., i., p. 126, pi. 12, fig. 19, 1848. Lower Oligocenc of Vicksburg, Mississippi. M. (/>.) contracts Conrad, Pac. R. R. Rep., v., Gcol., p. 325, pi. v., fig. 35, 1855. Pacific coast Tertiary. Eocene ? iM. (/).) ornatns Gabb, Pal. Cal., i., p. 184, pi. 24, fig. 166, 1865. Tejon Eocene of California. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA .!/. (/>.) miiltiradiatus Gabb, Pal. Cal., ii., p. 30, pi. 8, fig. 52, 1866. Miocene of California. ( Volsdla striata " Gabb," Meek, S. I. Checkl. Mio. Fos, p. 7, 1864, is probably a provisional manuscript name for this species.) There is a fine species in the Arago beds (Claibornian) of Oregon, which is probably identical with one of the above ; and I have another, as yet un- identified, from the Oligoccne limestone of Jacksonborough, Georgia. In the absence of authentic specimens of several of the above-mentioned nominal species it would be imprudent to attempt to describe either of these as new, while the wretched quality of a number of the figures renders an identification from them impossible. Modiolus (Gregariella) minimus n. s. PLATE 35, FIGURK 26. Shell small, broad, with turgid umbones in front, more or less attenuated behind ; hinge-line arcuate, convex, the opposite margin nearly parallel and concave, surface as in M. of if ex Say. Alt. 8, lat. 3.5, diam. 4 mm. This little shell is represented by a silicious pseudomorph, retaining but little of the external surface, from the Oligocene silex beds of Ballast Point, Tampa Bay, Florida ; the form is, however, unmistakable, and affords the opportunity of recording this group from that horizon. Modiolus (Botula) cinnamomeus Lamarck. MyKlus cinnamominus, etc., Che-inn., Conch. Cab., viii., p. 152, pi. 82, fig. 731, 1785. Moiiiola cinnamonica Lam., An. s. Vert., vi., p. 114, 1819; ed. Desh., vii., p. 25, 1835. Oligoccne of the Chipola marl, Chipola River, Monroe County, Burns ; of the silex beds at Ballast Point, Tampa Bay, Dall, and of Trinidad, West Indies ; Pliocene marl of the Caloosahatchie, Dall ; recent, nestling or boring into soft limestone rock or shell, from the vicinity of Cape Fear, North Caro- lina, to the West Indies. A valve from coral at Belize measures thirty-four millimetres in length, but it is usually smaller. I am not able to determine whether the East Indian shell usually called .I/, fxsciis Gmclin is the same or distinct specifically. The distribution of boring species is often very wide. It is certain, however, that Chemnitz's specimens, on which Lamarck founded the species, were West Indian. It seems remarkable that this species should be found in the Oligocene, but I am not, from my present material, able to find any differential characters whatever from recent specimens of the same size. TRANSACTIONS OF WAGNER 798 TERTIARY FAUNA OF FLORIDA This form differs from Lithophaga especially by the presence of a row of small but well-defined scars, extending in a radial manner towards the lower posterior basal angle of the shell, within the pallial line. These almost give the impression, when observed casually, of the presence of a pallial sinus. In the absence of fresh specimens of the animal I am unable to determine the function of these scars. There are a few species of Modiohts named in the literature which belong elsewhere. M. spiniger H. C. Lea (Trans. Am. Phil. Soc., ix., p. 244, pi. 35, fig. 30, 1845) is perhaps a Crcuclla ; the spines are probably due to some extraneous organism ; it is from the Miocene of Petersburg, Virginia. M. sitbpontis Harris (Bull. Pal., iv., p. 49, pi. 3, fig. 6 a, 1896), from the Midway Eocene of Georgia, has the aspect of a Modiolaria. M. lumstonia Harris (Proc. Acad. Nat. Sci. Phila. for 1895, p. 46, pi. i, fig. i), from the lower Clai- bornian of Texas, is probably a Lithopliaga, and specimens from the Orange- burg District of South Carolina, referred to his species by Harris, are certainly so. It should be carefully compared with L. subalvcata Conrad, from the Lower Miocene of Cumberland County, New Jersey. M. tennis Meyer (Ber. Senckenb. nat. Ges., 1886, p. 10, pi. ii., fig. 7) is a Crcnclla, and identical with C. latifrons Conrad (1860), from the Claibornian and Jacksonian Kocene of Alabama. Genus LITHOPHAG-A Bolten. Lithophaga Bolten, Mus. Bolt., p. 156, 1798; Ed. ii., p. 109, 1819; Miirch, Cut. Yoltli, p. 55, 1853. Lithophagus Megerle, Entwurf., p. 69, 1811 ; Dall, Bull. 37, p. 58, 1889. Lithodomus Cuvier, Regne An., ii., p. 471, 1871. Lithetcimus Nitsch, Ersch et Grub. Encycl., Sect, i, p. 175, 1825 ; Voigt, Cuv. Thierr., iii., p. 616, 1834. Lithodoma Verany, Cat. An. Invert., p. 13, 1846. Lithodomus Fischer, Man. Conch., p. 969, 1886. Leiosolcmis Cpr., Mazatlan Cat., p. 130, 1856. Myoforcepifvsf&Ri, Man. Conch., p. 969, 1886. The type in each of the first three cases cited is Mytilus lithophagus Linne. This was a compound of two species, the most common and best known of which was the Mediterranean form, which received the specific name of dactylus from Sowerby. The genus may be divided into sections as follows : Lithophaga Bolten, s. s. Shell subcylindric, with nearly terminal beaks ; sur- face polished, with no calcareous incrustation. Type L. dactylns Sby. FREE INSTITUTE OF SCIENCE 799 TERTIARY FAUNA OF FLORIDA Adula H. and A. Adams, 1857. Shell rhombic, with subcentral beaks; sur- face polished, clean. Type L. soleniforinis Orbigny. Leiosolcnns Carpenter, 1856. Shell like IMhophaga, but building a doubly tubular spout to the aperture of its burrow, and therefore probably furnished with elongated tubular siphons. Type L. spatiosus Cpr. Myoforccps Fischer, 1886. Shell as in Lillwphaga, but the animal has the habit of depositing a calcareous crust on the exterior of the valves, which covers them smoothly and projects in a twisted process from the posterior end of each valve. Type L. caudigcra Lamarck. Dilicrus Ball, 1898. Resembling Alyoforccps, but with two or more radial sulci extending backward from the beaks, with the incrustation plume like, arranged in a distinct pattern on the areas between the sulci, and, when projecting beyond the ends of the valves, apposited symmetrically, not alternate and twisted as in the last section. Type L. pluimila Hanley. The genus is commonly represented in the Tertiary rocks by casts of its burrows, but the shells are so thin and fragile as to be rarely preserved. Most of those here mentioned are silicious pseudomorphs which preserve the form and markings of the original shell. Lithophaga antillarum Orbigny. I.illii>,/niin/s iinlillaniin Orb., Moll. Cubana, ii., p. 332, pi. 28, figs. 12, 13, 1847 (Spanish edition and atlas, 1845). M,<,iioln i-omttfata Phil., Abbilcl. und Bcschr., ii., 147, pi. I, fig. i, 1846. Li//K>/in<* it'rrit^titi/s Reeve, Conch. Icon., x., pi. I, fig. I, 1858. I.ithtifiliti^iix ilactyliis Miirch, Cat. Yoldi, ii., p. 55, 1853 ; not of Sowerby, 1824. Lii/i,/iiii,'n.. 56, 1853. Lilluhloiinis cintillanini Reeve, Conch. Icon., x., pi. 2, fig. 7, 1857. Oligocene silcx beds of Ballast Point, Tampa Bay, Florida, Ball ; recent at Bermuda, and from South Carolina southward through the West Indies to Rio Janeiro, Brazil. Lithophaga nuda n. s. PLATE n, FIGURE 7; PLATE 35, FIGURK 27. Oligocene silex beds at Ballast Point, Tampa Bay, Florida, where it. is the most common species, and its burrows, or their casts, very numerous. Shell large, thin, closely resembling L. nigra, but from which it may be instantly discriminated by the absence of all transverse or radial striation. Alt. 17 (?), lat. 50, diain. 15.7 mm. Few of the specimens retain the outer markings of the shell, but those that do are easily recognized by the smooth surface, only sculptured by incre- mental lines. From the Diberns group, which also have unstriated shells, it is distinguished by its cylindrical form, large size, absence of sulcations and of the calcareous mantle. Lithophaga (Myoforceps) aristata Dilluyn. Mytilus aristatits (Solandcr MS.) Dillwyn, Cat. Rec. Sh., i., p. 303, 1817. Motliolti cai/digcm Lam., An. s. Vert., vi., p. 116, 1819 ; (after Enc. Mcth., pi. 201, tig. '8) Phil., Abb., ii., p. 149, pi. i, fig. 5, 1846. Mytilus caiKUgcnis Gibbes, Cat. S. Car., p. xxii., 1848. Lithodonms arista/us Forbes and Hanley, Brit. Moll., ii., p. 212, 1851. Lithodomus caudigerus Sby., Genera, Lith., fig. 4, 1824; Reeve, Conch. Icon., x., pi. iii., fig. 16, 1857. Lithophagus aristatus Stimpson, Checkl. Rec. Sh., p. 2, 1860. Lithophagiis forficattis Ravenel, Proc. Acad. Nat. Sci. Phila. for 1861, p. 44; Tryon, Am. Mar. Conch., p. 188, 1873 ; Dall, Hull. U. S. Nat. Mus., No. 37, p. 38, 1889. Oligocene of the silex beds at Ballast Point, Tampa Bay, Florida ; recent from Cape Fear, North Carolina, south to the West Indies, east to the Red Sea, west to Mazatlan on the Pacific coast of Mexico. Only fragments probably referable to this form were obtained at Ballast FREE INSTITUTE OF SCIENCE 80 1 TERTIARY FAUNA OF FLORIDA Point, but its wide distribution, evidently antedating the present conformation of Central American and Mediterranean lands, is much in favor of its antiquity. Lithophaga (Diberus) bisulcata Orbigny. J.it/t«<(i>i>nis liisti/fii/its Orb., Moll. Ctibann, ii., p. 333, pi. 28, figs. 14-16, 1847 (Spanish c-ilition and atlas, 1845). .Modio/a appcndicitliita, 1'liil., Abbild. und Bcsrhr., ii., p. 150, pi. i, fig. 4, 1846. Mytilus tit/cinialtis Gibbcs, Cat. S. Car., p. \\ii., 1848 ; not of Dcshayes. Lillwplia^ns iippciitUciihitiis Miirch., Cat. Yokli, ii., p. 56, 1853. Lithi'doinus iippi-iiiticitlatiis Reeve, Conch. Icon., x., pi. 4, fig. 21, 1857. I.itlwiioi/nis biexfavatiis Kccvc, op. fit., fig. 22, a-l>. I. it hop limits Insiih-atus Dall, Hull. U. S. Nat. Mus., No. 37, p. 38, 1889. Oligoccne of the silex beds at Ballast Point, Tampa Bay, Florida, Dall ; recent from South Carolina southward to the Gulf of Mexico, West Indies, and Rio Janeiro, Brazil. This species was found in the silex beds not only with the shell pre- served or reproduced, but with a complete pseudomorph of the calcareous mantle in which the lime was replaced by silica. Among the species reported in the literature of the American Tertiary is L. claibonicnsis Conrad (Journ. Acad. Nat. Sci. Phila., 2d Ser., i., p. 131, pi. 14, fig. 27, 1848; Aldr., Bull. Pal., 2, p. 17, pi. 5, fig. 14, 1895), from the Clai- bornian ; L. gaincscnsis Harris (Bull. Pal., 4, p. 50, pi. 3, fig. 7 a, 1896), from the Upper Midway Eocene of Georgia, which may be referable to Botttla ; L. incitri'a Gabb (Journ. Acad. Nat. Sci., 2d Ser., viii., p. 377, pi. 47, fig. So, iSSi), from the Pliocene of Costa Rica, which is certainly a Botitla and very close to /A cinnamomea Lam. ; and L. subalveata Conrad (Am. Journ. of Conch., ii., p. 73, pi. 4, fig. 4, 1866), from the lowest Miocene of New Jersey, a peculiar species with which Alodiola lioitstonia Harris (1895) should be carefully com- pared. L. dactylits Sby. is reported by Conrad (Am. Journ. Sci., 2d Ser., i, p. 2io)us having been found by Lyell in Georgia, but this is perhaps a mis- identification ; the species may have been L. niula. The figure of Byssomia pctricoloidcs Lea (Contr. Geol., p. 48, pi. i, fig. 16, 1833) much resembles a chipped Lithophaga, and the suggestion of Gregorio that it is identical with L. claiborncnsis Conrad is plausible. Genus CRENELLA Brown. Cn-iii-lla Ilrown, 111. Conch. Gt. Hrit., pi. 31, figs. 12-14, 1827; 2cl edition, p. 75, pi. 23. tigs. 12-14, '844. Type Mytilus dci'itsstitus Montagu, 1808. TRANSACTIONS OF WAGNER 802 TERTIARY FAUNA OF FLORIDA Stalagiiiiiini Conrad, Fos. Tcrt. Form., p. 39, Oct., 1833. Type S. margaritacettm Conrad, /. c. Hippagns Lea, Contr. Geol., p. 72, Dec., 1833. Type N. isocardioides Lea, /. c., pi. 2, fig. 50. Myoparo Lea, Contr. Geol., p. 73, Dec., 1833. Type J/. costatiis Lea, /. c., pi. 2, fig. 51. Nuculocardia Orbigny, Moll. Cubana, ii., p. 310, 1847 (Spanish edition and atlas, 1845). Type N. divaricata Orb., /. c., p. 311, pi. xxvii., figs. 56—59. Crenellodon Edwards, MS. Syst. List., Edw. Coll. B. M., p. 14, 1891. Type Crcndla pulchcrriina Edw., MS. Oligocene, Brit. Not Crcndla Sowerby, Conch. Man., p. 297, fig. 136, 1842. This interesting little group extends through the Tertiary and, owing to the little study given to its characters, has received many names. The shell is usually convex and ovoid, with more or less incurved beaks, a nacreous inner layer, thin epidermis which adheres closely to the shell, and a fine radial, often crossed by a concentric, striation. In young shells the provinculum is exceptionally well developed, sometimes recalling the hinge of Niictila by its strong and projecting denticulations. If the shell is thin, these become obso- lete with growth, but in some species are replaced by a series of denticulations directly consequent on the impingement of the external sculpture on the car- dinal margin, thus repeating a second time in the same individual the process by which the provinculum was originally initiated in its ancestors. At least that is the way in which the writer interprets the facts. When the shell is thick, or when the external sculpture is very delicate, no secondary denticula- tions appear in the adult, which is then left with a practically unarmed hinge- line. The appearance of the provinculum is not dependent on the existence of external sculpture, but the secondary denticulations are so dependent. The exterior may be almost perfectly smooth and polished with only microscopic striation ; finely radially striate without decussation (like C. scriccii), decussate, or with the radial sculpture strong and divaricate. Usually the sculpture is uniformly distributed over the surface, but occasionally there will be an area of unstriated separating two of striated surface, as in Modiolaria, but without the impressed boundaries of the latter genus. The form of the foot and the short siphons separate Crcnella generically from Modiolaria, as far as yet shown, but the modifications of the surface upon which the former has been divided into genera are, in the writer's opinion, of little more than specific value. Hippagus is a thick shell with feeble sculpture, and therefore the provinculum is not succeeded by a series of secondary den- ticulations. Otherwise it is an ordinary rather obese Crenella. Stalagmium FREE INSTITUTE OF SCIENCE 803 TERTIARY FAUNA OF FLORIDA is a typical Crenella, and ^fyoparo is, of course, a synonyme specifically and gcnerically of Conrad's form. Nncitlocardia is only a well-observed, strongly crenulate Crcnclla, and what else, if anything, the undescribed Crcnellodon may be is unknown. Crcnclla margaritacea Conrad has for a synonyme C. costata Lea; C. iso- cardioidca Lea (as Hippagus) and C. latifrons Conrad (+ Modiola tennis Meyer, 1887) are Claibornian. The last mentioned is a large, oblique, thin species, and extends into the Jacksonian. C. conccntrica Gabb (Pal. Cal., i., p. 186, pi. 24, fig. 169) is extremely similar to C. margaritacea and is found in the Martinez Eocene of California. A shell which is perhaps a Crcnclla (or a Limcea) was described from the Miocene of Petersburg, Virginia, by H. C. Lea under the name of Nuctila ceqitilatcra. Crenella divaricata Orbigny. iia divaricata Orb., Moll. Cubana, ii., p. 311, pi. 27, figs. 56-59, 1847 (Spanish edition and atlas 1845) ; Gabb, Geol. St. Domingo, p. 252, 1873. diriissata Dall, Blake Pelecypoda, p. 235, 1886. Oligocene of St. Domingo and Pliocene of Costa Rica, Gabb ; Pliocene of the Caloosahatchie and Shell Creek, Florida, Dall and Willcox ; recent from Cape Ilattcras to the West Indies (one hundred fathoms off Barbados), and also on the Pacific coast at Panama and in the Gulf of California. This little shell is not to be distinguished, except by its nearly white color, from the young of C. decussata of the same size. The examination of a much larger series of specimens than was at my disposal when preparing the Blake report shows that the size when fully adult is uniform and always smaller than the adult C. decussata. The young divaricata is proportionately less inflated and has a more circular outline than the full-grown shell. The color is yellowish or nearly white in all the specimens I have seen, and the epidermis hardly perceptible. Crenella minuscula n. s. PLATE 35, FIGURE 22. Oligocene of the lower bed at Alum Bluff, Chattahoochee River, Florida; Burns. Shell minute, thin, inflated, elongate ovate, feebly radially striated, the striations apparently diverging from a medial line on the disk ; not dichoto- mous ; the beaks smooth ; inner margins crenulate; valves nearly equilateral. Alt. 1.75, lat. 1.25, diam. i mm. 16 TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA This little shell is rare in the marl, and resembles in a general way C. divaricata Orb., of which it is the precursor, but has fainter sculpture and smooth beaks, besides being constantly of smaller size, and is more narrow in form than the young of C. divaricata of the same length. Crenella duplinensis n. s. PLATE 35, FIGURE 6. Miocene of the Natural Well, Duplin County, North Carolina; Burns. Shell small, thin, rounded ovate, delicately radially sculptured, with fine, rounded ribs crossed by delicate incremental lines ; smoother towards the beaks ; valves moderately inflated ; beaks recurved, stria; diverging from a line near the anterior third ; inner margin crenulated, the crenulae extending well up into the valve; the hinge with its crenulations short and delicate. Alt. 2.9, lat. 2.4, diam. 1.5 mm. This species is proportionally wider and less inflated than C. minitsaila, attains a larger size, and has more recurved beaks. From C. divaricata it differs by its feebler sculpture, somewhat smaller shell, and especially by its much weaker hinge, with less conspicuous and strong crenulations. The line of divarication of the sculpture is also more anterior and the beaks more recurved. The recent Crenella glandula Totten is reported as fossil in the Pleisto- cene beds at Montreal by Dawson (Geol. Rep. Can., 1863, p. 927), and at Sankoty Head, Massachusetts, by Verrill, But Dr. Dawson is now disposed to refer his specimens to C. faba Fabr. Genus MODIOLARIA Beck. Modiolaria Beck, in E. Robert, Zool. Voy. Recherche en Isl. et en Gronl., pi. 17, figs. 1-4, 1840; Loven, Ind. Moll. Scand., p. 33, 1846. Type Mytilus discors Linne. Lanistcs Swainson (as of Humphrey), Malac., p. 385, 1840 ; not of Montfort, 1810. Type Mytilus impactus .Herrmann. Lanistina Gray, P. Z. S., 1847, p. 199 (in place of iMiiistcs Sw.). Modiolacra Gray, in Dieffenbach, N. Zeal., ii., p. 259, 1843 ; fide Hutton, Cat. Mar. Moll. N. Zeal., p. 78, 1873; (a typographical error for Modiolaria?) sole ex. M. impacta Gray. Swainson quotes Lanistcs as of Humphrey, but there is no such genus in the Museum Calonnianum, where the Mytilus discors Lam. (not of Linne), otherwise M. impactus Herrmann (1776), is given the specific name of FREE INSTITUTE OF SCIENCE 805 TERTIARY FAUNA OF FLORIDA " Lanatus" By some confusion of this with Montfort's Lanistcs (which is cited by Swainson, p. 387, as Lanites) this error probably arose. I have not access to Dieffcnbach's New Zealand at this writing, but if the Modiolacra cited from it by Ilutton is correct, it is probably a typographical error for Modiolaria, and an earlier citation of Beck's name than is usually known. This genus is distinguished from Crendla by its elongated siphons, the branchial one being usually shorter and not closed along its lower side, but merely with apposited free edges ; the foot also differs, being long and taper- ing to a point, instead of clavate as in Crcnclla. It is somewhat difficult to apportion the fossil species, but they are perhaps best separated from Crendla by the impressed mid-lateral area which, in the typical Modiolaria, is usually smooth or not radially sculptured. The genus may be divided as follows : Modiolaria s. s. Shell with three areas on the disk, the central with feeble or entirely without radial sculpture, the others radially sculptured. Branchial siphon considerably shorter than the anal. Type Mytilns discors L. = M. discrcpans Mont. Liobcrus Ball. Shell with the radial sculpture obsolete or absent ; branchial siphon equal or nearly equal to the anal, both much elongated. Type Modiola castanca Say, Journ. Acad. Nat. Sci. Phila., ii., 266, 1822.* Rhomboidtlla Monterosato (1884). Shell rhomboid, the surface entirely covered with sharp radial striations. Type Modiola rlioinbca Berkeley. / PUiniinodiola Cossmann (1887). Shell modioliform rather than rhomboid, with the anterior radiated area very small and the valves rather com- pressed. Type Modiola sulcata Lam. (Parisian Eocene.) This section might quite as well be placed in Modioliis, from which it differs by no very important characters. It is very doubtful if it is a Modiolaria. The type is not the same as the recent Modiola sulcata of Lamarck (= M. (BrachydenUs) citrinns Boltcn). The earliest species in our Tertiary is probably M. snbfunitis Harris, from the Upper Midway, though its generic position is not positively determined. * This is probably the same as M. ligtua Reeve, Conch. Icon., x., Modiola, pi. 10, fig. 71, 1858. AJ. atstaiifa Say was mistakenly referred by Tryon to the young of AI. tut/fa Lam. in Am. Mar. Conch., p. 187, 1874. TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA M. alabamensis O. Meyer, from the Claibornian, is, however, a well-character- ized species. Modiolaria sp. indet. Oligocene of the Chipola River, Monroe County, Florida ; Dall. A single broken valve belonging to this genus was obtained from the Chipola marl. It is a species similar to M. latcralis Say, but marked especially by well-developed latticed sculpture in the interspaces of the radii. Modiolaria virginica Conrad. Modiolaria virginica Conrad, Am. Journ. Conch., in., p. 267, pi. 22, fig. 3, 1867. Yorktown, Virginia, Conrad; from the Miocene beds along the York River, Virginia, Harris. This small species is well-characterized by its rather angular shape, the reticulated sculpture of the posterior area, and the feeble sculpture of the anterior area. It recalls GregarieUa, and perhaps should rightly be referred to that section of Modiolus rather than be placed in Modiolaria. Modiolaria carolinensis n. s. ? PLATE 35, FIGURE 12. Upper Miocene of the Natural Well, Duplin County, North Carolina; Burns. Shell small, plump, rather elongate, with a shallow but well-marked radial furrow at the posterior edge of the medial smooth area; terminal areas radiately sculptured with small, radial, rounded threads, those on the anterior area fine and simple, those on the ridge of the posterior slope' more or less reticulated by concentric elevated lines and distally dichotomous, divergent from the summit of the ridge and stronger dorsally ; hinge-line straight, the margin above it angulated at its posterior termination ; the beaks nearly anterior, the posterior ventral termination of the valve rounded and produced ; inner margin crenulated ; on the hinge-line the crenulse are almost like teeth, and increase in strength backward distally being disproportionately large at the end of the series. Alt. 4.5, lat. 6.5, diam. 3.5 mm. This shell is very like M. virginica, which, however, is arched instead of angulated near the distal end of the hinge-line, and, in the specimens I have been able to examine, is more rounded and less produced behind and has a less conspicuous medial furrow. It may, however, prove, when a sufficiently large number of specimens are brought together, that these characters fall FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA within the limits of varietal rather than specific distinction. The specimen figured is somewhat blunted by fracture or other accidental causes at the lower posterior end, so that it does not show as much of the produced char- acter as the other smaller and less developed specimens which were collected with it. Modiolaria lateralis Say. Mylilliis liitcnilis Say, Journ. Acad. Nat. Sci. Phila., ii., p. 264, 1822 ; Binney's Say, p. 91, 1858. Crenel/a lateralis Tryon, Am. Mar. Conch., p. 190, pi. 40, fig. 523, 1874. Mint it/in- in lati-ntlis Dall, Hull. U. S. Nat. Mus., No. 37, p. 40, pi. 6, figs. 7, 8, 1889. Mmiiohi clliptica H. C. Lea, Am. Journ. Sci., xliii., p. 106, pi. I, fig. 2, 1842. Pliocene of the Caloosahatchie and Shell Creek marls, Florida, Dall and Willcox ; Pleistocene of Simmons Bluff, South Carolina, Burns ; recent at Portland, Maine (Fuller) ; Delaware Bay, Lea ; North Carolina, United States Fish Commission; South Carolina, Gibbes ; and southward through the Antilles to Venezuela ; situs on oysters and sponges (Tethyd). This pretty little species is much like M. mannorata Forbes of the British fauna. It is probable that specimens obtained north of Chesapeake Bay have been transported with " seed" oysters. Modiolaria translucida Gabb (Journ. Acad. Nat. Sci. Phila., 2d Ser., viii., p. 377, pi. 47, fig. 81, 1881) from the Plio- cene of Costa Rica is a very similar species. The recent northern species, M. nigra Gray and M. discors L., are reported by Dawson (Can. Nat., 2, p. 419, and Geol. Rep. Can. for 1863, p. 927) from the Pleistocene glacial beds of the Province of Quebec, near Montreal. FAMILY DREISSENSIID^E. The systematic position of this family cannot yet be said to be definitely fixed, and is not likely to be finally decided until careful anatomical and embryological investigations of such forms as Septifer, Mytilopsis, etc., are available. The nomenclature of this group has, so far as I know, never been pub- lished in the full and precise shape demanded by systematists of the present day ; those who have referred to it seem to vie with each other in omitting dates, references, and essential facts. To make such a review here is not called for by present necessities, and is impracticable for want of part of the literature. The earliest name appears to be Enoccphalns (Miinstcr MS., 1828) Keferstein (Geogn. Geol. Zeitschr., ix., p. 92, 1831), but it would seem as if the TRANSACTIONS OF WAGNER 808 TERTIARY FAUNA OF FLORIDA genus had not been specifically characterized, though two species were de- scribed under this generic name, and it was cited by Deshayes (Bull. soc. geol. de Paris, t. iii.) in 1833. In 1836 Goldfuss fully characterized the genus, which was founded on two fossil species. In 1835 the recent Mytilus fluviatilis of Pallas (J\I. wolgcz, Chemn., xi., p. 256, fig. 2028) was almost simultaneously named Dreissena (mel. Drcisscnsia) by Van Beneden and Tichogonia by Ross- massler, the former having a few weeks' precedence. In 1837 appeared the names Mytilina and Mytilomia Cantrainc. Jay, in 1836, used for the Danubian shell the name Dythalmia danubii (Cat. Coll., p. 25) but without description. There is also a large number of variants due to misprints or errors of the pen. The species D. fliciiatilis (or polyinorplius of many authors) differs from most of the fossils and from our American shells by the absence of the secondary myophore, and is doubtless generically distinct. Being unable to determine the status of Enocephahts, the -nomenclature of the American type may be provisionally stated as follows : Genus CONGEBIA Partsch. Congeria Partsch, Ann. Wiener Mus., i., p. 93, 1835. Mytilopsis Conrad, Proc. Acad. Nat. Sci. Phila. for June, 1857, p. 167. Type M. leiico- phceatus Conr. , 1831. Mytilus sp. Reeve, Conch. Icon., x., pi. x., 1858. Praxis H. and A. Adams, Gen. Rec. Moll., ii., p. 522, Dec., 1857. Mytiloidcs Conrad (lapsus), Proc. Acad. Nat. Sci. Phila. for 1874, p. 2y ; not of Brogniart, 1822. Partsch specifically mentions the myophore in his diagnosis, and an ex- amination of a number of his species shows that they agree in all essential systematic characters with the American shells. Congeria leucophseata Conrad. Mytilus Icucophaatus Conrad, Journ. Acad. Nat. Sci. Phila., vi., p. 263, pi. 11, fig. 13, 1831 ; Ravenel, Cat., p. 7, 1834 ; De Kay, New York Fauna, Zool., v., p. 184, 1843. Mytilopsis leticopho'attis Conr., Proc. Acad. Nat. Sci. Phila. for 1857, p. 167 ; Dull, Hull. U. S. Nat. Mus., No. 37, p. 40, 1889. Dreissena amcricana (Recluz MS.), in Reeve, Conch. Icon., x., pi. x. (Afyti/us), fig. 43, Jan., 1858; Fischer, J. de Conchyl., vii., p. 131, 1858. Dreissena Riisii (Dkr. MS.) Fischer, Journ. de Conchyl., vii., p. 133, 1858. Dreissena leiicoplurla Tryon, Am. Mar. Conch., p. 190, pi. 40, fig. 424, 1874. Pleistocene of North Beach, Osprey, Florida, Dall ; recent, especially FREE INSTITUTE OF SCIENCE 809 TERTIARY FAUNA OF FLORIDA about oyster beds, from Maryland to Florida, Nicaragua (Richmond), New Grenada (Totten), St. Thomas (Dunker), and Vieque, West Indies. A review of the American Congerias in the National Museum shows that besides the above-mentioned species there is found in the United States the C. Rossmflss/cri Dunker (1858, Rve., fig. 45, + C. Sallei Reeve, fig. 44, 1858, not of Reclux, 1852), which occurs near Tampa, Florida, and is said to extend to Brazil. It is distinguishable from the common Icitcoplucata by its more triangular, anteriorly flattened, heavier shell. The C. Gimdlac/ii Dunker (1858), which has a more conspicuous myophore, is found in Cuba, while the C. coclilcata is common at Colon, on the Isthmus of Darien. There may be one or two more identifiable forms in the West Indies, but the shell is variable, passing through about such a set of mutations as does Mytilus eiinlis, and too much stress should not be laid on slight differences. None of the other species mentioned has yet been found fossil, but a species is not uncommon in the Florida Pliocene which is obviously different from any of them. It is notable that the European type, Dreissciisia, does not occur in Africa or America, though it is represented by a species (D. Massiei L. Morlet) in Cochin China. In Africa, America, China, and the Viti Islands Congeria is present. Congeria lamellata n. s. PLATE 35, FIGURES 13, 14, 15. Pliocene marls of the Caloosahatchie and Shell Creek, Monroe County, Florida ; Ball and Willcox. Shell subtrigonal, externally smooth, except for concentric undulations due to irregularities of growth ; anterior side flattened below the beaks, the periphery of the flattened area rounding over towards the disk ; beaks subacute and slightly twisted outward, byssal gape very narrow ; dorsal slope sub- arcuate with no pronounced angle at the distal end of the hinge-line, in the vicinity of which the valves arc somewhat compressed ; internal margins smooth ; cardinal border with a wide groove for the reception of the ligament, this groove being continuous to the beaks ; septum small, separated from the groove by a A-shaped lamella which on the anterior side is conspicuously produced and extends along the anterior margin about twice the length of the septum beyond the septum ; myophore small, entirely hidden below the septum and formed by a callous eminence bearing the scar of the retractor muscle of the foot upon which the strain from the byssus comes; adductor TRANSACTIONS OF WAGNER 8lO TERTIARY FAUNA OF FLORIDA scars ovoid, elongate, and partly in contact, with a slight insinuation of the pallial line in front of them ; margin of the right valve somewhat impressed below the beak so as to pass behind the prominence on the margin of the opposite valve when closed. Alt. 17, lat. 10, diam. 10 mm. This is a much heavier and more triangular shell than C. leucoph&ata and more elongate than C. Rossmassleri, with a different hinge from either. Some very similar but not conspecific forms occur in the Vienna basin. Harris mentions the occurrence of a Dreissensia (= Congcria] in the Galveston artesian well, between the levels of two thousand one hundred and twenty-three and two thousand eight hundred and seventy-three feet below the surface. The horizon here is Upper Miocene. There are no species of Septifer determined from the Tertiary rocks of eastern North America, but, as elsewhere noted, Cooper has described a species from the California!! Tertiary. FAMILY JULIID^E. {Prasinidce, p. 529.) This family has not been hitherto represented in the faunal lists of American mollusks, recent or fossil, except through the inclusion of forms such as Phaseolicama and certain Paleozoic fossils, which in all probability belong elsewhere. Semper showed many years ago that the typical genus, Prasina, was suspiciously close to the older genus, Julia, of Gould. Fischer, in his manual, unites them as subdivisions of one genus. They are really identical, and the consolidated genus must take the older name of Gould and Prasina be relegated to synonymy, according to the rules of nomencla- ture. To Prasina and Julia Cossmann has added a shell from the Parisian Eocene, named by him Anomalomya, and Fischer has suggested that Bert/ic- linia Crosse may perhaps find a place in the same vicinity. Genus JULIA Gould. folia Gould, Proc. Bost. Soc. Nat. Hist., viii., p. 284, Feb., 1862; Otia, Conch., p. 241, 1862. Type./, exquisita Gould, /. c. Prasina Deshayes, Cat. Moll. Isle de Reunion, p. 25, 1863. Type /'. borbonica Desh., op. cit., p. 29, pi. iv., figs. 4-8. Prasinia Cossmann, Cat. 111. Eoc. Paris, p. 174, 1887. Fischer (Man., p. 950) separates Prasina from Julia on the ground that the latter is nacreous and has the borders finely crenulated, but both these FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA characters are non-existent in the one as much as in the other. Gould prob- ably used the word " margaritacea" to express the lustre often seen on polished porcellanous shells, and the " crenulations" are merely the faint incremental radiations common to all bivalves. The examination of authentic specimens of Gould's species (for which I am indebted to the authorities of Cornell University) enables me to make a positive statement in regard to these facts. The shell is not pearly and the margin is not crenulated in the strict sense of those words. The adductor scar is precisely as figured by Fischer for Prasina borbonica, and I can find no trace of any other scar, though the interior is so polished that this would be hardly visible at any rate if present. Julia floridana n. s. PLATE 35, FIGURES i, 2, 3. Oligocene marl of the Chipola River, Florida ; Burns. Shell small, inflated, smooth, arched above, rounded behind, the base nearly straight; the beaks prominent with a small impressed lunule imme- diately under them; below this lunule the valve projects forward to a rather acute point ; with the exception of the groove for the ligament the hinge-line is perfectly simple without teeth or crenulations of any kind ; the edge of the impressed lunule in the right valve is produced into a lamella which fits behind a less prominent extension of the corresponding margin in the opposite valve ; interior of the valves smooth, with no trace of muscular or other scars; exterior sculptured only by faint incremental lines; inner margin of the valves simple, not crenulated ; shell substance showing no traces of nacreous struc- ture, but rather porcellanous. Alt. 4.5, lat. 6.5, diam. 2 mm. This species evidently belongs to the same restricted group as the original Frasina borbonica of Deshayes. The chief difference is that the impressed lunule is smaller and not so deep, and that its margin in the left valve is not elevated into so evident a tubercle. Careful scrutiny of more than twenty valves collected failed to show any satisfactory muscular or pallial scars. This is the only species known from American deposits and, as far as I have been able to discover, the only fossil species known of the restricted group from any horizon. TRANSACTIONS OF WAGNER 812 TERTIARY FAUNA OF FLORIDA Order TELEODESMACEA. For reasons of convenience, some groups of this order having been completed in manuscript as much as two years ago, and it^eing desirable to print them as early as practicable, the series of families is here begun with the Teredinidce, an order the reverse of that appearing in the list of families on page 484 of this volume. Superfamily ADESMACEA. FAMILY TEREDINID^E. Genus TEREDO Linne. Teredo Linne, Syst. Nat., Ed. x., p. 651, 1758. Type T. navalis Linne. Xylophagus Meuschen, Zooph. Gronovianum, p. 258, 1781. Same type. The tubes of Teredo and its allies appear in all the Tertiary horizons of North America which have been well searched, and a number of names have been applied to them, but so far, I believe (unless Pliolas rhotnboidca Lea, from the Miocene of Petersburg, Virginia, be founded on a valve of Teredo), the valves of none of the species have been described or figured. This leaves the species of the genus in our Tertiary in a very unsatisfactory state, and it has even been suspected that some of the tubes described as teredine are really the shelly retreats of Serpulidce or other tubicolous worms. In this uncertainty, I shall content myself with giving a list of the names which have been proposed, with references, leaving to a more propitious time the task of examining into their validity or determining their synonomy. Eocene. 1. Teredo emacerata Whitfield, Lam. N. J., p. 242, pi. xxx., fig. 25, 1885. Eocene marl of New Jersey. 2. Teredo mississifpiensis Conrad, Wailes, Geol. Miss., p. 289, 1854; Eoc. Checkl. S. I., p. 24, 1866 (name only). Upper Eocene of Jackson, Mississippi. 3. Teredo piigctcnsis White, Bull. U. S. Geol. Surv., No. 51, p. 62, pi. 8, fig. I, 1889. Eocene of the Puget Group, Puget Sound, Washington, from Carbonado, Washington. 4. Teredo simplex Lea, Contr. Geol., p. 38, pi. I, fig. 6, 1833. Claiborrie sands at Claiborne, Alabama. FREE INSTITUTE OF SCIENCE 813 TERTIARY FAUNA OF FLORIDA This species is represented by a short piece of tube, apparently teredine, among Lea's types. DC Gregorio, however (Mon. Claib., p. 10, pi. I, figs. 30-33), has identified what he regards as a Scrpula tube from Claiborne with Lea's species, and for the true Teredo tubes which occur in the Claiborne sands has proposed the name of Teredo simplexopsis (pp. cif., p. 236, pi. 38, figs. 26 ii£itta Say, Journ. Acad. Nat. Sci., ii., p. 320, 1822; not of Tuomey and Holmes, I'leioc. Fos. S. Car., p. 103, pi. 24, fig. 5, 1858. rko/as i andt-ana Orbigny, Moll. Cubana, p. 215, pi. 25, figs. 18-19, '845. (Young shell.) Pleistocene of South Carolina and Florida ; recent from Cape Hatteras, North Carolina, to Bra/.il. This species is distinguished from the following one by the proportions and extent of the umbonal processes, which differ markedly in the two forms. Pholas (Thovana) producta Conrad. r/io/ns itl>fi»i£itta Tuomey and Holmes, Pleioc. Fos. S. Car., p. 103, pi. 24, fig. 5, 1858; not of Say. Wiolas producta Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 571, 1863. Miocene of the Sumter District and Peedee River, South Carolina ; Plio- cene of the Waccamaw River, South Carolina ; Holmes and Johnson. In this species the umbonal reflection is considerably longer in proportion than in the Pleistocene shell, and the anterior space between the reflected edge and the exterior of the valve in front of the umbo and below the level of the septa is much smaller and less conspicuous. The ribbing of the present species is less sharp and continuous. Pholas (Thovana?) Memmingeri Tuomey and Holmes. l'/i«/,is .}f,->iiiniiii;vi-i"t. and H., Pleioc. Fos. S. Car., p. 104, pi. 24, fig. 6, 1858. Miocene of the Sumter District, South Carolina ; Tuomey and Holmes. This species recalls Zirflni£ii Turton, Ditliyni ISrit., p. 527, 1822. Type X. dorsalis Turton. (Not .\y/«- pluii^iis Mciisclicn, 1788.) Shell like that of Teredo, but with a double protoplax and the internal apophyses obsolete; soft parts contained within the shell, without callum, siphonoplax, or calcareous tube. There is sometimes a calcareous lining to the excavation made by the animal, according to Fischer, but none of the borings I have seen from this animal exhibit it. If, according to the very obnoxious practice of some authors, the name Xylopliaga must be rejected on account of the existence of the ancient syno- nyme Xylopliagits, the name might be changed to Xylotomca, but our own opinion is strongly adverse to sucii changes. Xylopliaga Mississippi cusis Aldrich, 1886, has been described from the Eocene of Newton, Mississippi, but from the figure it is somewhat doubtful if the species is really a member of this genus. I'liolas rhomboidea II. C. Lea, 1845, from the Miocene of Petersburg, Virginia, is probably a Xylophaga. TRANSACTIONS OF WAGNER 822 TERTIARY FAUNA OF FLORIDA A species of Xylophaga too imperfect for description was obtained by Hender- son and Simpson from the Oligocene marl of Bowden, Jamaica. Subfamily TEREDININ^E Tryon. Shell forming an undivided callutn and tube continuous with the valves when adult, thus enclosing the animal completely, as in Fisliilana, with the external surface of the valves visible on the outside of the tube. Genus SCYPHOMYA Ball. Shell resembling that of Pholadidea s. s., and with similar dorsal plates ; callum voluminous, tube short, subconical, irregular, simple. Type Pliolas semicostata H. C. Lea (Bost. Journ. Nat. Hist., v., pi. 24, fig. i, 1844). Coast of the Carolinas. The shell differs entirely from that of Tcrcdina, but the manner of forming a tube is much the same. It is probable that there is a pedal fissure in the callum, but the specimens studied did not have this part intact. Lea describes apophyses, but they are no longer present on my .specimens, in which the cardinal margin recalls that of Xylophaga. Genus TEBEDINA Lamarck. Teredina Lamarck, An. s. Vert., v., p. 438, 1818. Type T. pcrsonata Lain., from the Lower Eocene of Paris. Shell like that of Xylophaga, with a pedal fissure in the middle line of the callum, the tube elongate, subcylindric, sometimes distally bifid or partially septate ; umbones covered by four accessory valves soldered to the dorsal ex- tension of the callum, probably representing a double protoplax and mesoplax. This group differs from Teredo by the inclusion of the valves in the tube and the absence of siphonal " pallets," as well as the presence of dorsal acces- sory plates. Teredina bowdeniana n. s. PLATE 36, KIGURK 4. Oligocene marl of Bowden, Jamaica ; Henderson and Simpson. The specimen obtained is the portion of a tube containing most of the left valve of a Tcrcdina, with very marked sculpture. The anterior border is formed by a narrow, irregularly broken strip of the shelly matter belonging to the missing tube. The thin posterior border of the valve is not intact, though enough remains to show the character of the sculpture. The sculpture of the anterior part of the valve is composed of small, four-sided lozenges, separated FREE INSTITUTE OF SCIENCE 82- TERTIARY FAUNA OF FLORIDA by sharp, narrow, arcuate Amoves in such a way as to produce the effect of a parting on the periphery of the valve. This grooved and faceted sculpture ceases abruptly behind, but the rows of facets are continued as wider longi- tudinal riblcts posteriorly. The umbonal reflection is heavy and radially striate ; the apophysis seems to have been obsolete and its remains appressed to the internal arch of the umbo. The whole is rather thick and solid, and the antero-postcrior length of the fragment is six and a half millimetres. The very distinct sculpture of this shell instantly distinguishes it from any other known Teredina. The only other Pholads of which I find any mention in our Tertiary liter- ature arc /-*. ovalis Say, which may be a Fistnlana, and will be later referred to under that head; and Pliolas petrosa Conrad (Bull. Nat'l Inst, ii., p. 193, pi. 2, fig. 4, 1842 ; and Am. Journ. Sci., 2d Ser., i., p. 213, pi. 2, fig. I, 1846), which is not a Pholad,* though externally much like one. Superfamily MYACEA. FAMILY GASTROCH/ENID/E. C,i mis G-ASTROCH^3NA (Spengler) Cuvier. (iiisfnii'/in-im Spender, Nova Acta Soc. Sci. Hafn., ii., p. 174, 1783; Desh., Traite de Conchy!., i., p. 26, 1844. ^ Cliana Retains, Nov. Test. Gen., p. 19, 1788; Schum., Essai, p. 94, 1817. -' Mytiliis ]5nigiiierc, Kncyc. Mcth., pi. 219, 1792. < Fistiilana liosc, Hist. Nat. Coq., ii., p. 208, 1802. Trapezium fl, M cleric, Entw., Neuen Syst. Schal., p. 69, 1811. (j<^ti-,h-/in-na Cuvier, Rcgne An., ii., p. 490, 1817 ; Lam., An. s. Vert., v., p. 446, 1818. Koffllaria (Klcurian MS.) Blainv., Diet. Sci. Nat., vol. 57, p. 244, 1828 (G. modiolina Lam.); Tryon, Mon. Pholad., p. 39, 1862. Roxi-llariu Menkc, Syn., p. 121, 1830; Agassiz, Norn. Zool., 1845. Gastrochana Fischer, Man. de Conchyl., p. 1128, 1887. * Phtnacomya n. g. Shell thin, feebly radially sculptured, pholadiform; more or less expanded anil truncate anteriorly, adult with a narrow dorsal gape in front of the beaks, shell closed below, equivalve; young with a wide anterior gape which is gradually closed with growth as shown by the incremental lines; shell attenuated and smoother posteriorly. Type 1'lioladomya cantata Sowerby, Desh., An. s. Vert. Bassin de I'.iris, i., p. 277, pi. ix., fig. 6-8, 1868. It is very doubtful if the group represented by this type has any very close relation to Phola- tiomya. The American representatives are Pholas pflrosa Conrad, above cited, and Fhol,iJomya Mauryi Harris, Hull. I'al., iv., p. Jl, pi. (>, fig. 17 a, 1896. All are Eocene and, so far as known, the genus is Eocene only. TRANSACTIONS OF WAGNER 824 TERTIARY FAUNA OF FLORIDA Shell regular, equivalve, inequilateral, ovoid, widely gaping, with the umboncs anterior; sculpture concentric, feeble, forming flask-shaped exca- vations (chiefly in shells and corals) which arc lined with calcareous matter, or when not protected by the burrow, forming a partial or complete shelly tube to which extraneous matter is attached. Type of the restricted group G. dubia Don. (-f- G. niodiolina Lam.). Subgenus SPENGLERIA Tryon, 1862. Valves truncated behind, the beaks not so near the anterior end, with an elevated area triangular and transversely lamcllo.se, radiating from the beak to the truncation on each valve. Type G. rostrata Spengler (-(- mytiloidcs Lam.). Under the impression that the adventitious tube was a constant character Gould separated G. lagcnula (= G. cyinbia Spengler) as a genus under the name of Cncitrbitida (Proc. Boston Soc. N. Hist., viii., p. 22, 1861), but later writers regard the formation of this sort of tube as accidental and possible with any of the species. Chama Rctzius is a complete synonvmc of Gastroch&na Spengler. Cuvicr was the first to restrict the genus and to discriminate between Gastrochana proper and Sptngieria. Rocellaria Fleuriau was founded on the type of Cuvier, ten years later, anil Rupettana Fleuriau was confused by Tryon with Rocellaria, probably by heterophemy. This genus extends well into the Mcsoxoic, and in the basal Eocene is represented by G. gaincscnsis Harris (Bull. Pal., iv., p. 70, pi. 6, figs. 12, \2a, 1896), from the Midway horizon of Georgia, G. Dalli Harris (as Martesia, op. cit,, p. 71, pi. 6, fig. 15), and G. (Spciiglcria /) cimitariopsis Harris (pp. fit., p. 70, pi. 6, fig. 13), from the same horizon. From the Claibornian come G. larva Conrad (Am. Journ. Sci., 2d Ser., i., p. 212, pi. 2, fig. 5, 1846; Aldr., Bull. Pal., ii., p. 71, pi. 5, fig. 12, 1895) and G. subbi partita O. Meyer, which has neither been described nor figured (cf. Bcr. Scnck. Ges., 1887, p. 12). Burrows are not uncommon, and have been described by Meyer from Clai- bornc and by Clark from the Eocene of Maryland and Virginia. G-astrochsena ovata Sowcrby. (.iiis/n't'/iit'iin in'ii/a Sowcrby, I". /.. S., 1834, p. 21 ; Hanlcy, Dcscr. Cat. Rec. Sli., p. 10, pi. ix., fig. 42, 1842; Cpr. Mazatlan Shells, ]i. 15, 1857. Koccllariii I'i'iita Tryon, Moil. 1'holad, p. 49, 1862. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA Recent from the Carolines to the West Indies, and on the west coast of America at Mazatlan. Variety rotunda Dall. Oligoccnc of the Chipola marls, Chipola River, Florida, Burns; of the silex beds at Ballast Point, Tampa Bay, Florida, Dall; of the Bowdcn marl, at Bowden, Jamaica, Henderson. Shell resembling the m>ata of the same size, but not attaining so large a size as the adult ovata, with a more rounded posterior end and rather shorter gape, the myophorc decidedly larger, wider, and more conspicuous. Lon. 7, lat. 3.5, diam. 2.8 mm. The differences between the recent and the Oligocene shells are so slight, and the range of variation in the living specimens so marked, that I feel unwilling, though the distinctive characters above mentioned seem constant, to give the fossil shells more than varietal rank until I have seen a larger number of specimens. Gastrochaena ligula II. C. I.ca. <;,fi/n>i-/i(i"ii(t ligitlii II. C. I.ea, Trans. Am. Phil. Soc., 2cl Ser., ix., p. 234, pi. 34, fig. 6, 1X45 ; Conrad, I'roc. Acad. Nat. Sci. Phila. for 1862, p. 571, 1863. Oligocene of the O.ik Grove sand at Oak Grove, Santa Rosa County, Florida, Burns; Miocene of the Natural Well, Duplin County, North Caro- lina, Burns; and of Virginia, at Petersburg, Lea. This shell is distinguishable from the others by its narrow and slender form and feeble concentric striation. Gastrochaena cuneiformis Spcngler. (i,is/ri>i-/iti-ini i inti-ifonius Spgl., Nova Acta Soc. Hafn., ii., p. 179, figs. 8-1 I, 1788 ; Lam., An. s. Vert., v., p. 447, 1X18; Shy., Gen., figs. 3-5, 1820; Orbigny, Moll. Cubana, ii., p. 228, 1845. /'/in/us /liuiis (imclin, Syst. Nat., vi., p. 3217, 1792. Chana cuneiformis Ret/ins, Diss. Nov. Test., p. 19, 1788. I'islitliiiiii nipi-stris ISosc, Hist. Nat. Coq., ii., p. 205, 1802. l\i>i-i-llitriii liitnis II. and A. Ads., Gen. Rec. Moll., ii., p. 336, 1856; Tryon, Mon. Pholacl., p. 47, 1862. Pliocene marl of the Croatan beds, North Carolina, Johnson; of the Caloosahatchie and Shell Creek, Florida, Dall and Willcox ; of Trinidad, Guppy ; Pleistocene of South Carolina, Florida, and the West Indies ; recent from Cape Fear, North Carolina, southward to the West Indies. TRANSACTIONS OF WAGNER 826 TERTIARY FAUNA OF FLORIDA This species can be readily recognized by its vast hiatus, nearly as long as the shell, and the rather blunt and wide posterior termination of the valves. Roccllaria antiqua Gabb from the Miocene of James River, Virginia, has not been figured, but the description (Proc. Acad. Nat. Sci. Phila., 2d Ser., v., p. 368, 1861) reads very much like the present species. Genus FISTTJLANA (Bruguiere) Cuvier. Fislnhina Bruguiere, Enc. Melh., i., p. xii., 1789; ib., pi. 167, 1792; name only, no species cited; Cuvier, Tabl. Elem. Hist. Nat., p. 432, 1798; {Teredo clava Linne ;) Lam., Prodrome, p. 90, 1799 (same type). Chcena Gray, P. Z. S., 1858, p. 315 ; (not of Retzius, 1788.) Gastrochtrna Tryon, Man. Pholad., p. 38, 1862 ; (not of Cuvier ;) Cossmann, Eoc. Bassin de Paris, i., p. 9, 1886. Bruguiere was the first to name Fistnlana, though he did not describe it or cite any species. Cuvier supplied a type, and this was adopted by Lamarck. For some time later, however, Fistulanas and Gastrochaenas were confounded in lists of the genus, while Gray injudiciously endeavored to utilize Clucna as a name for this group. Tryon became badly confused on the generic nomen- clature of this group, which was rectified by Fischer in 1866. Conrad (Fos. Tert. Form., p. 34, 1835) enumerates Fistidana clongata Des- hayes as a member of the Claiborne fauna, but it does not appear in his later lists, and may very possibly be the shell he called F. larva, which is a Gastro- chcsna. The only possible Fistnlana,SA here restricted, which appears to have been reported from the American Tertiarics, is F. f avails Say (as Plwlas), 1820, from the Miocene of Maryland, which has never been figured, and of which the type specimen seems to be lost. It is represented as being con- tained in a tube, yet also as boring into Pcrna torla, which suggests Gastro- cluzna. I am now able to include the genus in our fauna from an earlier horizon. Fistulana ocalana n. s. I'I.ATE 35, FIGURE 23. Oligocene of the Ocala or nummulitic limestone, Ocala, Florida; Willcox. Tube straight, claviform, with slight indications of annulation and ad- herent extraneous matter; anterior end larger, anterior disk convex, sub- circular. Lon. (incomplete) 55, lat. (ant.) 12.5, (post.) 9 mm. Though the specimen is merely a limestone cast of an external mold of the tube, there can be no question as to the generic place of the species. FREE INSTITUTE OF SCIENCE 827 TERTIARY FAUNA OF FLORIDA The little irregularities, especially notable near the anterior end, are probably due to attached particles of gravel on the original tube. FAMILY SAXICAVID/E. r.emis PANOPEA Mcnurd. l\infif>i-ii Mi-nard, Annales clu Mtis. Paris, ix., p. 135, 1807 ; doldf., Hanclb. d. Zool., p. 677, 1820. (I'/yi'init'i'fs Lamarck, Prodrome, p. 83, 1799. Type Mya gfycytneris l!orn. (Not Glyeymeru Da Costa, 1778, nor (//>'< /wrvv'v Lain., iSoi, nor Schumacher, 1817.) /\in<>/>u~ti Lain., Kxtr. d'un Cours., p. 108, 1812; An. s. Vert., v., 11.456, 1818; Valenci- cnnes, Arch, du Mus. Paris, i, p. 3, 1838. I'anofna Swainson, Malac., p. 367, 1840. lilycimcris H. and A. Adams, den. Rec. Moll., ii., p. 350, 1856; Gray, Fig. Moll. An., v., p. 30, 1857. This well-known genus, after the exclusion of the Saxicavoid species, forms a very natural group, related to the Myaddall. t'iin<>f>t-it l!i>Mfnssii \Vhitfii-ld, Min. M:\rls N. }., p. 89, pi. 16, figs. 9-13, 1895; IK it "I Wagner, 1838. ( Migoccne of the silcx beds at Ballast Point, Tampa Bay ; of the Chipola Rive-rand Oak Grove, Santa Rosa County, Florida, Burn's ; and mixed with Miocene species in the rehandled marl of Jericho, Cumberland County, New Jersey, Burns. This species differs from the typical Miocene I\ Goldfnssii Wagner in its smaller six.e, more e(|iiilatcral valves, and less expanded anterior region. Panopea Goldfussii Wanner. /'. d'ti^ffnxsii NVagner, Journ. Acacl. Nat. Sci. 1'liila., viii., p. 52, pi. I, fig. 3, 1838; Trans. \Vagnc-r Inst., v., p. 8, 1897. /'. /WvvrAi Conrad, Kos. Medial Tert., p. 71, pi. 41, fig. 2, 1842. Miocene of Maryland at Jones's Wharf, Plum Point, Langley's Bluff, St. Mary's, Calvert Cliffs, and on the Choptank River; of Virginia at Suffolk and on the Nansemond River, Nomini Cliffs, and Grove Wharf, Burns and Harris; and in the upper bed at Alum Bluff, Cliattahooehcc River, Florida, Burns. This species, though varying like the others, may almost always be distinguished by its expanded anterior end, and elongated and attenuated posterior part. It is very close to the European /'. Rudolf hii Eichwald, /'. liastcroti Valenciennes, and /'. Mcnardi Dcshaycs, which, from the figures, appear to be pretty much one and the same species. The last two are united by Deshaycs himself in manuscripts in my possession, I )esliayes's name being the prior one. 7'. porrccta Conrad is identical with this species. Panopea reflexa Sa\. /'. r<-//(-xu Say, Journ. Arad. Nat. Sci., iv., ]>. 153, pi. 13, fig. 4, 1824; Conrad., Mcd. Tert., p. 5, pi. 3, fig. 4, 1838. /'. /•'iiiijiisi Conrad, in Morton, Syn. Org. Rcm., p. 3, 1834; not of Mcnard. /'. i yiii/nifii Hcilprin, Trans. Wagner Inst., i.t p. 91, pi. y, fig. 20, 1887. /'. ri-J/i-.vti I'jnnions, (leol. Rep. N. Car., p. 300, fig. 299, 1858. Miocene of Gay Head, Martha's Vineyard, Massachusetts; of Grove Wharf and Suffolk, Petersburg, and York River, Virginia; of Wilmington, Magnolia, and the Duplin County Natural Well, North Carolina ; of the IVedee River and Darlington, South Carolina. TRANSACTIONS OF WAGNER 830 TERTIARY FAUNA OF FLORIDA This species is characterized by the swollen and rounded anterior end, without pedal truncation, and the attenuated posterior end, with the dorsal margin more or less reflected. It is a smaller shell and less equilateral than the Pliocene form confused with it by Heilprin. The distinctions he mentions between it and the original rcflexa, as figured by Say, are inconstant, and if the number of specimens had been as large as that at my disposal, doubtless he never would have separated them. The P. Mcnardi of Deshayes is related to P. Goldfussii, and much less so to this species. Stunted specimens of P. rcflexa are often quite broad and very puzzling. The depth of the pallial sinus differs quite markedly between individuals, and also its width, the shorter specimens, as usual, having the wider sinus. Panopea americana Conrad. P. americana Conr. , Fos. Medial Tert., p. 4, pi. 2, fig. i, 1838. Miocene of Calvert Cliffs, and very abundantly at Jones's wharf, also on the Patuxent and St. Mary's River, Maryland, and at Coggins Point, Vir- ginia. This fine species is the American analogue of the European P. glycymcris Born (1780), from which it differs by its smaller and. heavier shell and deeper and narrower pallial sinus. It is immediately recognizable by its pedal trun- cation and oblique posterior margin. The European shell is more generally known by the later name of P. Aldrovandi Menard, 1807. Panopea generosa Gould. P. generosa Gould, Proc. B. Soc. Nat. Hist., iii., p. 215, 1850; Moll. Wilkes Expl. Exp., p. 385, pi. 34, fig. 507. Glycimeris generosa Carpenter, Suppl. Rep. Brit. Assoc., 1863, p. 637 ; Cooper, Cat. Cal. Fos., 7th Ann. Rep. State Mineralogist, California, p. 241, 1888. Miocene of Contra Costa and Santa Barbara Counties, California ; Plio- cene of Santa Barbara and San Fernando, California; Pleistocene of Santa Barbara and San Pedro, California, Cooper; recent from Puget Sound south to the Gulf of California, Gould, Stearns, and Palmer. This fine species is widespread and variable. Gabb unites to it the Myu (= Panopea) abrnpta of Conrad (Wilkes Expl. Exp., Gcol., p. 723, pi. 17, fig. 5, 1849) and the Glycimeris cstrcllana Conrad (Pac. R. R. Reps., vii., p. 194, P'- 7. fig-s- 5. 5 aj '857). After a comparison of the figures and specimens I conclude that Conrad's two species are identical, and as Deshayes used the FREE INSTITUTE OF SCIENCE 831 TERTIARY KAUNA OF FLORIDA name udnipta for a Panopea in 1843, the specific name of cxtrellana would best be retained for this Miocene fossil of Oregon and California. The latter, however, seems entirely distinct from the P. gcnerosa, being a smaller, more slender, and more equilateral species. The latter has several varieties which are so market! in form that it is perhaps best to assign them varietal names. Panopea generosa Gould, typical form. t- Shell rather thin, nearly equilateral, the beaks slightly anterior, the dorsal and ventral margins in the full-grown shell parallel and nearly straight, the pedal margin evenly rounded, the nymph narrow, and the attached edge of the ligament very short, the pallial sinus wide and shallow. Lon. 182, alt. 1 10, diam. 60 mm. Puget Sound. Panopea (var.) solida Dall. Shell heavy, somewhat arcuate, the pedal region slightly obliquely trun- cated, the nymph strong, and the ligamentary attachment twice as long as in the typical form, the pallial sinus deeper. Lon. 177, alt. 97, diam. 62 mm. San Francisco, California. l\inopea (var.) globosa Dall. Shell thin, short, inflated, the beaks nearer the anterior end, which is expanded and rounded in the pedal region ; posterior end narrower, opposite margins not parallel ; posterior hiatus smaller than in the type and somewhat recurved ; nymph narrow, slender, somewhat longer than in the type ; pallial sinus small, wide. Lon. 160, alt. 120, diam. 80 mm. Head of the Gulf of California; Palmer. The last variety is only known from the locality cited, the other two are found from Pugct Sound to San Diego, California. Panopea floridana Hcilprin. r.Jloritiaiiii Hcilprin, 'Trans. Wanner Inst., i., p. 91, pi. 10, fig. 21, 1887. /'. .\/,'iuinfi Hcilprin, op. fit., p. 90, pi. 9, fig. 19, 1887 ; not of Deshayes. /'. ntniifiilti Hcilprin, op. n't., p. 91, pi. 10, fig. 22, 1887. Pliocene of the Caloosahatchie beds, on the Caloosahatchie, Shell Creek, and Alligator Creek, Florida ; Dall and Willcox. Recent at Cape Lookout, North Carolina, Bickmore ; and at Mobile Point, Mississippi, Conrad. The form referred to Meiiardi by Jleilprin is a distinct species from that and from the American Miocene forms usually called rcflc.va Say. In the writer's opinion there is but one species of Panopea in the Florida Pliocene, TRANSACTIONS OF WAGNER TKRTIARY FAUNA OF FLORIDA so far as yet described, and its mutations are analogous to those observed in P. generosa and other species of which a large series has been studied. If a varietal name be thought advisable for the arcuate form, mtriciila might be used in this sense. The form called by Hellprin florutana corresponds to the variety solida of P. generosa, and the form he referred to Menardi to the typical generosa. Panopea dubia H. C. Lea (1845), probably a Spltenia, is not a Panopca, as it has a chondrophore like My a. It is from the Miocene of Petersburg, Virginia. The various synonymes of the so-called Panopca norvegica will be found under Panomya. P. bitrnncata Conrad (Proc. Acad. Nat. Sci. Phila. for 1872, p. 216, pi. 7, fig. i) has not yet been found in a definitely fossil state, but is known as recent from North Carolina to Tampa, Florida. The Plioladomya abrupta Conrad (Fos. Tcrt. Form, p. 26, 1832) was wrongly referred to I'anopea by Deshayes and others; it appears to be allied to Plioladomya, is a pearly shell and the type of the genus Margaritaria Conrad (Mio. Checkl., 1863, + Actinomya C. Mayer, Mus. Zurich, 1870), and which may perhaps include subgenerically Argyroinya Fischer (Man., 1887), founded on the Panopea inargaritacea Deshayes, from the Parisian Eocene. « Genus PANOMYA Gray. I\inomvpca (.I/iv) iii>n>,-^ii-ti Spengler. Clu-iwpea C. Mayer, Tert. Moll. Mus. Zurich, iv., 1885. Panopca and Saxicava of authors. Shell solid, large, irregular, with a single cardinal tooth under the beak in each valve; the pallial line of unconnected rounded impressions ; the animal larger than the shell, with large, united siphons, diverging slightly at the tips and covered with a wrinkled coriaceous epidermis; a burrowcr in mud and gravel, never perforating stones. Type Panomya norvegica Spengler. .l/iw in»-i'cxi(ii Sp.nl., Ada Soc. Hist. Nat. Ilafn., Hi., p. 46, pi. 2, TIL;. 18, 1793. Clyciinci-h turtica Lam., An. s. Vert., vi., p. 458, 1819 ; Gould, 1m- . Mass., p. 37, lii;. 27, 1841. l\uwpi,-tt .S/V//;V(V7' Val., Arch, du .Mus. Paris, i, p. 15, pi. 3, fii;. 3, 1838; Chcmn., 111. Conch., pi. 4. I'IL;. 4. r,uiipica iit>r-,','gica. Mi4d. (pars), Mai. Ross., iii., p. 78, pi. xx., fig. u, 1849; not of Spcngler. Pleistocene of the North Pacific, Bering, and Okhotsk Seas, and recent in the same region. This differs from /'. iwrvc^ica by its much more heavy and rude shell, with a more expanded posterior region, and flatter, more irregular valves. Genus SAXICAVA Flcuriau d, IVlK-vuc. //itr/,-//ti Daudin, in Hose, Conchy]., iii., p. 120, 1802; Koi*sy, Man., vi., p. 385, 1805; Lam., Hist. An. s. Vert., vi., p. 29, 1819 ; tiray, List of lint. Moll., Brit. Mus., p. 88, 1851. Xii.u'i'in'ii rieuriau, linll. Snc. I'hilom., No. 62, pp. 5, IO, 1802 ; Lain., An. s. Vert., v., p. 501, 1818. Shell small, irregular, very inequilateral, the young with a cardinal tooth like Piiiwinya, the adult with the teeth obsolete; pallial line discontinuous, siphons naked, slightly separated at the tips and in normal specimens com- pletely retractile, shell burrowing, or nestling in gravel or broken shell, or perforating rocks, corallines, or dead shells like pholads. Type, J/jw arctica Li nne. It is unnecessary to repeat the formidable list of generic and specific synonymes which the curious may find in Gray's List of British Animals, vii., Mollusca, pp. 87-89, 1851. In this synonymy, which Dr. Gray separates into two parts, allotting Sa.vicai'a to S. rngcsa and Hiatclla to .S". arctica (which is the young of rugose?), he cites a rare memoir of Daudin's for the genus Hiatclla dating two years before the proposal of Saxica-ra by Fleuriau. Hose and Roissy do not refer to this memoir, but mention two species from Tranquebar TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA in Favanne's collection, both of which are figured in the atlas to Bosc's work. Lamarck without ceremony refers Bosc's figures to Alya arctica Linne, and cites but that single species under the genus. Dr. Gray cites Hiatella arctica from Daudin's memoir of 1800, but without mentioning page or figure for it, which leads to the suspicion that he may not have actually seen the paper himself. If his citations be correct, there would seem to be no doubt that Hiatella should be adopted in place of the later Saxicava, but in the doubt that remains I hesitate to make the change, and would prefer to leave it to some one who can consult the original memoir.* Brown in 1827 (111. Conch. Gt. Brit.) takes the same course that Gray did later with regard to the two names, but the Hiatella of Costa, 1828, is the same as Galeomma Turton, 1822. Saxicava arctica Linne. Mya-arctica Linne, Syst. Nat., Kd. xii., p. 1113, 1767; O. Fabr. Fauna (mini., p. 407, 1780. Sn/i'ii ininutiis Linne, op. cit., p. 1115, 1767. .My a bvssifcra O. Fabr. Fauna Gronl., p. 408, 1780. Mytilus pholadis Mohr, Osl. Naturh., p. 135, 1786. Saxicava slriata Fleuriau, Mem. sur les Vers litli., p. 10, 1802. Glycimcris byssifera Schum., Essai, p. 106, 1817. Saxicava riigvsa Lam., An. s. Vert, v., p. 501, 1818. Saxicava gatticana Lam., An. s. Vert, v., p. 501, 1818. Agina purpurea Turton, Dith. Brit., p. 54, pi. 4, fig. 9, 1822. HiatcUa oblonga Turton, Dith. Brit., p. 25, pi. 2, tig. 13, 1822. P/ioli'obia pracisa Brown, 111. Conch. Gt. Brit., pi. ix., fig. 6, 1827. Saxicava distorta Say, Journ. Acad. Nat. Sci. I'hila., ii., p. 318, 1822 ; Gould, Inv. Mass., p. 61, fig. 40, 1841. Saxicava bilincata Conrad, Medial Tert., p. 18, pi. 10, fig. 4, 1838. Saxicava grbtllandica Potiez et Mich., Gal. ii., p. 266, pi. 69, figs, i, 2, 1844. Saxicava rlimnbuities Wheatley, Cat., 2d cd., p. 4, 1844. Saxicava rubra Uesh., Expl. Algeria, Moll., pi. 66, fig. 72, 1848. Saxicava iiiigana Grevvingk, Verh. Kuss. Kais. Min. Ges., 1848-9, p. 354, pi. 6, figs. I rt-i c, 1850. Stixicava insita Conr., Am. Journ. Conch., v., p. 40, 1869. Saxicava incita Conr., op. cit., p. 101, 1869. Saxicava protcxla Conr., Kerr, Gcol. Rep. N. Car., p. 22, pi. 4, fig. 6, 1875. * Since this was written I have learned, through the kindness of Mr. Kdjjar A. Smith, of the lirili.sh Museum, that lliere is no mention of Hiatella in Daudin's Memoir of 1800. FREE INSTITUTE OF SCIENCE TKRTIAKY KAUNA OF FLORIDA ' •" Miocene of Maryland; of Duplin County, North Carolina; Shiloh, New Jersey ; and Alaska ; Pliocene of the Caloosahatchie beds, Florida, and of the California coast at San Pedro and Santa Barbara; Pleistocene of northern North America and Kurope; recent, almost universally distributed in the temperate and colder seas. Sa.vicava abntpta Conrad (Pac. R. R. Reps., v., p. 324, pi. 3, figs. 25, 25 a, 1856), from the Pleistocene of San Pedro, California, is indeterminable, but probably not a Saxicava ; the same may be said of S. parilis Conr. (Am. Journ. Conch., ii., p. 70, pi. 4, fig. 6, 1866), from the Miocene marl of Shiloh, New Jersey. S. pcctorosa Conr. (1834, Medial Tert., p. 18, pi. 10, fig. 3, 1838), from the Miocene of Virginia, is probably a Petricola, as is 6". legitmcn Deshayes, from the Pleistocene of San Pedro, California. The latter may be identical with P. canlitoidcs Conr. 5. myaformis Cotu. (Am. Journ. Conch., ii., p. 70, pi. 4, fig. 6, 1866) is a Thracia. S. lancea H. C. Lea (1845) >s n°t a Saxicara, but belongs in a group closely related to, or the same as, Sportella. The genus Saxicavella Fischer (Arciiiclla Phil., 1844, not Oken, 1815, nor Schum., 1817), founded on the little Mya plicata Montagu, though present in the European Pliocene, has not been detected in America. Genus CYRTODARIA Dauilin. I'vi-ttH/iiin- Pamlin, IJull. Soc. Philom., xxii., p. 170, 1799. I'vrtiiilaria Keuss, Kepertor. Coinin., p. 351, 1800. (//)•( inicris Lam., An. s. Vert., v., p. 457, 1818; not Lam., 1799. (/'/n i/iii'ra Hlainv. Malac., p. 571, pi. 80, tig. 3, 1825. Type Cyrtodaria siliqita Dauilin. Cyrtodaria siliqua Dauclin. (_'. silit/iia Dauilin, t'p. cit., 1799. Mya silit/im Clicmn., Conch. Cab., xi., p. 192, pi. 198, fig. 1934, 1795. (i'h'i'iiiit->is iiitTitssitta Lam., Syst. An. s. Vert., p. 126, 1801. Mya f>it'i'a \Vmxl, ('.en. Conch., p. 96, pi. 22, fig. 5, 1815. Pleistocene of the Arctic and boreal Atlantic coasts ; recent from Cape Coil northward to the Arctic coast, and west on the Arctic coast to the mouth of the Mackenzie River ; Richardson. This well-known shell does not seem to have penetrated to the region of Bering Strait, and is only represented in Bering Sea by a diminutive recent analogue, the C. Knniana Dunker. 18 TRANSACTIONS OF WAGNER 836 TERTIARY FAUNA OF FLORIDA FAMILY CORBULID^E. Genus CORBTJLA (Bruguiere) Lamarck. ;; Corbula Brug., Encycl. Meth., pi. 230, 1797 (not in Table, 1792) ; Lam., Prodr., p. 89, 1799; Syst. An. s. Vert., p. 137, 1801 ; Cuvier, Regne An., ii., p. 486, 1817; Lam., An. s. Vert., v., p. 494, 1818 ; Turton, Dithyra Brit., p. 38, 1822. Aloidis Muhlfeldt, Entw., p. 67, 1811. Sole ex. C. sulcata Lam. Lentitiium Cristofori et Jan., Catal., |>. 8, 1832, and Mantissa, p. 4, 1832 ; Villa, Disp. Syst., p. 45, 1841 ; Isis, 1842, p. 473. Type Corbula mediterranea Costa (+ macu- latum Jan.). Erodona Daudin, Mem. Moll. Vers et Zooph. ? 1800; Bosc, Hist. Nat. Coq., ii., p. 329, 1802. Type E. mactroidcs Daudin, Bosc, /. c. (but named on pi. 6, fig. I, Mya erodond). Azara Orbigny, Voy. Am. Mer., Pal., pi. vii., 1839, text, p. 161, 1842; Voy. Am. Mer., Moll., p. 572, 1846. Type Alya labiata Maton. Potamomya Sowerby, Min. Conch., vi., Index, p. I, 1835; M;ln- Conch., p. 88, 1839; (not of Orbigny, Voy. Am. Mer., Moll., p. 573.) Corbulomya Nyst., Coq. Tert. Belg., p. 59, 1846. Type C. coinpliiintla Sby. ? Harlca Gray, Synops. Brit. Mus., pp. 78-91, 1842 (itom. nuduin). ? Ralcta Gray, op. cit., p. 91, 1842 (noin. nudiini) ; ibid., p. 78, 1844. ? Tomala Gray, op. cit., p. 91, 1842 ; ibid., p. 78, 1844 (twin, nudiini). Erodina Gray, P. Z. S., 1847, p. 191. Pachydon Gabb, Am. Journ. Conch., iv., p. 198, 1868. Type P. flbliqua. Gabb ; not Pacyodon (Beck MS.) Gray, P. Z. S., 1847, p. 191, nor Pacliyodon Stutchbury, 1842. Agina Gray, P. Z. S., 1847, p. 191 ; Conrad, Am. Journ. Conch., iv., App., p. 63, 1868 ; Cossmann, Fos. Paris, i., p. 34, 1886; not of Turton, 1822. Anisothyris Conrad, Am. Journ. Conch., vi., p. 196, 1870 (Oct.). Anisorhynchus (Conrad MS.) Meek, 2d Prel. Rep. U. S. Geol. Surv. Terr., p. 293, 1872. Type Corbula pyriformis Meek. Cuneocorbtthi Cossmann, Cat. Coq. Fos. Bassin de Paris, i., p. 37, 1886. Type C. bian^u- lata Deshayes. Bothrocorbula Gabb, Proc. Acad. Nat. Sci. Phila. for 1872, p. 274. Type Coi-bula I'iminca Guppy. Bicorbula Fischer, Man. de Conchyl., p. 1125, 1887. Type C. gallic a Lamarck. Himella H. Adams, Ann. Nat. Hist., vi., p. 455, 1860; type //. flitviatilis Ads. Not of Dallas, 1854. Not Corbula Bolten, Mus. Boltenianum, p. 174, 1798; Ed. ii., p. 128, 1819 (= Asaphis Modeer, etc.). The synonymy of this genus is quite involved. The several valid sections are chiefly separated from each other by differences of form, which intergrade distally, and for convenience in bringing together the various names and refer- FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA ences they are included in the above synonymy. The original publication of Bruguiere's name is to be found on Plate 230 of the Encyclopedic Methodique, and not in the earlier printed table of genera. There is, of course, no diag- nosis ; no species are named, and no references given ; merely the name at the top of the plate, upon which the shells figured are not all Corbulas. Authors who accept a name on such a basis have no right, logically, to take exception to any of Bolten's names. Lamarck cited no example in the Pro- drome, and the list of specific names in the Systeme, beginning with C. sulcata, appears to be the first occasion when the requirements of nomenclature were complied with. No type was cited even at that time, or for much later, and, curiously enough, the shell figured by Bowdich to illustrate the genus in 1822 is probably not a Corbula. Megerle's name was the first applied to C. sulcata exclusively, and must be retained for the section of the genus typified by that species. The typical section of Corbula will necessarily be reserved for some one of the other forms included in the list of 1801, which are also figured on the above-mentioned plate. This leaves only a choice between C. margaritacea and C. gallica Lam., and, as the former seems to be some kind of an Anatina, we are obliged to fall back upon C. gallica as the type of Corbula in the stricter sense. This agrees with the arrangement of Nyst, whose first species of true Corbula, after segregating Corbnloinya, is C. gallica. The C. sulcata group is not sharply separated from the typical Corbula, and the peripheral species merge. Asara and Potainomya are exact synonyms of ILrodona. Corbnloinya is identical with the earlier Lciitidhnn. Gray has contributed a group of nomina nuda, based on undescribcd species supposed to be Corbulce. An error of Gray, by which Agina Turton (based on Saxicava arctica) was referred to the Corbitlidte, has been widely copied. The supposed type, Corbula gibba Olivi, is a true Corbula. A group of very remarkable and very variable brackish-water Pliocene species is comprised under the name of Anisotkyris Conrad (+ Pachydon Gabb). The other names stand for fairly distinct sections of the genus. The following arrangement of the group is proposed : Genus COBBTJLA sense lato. Valves unequal, the right usually larger, both more or less rostrate; hinge of (in the right valve) a single large tooth below the beak with a deep resiliary pit behind it and no lateral lamina ; the left valve without laterals, TRANSACTIONS OF WAGNER 838 TERTIARY FAUNA OF FLORIDA with a more or less prominent process upon which the resilium and ligament are inserted, in front of a socket into which the cardinal tooth of the right valve fits; the posterior margin of this socket is sometimes elevated like an indistinct tooth ; beaks prominent, prosogyrate or erect, the right one usually superior to the left; sculpture variable, often discrepant on the two valves, rarely reticulate, and never strongly radial ; pallial line with a small sinus or none ; lunule and escutcheon usually absent ; ligament chiefly internal ; siphons complete, usually short, and fringed distally; mantle with a pedal opening but mostly closed ventrally. Chiefly marine. Section Corbula s. s. Shell subtrigonal, ligament internal ; globose ; valves feebly concentrically sculptured with no rostral keels, sculpture discrepant on the two valves. Type C. gallica Lam. Bicorbitla Fisher is identical. Section slloiilis Megerle. Like Corbula, but with strong concentric sculpture and keeled rostrum. Type C. sulcata Lam. (+ A. gniitcensis Meg.). Section Lcntidium C. and J. Shell compressed, trapezoid, feebly concentrically sculptured ; the liga- ment appearing externally through a fissure in the right mnbo. Type C. mcditerranea Costa. Corbuloinya Nyst is identical. Recent and Tertiary. Section Cidit'oiorlnila Cossmann. Shell elongate ovoid, with two elevated radial keels on the rostrum, which is distally truncate; the valves similarly sculptured. Type C. biangnlata Deshayes. Recent and Tertiary. This group may be extended to cover the American species with similarly sculptured valves, like C. contracta Say, in which the keels are less pronounced and the dorsal one sometimes obsolete. Section Tiza ilc ( '.rr^orio, 1890. Shell very inequilateral, twisted, and produced behind, the right valve convex, the left flattened or even concave, pointed behind ; surface smooth, valves similarly sculptured, pallial sinus obsolete. Type C. alta Conrad, Journ. Acad. Nat. Sci. Phila., 2d Sen, ii., pi. i, fig. 3, 1850 (not i., pi. 12, figs. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA 33-35, 1848) ; = C. aliforinis Conrad, Am. Journ. Conch., ii., p. 76, 1866; Shell Bluff group, Vicksburg, Mississippi; + C. (Tiza) ainara de Greg., Mon. Claib., p. 234, pi. 37, figs. 12-14. Section Aiihvthyris Conrad. Like Corbnla, but larger, with heavy, smooth shells, the beaks strongly prosogyrate, thus twisting the plane of the ligament out of the vertical into an oblique or nearly horizontal direction ; form very variable; inhabiting fresh or brackish water. Type A. oblitjita Gabb. Fresh-water Tertiaries of the Amazon. Section Anticorbitla Dall. Shell thin, the left valve larger, the hinge reversed ; the ligament exter- nal; resiliuni as in Anisolhyris. Type A. (Himella) fluviatilis H. Adams. (Hiinella Ads., 1860, not Dallas, 1854.) Recent, Amazon River. Section Anisor/iviif/itis Conrad. Valves subequal, smooth or concentrically undulated, the shell rounded and inflated in front, prolonged into a long rostrum behind, with an escutch- eon-like area defined by two dorsal keels behind the beaks; hinge and other characters like Corlmla. Type Corbnla pyrifontiis Meek. Brackish-water Tertiaries of Montana. Section I'.riniona Daudin. Shell elongate triangular, feebly concentrically sculptured with a con- spicuous epidermis, the left timbo superior, though the left valve is not the larger; hinge of a strong, nearly vertical process supporting the resilium, with a small socket on each side in the left valve; in the right valve a deep central pit for the resilium, the edges of the hinge-plate bordering it turned up on each side as a narrow projection fitting into the sockets opposite, but no well-defined cardinal tooth or laterals ; the ligament is obsolete. Type ]\Iya lalriata Maton, from Brazilian estuaries. l\>tanioinya Sby., 1835, and Azara Orbigny, 1839, arc synonymes. Section Hot/inx-nrlnifa Gabb. Shell ovate, solid, pointed behind; valves similarly sculptured with strong concentric ridges; lunular region impressed, sometimes forming a globular cavity in the hinge-margin; shell otherwise like Cuncocorbiila. Type Corbnla ia (iuppy. Oligoccne to recent in the Antillean region. TRANSACTIONS OF WAGNER 840 TERTIARY FAUNA OF FLORIDA Subgenus CORBULAMELLA Meek and Hayden. Proc. Acad. Nat. Sci. Phila. for 1857, p. 143. Shell subglobular, inflated, like Corbula s. s., except that the posterior adductor is inserted in each valve on a raised lamella, recalling that of Citcul- Icea. Type C. gregaria Meek and Hayden. Cretaceous of Nebraska. I have examined a very large number of adult Corbulas, and in none of them have I found any traces of lateral teeth or any more than a single cardi- nal tooth, well developed, in the right valve. When not erect the beaks are invariably prosogyrate ; but Bernard has shown that in the nepionic young there are traces of an anterior and posterior left cardinal and two left anterior lamellae, and similarly in the opposite valve are traces of denticulation, which become obsolete in the adult, but which tend to show the relations of the group to the Myacea. In the Eocene of the Pacific coast are found Corbula (Anisorliynclins) al&formis Gabb, 1868, and C. (A.) cultrifonnis Gabb, from the Tejon and the Martinez group respectively. If the name of the former be regarded as insuf- ficiently distinguished from C. aliformis Conrad, 1866, it might be changed to C. Gabbii. C. {Cuneocorbula) Evansana Shumard, 1858, from the Port Orford coal measures (Arago beds), C. (C.) Hornii, C. (C.) f>ari/is, and C. (?) pritno rsa Gabb, 1868, from the Tejon of California, complete the list of Pacific coast Eocene species so far recorded. From the brackish-water Tertiaries of the West, Meek (1877) has de- scribed Corbula (Anisorhynchus) pyrifonnis, for which C. concentrica Meek (1861) was an earlier but preoccupied specific name. With it in Utah was found C. (Cnncocorbula) Engelniannii Meek (1877). From Nebraska Corbulamella gregaria and Corbula (Aloidis f) pernndata, C. (Erodona) mactriformis, and C. (E.) snbtrigonalis Meek and Hayden were described in 1857. The peculiar and polymorphous section Anisothyris from the Pebas clays of the upper Amazon is represented by the following species : C. (A.) atna- zonensis (Gabb as TelKna), C. (A.) tennis Gabb (+ Hauxit'elli Woodward, + ovata Conrad), C. (A.) erccta Conrad, C. (A.) obliqna Gabb, C. (A.) armifcra Ball (+ carinata Conrad non Phillips), C. (A.) spheniella Ball (+ cuneata Con- rad non Say), and C. (A.) ledcefonnis Ball. Species of the Eastern Eocene. Turning now to the eastern Tertiary of the United States, the earliest FREE INSTITUTE OF SCIENCE 841 TERTIARY FAUNA OF FLORIDA species is C. (Cuncocorbula) siibcompressa Gabb (1860) from the Midway of Tennessee, Alabama, and Arkansas. From the Chickasawan (or Lignitic) we have the following : 1. Corbiila concha Aldrich, Bull. Pal., ii., p. 7, pi. 5, fig. 6, 1895 ; Harris, Bull. Pal., ix., p. 66, pi. 13, fig. 1 1, 1897. 2. Corbula Aldriclii Meyer, Am. Journ. Sci., xxx., 1885, p. 67; Bull. Ala. Geol. Surv., i., p. 83, pi. I, fig. 21, 1886; Harris, Bull. Pal, ix., p. 67, pi. 13, figs. 12, 13^, 1897. 3. Corbula subcngonata Dall, Harris, Bull. Pal., ix., p. 68, pi. 13, fig. 14 rf, 1897 (as alabatuicnsis Lea, var.) ; Aldrich., Bull. Ala. Geol. Surv., i., p. 58, 1886 (as C. cugonata Conrad). This form is smaller, less inflated, thinner, and with more nearly parallel dorsal and ventral borders than C. alabainicnsis. The sculpture is finer than in C. cugonata, which is a more elongated species. 4. Corbula Grcgorioi Cossmann, Ann. Geol. et Pal., No. 12, p. 6, pi. I, figs. 4, 5, 1894. The first is a typical Corbula with nearly smooth surface; the others belong to Cnneocorbula. The last is abundant in the Claibornian, where it has generally been mistaken for the young of C. nasnta Conrad. The Clai- bornian contains a number of species some of which are restricted to this horizon, but others are found in the beds below or continue into the Jack- sonian. Corbula (Cuneocorbula) alabamiensis Lea. Coi-hu/a tiliilMinii-nsis I.c;i, Contr. C.ccil., p. 45, pi. I, fig. 12, Dec., 1833. Curhnla nasiita Con rail , Kos. Tert. Form., p. 38, Sept., 1833; Am. Journ. Sci., N. S.,i., p. 398, pi. 4. fig. 4, May, 1846; Harris, Reprint Fos. Tert. Form., pi. 19, fig. 4 ; not of Sby., I1. /,. S., 1833, p. 35. (.'iv/iii/ii (\t-ii-ni) i/ii.ut/d de Gregorio, Mon. Claib., p. 231, pi. 36, figs. 36-50, 1890. ( _',»-/>H/II \///'//(7\//AM)rl)igny, 1'rodr. Pal., p. 382, 1850. ? Corlnila iiiimitti var. hint tie (Ireg., <>/>. <•//., p. 23 1, pi. 37, figs. 5-8, 1890. Claibornian Eocene of Orangeburg, South Carolina; Clarksville and Clai- borne, Alabama; White Bluff, Arkansas, and the Gatun beds of the Isthmus of Panama. Also, according to Clark, in the Eocene of Virginia and Mary- land. The C. nasnta of Sowerby is a recent species from the west coast of Central America, described in March, 1833. It is somewhat difficult to dis- TRANSACTIONS OF WAGNER 842 TERTIARY FAUNA OF FLORIDA criminate the young of alabainicnsis from the young of C. dcnsata, which is often mixed with it, and which Gregorio has described as a variety tccla of this species. I am unable to identify his variety ima from the figures; it much resembles some of the forms of Grcgorioi Cossmann. The C. nasnta Conrad of the Mex. Boundary Rep., i., p. 161, pi. xix., fig. 4, 1857, from western Texas, is obviously a distinct species, which may take the name of C. Conradi. Corbula (Cuneocorbula) densata Conrad. Corbitlii tit-lisa fa Conr., Proc. Acad. Nat. Sci. IMiila., vii., p. 258, 1855; Wailes, Rep. Geol. Miss., p. 289, pi. 14, fig. 9, 1854. Corbula nasiita var. tccla Gfegorio, Mon. Claib., p. 231, pi. 37, figs. 9—11, 1890. (Young shell.) Claibornian Eocene of Orangeburg, South Carolina; Clarksville and Claiborne, Alabama, and Carson's Creek, Mississippi ; Jacksonian Kocene at Jackson, Mississippi ; Wailes. This is a large, irregular, coarse, and strong species, more common in the Claiborne sands than in the Jacksonian, from which it was first described. It is more coarsely sulcatc and much more trapezoidal than C. alabainicnsis, with which it is usually associated. Corbula (Cuneocorbula) compressa Lea. Corbula compressa Lea, Contr. Geol., p. 47, pi. i, fig. 15, 1833; Gregorio, Mon. Claib., p. 233, pi. 36, figs. 34, 35 (not fig. 33 i"hn/ti I'dM/n'i'ssii var. tin\^i Cossm., Ann. Geol. et Pal., 12, p. 6, pi. i, figs. 4, 5, 1894. (',i/-/n//,i .Uif>ii-/ii \ ar. sinitlr,'illi-nsis Harris, Proc. Acad. Nat. Sci. Phila. for 1895, p. 52, pi. 3, fig. 5", 1895. Eocene of Prairie Creek and Coffeeville, Alabama; of Newton and Wah- tubbee anil Clarke Count}', Mississippi ; of Meridian and Claiborne, Alabama; Mount Lebanon and Montgomery, Louisiana; Lee County, Texas; the Gatun beds of the Isthmus of Darien, and in the Jacksonian of Clarke County, Mississippi. This small and rather variable form seems to me specifically distinct from either of the species to which it has been referred as a variety. Corbula (Aloidis) oniscus Conr.nl. Curbulii iv/Avv/.v Conr. , Am. Journ. Sci., xxiii., p. 341, Jan., 1833 ; and same, N. S., i., p. 219, pi. 4, fig. 13. 1846. Cur/nitti Minr/iisi'iiii Lea, Contr. (",eol., p. 46, pi. i, fig. 13, Dec., 1833; Gregorio, Mini. Claib., p. 231, pi. 37, figs. 22-39, .P1- 3-s. "Ks- i-'3. l89°- <'i>rt>n/ii ifi/'/iii.'iit C'onr., Am. Journ. Conch., i, p. 3, 1865 ; not of Lea. (.'nr/ni/ii ;v/ it fa (\i-n-i;>) i^/in/,1 (ircgorio, c/. cil., p. 232, pi. 37, figs. 15-18, 1890 (smooth valve). ('i>rhnlii /iiisnfi! ("in-gorio, <>/>. if/., p. 232 {in synonymy, not of Conrad, 1833). Eocene of the Chickasawan stage at Wood's Bluff, Alabama; of the Claibornian at Claiborne and Clarksville, Alabama; and of the Jacksonian at Jackson, Mississippi. This species is subject to a scaling off of the outer sculptured layer of the shell, leaving the latter in an apparently perfect condition, nearly smooth, and with sundry sulci on the dorsal side of the rostrum which do not appear on the uninjured shell. In this state it has every aspect of a distinct species. The left vulvc has apparently been described by de Gregorio as a distinct species, the sculpture and form being quite different from that of the right valve. This species belongs to a group of closely related forms which appear to be distinct, though the characters might be regarded at first as varietal. They appear in different horizons, and they do not seem to grade into one another, so I have regarded them as species. TRANSACTIONS OF WAGNER 844 TERTIARY FAUNA OF FLORIDA Corbula (Aloidis) fossata AUlrich. Corbula Murchisoni Lea var. fossata Aldr., Journ. Cin. Soc. Nat. Hist., ix., p. 45, pi. 2, fig. 22, 1886. Eocene of Newton and Walitnbbee, Mississippi, and of Mt. Lebanon, Bienville Parish, Louisiana (Vaughan). This form is very abundant in the Wahtubbee Hills and very constant in its characters. It differs from oniscus in having a furrow before the rostral carinn, behind which the concentric ribs are doubled in number and halved in size, while the carina is more prominent than in oniscus, though the general form is the same. Corbula (fossata var. ?) extenuata Dall. PLATE 36, FIGURE 6. Eocene of the Orangeburg District, South Carolina; Burns. This differs from fossata by being less high and more elongated, with two very strong keels on the rostrum, the end of which is emarginate between them ; the anterior keel projects below the ventral margin of the rest of the valve, with an emargination in front of it ; the rostrum is produced, recurved, and sculptured as in fossata ; the beaks are small, pointed, and incurved; the left valve is smooth and very turgid. Lon 8, alt. 6, diam of right valve 3.3 mm. Corbula (Aloidis) perdubia de Gregorio. — Lesueur, Walnut Hills Fossils, pi. v., fig. 16, 1829. Corbula (Neeerd) perdubia Greg., Mon. Claib., p. 233, pi. 36, figs. 31, 32, 1890. Corbula laqucata Conr., Am. Journ. Conch., I, p. 3, 1865 ; Checkl. For. Fos. N. Am., p. 28, 1866. (Name only.) Corbula fifasa Conrad, Am. Joufn. Conch., I, p. 145, 1865 ; not page 137, plate 10, tig. 7. Jacksonian Eocene at Jackson, Red Bluff, and near Enterprise, Missis- sippi ; Natchitoches, Louisiana, and Rust County, Texas ; in the Vicksburgian at Vicksburg, Mississippi. This species has had some vicissitudes. Conrad named it in manuscript laqueata and included the name in his check-lists, but when he wrote a de- scription he headed it " filosa" a name he had used for another species only a few pages earlier in the Journal. Moreover, in the reference to the figure of the original filosa on page 212 he refers not to the original description, but to the second one. The species is notable for the absence of rostral keels, and is usually small, but some of the specimens attain nearly the full size of C. oniscus, I FREE INSTITUTE OF SCIENCE 845 TERTIARY FAUNA OF FLORIDA have not seen it from the Claibornian. Gregorio's specimens were not loeated, but probably are Jacksonian. Corbula (Aloidis) gibbosa Lea. Corbvla gibbosa Lea, Contr. Geol., p. 46, pi. i, fig. 14, 1833. Corbulti (.\'i'n'/'ii) gilibflsa tie dreg'., Mon. Claib., p. 233, pi. 36, figs. 26-30, 1890; Coss- mann, p. 6, 1894. Claibornian Eocene of Claiborne, Alabama, and near Meridian, Mis- sissippi ; at White Bluff and other localities in Arkansas. As shown by Cossmann, this is an excellent species which has frequently been confounded with C. oniscus. Corbula (Aloidis) milium n. s. PLATK 36, FIGURE 19. Chickasawan Eocene, Wood's Bluff horizon at Thomasville, Clarke County, Alabama ; Burns. Shell minute, rounded, inflated, with prominent beaks a little in advance of the middle line of the valves ; right valve larger, sculptured with fine, even, concentric threads separated by narrower interspaces ; there is no radial stria- tion, but near the posterior cardinal margin a well-marked sulcus extends from the beak to the upper posterior margin, the surface above it and next to the cardinal margin turgid ; in front of the strongly prosoccelous beaks the valve is impressed, though without any defined lunule; left valve smaller, less inflated, nearly smooth or with faint incremental lines; a strong radial rib close to the posterior hinge-margin ; interior and internal margins of the valves polished ; a small ridge near the hinge reflects the posterior external sulcus of the right valve; cardinal tooth small, conical, rather prominent, the chondrophore hidden under the cardinal margin ; left valve with the chon- drophore flat, squarish, projecting, and a socket for the point of the right cardinal. Lon. 2.2, alt. 2.3, diam. 1.6 mm. This interesting little species recalls C. laqncata Conrad on a smaller scale and with proportionately finer sculpture. Though so small, there is no reason to doubt that it is an adult form. Corbula (Aloidis) texana Gabb. ( '«>-/n/ln ti-.viitiit Gabb, Journ. Acad. Nat. Sci. Phila., 2d Ser. , iv., p. 387, pi. 67, fig. 54, 1860. Eocene of Lee County, Texas ; Singley in United States National Museum. This appears to be distinct from any of the others, being flatter, less involved, and more distinctly triangular. It is a peculiarly solid shell. TRANSACTIONS OF WAGNER 846 TERTIARY FAUNA OF FLORIDA Corbula (Aloidis) Wailesiana Harris. Corbula I\'iu7,-siiiiiii Harris (MS. in Coll. U. S. Nat. Mus.). Corbitla bicannata Conrad, Proc. Acacl. Nat. Sci. I'hila., vii., p. 258, 1855 ; \Vailes, Rep. Geol. Miss., p. 289, pi. 14, fig. 3, 1854; not of Sby., P. Z. S., 1833, p. 35. Jacksonian Eocene of Jackson, Mississippi ; Drew and Cleveland Counties, Arkansas, and Montgomery, Louisiana. This is a fine species, closely resembling the C. onisats, but separable by minor details. The other species which have been referred to the Eocene are : C. filosa Conrad (Am. Journ. Conch., i., p. 137, pi. 10, fig. 7, not p. 145, 1865), from the Jacksonian of Mississippi ; C. nasiitoides Whitfield (Lam., Raritan Clays, p. 239, pi. 30, figs. 1 8, 19, 1885), from the Eocene marl of New Jersey, which is possibly not a Corbula, and C. pearlensis Meyer (Bull. Ala. Geol. Surv., i., p. 83, pi. 3, figs. 16, i6/>. <://., p. 582, pi. 26, fig. 6. (Left valve.) Ci>r/>if/n ilisfiarilis Dall, Proc. U. S. Nat. Mus., xix., No. mo, pp. 327, 329, 1896. (Not of Orbigny.) Oligocene of Manzanilla and other localities in Trinidad ; Pliocene of Matura, Trinidad, Guppy; and of Port Limon, Costa Rica, Hill. In my review of Mr. Guppy's fossils above cited this form was referred to C. disparilis Orbigny, to which it is nearly related. A more thorough study of a large amount of material of this puzzling group has shown, how- ever, that there are constant, if not very conspicuous, differences between them, and I have, accordingly, restored the form to specific rank. The recent shell is larger, less compact, less regularly sculptured, and decidedly more rostrate. TRANSACTIONS OF WAGNER 850 TERTIARY FAUNA OP FLORIDA Corbula (Aloidis) heterogenea (hippy. PLATE 36, FIGURE 15. Corbttla hftcivgcnca Guppy (MS. in Coll. U. S. Nat. Mus.). Eocene of Vamos-vamos Station on the Panama Canal and at Gatun, Isthmus of Darien ; Oligocene of the Bowden beds, Jamaica, the Chipola River, and the lower bed at Alum Bluff, Chattahoochee River, Florida; Upper Oligocene of Oak Grove, Santa Rosa County, Florida; Miocene of the upper bed at Alum Bluff, and of Magnolia, Duplin County, North Carolina; Plio- cene of Walton County, Florida, and of the marls of the Caloosahatchie and Shell Creek, Florida ; Willcox, Dall, and Burns. This form is very close to C. vie la, but differs from it in having the beaks narrower, less elevated, and less prominent, and the posterior part of the shell more produced. Lon. 9.5, alt. 8, diam. 5 mm. After examining many hundred specimens and finding the above differ- ences constant, I have considered them to be of specific value. In other respects the shells are practically identical. Corbula (Bothrocorbula) viminea Guppy. Corbula viminea Guppy, Quart. Journ. Gcol. Soc. Lond., xxii., p. 293, pi. 18, fig. II, 1866. ? Corbula Bradley! Nelson, Trans. Conn. Acad. Sci., ii., p. 17, 1870. Bothracorbula vitninea Gabb, Proc. Acad. Nat. Sci. Phila. for 1872, p. 274, pi. 10, figs. 3, 3 a ; Geol. St. Domingo, p. 247, 1873. Eocene of Vamos-vamos Station, Panama Canal, Isthmus of Darien ; Oligocene of St. Domingo (Gabb) and Bowden, Jamaica ; Henderson and Guppy. This is a large and solid species in which thejolnular depression is deep and subspherical ; if the other species possessed . tfiis character to an equal degree the group would undoubtedly be of gene^jc value, but, as will be seen, they vary in the amount of depression, so that'll connecting series of species leads to Cttneocorbula without any marked break. For this reason I have not considered the group as possessing generic value. Corbula (Bothrocorbula) synarmostes n. s. PLATE 36, FICURES 12, 13. Oligocene of the Chipola beds, Chipola River, Florida; Dall and Burns. Shell of moderate size, solid, ovate, pointed behind, nearly equilateral; FREE INSTITUTE OF SCIENCE 851 TERTIARY FAUNA OF FLORIDA beaks moderately elevated, small ; anterior end rounded, base prominently arcuate ; posterior end pointed, hardly rostrate, with a single rostral carina, below which the base is slightly emarginate ; sculpture of strong, rounded undulations (about nine in number) not extending behind the carina, separated by about equal interspaces; sculpture feebler on the beaks; rostral area con- centrically striated ; lumilar area slightly impressed but without any cellular excavation ; surface, when perfect, with fine incremental lines and minute, irregularly distributed radial threads; cardinal tooth strong; a small tubercle on the hinge-margin of the left valve behind the chondrophore ; muscular scars deep; pallial line with a small sinus. Lon. 15, alt. 10, diarn. 7.6 mm. This species, though smaller, is externally very like the C. viminea, except that the lunular area is only slightly depressed, so that if attention were not particularly directed to it the depression might pass unnoticed, as it is not definitely limited. Corbula (Bothrocorbula) radiatula n. s. - ]'I.\TK _;6, FII;URKS 1-3. Upper Oligocene of Oak Grove, Santa Rosa County, Florida; Burns. Shell resembling the last species, but smaller, less high in proportion, and longer, with the radiating threads more numerous and constant and the lunular area more deeply impressed, forming an elongated cellule with Sefinite limits. Lon. 13, alt. 8.6, diam. 6.2 mm. Variety tcnclla Dall ; shell quite thin and delicate, the surface closely covered with minute radial threads. This species has the lunular depression intermediate in depth between that of the last species and C. viininca. To complete the account of this group, the following Pliocene species is brought in here, somewhat out of its geological associations: Corbula (Bothrocorbula) Willcoxii n. s. PLATE 36, FIGURK 9. This species has the form of C. viininca, but is materially smaller ; it has a deep hemispherical lunular depression unequally divided between the two valves, much the larger part being excavated from the margin of the left valve; the surface is sculptured like that of C. synarinostcs, the radial threads being rather more numerous and the lunule quite different; in other respects the hinge is similar to that of that species, and the general appearance of the shell, except of the lunule, is much the same. Lon. 16, alt. 10, diam. 8 mm. '9 TRANSACTIONS OF WAGNER 852 TERTIARY FAUNA OF FLORIDA This species is rather common in the Pliocene marls of the Caloosa- hatchie and Shell Creek. Stimpson reports having dredged a living Bothro- corlntla in the deep water of Florida Strait ; he referred it to C. vitninca, but it was probably this species. As the specimens were lost in the Chicago fire, a positive identification must be delayed until the shell can be re-collected. C, contracta Say and C. disparilis Orb. have been mistakenly included among Antillean Oligocene species. Miocene and Pliocene Species. The cooler waters of the Miocene epoch were less favorable to mollusks of this genus than those of the Oligocene, and the species are not so numer- ous. The \varm water of the Pliocene induced some of the subtropical types to return, but the relatively short duration of this epoch may explain why but a few species came in while it lasted. Corbula (Corbula) idonea Conrad. Corbula idonea Conrad, Am. Journ. Sci., xxiii., p. 341, 1833; Fos. Medial Tert., p. 6, pi. 10, fig. 6, 1840. Miocene marl of New Jersey, Whitfield ; Calvert Cliffs, Choptank River, St. Mary's River, Jones's Wharf, and Plum Point, Maryland. This, the finest of our Tertiary Corbulas, belongs to the typical section. Corbula (Aloidis) elevata Conrad. Corbula elevata Conrad, Fos. Medial Tert., p. 7, pi. 4, fig. 3, 1840 ; Whitfield, Miocene N. J., p. 86, pi. 15, figs. 15-19, 1895. Corbula Icvata Meek, Geol. N. J., p. 297, 1863. (Typographical error.) Corbula curta Conrad, Am. Journ. Conch., iii., p. 269, pi. 21, figs. 6-8, 1867. (Decor- ticated shell.) Miocene marl of Shiloh, New Jersey, Burns ; Plum Point, Patuxent River, and other localities in Maryland, Burns and Harris. This is a rather large and tall shell, usually in poor preservation and frequently entirely stripped of its outer coat, as mentioned in connection with C. oniscus. In this latter state it is the curta of Conrad. C. (Aloidis) galvestonensis Harris (Bull. Pal., iii., p. 94, pi. 2, figs. 5, 5 a, 1895), from the Upper Miocene of the Galveston artesian well, between the two thousand four hundred and forty-three and two thousand six hundred and fifty foot levels below the surface, is a small shell, recalling perdiibia Gregorio or laqncata Conrad. FREE INSTITUTE OF SCIENCE 853 TERTIARY FAUNA OF FLORIDA Corbula (Aloidis) caloosae n. s. PLATE 36, FIGURE 16. Pliocene marls of the Caloosahatchie, Shell Creek, and Myakka Rivers, south Florida ; Ball and Willcox. Shell inflated, very inequivalve, nearly inequilateral ; within the right valve a high, prominent, incurved beak ; in the left valve the beak is much lower and less curved ; the general form is ovate, hardly truncate behind, with no differentiated rostrum or rostrum keels ; in some specimens the latter are represented by obsolete rounded ridges which fail towards maturity; sculp- ture of fine incremental lines, and on the right valve strong concentric undula- tions which cover the shell as far back as the margin of the posterior dorsal area, but are not absolutely in harmony with the lines of growth ; the left valve has no undulations, but shows sparse, irregularly distributed radial threads ; cardinal tooth strong, chondrophore in the left valve lamelliform and rather long. Lon. 12.5, alt. right valve 10, left valve 7.5, diam. 6.5 mm. This species is more elongated, less triangular, and less distinctly rostrate than the recent C. (A.} disparilis Orbigny of the Antillean region. In the latter there is a distinct recurvature of the posterior dorsal slope, while in the former there is under the posterior dorsal margin a ledge or ridge against which the edge of the left valve fits, and which is quite absent in the recent shell. Corbula (ILrodona ?~) priscopsis Harris (Bull. Pal., iii., p. 94, pi. 2, figs. 5, 5 a, 1895), from two thousand four hundred and forty-five feet below the surface in the Galveston, Texas, artesian well, belonging to the Upper Miocene, if really an Erodona is the only North American species from any of the marine Tertiary beds of the coastal region. Corbula (Cuneocorbula) insequalis Say. ('i»-hiiln iiiti-(/ini/ii Say, Journ. Acacl. Nat. Sci. Phila., iv., p. 153, pi. 13, fig. 2, 1824; not of Conrad, Med. Tert., p. 6 ; Tuomey and Holmes, Pleioc. Fos. S. Car., p. 76, pi. 20, fig. 12. ('i'1-liitlii cunt-ata Conrad, Fos. Medial Tert., p. 5 (excl. diag.), pi. 3, fig. 2, 1840; Harris, Bull. Pal., v., pp. 329, 346, pi. 13, fig. 2, 1896; not of Say, 1824. (.'nrhitla inaqualis Meek, Checkl. Inv. Fos. N. Am. Miocene, p. 12, 1864. Miocene of Maryland at Calvert Cliffs, Jones's Wharf, Fairhavcn, Plum Point, Greensborough, St. Mary's, the Choptank and Patuxent Rivers; of Vir- ginia, at Suffolk, on the Nansemond and York Rivers; at Magnolia and Wilmington, North Carolina; Turkey Creek, South Carolina; and in the TRANSACTIONS OF WAGNER 854 TERTIARY FAUNA OK FLORIDA upper bed at Alum Bluff, Chattahoochee River, Florida; also in the Pliocene of the Waccamaw River, South Carolina, at Tilly's Lake. In describing this species, by a typographical error it was referred to figure 3, plate 13, which represents C. cuneata. Conrad, with his usual care- lessness, not only did not detect this error, but figured in the Medial Tertiary by the side of a copy of Say's figure of cuneata what seems to be the left view of a specimen of incequalis, and connected them by a dotted line, as if they were the same species. It is only necessary to read the descriptions carefully in connection with a series of the shells to see the blunder. This is the commonest of our Miocene species, identifiable by its short, high form, unequal valves, and coarse, irregular undulations. It is rather variable, and the undulations sometimes become obsolete, leaving only the incremental striae, but the totality of characters will usually leave little dif- ficulty in identifying it. . Corbula (Cuneocorbula) cuneata Say. Corbula cuneata Say, Journ. Acad. Nat. Sci., iv., p. 152, pi. 13, fig. 3, 1824. Corbula ina-quale Conrad, Fos. Med. Tert., p. 6, pi. 3, fig. 3 (left hand one), l84o(diagn. and remarks excluded). Not C. cuneata Tuomey and Holmes, Pleioc. Fos. S. Car., p. 75, pi. 20, fig. 11, 1855; nor of Emmons, Geol. N. Car., p. 290, fig. 2157?, 1858; nor of Hinds, 1844; nor Conrad (Anisothyris), 1870. Miocene of Maryland, on the Choptank River; of Virginia, on the York River; of the Natural Well and Magnolia, Duplin County, North Carolina; of Darlington, South Carolina; Pliocene of the Caloosahatchie River, Florida (rare). In this case, as in the preceding, Conrad, while copying the diagnosis, transposed the figures. Emmons's figure represents a different species, more like C. nasuta Conrad, and the figure of Tuomey and Holmes is probably intended to represent C. contracta. C. cuneata Say has not been found in the recent state, and seems rather rare everywhere. It is at once separable from the varieties of iiuzqnalis by its nearly straight basal margin, its fine, even, concentric sculpture, and its sharp rostral keel. Corbula (Cuneocorbula) subcontracta Whitfield. Corbula subcontracta Whitf., Fos. Mioc. Marls N. J., p. 88, pi. 15, figs. 11-14, '895. Miocene marl of Shiloh, Cumberland County, New Jersey; Burns. This is a small, cuneate species, with coarse, irregular undulations, quite distinct from any of the other Miocene species. FREE INSTITUTE OF SCIENCE 855 TERTIARY FAUNA OF FLORIDA Corbula (Cuneocorbula) Swiftiana C. B. Adams. Adams, Contr. Conch., xii., \i. 236, 1852; Dall, Bull. Mus. Comp. Xool., ix., p. 114, 1881 ; xii., p. 314, pi. 2, figs. 5 a-c, 1886; Bull. U. S. Nat. Mus., No. 37, p. 70, pi. 2, figs. 5 n-i , 1889; Harris, Bull. Pal., iii., p. 94, pi. 2, fig. 6, 1895. Typical form, recent from Cape Hatteras, North Carolina, to Venezuela. Variety nuclcata Dall. Plate 36, figure 17. Miocene of the upper bed at Alum Bluff, Chattahoochec River, Florida; Pliocene of Walton County, Florida, and Mrs. Guion's marl bed, on the Waccamaw River, South Carolina. Variety Harrisii Dall. Upper Miocene of the Galveston artesian well, from a depth of two thousand nine hundred and twenty feet upward. The typical form of this species has rather irregular, sometimes rather coarse, concentric sculpture, fainter near the beaks with faint traces of radi- ating striae. When adult the rostrum, though small and narrow, projects prominently and is squarely truncate ; the basal margin of the right valve is very flexuous. In the variety nuclcata the shell is shorter, more globose ; the concentric sculpture is nearly uniform and equally fine over the whole shell except the extreme point of the beaks ; the rostrum is but little differentiated, short and very obliquely, if at all, truncate. In the variety (?) Harrisii (Harris, op. cit., pi. 2, fig. 6) the shell is stated to be fifteen millimetres long, which is nearly twice the size of the typical Swiftiana, the rostral keel is much straighter, and the border less emarginate below it than in the typical Swiftiana. It should be noted that specimens closely agreeing with the recent shells, and some which resemble the variety nuclcata, were also obtained from the well at various depths. The C. caribiea Orbigny is very close to C. Siviftiana, and is found recent in the Antilles and has been reported by Guppy (1874) from the Pliocene of Trinidad. If the two, on comparison of authentic examples, should prove to be identical, Orbigny's name has seven years' precedence. Corbula (Cuneocorbula) contracta Say. Corbula contracta Say, Journ. Acad. Nat. Sci. Phila., ii., p. 312, 1822 ; Conrad, op. eft., vii., p. 153, 1834; Gould, Inv. Mass., p. 43, fig. 37, 1841; Reeve, Conch. Icon., a, pi. iv., fig. 27, 1844. TRANSACTIONS OF WAGNER 5 TERTIARY FAUNA OF FLORIDA Corbula ffi-ruginosa Greene, Mass. Cat., 1833 ; not of Wood. Azara contracta H. and A. Ads., Gen. Rec. Moll., ii., p. 357, 1856. Corbula cuneata Tuomey and Holmes, Pleioc. Fos. S. Car., p. 75, pi. 20, fig. n, 1855 ; not of Say or Conrad. Corbula contracta Holmes, P.-Pleioc. Fos. S. Car., p. 56, pi. 8, fig. 17, 1858 ; Dall, Bull. U. S. Nat. Mus., No. 37, p. 70, pi. i, fig. 6 a-b, pi. 59, fig. 10, 1889. Pliocene of the Croatan beds, North Carolina, and of the Caloosahatchic marls in south Florida; Pleistocene of Heislerville, New Jersey, and Sim- mons Bluff, South Carolina, and Sankoty Head, Massachusetts. Recent from Cape Cod, Massachusetts, to Jamaica. This species has been reported from the Oligocene of St. Domingo and the Pliocene of Costa Rica by Gabb, but it is probable that some of the allied species were confounded with it. I have seen no specimens from beds older than the Pliocene. Corbula (Cuneocorbula) Barrattiana C. Ii. Adams. Corbula Barrattiana Adams, Contr. Conch., xii., p. 237, 1852 ; Dall, Bull. U. S. Nat. Mus., No. 37, p. 70, pi. 2, fig. 7 a-c, 1889. Pliocene of the Waccamaw beds at Tilly's Lake, South Carolina, and in the marls of the Caloosahatchie and Shell Creek, Florida ; Dall and Willcox. This shell resembles somewhat C. engonata Conrad, but has finer, closer, and more even sculpture, and a strongly marked rostral area, on which, when perfect, fine radial lines can be made out which do not occur on the disk of the shell. Corbula (Cuneocorbula) Dietziana C. B. Adams. Corbula Dietziana Adams, Contr. Conch., xii., p. 235, 1852 ; Dall, Bull. U.S. Nat. Mus., No. 37, p. 70, pi. i, fig. 5 a-b, 1889. Pliocene clays of Port Limon, Costa Rica; Mill. Recent, from Cape Hatteras, North Carolina, to Barbados. This strongly marked species is rare in the fossil state, but not uncommon in the recent fauna. Corbula diegoana Conr. (P. R. R. Rep., v., p. 322, pi. 3, fig. 16, 1855) and Corbula luteola Cpr. (1863) have been reported from the Pleistocene of the Pacific coast; C. carinifera Gabb (Geol. St. Dom., p. 258, 1873) from that of St. Domingo. FREE INSTITUTE OF SCIENCE 857 TERTIARY FAUNA OF FLORIDA FAMILY MYACIDvE. (•etuis MYA (Linnd) Lamarck. < Mya Linne, Syst. Nat., Ed. x., p. 670, 1758. ^ Hiatula (auct.) Schroter, Einl. Conch., ii., p. 599, 1784; Modeer, K. Vetensk. Handl., xiv., pp. 178, 182, 1793. = Mya Lam., Prodr., p. 83, 1799. Type Mya truncata L. Not Mya Modeer, op. fit., 1793, nor Mya Humphrey, Mus. Calonnianum, p. 59, 1797; = Unio Ret/ius, 1788. Mya truncata Linne. Mya truncata L., Syst. Nat., Ed. x., p. 670, 1758 ; Gould, Inv. Mass., p. 42, 1841 ; Jeffreys, Brit. Conch., Hi., p. 66, pi. 3, fig. I, 1865. Mya ova/is (young) and Splu-nia Siuainsoni Turton, 1822. Mya prcfdsa Gould, Proc. Host. Soc. Nat. Hist., iii., p. 215, 1850; Moll. U. S. Expl. Exp., p. 585, fig. 498. Pleistocene of the Arctic and boreal shores of the North Atlantic and Bering Seas; at Portland, Maine; in the Leda clays of the St. Lawrence River, at Quebec, Montreal, and Beauport; Polaris Bay, Greenland; Bessels; and south to Massachusetts, and in Alaska to the Sitkan region. Mya arenaria Linne. Mya arenaria L., Syst. Nat., Ed. x., p. 670, 1758 ; Gould, Inv. Mass., p. 40, 1841 ; Verrill, Inv. An. Vineyard Sound, p. 672, 1873 ; Dall, Bull. U. S. Nat. Mus., No. 37, p. 70, pi. 49, fig. 9 ; pi. 55, fig. 2 ; pi. 69, fig. 2, 1889. .]/)'<' incrci-iiaria Say, Journ. Acad. Nat. Sci. Phila., ii., p. 313, 1822. Mya ai:nla Say, <>/>. fit., p. 313, 1822. Mya alba Agassi/:, Mem. Soc. Sci. Nat. Neuchatel, ii., p. I, pi. I, fig. 2-8, 1839. Mya ][t-mt>liiltii Ncwcomb, Proc. Gala. Acad. Nat. Sci., v., p. 415, 1874. Mya corftiili-nta Conrad, Fos. Medial Tert., p. 68, pi. 39, fig. i, 1845. Miocene of York River and Petersburg, Virginia, Burns ; of Gay Head, Massachusetts, Dall ; Pleistocene of the Atlantic coast from Labrador to South Carolina ; recent from Nova Scotia southward to North Carolina. Introduced with seed oysters on the Pacific coast, and erroneously attributed to Porto Rico (Agassiz). This well-known and widely distributed species was not originally a native of the Pacific coast, where it was represented by a form which may be called Mya intcrnifilia, which is intermediate in character between M. arenaria and M. truncata, strongly recalling the glacial M. nddevallcnsis of Sweden. This shell grows to a very large size on the Alaskan Peninsula and is very puzzling. TRANSACTIONS OF WAGNER 858 TERTIARY FAUNA OF FLORIDA Carpenter referred it to M. irtincata as a variety, and Grewingk figures an unusually pointed specimen as M. arenaria. It occurs recent and in the Miocene of Unga Island, Alaska, and also in the Alaskan Pleistocene. Since M. arenaria was accidentally introduced into Californian waters it has spread remarkably and is reported to have reached the coast of Oregon. Mya producta Conrad. Mya producta Conr., Fos. Medial Tert., p. i, pi. i, fig. i, 1838; Proc. Acad. Nat. Sci. Phila. for 1862, p. 572, 1863. Mya prcelong a Conr., Bull. Nat. Inst., ii., p. 185, 1842 ; name only. Miocene of Yorktown, York River, Virginia, Wagner ; Patuxent River, St. Mary's County, Maryland, Conrad and Burns. This is a very distinct species, and seems to be very restricted in its dis- tribution. Mya montereyana and subsinuata Conrad, from the Miocene of Monterey, California, are poorly described, badly figured, and have not since been identi- fied (cf. Pac. R. R. Reps., vi., p. 70, pi. 2, figs. 4, 5, 1857). Mya crassa Grewingk (Verh. Rus. Min. Ges. fur 1848-9, p. 355, pi. 5, fig. i a-d, 1850), from the Miocene of Alaska, appears from the figures to be distinct from M. intermedia. Mya bilirata Gabb, from the Miocene of California, is said to be a Sphenia. Mya abrupla Conrad (1849, not 1856) is a Panopca from the Miocene of Astoria, Oregon. Mya reflexa H. C. Lea, from the Miocene of Petersburg, Virginia, is a doubtful species, the description and figure being insufficient to determine its generic place. (See Trans. Am. Phil. Soc., ix., p. 236, pi. 34, fig. 10, 1845.) Mya simplex Holmes, from the Pleistocene of South Carolina, is a synonyme of Fulcrella simplex. Genus PLATYODON Conrad. Platyodon Conrad, Journ. Acad. Nat. Sci. Phila., vii., p. 235, 1837 ; Carpenter, Suppl. Rep. Brit. As., p. 637, 1863. Differs from Mya by its sculpture, irregular pallial line, and the presence on the distal end of the siphons of valvular horny appendages which some- times are more or less testaceous. These appendages are analogous to those of Tresns and some Plioladacea, and are doubtless due in all cases to the same dynamic and selective influences. There is but one species known, P. cancel- latus Conrad (pp. at., p. 236, pi.- 18, fig. 2), which is found recent and in the Californian Pleistocene. FREE INSTITUTE OF SCIENCE 8^9 TERTIARY FAUNA OF FLORIDA Ocnns CRYPTOMYA Conrad. Sphcfnia Conrad, Journ. Acad. Nat. Sci. Phila., vii., p. 234, 1837. Cryptomya Conrad, 1'roc. Acad. Nat. Sci. Phila., iv., p. 121, 1848. Shell like a small Mya, but the pallial sinus absent or obsolete. Type: v Cryptomya californica Conrad. Sfilurnia califoriiicti Conrad, Jonrn. Acad. Nat. Sci. Phila. , vii., p. 234, pi. 17, fig. 11, 1837- C>yplt»uy,i calif untif a Conrad, Proc. Acad. Nat. Sci. Phila., iv., p. 121, 1848; viii., p. 3H, i»57- Cryptomya ovalis Conrad, Pac. R. R. Reps., vi., p. 69, pi. 2, fig. 2, 1856. Miocene of California in many localities, also Pliocene and Pleistocene, and recent from British Columbia to Lower California. Genus SPHENIA Tnrton. Sp!i,-nia Tiirton, Dithyr. Brit., p. 37, 1822. Type S. Binghami Turton. S/>liii'iiiti Conrad, 1837; Sphccna Defrance, Tabl., p. 105, 1824; Spliena Deshayes, Enc. Moth., iii., p. 965, 1832 ; and Spha-nia Gabb, Pal. Cal., ii., p. 90, 1869. Shell small, irregular, nestling, with an irregular pallial line and deep sinus, short siphons, and the chondrophore narrow and very oblique. Most of the diagnoses of Sphenia are faulty ; there are no teeth, the chondrophore is very narrow and oblique, borne by the smaller left valve as in Mya, from which the genus is barely separate. The only species recorded in our Tertiary are Sphenia californica Conrad, which is the type of Cryptomya, and S. bilirata Gabb (Proc. Acad. Nat. Sci. Phila., xiii., p. 369, 1862), from the Tertiary of Santa Barbara, California, which seems to have been omitted from Gabb's Paleontology of California. S. ornatissima and alternate Orb., reported by Gabb from the Tertiary of St. Domingo, are species of Cuspid aria. Sphenia dubia H. C. Lea. I'anopca ii tibia H. C. Lea, Trans. Am. Phil. Soc., ix., p. 236, pi. 34, fig. 9, 1845 (extra copies p. 10). Miocene of Petersburg, Virginia, Lea ; of York River, Virginia, Harris ; of North Carolina, at Magnolia and the Natural Well, Duplin County, Burns. This is a small, irregular little shell which is found sparsely at the locali- ties indicated. TRANSACTIONS OF WAGNER 860 TERTIARY FAUNA OF FLORIDA Sphenia attenuata n. s. PLATE 35, FIGURE 9. Pliocene marl of the Caloosahatchie River, Florida ; Ball. Shell small, irregular, solid, wider, and rounded in front, attenuated be- hind ; nearly equilateral, moderately inflated ; exterior with small, irregular, concentric ridges and radial wrinkles due to irregularities of situs ; adductor impressions large, especially the posterior ones; pallial sinus moderately deep. Lon. 9.5, alt. 6, diam. about 4 mm. The most conspicuous feature of this irregular little shell is the attenua- tion of the rather pointed posterior end. It is a decidedly heavier and larger shell than 5. dubia. Genus TUGONIA Gray. Tugonia Gray, Synops. Brit. Mus., p. 91, 1842 ; name only. Type Pliolas tugon Adan- son, = Mya anatina Ch. Tugonia Recluz, Revue zoologique, p. 168, 1846. Type Mya anatina (Chemnitz) Gmelin. This genus has a reticulated sculpture and a globose shell, short behind, with a posterior truncation forming a somewhat contracted hiatus, the beaks quite posterior and the chondrophores subequal in the two valves ; pallial sinus shallow ; shell of moderate size. (PSubgenus) TUGONIOPSIS Dall. Shell minute, externally with concentric sculpture or none, plump, irregular, when normal very inequilateral ; beaks very posterior ; valves trun- cate behind and gaping ; chondrophore of the left valve as in Mya, in the right valve subumbonal, but becoming more prominent with age, as if seated on a shelly callus; the hinge-margin grooved on each side of the beak, in the right valve in the adult, with a dentiform projection behind the chondrophore and unconnected with it, seated on the cardinal margin and recalling the tooth in Corbula, but less prominent, and in the young hardly developed ; pos- terior adductor scar very conspicuous and deeply impressed ; pallial sinus moderate. Type : Tugoniopsis compacta n. s. PLATE 35, FIGURE 10. Miocerte of Magnolia, Duplin County, North Carolina ; Burns. Shell small, plump, usually more or less irregular, and evidently a nest- ler; surface finely concentrically wrinkled; beaks nearer the posterior end, FREE INSTITUTE OF SCIENCE 86 1 TERTIARY FAUNA OF FLORIDA small and pointed; general form rounded ovoid; other characters as in the. subgeneric diagnosis. Lon. 6, alt. 5, diam. about 4 mm. This is an interesting little shell, intermediate between Tugonia proper, Sphcnia, and Mya. Genus PARAMYA Conrad. J'tiniinvii Conrad, Prbc. Acad. Nat. Sci. Phila. for 1860, p. 232 ; for 1862, p. 572, 1863 ; Meek, Checkl. Inv. Fos. N. Am., Miocene, p. 12, 1864; Dall, Bull. U. S. Nat. Mus., No. 37, p. 70, 1889. ^Tyalina Conrad, Fos. Medial Tert., p. 65, pi. 36, fig 4, 1845 ; not of De Koninck, 1842. Shell subquadrate, small, concentrically striated (equivalve ?), inequi- lateral, with beaks anterior to the middle line; hinge with a triangular verti- cally directed pit for the resilium, the lateral borders of the pit sometimes carinated, the basal margin depressed ; no hinge-teeth or external ligament ; the pallial line more or less broken up, as in Saxicava, a feature more promi- nent in the young; pallial sinus none in a strict sense, the pallial line slopes forward from the posterior adductor scar in a right line, joining the basal portion at an obtuse angle without any curve or insinuation ; this part of the pallial line is notably distant from the posterior end of the shell. Type P. subovata Conrad. This curious little shell was referred to the Saxicavidce by Conrad, Meek, and Tryon, and to the Corbulidce by the present writer, but its true place seems still uncertain and is likely to remain so until the anatomy is made known. In quite young shells the pallial line is distinctly broken up, in old specimens the original patches have become confluent. If the chondrophore of Mya was turned down into the vertical plane of the valves and the surface of attachment in the opposite valve elevated into the same plane, the result would be analogous to the hinge of l\iramya. There are analogies to be traced in Kastcrotia and Fabagclla. On the whole, I am disposed to think that Paramya should be referred to the Myacida, subject to future correction. I have never seen an indubitable pair of valves, and it is uncertain whether the valves are equal or not, but I am inclined to suspect that they are somewhat unequal. Paramya subovata Conrad. Myalina subovata Conrad, Fos. Medial Tert., p. 65, pi. 36, fig. 4, 1845. Paramva subovala Conrad, Proc. Acad. Nat. Sci. Phila. for 1860, p. 232 ; for 1862, p. 572, 1863; Meek, Checkl. Inv. F63. N. Am., Miocene, p. 12, 1864; Dall, Bull. U. S. Nat. Mus., No. 37, p. 70, 1889. TRANSACTIONS OF WAGNER 862 TERTIARY FAUNA OF FLORIDA Miocene of the York River, Virginia, Harris ; and of the Natural Well, Duplin County, North Carolina ; Pliocene of South Carolina, on the Wacca- maw River; Pleistocene of South Carolina, and living, in from twelve to thirty fathoms, from the vicinity of Beaufort, North Carolina (Stimpson), southward to Florida ; Uall and Rush. The recent shell does not appear to differ in any respect from the Miocene fossil. Stimpson was of the opinion that Mya simplex Holmes (P. -PI. Fos. S. Car., p. 55, pi. 8, fig. 16, 1858), from the Pleistocene of Simmons Bluff, South Carolina, is identical with Parainya, but Holmes's species has a narrow chon- drophore, much as in Splicnia, but smaller, with a prominent tooth in front of it, and, as far as one can judge from the shell alone, belongs in the vicinity of Basterotia, probably in the subgenus Fiilcrella. Superfamily MACTRACEA. With the exception of Neumayr's and Bittncr's investigations, the Mac- troid hinge appears to have been studied without reference to large series of specimens of a single species, and with little consideration of evolutionary progress or dynamic modification.* In order to discuss it properly it is necessary to pay much more minute attention to its details and the relations of its parts than has hitherto been thought required. To make these details clear and avoid excessive verbiage, it becomes necessary to name the parts of the hinge, and for clearness I prefer to use, for the most part, plain English terms, applied for the occasion in a particular and exclusive sense. The memory is thus not burdened with the task of learning a wholjy new vocabulary, and can devote its energy solely to following the description. The essential parts of a true Mactroid hinge are as follows : In the left valve, an anterior and posterior lateral lamina, and a bifid or A-shaped car- dinal tooth in front of a pit for the resilium ; above the latter a scar or surface of insertion for the ligament. In the right valve, two anterior and two pos- terior laminae, between which the laterals of the opposite valve are received ; two lamellar cardinal teeth, inclined to each other at an angle above and usually more or less solidly united at this line of junction, below which the cardinal of the opposite valve fits ; behind them the chondrophore, and above *The excellent studies of Bernard, Bull. Soc. Geol. de France, 3me Ser., t. xxiii., pp. 141-144, 1895, appeared after the preparation of this part of my manuscript. — W. II. U. FREE INSTITUTE OF SCIENCE 863 TERTIARY FAUNA OF FLORIDA it the scar of the ligament. The ligament and cartilage start in the youngest stage 'of the shell from a point immediately under the beaks. Once started, each remains continuous between the two valves of the shell and persistent, so that as they lengthen with growth the portion below each umbo remains intact. According to the amount of expansion of the shell margin between the beaks and the direction of growth of the valves, the form of the adult cartilage and ligament may be crescent-shaped, with a posterior convexity ; sagittate, like a barbed arrowhead ; or lanceolate, like a leaf-shaped spearhead. The distance between the points of the barbs is determined dynamically by the distance between the umboncs of the valves : when they are widely separated, as in Mactra Spenglcri, we have the most extreme crescent shape ; when they are but slightly separated, the sagittate form ensues ; when the um- bones are close together, the species must have a lanceolate ligament. A steep slope of the dorsal shell margin backward from the umbonal region necessitates a short ligament, while a nearly hori/.ontal long posterior cardinal margin promotes a long and narrow ligamentary connection. The correla- tions are purely dynamic. There is little doubt that the existence of a separate resilium and ligament is due to mechanical forces acting on a thick ligament, as I have elsewhere shown.* Why the ligament should become embedded in the cardinal border so as to become subject to these forces is not so clear, but is probably accounted for in part by the fact that the hinge-line is rigid in proportion to its length, and, in general, if high up in the dorsal arch it must be short, and can gain length only by descending. Whatever the reason may be, it is doubtless analogous to that which would account, in a species where ligament and resilium have become fully differentiated, for the further subsidence of the ligament until it, in its turn, may be wholly sub- merged below the cardinal margin, so that the latter closes over it, leaving no ligamentary substance whatever external to the shell. In the Mactridte every stage of this process may be observed, from the condition where we have a marginal external ligament, walled off by a lamina of shell from the resiliary pit, to one where ligament and resilium occupy different portions of a single cavity, wholly invisible from the exterior when the valves are closed. The shelly portions of the hinge arise from a shelly basis stretched antero-posteriorly between the limbs of the arch forming the cardinal margin. This basis is called the hingc-plnlc, and it may have its surface "flat," Am. Joiirn. Sci. and Arts, vol. xxxviii., Art. 55, L»cc., 1889. TRANSACTIONS OF WAGNER 864 TERTIARY FAUNA OF FLORIDA i.e., nearly parallel to a vertical plane between the closed valve-margins, or " oblique," that is, inclined at an angle so that its dorsal edge starts from the valve within the dorsal margin of the latter. When the hinge-plate forms a marked angle with the valve, the space between the ventral edge of the plate and the dorsal margin of the valve is said to be " excavated," forming a V-shaped valley on each side of the chondrophore, a state of things which some of the older writers tried to indicate by the objectionable expression that the hinge was " double-edged." In Mactra the hinge-plate is never perfectly flat (such as we find, for instance, in Astarte), and in some of the thin-shelled forms, like Pteropsis or Labiosa, the excavation is deep and sharp, and is in- dicated on internal casts of the fossils by two areas set off from the general mass by deeply incised lines parallel with the dorsal margin. A hinge-plate is always present, however, and we never find a Mactroid hinge set directly upon the cardinal margin, as in Area. As the shelly projections usually called lateral teeth are very variable and often ill-defined compared with the cardinal teeth, I have found it con- ducive to clearness to term them " laminae" rather than " teeth." The cardinal teeth are essentially in origin like the teeth of Cyi'cna, but in the process of evolution the two outside teeth have gained strength by retaining a union at the angle where they join, and the inner bifid tooth (that of the left valve) has become more triangular, in harmony with the bearing surfaces of its neigh- bors. That this is not merely a speculation may be seen by comparing a regular Mactra with Rangia or some of the Mulinias which do not continue to unite the outside cardinals, and it will be seen that the form of the inner cardinal is much more triangular and constant in its shape in the first men- tioned. The study of very young shells has shown in every case that the arms of the cardinal tooth of the right valve in Mactra, after separating from the inner ends of the laminae, are distinct teeth, and in Mnlinia and some species of Mactra, as well as Rangia, they remain separated, more or less completely, even in the adult. The diverging branches of this compound tooth I call its anterior and posterior " arms." The single tooth in the oppo- site valve is sometimes excavated in the middle line and curved upward like the petal of a lily; such teeth I name " petaloid." The angular space between the anterior arm of the cardinal tooth and the dorsal margin of the valve I call the "anterior sinus" of the hinge; the other one, behind the cartilage- pit, the " posterior sinus." The space between the arms of the cardinal tooth is the "ventral sinus." There are some parts of the nepionic lamina: which FREE INSTITUTE OF SCIENCE 865 TERTIARY FAUNA OF FLORIDA become obsolete in the adult, or are represented only by frail remnants. One such is between the side of the cardinal tooth and the surface of the resilium in the left valve (4$ of Bernard's notation); others are parallel to the arms of the cardinal teeth in the right valve. These thin sheets of shelly matter in the adult I call " accessory lamellae." As might be expected, they are very inconstant and excessively fragile if well developed ; usually, whether by breakage or otherwise, they appear merely as low ridges parallel to the normal teeth and laminae. These lamellae are often referred to as " teeth" in descrip- tions of species, and, to the rather frequent presence of the accessory lamella (4 b) of the posterior arm of the left cardinal tooth is probably due the ascrip- tion by the older authors of three cardinal teeth to the valve in the genus Mactra. When the hinge-plate is excessively oblique, as in Mactra alata Spengler, the thin and slender teeth are sometimes reinforced by horizontal or vertical buttresses, which extend from the teeth to the hinge-margin. In using ad- jectives denoting the direction of plane surfaces in this paper the shell is con- ceived of as suspended by the umbones with its longest antero-posterior line in a horizontal plane. When, therefore, a buttress extends in a plane sub- stantially parallel with the plane including the margin of the valve, it may cover part of the sinus so that the portion covered is either wholly filled with shelly matter or is merely roofed over by a shelly plate. The former condition is more common. In other cases the buttresses may extend in a plane at right angles to the plane of the valves and inclined at any angle to the plane of their transverse diameter which will give the greatest strength with the least expenditure of material. Such buttresses cut the sinus into two or more cavities, those nearer the beaks being cellular. This variety of buttress I call a "septum." (See pi. 27, fig. 14^.) It is somewhat rare, and when present curiously complicates the hinge. The initiation of hinge-teeth is illustrated in a curious way in Schi.witcsina Speiigleri, where the ridge sup- porting the ligament is produced at the margin of the valve into an obscure prominence, which is partly received by a slight depression in the opposite valve. This requires very little encouragement to develop into an entirely new type of tooth, at least compared with the primitive teeth of the hinge of Mactra. In the situation and form of the different teeth upon the hinge-plate the influence of the different strains and stresses involved in the mechanical action of the hinge are clearly discernible if intelligently looked for. A study of TRANSACTIONS OF WAGNER 866 TERTIARY FAUNA OF FLORIDA the hinge taken in connection with its secreting surfaces shows that the different shelly parts of the two valves which combine to form the hinge rarely touch each other. No matter how close the hinge may fit, there is an intervening space between the most approximated surfaces, into which a delicate secretive film, a portion of the dorsal mantle margin, extends, and probably, during life, permanently remains. It is true that this membrane may contract more or less at times, leaving the space between two surfaces unoccupied, but an examination of many specimens, which have been put into alcohol while still alive, leads me to conclude that normally the whole hinge-surface is in contact with the secretive film. It is known to all close students of the mollusks that the mantle possesses the faculty of absorbing shell-substance inconvenient to the animal, as well as of secreting that which is needed. The method of operation is still not understood, but the process is perhaps connected with ciliary action. At all events, the operation takes place ; consequently the stresses upon the parts of the hinge act first by being communicated to the soft tissues between them and not necessarily by direct friction or pressure. Intermittent pressure appears to produce increased se- cretion, and thus thickening of the shelly surfaces concerned; continuous pressure leads to absorption by the: tissues in self defence; the marks of it are often clearly visible in old shells on the posterior face of the anterior arm of the left cardinal tooth, where the most continuous and direct pressure felt by any part of the hinge is most constantly applied. (See pi. 27, fig. 1 6 s.) It is to be noted that the growth of the hinge does not always march uniformly with the growth of the valves, though discrepancies here are much less marked than in the structures of Gastropods, which are superimposed upon the oral surface of their shells. With the separation of the ligament and resilium a space more or less marked intervened between their adjacent parallel sides. In one group, the typical Madras, this space has become more or less occupied by a shelly ridge, which, when the valves arc closed, more or less completely cuts off the ligament from the resilium, partition-wise. This ridge or shelly wall naturally belongs to the posterior slope of the shell, and may become coalesccnt, over the apex of the resiliary pit, with the spur. In a small antipodean group of species the partition is accomplished in another way, — the spur projects and is continued in a more or less irregular shelly rod, which is laid close to the ventral border of the ligament, and is attached to the shell, though not heartily coalcscent. Alaclra ovata Gray offers a good example of this forma- FREE INSTITUTE OF SCIENCE 867 TKKTIAKY FAUNA OF FLORIDA ' tion. Ill a single species the ligament, while quite separate from the pit, has itself sunken below the dorsal shell margin, only its most anterior point re- maining at the surface. (J/. trisfis Reeve, Conch. Icon.) Having indicated and named the characteristic portions of the hinge- armature, it remains to say a few words as to the relative attitude of the different parts. It must be borne in mind that the proliferations of the mantle, which supply the exudations from which the shell substance is crys- tallized out, arc delicate and filmy, unable to "stand alone." If, by some accident, the beginning of the hinge or any part of it is abnormally shaped, subsequent depositions must be laid clown upon the abnormal basis and correspondingly modified. In short, as soon as the shelly valves are formed the}- represent, in relation to the soft parts they enclose, an extraneous rigid mold or body composed of two parts which react dynamically upon each other through the intermediation of the soft parts contained between them. The initiatory form of the shell is as purely genetic as any portion of the animal can be ; the subsequent development must be largely guided by it. Mutations foreign to this plan can only be brought about by environmental forces still more energetic. The distribution of the parts of the hinge in single species is remarkably uniform, but if groups of species are considered, the types are seen to gradu- ally approach and almost merge, one in another. Sharp generic distinctions can seldom be drawn, and there are many groups named, sectionally or even generically, which owe their verbal distinctness to wilful or unconscious ignoring of the details of structure in other parts of the family. The lateral lamina: were originally determined from the umbones as a focus, but this was an ancient event and, for practical purposes, is much obscured in the existing conditions of the hinge. The distance to which they extend on either side of the beaks, and their greater or less continuity between the beaks and the distal portions of the teeth, are variable dynamic functions depending upon the form of the dorsal arch of the valves and the strains to which the valves arc subjected in the station preferred by each particular species. In general, the geologically more ancient forms have the lateral lamina; more adjacent than in their modern descendants, other things being equal, which is what might be expected theoretically. Taking the different species in one contemporaneous group, much variation may be found in the distance of the laterals from the beak, as well as in their form, but these features do not seem to possess any very great systematic importance. 20 TRANSACTIONS OF WAGNER 868 TERTIARY FAUNA OF FLORIDA The lateral laminae may be set frankly on the hinge-plate, or more or less confluent with its ventral margin ; usually long, slender, and simple, they are sometimes fluted longitudinally with the distal angle recurred. The pafred laminae are more variable than the single ones. The former vary from little elevated ridges on either side of an indentation in the substance of the hinge- plate, to thin, sharply defined lamelke ; the dorsal one of the pair may be nearly confluent with the dorsal margin of the valve, or it may be a clean-cut, independent lamina rising sharply from the hinge-plate. In the more trian- gular species the laterals are shorter and closer to the beaks, and in some of the very thin-shelled forms (such as Pleropsis or Labiosd), where no great strain is ever brought upon them, they are always imperfectly developed. In Harvella, however, we find them clearly defined, notwithstanding the thinness of the shell. In some groups (such as that typified by Spisula solidissiiiur) the tendency of the valves to rotation on the resilium as an axis is opposed by the development of transverse grooves on the opposed surfaces of the laterals, and in a few species this grooving has become so pronounced that the valves can hardly be separated without the use of force sufficient to fracture the laterals. It is an illustration of the same principle which de- veloped the hinge of Area, but applied secondarily upon a type of hinge which, when adult, is the exact antithesis to that of the Prionodont. In studying the development and mutations of the cardinal teeth, besides the changes which result from the dorsal coalescence of previously distinct parts, another set of variations present themselves which a complete series of the stages of growth in any single type would doubtless show to be dyna- mic. It is obvious, in species with sagittate ligaments, that the sinus between the barbs of the ligament is filled by a pointed process of each valve, forming part of the dorsal margin, which extends backward, and in a single valve is seen to be situated over the resiliary pit, or partially so. This may be called the cardinal spur. Its tip is sometimes slightly recurved or callous. The cardinal teeth are situated under the anterior part of the spur, and in mature specimens the posterior arm of the cardinal tooth in the right valve is often coalescent with the spur. In that group which has the ligament partly or wholly walled off from the cartilage-pit by a shelly ridge, this ridge unites the spur with the dorsal shell margin, between the scar of the ligament and the pit, or chondrophore, properly so called. Now the dynamical feature to which I would direct attention in con- nection with the cardinal teeth, especially in the right valve, is that the two FREE INSTITUTE OF SCIENCE 860 TERTIARY FAUNA OF FLORIDA arms of the cardinal seem (when different sections of the genus are compared) to rotate, as it were, on an imaginary axis nearly coincident with the angle at which the two teeth are soldered together. From this it results that the anterior arm of the consolidated cardinal may be coalescent with the dorsal shell margin (in which case the anterior lamina: will radiate from the ventral sinus), or may be superimposed exactly upon one of the -lamina; (usually the ventral one, when the hinge appears to have lost one of its anterior laminae), or may rise from the hinge-plate on a radial line behind that of the ventral anterior lamina. Concurrently the posterior arm of the tooth may be directed vertically downward with an empty triangular space between it and the ante- rior verge of the pit (in which case there is often an accessory lamella at the verge), or it may rise directly from the verge like a wall, or it may project out over the pit supported only by its attachment to the cardinal spur. The angle at which the two arms of the cardinal tooth unite is usually quite con- stant in the same species, and the triangle or ventral sinus enclosed between them is therefore quite uniform in shape. By following this rather long but necessary dissertation upon the ex- amples of the hinge, which have been figured and lettered for the pur- pose, it will be found comparatively easy to apply the terms used to the description of particular hinges and to comprehend the relations of the several parts. The earliest Mactrida yet recognized are Mesozoic. In the Chico beds of California, now thought to represent the lower part of the Upper Creta- ceous, are several genuine Mactras, described by Gabb under the name of Cymbophora. In the early Eocene Ptcropsis Conrad hardly differs from Raeta. In the Middle Tertiary a very large number .of species are said to occur, ex- ceeding the recent forms in abundance; many of these, however, are probably synonymes and should not be counted. The group is an essentially modern one, and is probably represented to-day by as many living species as were present in any antecedent fauna. A number of groups which should properly belong to the family have been scattered in different families, or even orders, by systematists devoted to single characters or morphologists having little acquaintance with the details of character. A number of groups which have closely related shells present marked differences of superficial anatomy, as, for instance, the Mesodcsinat'nln-, which have Mactroid shells and Tellinoid free siphons; others defy final classification, owing to our ignorance of their anatomy. The place of various TRANSACTIONS OF WAGNER 870 TERTIARY FAUNA OF FLORIDA fossils, such as Mactropsis Conrad, must be governed by the general habit of the shell, since no other means is left us to decide by. Mactra is, on the whole, a somewhat active animal, and seems to prefer clean sand, through which it ploughs at times with its strong Cardium-\\\iQ foot, leaving long furrows behind it. Certain forms seem to favor a sedentary life, many of the Mulinias and Rcingia, and in these the foot has become smaller, ' and the hinge more amorphous in appearance. In a still more modified division, which has, to all intents and purposes, become absolutely sedentary, and which inhabits deeper water than the above-mentioned Mulinias, the dynamic modifications characteristic of this class of vertical borers have been more or less fully adopted. The body has become elongated, the siphons • lengthened, the epidermal sheath necessary for protection to the permanently extruded siphons is continued to their ends, the mantle has become soldered ventrally as closely as the use of the foot for boring will permit, the shell has become more asymmetrical relative to the hinge. The mollusk, which has really made of its permanent tunnel an artificial shell, does not materially suffer by the exposure within that tunnel of a greater proportion of shell-less surface, and from the gradual degradation of a hinge which has become no longer <>f vital importance. All these modifications are of the kind I class as " dy- namical," and though, by heredity, they may eventually be permanently im- pressed on the organism, yet it will hardly be claimed that they have as great a value for the higher systematic divisions as those characters which, derived from unknown antiquity, we are able to recognize as genetic. Yet it is found in one of the latest morphological essays at a systematic arrangement of the Pelecypods that Lutraria is put in a different Order from Mactra because of the closure of the ventral opening of the mantle in part of the species ! Such characters are common to forms as fundamentally divergent as Solemya, Solc/i, Glycimeris, Tagcli/s, Mya, and Cyrtoilaria, and indicate nothing more than a common (and inevitable) response to common dynamic conditions of life. Such conditions have existed, it is true, from the beginning, and Solcinya is witness to a very ancient response ; nevertheless, there is nothing in any of the mutations which is indicated as a permanent necessary part of the or- ganism, or which might not pass away with ease under a prolonged change of conditions. Before proceeding to discuss the various groups of Mactracca, it is de- sirable to refer more particularly to the views of the late Professor Neumayr, to whom we owe such a stimulating and important discussion of the morph- FREE INSTITUTE OF SCIENCE 871 TERTIARY FAUNA OF FLORIDA ology of the hinge of bivalves.* Having independently arrived at conclu- sions in regard to many points in this connection agreeing with those deduced by Professor Neumayr, it will not be due to any want of appreciation of his talents that I find myself in some particulars unable to follow him as regards details. In accepting most of his views in regard to the initiation of the various types of dental armature, — and, among others, that which derives some part of his so-called Desmodont type of tooth from plications correlated with the submergence of the protoligam^nt, a view independently proposed by me in 1889, — I cannot accept his homologies of the parts of the Mactroid hinge considered in detail, nor do I believe that his Dcsmodonta form a valid group. In fact, a fuller consideration of the types of hinge displayed by recent Pclecypods has shown the distinguished and lamented Austrian the fallacy of this earlier conclusion. f The secondary submergence of the liga- ment is a dynamic process which might be looked for and does occur in all the groups of bivalves to which I have attached an ordinal significance, in- cluding the Neumayrian Dcsmodonta, Taxodontii, Heterodtatta,vnA Dysodonta; and the association with this submergence of plications which give rise to teeth is a dynamic result which depends solely upon the efficiency of the hinge through which the submergence takes place. \ When, as in the case of the Pritniodonta ( Taxodontd), the rigidity of the valves is sufficiently provided for by a long series of interlocking processes, there, is no demand for the development of additional guards to the desired stability of motion in a trans- verse vertical plane, and hence their development in such forms as the taxo- donts is not to be expected. But where the hinge is imperfectly provided with dental leaders, and their place is not supplied by the presence of an * Silzb. K;iis. A cad. Wiss. \Vien., Ixxxviii., p. 385, 1883. f Cf. Morph. tier Hiv. Schal. J Bernard has shown, in his interesting and important studies of the development of the hinge of bivalves, that the nepionic ligament lies between the thin edges of the valves and more or less obliquely across them, so that it is both internal and pnrtly external. The changes by which the ligament and resilium become wholly external in many bivalves must involve an elevation of the organs mentioned. The paleontological history of such forms as Crassalellites shows that their pre- cursors had an external, or nearly external, ligament; and, as we follow the members of the group in time, the ligament and resilium become larger and more internal in the successive species, until the modern type is reached. Therefore the internal position in such cases is properly referred to as the result of submergence, notwithstanding the fact that it is partly a return to a state originally normal and universal. Crassatellites, Mactra, etc., are not forms in which the originally sunken ligament has specially developed in place, but in which it has risen to the exterior and been again submerged. TRANSACTIONS OF WAGNER 872 TERTIARY FAUNA OF FLORIDA exceptional adductor muscle sufficient for the purpose, then, in time, other teeth will appear and contribute their quota to the dental armature. Specifically, in the case of Mactra, Neumayr (pp. cit., If 4) homologizes, first, the nymphre of Glycimcris (Aldrovandi) and Mya tnrncata, showing their intimate relationship. He does not mention the fact that the ligament in both these forms is composed of an outer, posterior, slightly greenish, ligamentary portion, and an inner, more ferruginous part, set off by a calcareous uncon- solidated layer from the former. Tlfe latter is really an internal "cartilage" or resilium, and ,the scars of insertion of the two parts are readily distinguished on careful examination. In the fresh or alcoholic specimen the distinction of color enables one to recognize the parts at a glance. He proceeds to com- pare Mya with Thracia (phaseolina), and here again the homology is readily recognized. But when he continues by homologizing the cardinal teeth of Eastonia (rugosa) with the marginal ridges of the resiliary pit, and these with the stout rib below the ligamentary groove of Panopea or T/iracia, a halt must be called at once. They are in no respect homologous. The ridge in Panopea is- homologous with the /// of Mactra. In the former it is convex, in the latter concave; in both it is the seat and fulcrum of the resilium, whose very existen.ce has not been recognized because it is, so to speak, wrapped in the ligament in Panopea. It is probable that Neumayr's observations on Mactra were based on fossil specimens, or recent ones which had lost their ligament and resilium in drying. Otherwise some of his remarks would be incomprehensible. The error into which he has been led is still more obvious in the contin- uation, where he separates Rangia, as having a typically Heterodont hinge, from Mactra, which he regards as a true Desmodont. I have elsewhere shown that both in its gross anatomy and its hinge Rangia is truly Mactroid, and cannot be separated when young from a young Alii/inia. If one is the other must also be Heterodont. The peculiarities of the sunken ligament and resilium are shared with Mulinia, and the deep pit to which attention was especially called by Neumayr is the dynamic result of the wide separation of the umbones and the persistency of the resilium. He would have found the same extended ligament, uncovered, in Schizodcsma ; and, in fact, in all Mactridce the ligament starts at the beak of the shell or nearly so, and its termini are widely separated or close together according as the beaks are far from or near to each other. In Mactra the cardinals represent radiating arms of a bent lamina primi- FREE INSTITUTE OF SCIENCE 873 TERTIARY FAUNA OF FLORIDA lively coalesccnt above. The anterior edge of the cartilage-pit is not con- cerned with an}' of the teeth of Mactra except when they are accidentally superposed upon it. The laterals also arc not related to any part of the pit, as such, though possibly they may have originated through plications not unconnected with the ancestral proto-ligamcnt. In short, Neumayr was mis- taken in supposing Mactra to be a Desmodont, as sufficient material will show any one. FAMILY MACTRID^E. The family Mactrida, when divested of some extraneous matter, is divisible into several groups from our present knowledge. These groups will be regarded here as subfamilies, though, as in many other cases, it is by no means determined whether their systematic value is precisely equivalent to other groups of the same nominal rank. It suffices that they seem to be natural groups, within the family, of higher than generic value. Subfamily MACTRIN^E. Shell subequilateral, -nearly closed; hinge normal (as previously de- scribed, p. 862), fully developed; siphons partially or wholly naked, wholly retractile within the shell ; mantle, between siphons and anterior adductor, chiefly open ventrally. Subfamily PTEROPSIDIN^E. Shell subequilateral, nearly closed, thin ; hinge feeble, concentrated, the laterals partly obsolete or much reduced ; siphons wholly retractile, naked ; mantle partially closed ventrally. Subfamily LUTRARIINJE. Shell inequilateral, widely gaping ; hinge tending to be irregular, the laterals partly reduced or obsolete; the chondrophore free, in the plane of the hinge-plate; siphons contractile, not retractile within the shell, clothed with a horny epidermis to their tips; ventral opening of the mantle short, and the foot correspondingly reduced in size. An opisthopodial orifice some- times present. Subfamily ZENATIINiE. Shell inequilateral, compressed, thin ; hinge concentrated, irregular, the laterals tending to become obsolete or absent; chondrophore bent out of the plane of the hinge-plate and more or less adherent to the valve ; siphons contractile, naked ; ventral opening of the mantle and foot variable. TRANSACTIONS OF WAGNER 874 TERTIARY FAUNA OF FLORIDA ? Subfamily ANATINELLIN^. Shell inflated, gaping, radiately striate; hinge with a prominent large, narrow chondrophore, a short external ligament, a narrow cardinal tooth, and accessory lamella in each valve without laterals. The pallial line distinct without a sinus. Soft parts unknown. In order to classify our Tertiary Mactridce it became necessary, owing to the confused state of the group, to go over and revise the whole of it, and this investigation has resulted in numerous rectifications and changes, since no revision of the group has been made in many years. With the idea that these results may be useful for paleontologists, the subjoined synopsis of the different groups is presented.* Subfamily MACTRIN^E. Genus MACTRA Linu6, 1758. Mactra (L.) Lam., 1799. Type Af. sliiltonnn Linnc. Trigonella Da Costa, 1778 ; not Walch, 1762, or Schroter, 1776. Crassatclla Lam., 1799. Type C. cygnea (Chemn.) Spongier. Macttu Dall, Nautilus, viii., p. 26, July, 1894. Dentition normal in number and distribution of teeth ; ligament set off by a shelly lamina rising between chondrophore and ligament ; cardinals generally coalescent above ; laterals smooth or finely granular. Subgenus MACTRA s. s. Type Af. stultorum Lin. Shell subequilateral, ovate-trigonal ; spur distinct, roofing the apical part of the chondrophore; anterior laterals radiating from the anterior sinus, not confluent with the anterior arms of the cardinals, and the latter without ac- cessory lamella; dental armature not concentrated. The majority of old-world Mactras belong to this group, which is repre- sented only by a single small species in the Caribbean and none on the Pacific shores of America. There was no type mentioned by Linne, but his rule of regarding the best-known, most common, or officinal species as the type would have pointed to M. stultorum, which was actually selected as the type by Lamarck in 1799. Da Costa was not a consistently binomial writer, except in his last work, and *An abstract of the classification here adopted was published in the Proceedings of the Malaco- logical Society, vol. i., pt. 5, pp. 203-213, London, March, 1895. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA is therefore not entitled to be cited for earlier work in synonymy. However, if he were, the name Trigonclla, which he applied to the Mactras, was preoc- cupied by other authors. Subgenus CCELOMACTRA Dall, 1895. Type J/. viftlucea (Ch.) Gmelin. Shell equilaterally oval, thin, inflated, with a thin lineated epidermis ; dorsal areas grooved ; beaks adjacent ; pallial sinus very short, high, rounded behind ; valves nearly close-fitting, convex ; ligament sagittate, linear, com- pletely shut off from the chondrophorc by shelly matter; dental armature not concentrated ; laterals long, thin, and flexuous, distally confluent with the hinge-plate margin, as is the anterior ventral lamina ; anterior sinus roofed by a buttress upon which stands the anterior arm of each cardinal, and from under which the laterals emerge; chondrophore roofed at the apex; right cardinal not coalescent above, the anterior arm adjacent to the dorsal shell- margin ; hinge-plate very oblique, especially in front, forming a deep recess extending to the beaks. This group, recognized, but not named, by Gray in 1837 (Mactra D\ is the analogue in the Mactra line of Scliizodcsina in the Sfisula line, from which it differs in its ligament, set off by a shelly floor, in its short, high, almost obsolete pallial sinus, the light, inflated valves, the remarkable anterior sinuses, and the disposition of the cardinal teeth. Mactra turgida Gmelin (tmnida [Ch.] Rve.), and probably M. Ciiiningii Reeve (= Cuvicri Desh.), have similar features. It is a tropical old-world group of species. Subgenus MACTRODERMA Dall. Mit,-/n>iit-rina Drill, Nautilus, viii., p. 39, 1894. Type M. Tf/ir/,! 1'hil. Shell inequilateral, rude, with a coarse epidermis, pronounced pedal gape, a lanceolate sunken ligament, an inconspicuous spur; dental armature con- centrated, teeth and laminae short, the anterior arm of the right cardinal lying in the plane of the ventral lamina; otherwise as in Mactra. Section Mai-tnnli-rma s. s. Shell elongated. Distribution, west America. Mactra velata Phil., Panama. Section Cyclomactra Dall, 1895. Shell subcircular, compressed, pedal gape obsolete, ligament submerged except the tip, but wholly separated from the resilium; remainder of char- TRANSACTIONS OF WAGNER 876 TERTIARY FAUNA OF FLORIDA acters like Mactrodcruia. Distribution, Australian seas and New Zealand. M. tristis Gray may serve as type. Subgenus MACTROTOMA Dall. Mactrotoma Dall, Nautilus, viii., p. 26, 1894. Type M.fragilis Gmelin. Shell subequilateral, elongate; with a thin, silky epidermis, posterior dorsal areas bordered by an impressed fasciolc over which the epidermis is darker colored and differently wrinkled ; beaks adjacent ; pallial sinus large; valves convex, gaping markedly; ligament lanceolate; chondrophore large, shallow, apically roofed ; anterior laminae issuing from the dorsal sinus ; cardinals prominent, thin, their posterior arms projecting over the chondro- phore ; each anterior arm attended by a high accessory lamella in nearly the same plane, closely appressed in the right valve to the ventral lamina, and in the left valve to the anterior lateral, so that, to a cursory inspection, the lamina appears tridentate and the tooth bidentate. (See pi. 27, figs. I, 4, 8, 18.) This group is widely distributed over the world in the tropics, usually a single species in each fauna. The type is better known as M, brasiliana Lam. . These species have been confounded with Slandella Gray, which was based on M. pellucida Chemn. (which Gray by an error referred to zsfrag'dis Chemn., another species figured on the same plate of the Conch. Cabinet) and M. (egyptiaca Dillwyn, species belonging to the Lutrariince. Gray's error of reference is explained by manuscript notes of Deshayes in the writer's posses- sion and by specimens identified after Gray by Cuming for the United States National Museum ; but the details make too long a story to recapitulate here. The soft parts of this group (as might be anticipated from the shell characters) show modifications pointing towards Lutraria. Standclla has a spisuloid ligament. Section Simomactra Dall . Nautilus, viii., p. 40, 1894. Type M. dolabrifnrmis Conrad, Gulf of California. Shell inequilateral, flattened cuneiform; pallial sinus smaller; siphonal gape inconspicuous ; accessory lamellae distant from the laterals ; otherwise as in Mactrotoma s. s. Section Micromactra Dall. Nautilus, viii., p. 40, 1894. Type M. californica Conrad, non Deshayes. Shell small, solid ; hinge like Mactrotoma s. s. ; beaks silicate. (See pi. 28, fig. 12, and pi. 37, fig. 23.) FREE INSTITUTE OF SCIENCE 877 TERTIARY FAUNA OF FLORIDA The type is found in California, and the group is represented in the Oli- gocene of Florida and the Eocene of Trinidad. Subgenus MACTRELLA Gray, Jan., 1853. Dall, Nautilus, viii., p. 40, Aug., 1894. Type i\f. alata Spgl. (-)- Papyrina Morch, April, '853). Shell trigonal, thin, inflated, the posterior dorsal area marked off by a keel or angle; beaks prominent; ligament narrow, sagittate; dental armature concentrated, anterior laterals short. Section Mactrclla s. s. PLATE 27, FIGURE 14. Mactrella Uall, Nautilus, viii., p. 40, 1894. Chondrophore small, oblique, apical ly roofed ; the pit walled in front by the posterior cardinal arm in the right and by a well-marked accessory lamella in the left valve ; anterior laterals very small and short ; both ventral laminae formed by the upturned edge of the hinge-plate ; cardinal tooth in the left valve rather petaloid, the anterior arm stronger than the other, sup- ported at the angle and at the ventral extremity by a septum extending to the dorsal margin of the valve ; there is a feeble anterior accessory lamella superposed on the root of the anterior lateral lamina and a posterior ditto walling the chondrophore ; in the right valve the arms of the cardinal are not coalescent above ; the anterior arm is supported by a septal buttress at each end, and has a small projection below it on the edge of the hinge-plate, representing an accessory lamella'; the gape is short and wide; the surface of the valves is smooth. Section Harvella Gray, 1853. Dall, Nautilus, viii., p. 40, 1894. Type M. clegans Sowerby. Hinge like the typical section ; surface of the valves plicate ; shell ex- tremely thin. This group includes J\f. ritrca Ch. and M. Rccvcsii Gray. Section Mactrinula Gray, 1853. Type M. plicataria Lamarck. Shell externally like Harvc/la, the dental armature less concentrated, the chondrophore large and narrow, laterals well-developed, emerging in the right valve anteriorly from a roofed sinus, on the roof of which is set the anterior cardinal arm; in the left valve the posterior cardinal arm projects over TRANSACTIONS OF WAGNER 878 TERTIARY FAUNA OF FLORIDA the chondrophore, while the anterior qne is continued ventrally by a narrow accessory lamella ; hinge-plate quite oblique, without buttresses to the cardinals. The species of this group are rare tropical forms, a single species being found in a fauna when present at all. Geologically they go back to the Oli- gocene. Genus SPISTJLA Gray, 1838. Dall, Nautilus, viii., pp. 26, 40, 1894. Type Mac tra solida (L.) Gray, 1847. Shell small, subequilateral, trigonal, with a thin epidermis, adjacent beaks, and concentrically grooved dorsal areas ; pallial sinus small, rounded ; gape obsolete ; valves convex ; ligament sagittate, set in a callous area close to the dorsal margin and not set off from the chondrophore by any shelly ridge ; dental armature normal, strong, not concentrated ; the opposed surfaces of the laterals transversely grooved ; left cardinal small, prominent, with a small posterior accessory lamella, the posterior ends of both projecting over the chondrophore; right cardinal with the arms coalescent above, the anterior arm close to the dorsal shell-margin ; hinge-plate thick and flatfish ; exterior smooth or concentrically striated; the dorsal areas ill-defined. Subgenus HEMIMACTRA Swainson, 1840. Dall, Nautilus, viii., p. 26, 1894. Type M. solidissima Dillwyn. Shell large, ovate-trigonal, with grooved laterals and rather concentrated hinge; the dorsal areas are not grooved and the anterior arm of the right cardinal is confluent with its ventral lamina ; cardinals markedly compressed. Hemimactra is a new-world type, for the most part, while the typical Spisula is old world, especially European, in its recent distribution, though represented in the American Tertiaries. Section Mactromeris Conrad, 1868. Dall, Nautilus, viii., p. 26, 1894. Type M. polynyma Stm. Shell like Heinimactra, but the laterals smooth, the cardinals not com- pressed, and the anterior arm of the right cardinal not confluent with the ventral lamina. (See pi. 27, figs. 3, 7, 13, 16, 24.) This type is especially characteristic of northwest America. Mactro- dcsma (pondcrosa) Conrad is merely an extremely ponderous rotund Mactro- meris of Miocene age; Pscudocardium Gabb also seems nothing more than an unusually heavy, short, and elevated species of Mactromeris ; Vclcda Con- FREE INSTITUTE OF SCIENCE 879 TERTIARY I;AUNA OF FLORIDA rail is based on V. lintea, a small species of the same general type, though perhaps more strictly referable to the submenus Cymbophora referred to below. Section Oxypcms Miirch, 1853. Type- M. triangularis [.am. This section is characterixed by its more crudely triangular shape and rather strong concentric sulcation of the surface of the valves. It is chiefly Indo-Pacific in its distribution. Subgenus LEPTOSP1SULA Dall, 1895. T\|>i- Mill Ira stn\ili'//it Lam. Sliell tliin, inflated, with undulated beaks, the dorsal areas smooth ; pallia! sinus large, deep; gape well marked; valves convex; ligament sagit- tate, dental armature concentrated ; opposed surface of the laterals smooth ; anterior arm of left cardinal coalescent with the lateral ; anterior arm of right cardinal coalescent with the dorsal lamina ; hinge-plate thin and excavated ; spur prominent, but the chondrophore not roofed at the apex. This group in the Spisuloid division represents the Mactrclla type in the Mactroid section. The type of the submenus is said to come from India. Subgenus CYMBOPHORA Gabb, 1869. Type Mcictra Ashbiimcri Gabb. A careful study of the typical species of this group shows that it differs from Spisula only in the following features. The attached ends of the re- silium were convex instead of flat (as is sometimes seen in recent species), and the margins of the pit are therefore elevated ; while the posterior sinus, instead of being (as usually in the later types of Spisula) roofed over or filled up with a solid mass of callus at the apex, upon which the ligament is attached, is vacant, so that the ligament was fixed on the convex margin of the pit, or on the side of tin- ventral lamina, or partly on both, all being very close together. This character would seem to be trifling until it is observed that all the Mcso- xoic species are characterixed by this feature, though, as in recent Spisitfn, the external form may vary, the dorsal areas be smooth or grooved, the teeth sulcate or smooth. As it is common to all the Cretaceous Mactr'uLc of which I have been able to examine a hinge, I have thought it best to retain the name in a subgeneric sense for that stage of development of the group. Gabb's figures are too formalized and do not bring out the features clearly. TRANSACTIONS OF WAGNER 880 TERTIARY FAUNA OF FLORIDA His Lutraria truticata and Schizodesma abscissa are both referable to Cyinbo- pliora and differ chiefly in form. Subgenus SCHIZODESMA Gray, 1837. Type Mactra Spcn^leri Linne. Scissodcsina Gray (olim), 1842 ; Mactra Morch, 1853 ; not Lam., 1799. The type species of this group is a very remarkable form, which, if isolated, would deserve generic rank. The other species, however, smooth the way to the ordinary sagittate ligament, being in every way comparable in the Spisula series to Mactrella in the Mactra series. The hinge, apart from the purely dynamic features due to the distance between the beaks, presents an interesting illustration of the inception of teeth at points subject to per- cussion. The end of the strong rib which guards the ligamentary slit in either valve in one valve has developed a nascent tooth or projection, and in the other an obscure socket to receive it. This appears to be unique in the family. The species are confined to the African coasts. Genus MULINIA Gray, 1837. Dall, Nautilus, viii., p. 27, 1894. Type N. typica Gray (=;!/. ednlis King). Shell with the ligament and resilium both enclosed in a single pit and invisible externally. Laterals subequal, moderately distant ; teeth normal ; valves closing almost hermetically; pallial sinus short and small; siphons short; foot narrow, pointed. (See pi. 28, figs. 4, 6-9, 14.) Widely distributed in estuaries of the tropics and temperate seas over most of the world. The most conspicuous species are from South America. Gciius RANGIA Dcsinoulius, 1832. Type A', cuncata Gray (-(- cyrenoiiies Desm., 1832). Shell like Mulinia, but with the proximal end of the anterior lateral vertically hooked; laterals curved, cross-striated, more or less unequal, the posterior longer ; pallial sinus small. Subgenus RANGIANELLA Conrad, 1868. Type Mactra nicmlica did., 1851 ( |- Cnatli. tri^oniiin Petit, 1853). Shell small, rostrate, with the laterals short, straight, and nearly smooth ; pallial sinus obsolete, teeth normal. All the recent species of the genus are from the warmer estuaries of North America. FREE INSTITUTE OF SCIENCE 88l TERTIARY FAUNA OF FLORIDA Section Miorangia Dall, 1894. Type Gnathinhin Jolinsoni Dull. Miocene of Mississippi. Shell small, extremely inequilateral ; pallial sinus obsolete ; cardinals reversed from the normal, that in the left valve fitting over the other. This a peculiar little form from the newer Miocene of the Gulf border. So far as my observations go, it is the only species in the whole family which presents us with a superior left cardinal. Subfamily PTEROPSIDIN^E. Genus PTEROPSIS Conrad, 1860. Type Luli-aria pa/iyria Conr., 1833 (= Af. dcnlata Lea). Shell subequilateral, thin, inflated, with a more or less vermiculate surface; pallial sinus deep, narrow, pointed ; siphonal gape small ; ligament sagittate, not set off by a shelly lamina from the chondrophore ; dental armature strong ; chondrophore large, shallow ; left cardinal tooth wide, the anterior arm super- posed on the root of the anterior lateral, the posterior arm walling the pit ; posterior lateral long and well marked ; right cardinal wide, the anterior arm walling the pit, the posterior smaller, appressed upon the dorsal shell-margin ; arms of the cardinal coalescent above, spur perceptible, not roofing the pit ; lumimu short, smooth, the anterior emerging from the ventral sinus ; hinge- plate very oblique, thin ; dorsal areas obscure. This group comes from the Lower Eocene, Lisbon or Buhrstone horizon, and the Claiborne sand, where it is represented by a single species in each horizon. The Claiborne species is the type ; that from the Buhrstone is Lutraria lapidosa Conr. (1846), of which Astarte Conradi Dana (1863, Man. Gcol., fig. 800) is a synonyme. This group is, without doubt, the precursor of Raeta, and should be looked for in the Tertiaries of Eastern Asia. It differs from Raeta in the strong, not concentrated hinge, well-developed laterals, broad, rotated right cardinal, and in having no shelly lamina between the ligament and resilium. It corresponds to Spisula, as does Raeta to Maclra in the Mactrince. Genus LABIOSA (Schmidt) Holler, iS32. Type Mat (/-a analina Spengler, 1802. Shell large, thin, inflated, broad and gaping behind, beaks adjacent; sur- face concentrically striate ; dorsal areas well defined, the posterior area set off by an elevated line; pallial sinus short, rounded, wide; siphonal gape wide ; TRANSACTIONS OF WAGNER 882 TERTIARY FAUNA OF FLORIDA ligament marginal, set off by a prominent lamina of shell from the pit ; left car- dinal with a very short posterior arm projecting over the pit, with an accessory lamella above apprcssed to the ligamentary ridge over the apex of the chon- drophore ; a single obsolete and very short lateral in each valve before and behind the pit ; hinge-plate flattish behind, depressed and excavated in front. A single species on each shore of America inhabiting the warmer re- gions. Geologically the group goes back to the Pliocene. Subgenus RAETA Gray, 1853. Type Lutraria caiia/ii ulata Say, 1822. Shell large, inequilateral, thin, inflated, acutely rostrate behind, concen- trically plicate; dorsal areas obscure, the surface of the valves more or less vermiculate ; pallial sinus deep, narrow, pointed ; siphonal gape small ; liga- ment submerged except at the anterior end, set of by a shelly ridge which roofs the apex of the pit and partially supports the posterior arm of the cardinal tooth; dental armature concentrated ; chondrophore large; left car- dinal small, its posterior arm shorter, with a small accessory lamella above, both projecting over the pit; right cardinal with the arms coalescent above, the anterior larger, superposed on a feeble anterior lateral, the posterior arm much shorter, projecting over the pit ; a single anterior and posterior lateral in each valve but no paired laminae. Distribution the same as Labiosa. Geologically the group goes back to the Miocene. Section Raetina Dall, 1894. Type R. indica Dall n. s. Shell like Ra'eta but small, with the posterior laterals wholly wanting ; the hinge-plate normal, its ventral margin not upturned ; the anterior sinus excavated, and roofed at the apex.* Subgenus RAETELLA Dall, 1894. Type R. tennis Dall.f Shell very small and thin, surface concentrically plicate, not vermiculate, polished ; dorsal areas well defined ; sinus short and rounded ; valves inflated, * R. indica n. s. Shell white, elongate, concentrically finely plicate, very thin ; pallial sinus very deep and narrow ; beaks small, inflated, nearer the anterior end, which is full and rounded, the posterior end being produced, attenuated, and laterally compressed, forming a bluntly pointed rostrum. Alt. of shell 28.5, Ion. 43, diam. 20 mm. Bombay, U. S. Nat. Mus.,No. 90,276. This species resembles A', rostralis Deshayes ( = pulchelhi Ad. and Rve.) but is larger, while in FREE INSTITUTE OF SCIENCE 883 TERTIARY FAUNA OF FLORIDA suborbicular, subequilateral, with a short, pointed rostrum ; no lateral lamina? in either valve, the edge of the very oblique hinge-plate being produced on each side in each valve, near the chondrophore, to perform the office of laterals ; ligament very short, external ; the cardinals and chondrophore well- developed, normal. The genus lUaini'iHia Hupe, 1854 (not Rob. Desv., 1830), has been re- ferred to this vicinity by authors. It doubtless is identical with dementia Gray and belongs elsewhere. Gray's name must be retained. Subfamily LUTRARIIN/E. Genus LTJTRARIA Lamarck, 1799. Type L. oblonga Gmelin. / :t/rici>/ii Blainville, 1825 ; | J'miininofiltilii (I.cach) Brown, 1827 ; + Lit/aria Philippi, 1853 ( | Clifiiia (iistcl, 1848, fide Hcrrmannscn). Shell inequilateral, thin, compressed, siliquiform ; dorsal areas ill-defined ; surface smooth or concentrically striated; beaks anterior, adjacent; pallia! sinus deep; siphonal and pedal gapes well-marked; ligament short, feeble, not separated from the chondrophore by a shelly lamina; dental armature concentrated ; chondrophore large, oblique ; resilium continuous and homo- geneous between the valves ; left cardinal compressed, prominent, with an rosti'ulis the anterior end is longer than the posterior. The latter is a Chinese species. R. indica differs in form and proportions from R. Abcrcrombiei Melvill, also a Bombay species. In the absence of specimens it is impossible to speak positively, but it is probable that several other form* described from the China Seas and lndo-1'acific region should be grouped in this section. This and the following recent form are included here in order to complete the revision of the group. f R. tennis " Hinds," in Ads. Gen. Rec. Moll. The shell is excessively thin, yellowish, polished, with a nacreous sheen of much brilliancy, but internally pale straw color without nacre; the beaks are small and prominent, the surface regularly plicate with concentric waves, increasing in breadth as they approach the margin, about forty in all, the small rostrum remaining, as well as the anterior dorsal area, nearly smooth ; the cardinal teeth arc well developed and prominent, the cartilage pit small and nearly vertical. Alt. 10, Ion. 13, diam. 6 mm. This elegant little shell does not appear to have been described, though the name has been in the catalogues for a long time. The specimen described here was dredged in Hong Kong harbor in about eight feet of water, muddy bottom, by Stimpson, in 1X5;. It has been compared with a specimen, bearing the same name, in the British Museum, by Dr. P. 1'. Carpenter, and is No. 519 on tin- Museum Register. R. pulchella Ads. ami Kvc. (i-oslnilis Desli.) h.is tin? same pseudo-nacreous surface, probably due to some peculiarity of structure in the epidermis, and in its general characters dill'ers only l>y the presence of a trace of dorsal lamina anteriorly in the right valve, and in having the hinge-margin somewhat more effectively modified into laterals. It should doulitless be comprised in ilic' same group. Our specimens were drrd^nl at IlaKodadi in six fathoms liy Stimpson. 21 TRANSACTIONS OF WAGNER 884 TERTIARY FAUNA OF FLORIDA accessory posterior lamella ; laterals very short and feeble, the posterior one obsolete or even absent. Right cardinal with the arms not coalescent above, the anterior arm adjacent to or superposed upon the ventral lamina ; dorsal lamina; and the posterior ventral lamina frequently absent or obsolete ; hinge- plate strong, narrow, and flattish. This group is not represented in America, but has representatives in Europe, the China Seas, and part of the Inclo-Pacific region. Species described as Liitraria, from American beds (such as Traskii and transutontana Conrad), belong to other genera. Section Guiiioiiuicti-a C. Mayer, 1867. Type Littrariii i>nplt>n Conrad, 1837, not Turton, 1822; i S, lii -.,<>ve, the anterior arm superposed upon the ventral lamina, posterior arm walling and overhanging the pit. Gills, foot, palpi, and mantle-margin not dil'lering in any essential particular from those of Sfisn/n siniilis Say. The siphons are large, united to the tips, firmly clothed with a coarse epidermis; siphonal orifices papillose; the end of the united siphons when the papillose tips are retracted shuts like a book instead of contracting circu- larly, and the horny epidermis accumulates with growth on the flat lateral portions which correspond to the covers of the book and forms flattish masses which sometimes resemble " horny valves," as described by Conrad, but which are a purely mechanical product not comparable to the "pallets" of Teredo. Northern specimens have the siphonal tunic more rugose and the siphonal " valves" less clearly formed than in the southern ones. Something of the same sort can be observed at the ends of the siphons in Mya tntncata, Platyo- dcii ctinccllalus, and, doubtless, in other burrowers with long tunicatcd siphons. The chief feature in which Tresus differs from the Spisitla referred to, apart from its permanently cxscrtcd siphons and slightly less open mantle, is the great development of a thin membrane behind and extending from the siphonal septum towards the gills, to which it is attached. In Spisti/a the edges of the gills are closely adjacent to the siphonal septum with little membrane intervening. The gills in Trcsnx are more coarsely plicate than in Spisnla and proportionately somewhat smaller. The osphradial raphc which bisects the current from the branchial siphon in Spisnla is less prominent and more ventrally situated in Trcsits. In other respects the gross anatomy did not differ more than one would expect to find in two species of the same genus. TRANSACTIONS OF WAGNER 886 TERTIARY FAUNA OF FLORIDA In order to compare Trcsus with another group to which it has been affiliated, a specimen of Mya truncata from Bering Sea was examined. The difference here was more decided ; so far as general appearances go the two animals looked very different, but an analysis of the differences does not reveal anything very striking. The gills in Mya were smoother than in either of the Mactroids, and their anchorage to the siphonal septum was more like that of Spisnla than Trcsus. The foot in Mya is much reduced. The palpi are smaller and much less adherent to the mantle; the mantle is much more closed ventrally and the gills are more posterior as a whole than in cither of the Mactroids. There is no elevated osphradial raphe apparent in the Mya. In other features all three genera seemed pretty much alike. Through the kindness of Dr. Nolan, secretary of the Philadelphia Academy, I have received information showing that the signature of the Academy's Proceedings which contained the description of Schhotluents by Conrad was published about the end of, January, 1853, while Gray's Trcsns appeared in the January number of the Annals of Natural History, which was doubtless issued in the first days of the month. Tresus will therefore take precedence. The distinction attempted to be drawn between Trcsus and Schizothcerus by Conrad in his Catalogue of Mactridcs is without sufficient basis in fact. There is but one species, which varies (like Mya) considerably in form and proportions. It is found on both sides of the North Pacific and fossil in California. Genus STANDELLA Gray, 1853. Type Mactra fragilis Gray non Chemnitz = M. pellucida (Ch.) Gmelin, 1788; not Standella H. and A. Adams, 1856. Shell short, subequilateral, thin, compressed, dorsal areas obscure; sur- face striated or vermiculate; beaks low, adjacent; pallial sinus deep; siphonal gape moderate ; ligament not set off from the chondrophore by a shelly septum; dental armature concentrated; chondrophore moderate, oblique; resilium homogeneously continuous between the valves ; left cardinal wide, prominent, with a very small posterior accessory lamella; anterior lateral short, high, adjacent to the cardinal ; posterior lateral longer, both well de- veloped and partly confluent with the ventral edge of the hinge-plate; right cardinal wide, the posterior arm walling the pit, the anterior arm superposed on the ventral lamina; both lamina; present before and behind the pit; the posterior sinus in the right valve distinctly roofed. Owing to a confusion between two of Chemnitz's figures, by which his FREE INSTITUTE OF SCIENCE 887 TERTIARY FAUNA OF FLORIDA pclhicida was identified as frftgilis by Gray, most of those who have used the name Standclla have applied it to shells resembling M. fragilis Gmelin, better known as M. brasiliana Lamarck. The ligament in Standclla is Spisu- loid while in M. (Afnctrototna) fragilis it is distinctly Mactroid. The true Standclla was called Spissula'\sy Morch, but it is not Spisula of Gray. The species have much the same distribution in the old world as Lutraria. None is known from North America, but a west African species is found on the coast of southern Brazil. The genus is found in the French Miocene (Helve- tien of Pontlevoy). Subgenus EASTONIA Gray, 1853. Type Miiclra ritgosa Gmelin. This form is like Slandella, but has the surface radiately striate. The type has the shell less compressed ; the left cardinal narrow, compressed, with a very small, thin accessory posterior lamella (usually lost), and the anterior lateral well separated from the cardinal. Other characters as in Standella. Eastonia nicobarica Gmelin (agyptiaca Reeve non Chemnitz) has a hinge like Standella pcllncida. E. Stimpsoni Ball, a species with finer sculpture, from the China Seas, has the hinge similar, but depauperate. This group is iMtricola Blainville, ex parte, 1825, and Merope H. and A. Adams, 1856. The distribution of Eastonia is confined to the warmer seas of the old world. Genus HETEROCARDIA -Deshayes, 1854. Type //. £i/>/>i>sit/ti (Desh.) H. and A. Adams, Gen. Rec. Moll., ii., p. 387, 1856. Shell subequilateral, short, with an arched posterior dorsal slope, and finely vermiculate surface concentrically striated ; hinge-plate produced be- hind and excavated ; pallial sinus deep ; ligament short, external, set off by a shelly lamina; chondrophore moderate, rooljed at the apex; left cardinal wide, small, its posterior arm walling the pit, the anterior arm short, inclined dorsally, crossing the root of a short, high anterior lateral ; posterior laterals short, strong, as in Standclla ; right cardinal wide, posterior arm walling the pit, and the anterior appressed to the dorsal hinge-margin over a buttress roofing the anterior sinus; anterior dorsal lamina short, small; the ventral high and spur-like ; the posterior laminae longer, subequal, rather short. This genus bears to Standclla the relation which Jfaclra bears to Spisula; and is especially characterized by its very short, high anterior ventral lamina, and the manner in which the anterior arms of the cardinals arc inclined towards the dorsal shell-margin. The long, excavated backward extension TRANSACTIONS OF WAGNER xxx TERTIARY FAUNA OF FLORIDA of the hinge-plate is noteworthy. The genus .was named by Dcshayes, but defined by Adams, who selected the type. Not having access to that species, the characters have been taken from H, Denisoniana H. Ads. It is an Indo- Pacific genus. Subfamily ZENATIIN/E. Genus ZENATIA Gray, 1853. Type Z. acinaccs Quoy and Gaim. (-)- Z. selandica Gray). Metabola C. Mayer, 1867 ; same type. Shell inequilateral, thin, compressed, siliquiform, smooth, with a con- spicuous epidermis; dorsal area obscure; beaks inconspicuous, adjacent, very anterior; lunular area encroaching on the inner dorsal margin, hardly visible externally; pallial sinus very deep, gapes conspicuous, the valves hardly touching, except at the hinge and on the ventral margin ; ligament lanceolate, short, somewhat sunken, not set off by any shelly barrier from the pit ; chon- drophore oblique, large, posteriorly depressed below the hinge-plate, resilium homogeneous and continuous between the valves ; dental armature concen- trated ; left cardinal large, with an obscure accessory lamella between it and the ligament; a short, high anterior lateral parallel with the anterior arm of the cardinal, above which descends the lunular area;' behind the ligament a very small, narrow posterior lateral (often lost) lies adjacent to the dorsal margin ; valves below the cardinals reinforced by an obscure, thickened ray of shell-substance, but which does not support the chondrophore ; upon this ray, behind the adductors and below the ventral sinus of the cardinal, are the scars of the pedal retractors ; right valve with the cardinal wide, hardly coales- cent above, with two very small posterior but no anterior lamina; ; both the cardinals are wholly exterior to the pit. The species of this genus are confined to New Zealand. The above description is taken from Z. Dcsliaycsii Reeve (Littraria sole noidcs . Desh. non Lam. + L. acinaces Rve. non Quoy and Gaimard). The type of the genus (Z. acinaces Quoy and Gaim., 1834 + Z. selandica Gray, 1837 + L. Cumingiana Desh., 1854) differs from Z. Dcs/iayesii by the total absence of lateral teeth or laminae, but these are so feeble when present, even in the targe Z. Deshaycsh, that it would seem inadvisable to divide the genus, even sectionally, on that account. The lunular area is obsolete in Z. acinaccs. The siphons arc naked and wholly united, the gills continuous, and the mantle edges united behind the foot in this genus. FREE INSTITUTE OF SCIENCE 880 TERTIARY FAUNA OF FLORIDA Genus RESANIA Gray, Jan., Type A', liuici'iilata Gray j / \niifniii-llii ( 7\rv/<>n') ( iray. June, 1853 + Afyiiinactra C. Mayer, 1867 -f Lnminaria C. Mayer, 1867. Shell inequilateral, thin, compressed, lanceolate, smooth, with a conspicu- ous epidermis; dorsal areas obscure; beaks very low, adjacent, somewhat posterior; pallial sinus short, broad, gapes conspicuous; ligament small, short, lanceolate, not set off from the pit by a shelly ridge ; chondrophore large, oblique, posteriorly depressed below the hinge-plate and resting on a radial thickened rib, which extends from the beaks towards the base behind the posterior adductor; a second rib of the same sort reinforces the valve behind the anterior adductor ; resilium homogeneous, dental armature concentrated ; left cardinal strong, prominent, petaloid, with a thin posterior accessory lamella, which, with posterior arm of the tooth, projects slightly over the pit ; a short, thin, well-elevated lateral tooth on each side of the beak ; a small but deep lunular inflection of the anterior dorsal margin ; right cardinal low, wide, the anterior arm superposed on the ventral lamina ; the anterior dorsal lamina very small between the arm of the cardinal and the lunular inflection ; posterior arm of the cardinal projecting a little over the pit ; the posterior laminae small but distinct. The gills are discontinuous on one side, and the whole mantle edge free between the adductors. A single species is known from New Zealand. Genus DARINA Gray, 1853. Type I), sti/cnoiilcs King (not Lufraria s/>/<->toiistt/ii ('.lay, Ma;.;. Nal. Hist., i., X. S., ]i. 372, 1838. S/>i'.<.\H/ii I'liil. nun Miircli ; S/i/:/t/ir />vg»itza Lea), M. decisa, and prcetauiis Conr., all of which belong to the genus Spix/i/a, and even to its typical section, as I have determined by an examination of the type specimens. In other Eocene beds are Sfisula albit upiana Harris from White Bluff, Arkansas ; Spisuln mississippiensis Conr. and S. fitncrata Conr. from Vicksburg, Mississippi, a variety of the latter having been named i/i- cquilatcralis by O. Meyer. There is another form which differs barely, if at all, from funcrata, in the Jacksonian. M. dcntata Lea was founded on the hinge-plate of Pteropsis pafyria Conr. of the Claibornian. In the Miocene we find a more numerous and richer development of the genus. Subgenus HEMIMACTRA Swainson. This comprises a group of species which differ from the typical Sfisula in being thinner, usually larger and more elongated, and agree with it in having the lateral lamina; cross-striated, while in the section Mactromeris Conrad they are smooth, though this character is not one to which I attach any great importance. The following species have smooth laminae, and the large recent 5. walls Gould also retains this character. Section Miu-liviiicj-h Connul. Spisula (Hemirnactra) dodona n. s. PLATE 27, FIGURES 7, 13, 25. Oligoccne sands of Oak Grove, Santa Rosa County, Florida; Burns. Shell of moderate size, compressed, subtriangular, arcuate, nearly smooth or with fine incremental lines, subequilateral; the anterior side a trifle shorter, anterior slope impressed, slightly concave, anterior end rounded; base arcuate ; posterior slope convex, mcsially impressed, bounded by a slender, elevated line, with the intervening area minutely wrinkled; pallial sinus rounded, ex- tending in front of the vertical of the beaks; hinge concentrated, the anterior FREE INSTITUTE OF SCIENCE 897 TERTIARY FAUNA OF FLORIDA arm of the right cardinal in line with the ventral lamina, both very short. Lon. 50, alt. 34, diam. 15 mm. This species is perhaps as near S. dcliuubis as any other, but is smaller and more compressed. The lamina: are quite short and not striated. Spisula (Hemimactra) delumbis Conrad. Pl.ATK 27, Fl<;iIRF. 26. Ma,-lra ,/i-/iiiii/iis Conr., Fos. Sh., p. 26, pi. 11, 1832; Ten. Fos., p. 27, pi. 15, fig. i, 1838; 1'roc. Acad. Nat. Sci. 1'liila. 1862, p. 372, 1863. Mtiilra I'ir^iniana Conr., Am. Journ. Conch., iii., ]>p. 188, 269, pi. 22, fig. 4, 1867. Chesapeake Miocene of the James River, Virginia, at Smithficld and Suffolk ; of the York River, at Yorktown, Virginia, and in Maryland, at St. Mary's City ; Burns and Harris. This fine species was early described by Conrad, who, many years after, obtaining specimens of S. marylanttiea, perpetrated one of his characteristic blunders by re-describing the old species and leaving the new one still name- less, his intention, of course, being to do just the reverse. Spisula (Hemimactra) marylandica n. s. PLATE 28, FIGURE 5. Chesapeake Miocene of Jones's Wharf, Patuxent River, Maryland, of St. Mary's River, Maryland, Burns ; and of Walton County, Florida, L. C. Johnson. Shell large, subovate, thin, inflated, with a nearly smooth surface, marked chiefly by incremental and obsolete radiating lines ; beaks high, subcentral, adjacent ; anterior end excavated above, rounded in front, posterior sloping to a bluntly pointed end behind; anterior dorsal area rather smooth and deeply impressed; posterior area somewhat depressed, striated, flexuous, with three- obscure, elevated lines, extending from the unibo to the margin outside of the area ; base arcuate ; pallial sinus rather narrow, extending nearly to the middle of the shell, bluntly pointed in front; hinge strong, with a large oblique chon- drophore, very short, smooth lateral lamin;u, and the anterior arm of the right cardinal tooth coalescenl with the ventral lamina. Lon. 90, alt. 67, diam. 40 mm. This fine species is at once differentiated from S. ilclituibis by its more equilateral and inflated shell, and by having instead of only one three elevated lines radiating backward from the beak. TRANSACTIONS OF WAGNER 898 TERTIARY FAUNA OF FLORIDA Spisula (Hemimactra) duplinensis n. s. PLATE 30, FIGURE i. Chesapeake Miocene of Duplin County, North Carolina ; Willcox. Shell subovate, thin, moderately inflated, beaks subcentral, not prominent, adjacent; surface smooth, except for incremental lines, which are most promi- nent towards the ends ; the middle of the valve is more or less polished, anterior end somewhat shorter than the posterior, both moderately rounded ; dorsal slope nearly equal on both sides of the beak ; dorsal areas obscure, the posterior smoother and more impressed; hinge much as in S. marylandica, but the pit larger and with a more projecting ventral margin ; pallial sinus reaching forward more than half the length of the shell, pointed in front ; basal margin curved but not arcuate. Lon. 58, alt. 42, diam. 22 mm. This species at first sight looks very close to 5. marylandica, but has a longer pallial sinus, less prominent beaks, more equal dorsal slopes, and less arcuate basal margin. The lateral laminae are finely granulated, and not striated, which separates it at once from the siniilis group, and the propor- tions are quite different from those of the young -S. polynyma Stm. of the same size. It is probably the shell referred to S. similis Say by Tuomey and Holmes (Pleioc. Fos., p. 97, pi. 23, fig. 8) and Emmons. Spisula (Hemimactra) curtidens n. s. PLATE 27, FIGURES 2, 24. Chesapeake Miocene of Burch, on the Patuxent, and near Easton, on the Choptank River, Maryland; of Magnolia, Duplin County, North Carolina; Burns. Shell large, not heavy, subtrigonal, with low, narrow, rather pointed beaks, the anterior being markedly longer than the posterior end; surface smooth or striated by incremental lines, and near the base by fine, obscure, irregular longitudinal wrinkles ; valves moderated, inflated ; anterior end pro- duced, depressed above, rounded in front; posterior end short, flattened in front of the beaks, posterior dorsal area impressed and bounded by a rounded ridge which extends from the beak to the margin ; anterior dorsal area im- pressed, with a somewhat flexuous surface; hinge with a large but not pro- jecting chondrophore ; in the right valve the dorsal lamina; are very short and smooth, the cardinal tooth quite compressed. Lon. (of young shell) 22, .ill. 17, diam. about 9 mm.; but judging from the fragments found, the species reaches when adult a height and length of 90 mm. FREE INSTITUTE OF SCIENCE SQQ TERTIARY FAUNA OF FLORIDA This fine Spisula is sharply distinguished from any other American species by its high and triangular form, short, excavated hinge-plate, and the inequilaterality of the shell. Spisula (Hemimactra ?) maguoliana n. s. PLATK 27, FIGURK 29. Chesapeake Miocene of Magnolia, Duplin County, North Carolina; Burns. Shell small, equilateral, somewhat compressed, with small, little-elevated, pointed, adjacent beaks ; surface smooth except for lines of growth and a feeble angulation extending backward from the umbo to the lower posterior margin ; ends nearly equally rounded, the posterior slightly more pointed, the base moderately and evenly curved; pallial sinus small, angular, very short; hinge normal, feeble, with short granulose laterals. Lon. 17, alt. 10, diam. 7 mm. A single left valve was obtained by Burns, which much resembles a MH- linia except in the character of the ligamentary attachment. It differs from the other species of the formation by its rounded ends and subcylindric form. Spisula (Hemimactra) subponderosa Orbigny. PLATE 27, FIGURES 3, 16. Miii'li'it poiiilt-msti Conr., Jouni. Ae.ul. Nat. Sci. Phila., vi., p. 228, 1830 ; Medial Tert., p. 25, pi. 14, fig. i, 1838 ; not of Eichwald, Nat. Skizze von Lith., p. 207, 1830, nor of Philippi. Muctra siibpfliiifi-rosa Orb., Proclr. Pal., iii., p. '100. Mactrodesma ponderosa Conr., Am. Journ. Conch., iv., p. 247, 1869. Chesapeake Miocene of St. Mary's, Maryland ; Burns. This fine shell differs from the typical Mactnniicris of Conrad only in its shorter and more inflated shell and thicker valves, features which can hardly be claimed to have more than a specific value. If .S". marylandica had a thick shell it would closely resemble the present species. But Mactroincris differs only from Hemimactra in having the laterals smooth or granular without cross- striation, and very little study will convince anyone that this character has very slight systematic value. Conrad's name having been used previously by Eichwald, Orbigny substituted for it in the same year the term mbponderosa, which should be adopted under the rule that such rectifications are not to be disturbed by subsequent generic references of the species to which they refer. 22 TRANSACTIONS OF WAGNER QOO TERTIARY FAUNA OF FLORIDA Other species of Spisula in the Miocene of the eastern United States (chiefly Hemimactrd) are S. confragosa Conrad (= Mcsodcsma confragosa Conr., Am. Journ. Sci., xxiii., p. 340, July, 1833; + Mactra fragosa Conr., Medial Tert, p. 26, pi. 14, fig. 2, 1838; + Mactra incrassata Conr., Medial Tert., p. 24, pi. 13, fig. 2, 1838; + Mesodcsma confraga Conr., Proc. Acad. Nat. Sci., 1862, p. 574, 1863) from Maryland, Virginia, and North Carolina; S. (Afac- iroiiicris) snbparilis Conr., 1841, from Wilmington, North Carolina; A", modi- cella Conr., 1833, York River, Virginia; this last is not the same as RFactni clathrodonta Lea, as supposed by Conrad; S. snbcuneata Conr., 1838, Mary- land; and A", medialis Conr., 1863, which is probably from North Carolina, though the provenance of the types is not precisely known. Section Hcnrimactra s. s. Spisula (Hemimactra) densa m s. PLATE 27, FIGURE 22. Oligocene sands of Oak Grove, Santa Rosa County, Florida ; Burns. Shell small, solid, smooth, or concentrically scuptured, with fine incre- mental lines, and sometimes obscure radial striae near the margin ; subtri- angular, subequilateral ; beaks small and low, hinge strong, the lamina; sharply cross-striated; pallial sinus rounded, small, and very short; Ion. 14, alt. 9.5, diam. 6 mm. This solid little species is stronger and larger than the majority of the Eocene forms, and has the aspect of a Midinia. Its height is less than in the allied Miocene types of about the same size, and its ends are more pointed. Genus MTJLINIA Gray. This form presents the last term in the submergence of the ligament, and does not appear in the older Tertiary or even in the Oligocene, but in the Miocene and subsequently it has attained a profuse development. The student should bear in mind that much variation of outline exists within specific limits in this genus and a new species should be founded in general on a large number of specimens, otherwise the estimate of its characters is sure to be defective. Mulinia congesta Conrad. j\lit<:ti-a congesta Conr., Am. Journ. Sci., xxiii., p. 340, 1833; Medial Tert., p. 27, pi. xv., fig. 2, 1838. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA Maftra cnissiiti-ns Conr., Medial Tert., p. 69, pi. xxxix, fig. 5, 1840; Am. Journ. Sci., xli., p. 347, pi. 2, fig-, it, 1841. Mactni lii'/it/niif,-s (l)eshaycs), P. /.. S., 1854, p. 63; Reeve, Conch. Icon., Mactra, fig. 103, 1854. Slniiili-l/ii liili-riilis Cinir., Pruc. Acad. Nat. Sci. Phila. 1862, p. 573, 1863. Muliiica latcritlis Conr., Am. Journ. Conch., iii., Suppl., p. 31, 1868. Chesapeake Miocene of Duplin County, North Carolina, and the Pasca- goula clays of Mississippi ; Pliocene of the Waccamaw beds of South Caro- lina, the Caloosahatchie River and Shell Creek in Florida ; the Pleistocene from Maine to Texas, and the recent fauna from Massachusetts Bay south- ward. This species shows the same variations in form as the preceding. The shells are smoother and less rude in the southern portion of their range, and the variety i-crlm/oiitcs is relatively more abundant in the south, but may be found represented wherever the species is distributed. It bears to the typical form a relation analogous to that which .If. triqiictra bears to the typical M. congcsta or Spisn/a Ravcucli to S. siuii/is Say. TRANSACTIONS OF WAGNER QO2 TERTIARY FAUNA OF FLORIDA Mulinia Milesii Holmes. Mulinia Milesii Holmes, P.-P1. Fos. S. Car., p. 42, pi. vii., fig. u, 1859. Mulinia parilis Conr., Am. Journ. Conch., iii., p. 269, pi. 22, fig. 5, 1868; not Mactra parilis Conrad. Mitliniii caivliniana Conr., MS. label Coll. Acad. Nat. Sci. Mactra contracta Conr., Am. Journ. Conch., iii., p. 268, pi. 22, fig. 6, 1868. Uppermost Chesapeake Miocene of Virginia, North and South Carolina, and Florida; Holmes, Johnson, Burns, ct al. This form is probably an extremely elongate variety of coiigcsta, of which parilis is the young. The reference of the type of contracta to Mactra by Conrad was an error due to the breaking away of the thin roof of the cartilage-pit and subsequent wear on the broken edges. Mulinia caloosaensis n. s. PLATE 28, FIGURES 4, 6. Pliocene of the Caloosahatchie beds on the Caloosahatchie and Shell Creek, Florida ; Ball and Willcox. Shell small, solid, thick, elongate ovate, subcquilateral, sculptured chiefly by concentric lines of growth ; form somewhat variable, but in general with the anterior side shorter, rounded, the posterior longer, narrower, the dorsal slope descending more rapidly than in front, and terminating in a more or less distinct, somewhat oblique truncation, with its basal angle almost pointed ; dorsal areas polished, with obscure boundaries ; beaks small, pointed, distant, with a keel or angular line extended from the umbo to the posterior basal angle of the shell; interior smooth; pallia! sinus small, pointed in front; hinge normal, solid, strong, the laterals short, finely granular, not cross- striated; the chondrophore completely roofed in, but frequently showing a fissure above due to erosion. Lon. 22, alt. 15, diam. 12 mm. Larger specimens than the one above described arc not uncommon ; the most characteristic features are the broad area set off by the posterior keels, and the somewhat quadrate general form. Mulinia sapotilla n. s. PLATE 28, FIGURES 7, 8, 9, 14. Pliocene of the Caloosahatchie beds ; Dall and Willcox. Shell small, solid, compressed, very inequilateral, varying in form like the rest of the genus, but in general with the beaks at the anterior third of FREE INSTITUTE OF SCIENCE TRRTIARY FAUNA OF FLORIDA the length ; umbones small, low, pointed, adjacent; surface marked only with lines of growth ; anterior end short, evenly rounded from the beaks to the base; posterior end long, dorsal slope nearly rectilinear, ending in a rounded point ; base rather arcuate ; dorsal areas and umbonal angle obscure or un- • defined ; pallia! sinus very wide and short ; hinge feeble, the lateral laminae finely granulose or smooth, the posterior markedly longer than the anterior; left cardinal with a well-marked posterior accessory lamella ; chondrophore small and inconspicuous; hinge-plate very narrow. Lon. 27, alt. 14, diam. 10 mm. This is a very interesting and peculiar species. The figured specimen is rather shorter and higher than that of which the dimensions are given above. The young vary considerably in form from subtrigonal to quite elongate, but these differences become less marked in the adult, though not wholly eliminated. It is one of the most characteristic species of the Caloosahatchic beds. Genus RANGIA Desmoulins. (Gray) Sowerby, Gen. Shells No. 36, Dec., 1831. (Type G. cuneatus Gray) Dall, Mon. Gnath., I'roc. U. S. Nat. Mus., xvii., p. 85, 1894. n^ni Desmoulins, Actes Soc. Lin. de Bordeaux, v., No. 25, p. 50, Feb. 15, 1832. (iiin/<>it(»i K:ui£, Nouv. Ann. du Mus., iii., p. 217, 1834. Co/iiiii/iin lilainville MS., Rang, op. tit., p. 217. C/if mi Goldfuss, Man. Zool., 1820. The reader is referred to the writer's monograph above mentioned for all details. Its Mactroid character and close relationship to Mulinia is there fully established. The synonymy is here finally rectified by the rejection of (,'iMt/nnlon, which turns out to have been used by Goldfuss for a genus of fishes in 1820. In the monograph I mentioned that Gray received his specimens from Canada, which he described (as stated by Conrad) under the name of Clathro- ilon, and sent the MSS. to the American Journal of Science to be published in America about 1830; also that the publication was not made. It is a singular circumstance that immediately after reading the last proofs of my paper on Gnathodon, while engaged in examining a miscellaneous lot of papers from the library of the late Dr. Isaac Lea, presented to the Smith- sonian Institution by his son-in-law, Dr. L. T. Chamberlain, I came upon a TRANSACTIONS OF WAGNER QO4 TERTIARY FAUNA OF FLORIDA sheet of manuscript with a drawing attached, which proved to be the original MS. of Dr. J. E. Gray above alluded to. It is in Mrs. Gray's handwriting, with the specific and generic names inserted in Dr. Gray's hand. It seems that he received the specimens from Mrs. Mauger, who obtained them from Canada. The first name inserted was not Clathrodon, but Cladodon, which is crossed out and Gnathodon substituted for it. The drawing, exquisitely made, is by E. I. Gray. Dr. Lea has endorsed on the envelope : " Wrote Mar. 6, 1832, a second time for instructions respecting this." As the genus had, several months earlier, been published by Sowerby, it is probable that Dr. Gray paid no further attention to the matter. Rangia cuneata dray. Gnathoilon ciincatns (Gray) Sowerby, den. Shells, No. 36, figs. 1-7, 1831 ; Dall, Mon. Gnath., Proc. U. S. Nat. Mus., xvii., p. 93, pi. vii., figs, i and 10, 1894. Rangia cyrcnoidcs Desm., Actes Soc. Lin. de Bordeaux, v., p. 57, figs. 1-3, 1832. Gna/lnnlon Grayi Tuomey and Holmes, Pleioc. Fos. S. Car., p. 99, pi. 23, fig. II, 1857 ; not of Conrad. Gnathodon minor Holmes, Post-Pleioc. Fos. S. Car., p. 41, 1860. Pliocene of the Carolinas and of Florida, rather abundant in the Caloosa- hatchie beds ; Pleistocene of Cornfield Harbor, Chesapeake Bay, and Wailes's Bluff, Potomac River; of South Carolina, Florida, and the whole north coast of the Gulf of Mexico, and of Matamoras, Mexico ; living in Mobile Bay, Alabama, and westward to Vera Cruz, Mexico, in shallow, especially brackish, water. The shell is variable in form, and very abundant when it occurs at all. Rangia clathrodonta Conrad. Afactra clathrodonia Conrad, Am. Journ. Sci., 1st Ser., xxiii., p. 340, 1833. Gnathodon Grayi Conr., Medial Tert., p. 23, pi. 13, fig. i, 1838 ; Emmons, Geol. N. Car.. p. 298, fig. 226 a, 1858. Gnatliodon minor Conr. (young shell), Medial Tert., p. 69, pi. 39, fig. 6, 1840; not of Whitfield. Rangia (Perissodon) clathrodonta Conr., Proc. Acad. Nat. Sci. Phila. 1862, p. 573, 1863. Gnat/ifldiin clathrodon Dall, Mon. dnath. Proc. U. S. Nat. Mus., xvii., p. 95, pi. vii., fig. 9, f894. Chesapeake Miocene of James and York Rivers, Virginia, and North Carolina, Conrad, Ruffin, and Yarrow ; Pliocene of the Croatan beds in North Carolina, Johnson. This is the oldest species of the genus, but seems to be quite limited in FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA its distribution. I have seen no specimens from south of North Carolina. The subgenus Perissodon of Conrad was never defined, and rests upon purely specific characters. His G. minor is merely a young shell of the same species. Section Afioniiigiti Dull. Rangia Johnson! Dal I. PLATE 22, FIGURK 18. <;ii(t//it>i/«/i Jolniioni Dall, Trans. Wagner Inst., iii., p. 337, pi. 22, fig. 18, 1892 ; Proc. U. S. Nat. Mus., xvii., p. 96, pi. vii., fig. 7, 1894. Chesapeake Miocene of the Pascagoula clays, at Shell Bluff, Pascagoula River, Greene County, Mississippi ; also at a depth of seven hundred feet in the artesian well at Biloxi, Mississippi, and seven hundred and thirty-five feet in the artesian well at Mobile, Alabama; L. C. Johnson. This species is smaller and more peculiar in form than any of the others, and presents the peculiarity (extremely rare in this family) of having the superior cardinal tooth in the right instead of the left valve. The anterior lateral tooth is shorter relatively than in any other species, and the shell is more drawn out behind the beaks. In the Miocene (?) of Carrizo Creek,' Colorado Desert, California, Dr. Leconte found a fossil species of Gnathodon, which was named G. Lecontei by Conrad. It is nearest related to R. ciincata. A curious little shell is described and figured by Harris in the Fifth Annual Report of the State Geological Survey of Texas under the name of G. qnadriccntennialis. A careful examina- tion of specimens submitted by Mr. Harris leads me to believe that the species may best be referred to Sfisnla, as the cartilage-pit is not closed above. It is found at a depth of twenty-one hundred to twenty-two hundred and fifty feet in the Galveston artesian well, and belongs to the Upper Miocene. Rangia? minor (Conr.) Whitfield, from the Miocene marl of Shiloh, New Jersey, is founded on a young Jlhilinin in the collection of the U. S. Nat. Museum, and is probably not identical with Conrad's species. Gnathodon / tennidens Whit- field, based on an internal cast from the Cretaceous " Plastic Clays" of New Jersey, is probably referable to Isocardia or some analogous form, and has nothing but the prominent and distant beaks to connect it with Rangia. Several foreign species referred by authors to Rangia are with little doubt more correctly placed in other genera. No undisputed species of Rangia has been found earlier than the Middle Miocene, or in any region exterior to the North American continent. TRANSACTIONS OF WAGNER 006 TERTIARY FAUNA OF FLORIDA Subfamily PTEROPSIDIN^E. r.cmis PTEROPSIS Conrad. I have chosen this genus from which to form the subfamily name, as it is the prototype of the more modern Labiosa and Raeta. The typical species was described by Conrad under the name of Lntraria papyria (Fos. Sh. Tert, p. 41, Oct., 1833), while two months later Dr. Lea gave the name of Martra dentala to a perfectly recognizable fragment of the same species. Genus LABIOSA (Schini.lt) Mollcr. The name Labiosa proposed in MS. by Schmidt for the Anatina of Schu- macher (1817, non Lam., 1809) was printed in an abstract of this MS. after Schmidt's death by Moller in 1832, though without any diagnosis. As it is perfectly identifiable it must be allowed to stand. It is the Cypricia of Gray (1840) and the Lcitcoparia of Ch. Mayer in 1867. The typical form does not seem to antedate the Pliocene in Americaj though in the later Miocene the subgenus Raeta is fully developed. Labiosa lineata Say. Littraria lincata Say, Journ. Acad. Nat. Sci. Phila., ii., p. 310, i8ai. Mactra Nuttallii Rve., Conch. Icon., Mactra, fig. 125, 1854; not 1 .iilriiriu \ 'ntlallii Conr. Mactra recurua Gray, Wood's Ind. Test., Suppl., fig. 2, 1828. Mactra papyracca Auct., non Lam. Pliocene of the Caloosahatchie River and Shell Creek, Florida, Dall and Willcox ; Pleistocene of the southeastern United States ; living from the coast of New Jersey to San Paulo, Brazil. The fossil specimens do not seem to differ at all from the recent ones and run through a parallel series of variations chiefly in the outline and inflation of the valves. The only other typical Labiosa is found on the Pacific coast of middle America, the L. aiiatina Spengler (1802), also named pclliiciila by Schumacher (1817), L. papyracca by Lam. (1818), and L. (Cypricia) cyprinns by Gray (1828). It is not known to occur in a fossil state. Subgenus RAETA Gray. Raeta Gray, Ann. Nat. Hist., ii., p. 43, 1853. Cryptodon H. and A. Adams ; not of Conrad or Turton. Lovellia C. Mayer, 1867. Type L. (A'ni-fa) canaliculala Say. FREE INSTITUTE OF SCIENCE 007 TERTIARY FAUNA OK FLORIDA Labiosa (Raeta) canaliculata S;iy. i,! i-nnafii'iifu/it Say, |oiini. Acad. Nat. Sri. 1'liila., ii., p. 310. 1821. Miii-/r,i fditiiliiiiltitii Kecvi1, Conch. Icon., Maftni, fi^. 122. 1854. Miiftra i 'iiinpct 'ht'iisis ( I ray, Wood's Ind. Test. Suppl., lit;. 3, 1828. Post Pliocene of South Carolina, Burns ; and of North Creek, Little Sarasota Bay, Florida, Ball ; living from New Jersey southward to southern Brazil, United States National Museum. I have not yet seen this species from the Pliocene, though it may very likely be found in that formation in the future. The variations in outline and especially in the recurvature of the rostrate end of the shell in the living form are very remarkable. They seem to be purely individual. Notwith- standing the fact that dead valves of this shell are found in windrows on the beaches at some points of the southern coast, the character of the soft parts is unknown, and I shall be very greatly obliged to any one who can furnish me with a specimen of the animal in spirits in order that its systematic posi- tion may be positively settled. Labiosa (Raeta) alta Conrad. PI.ATK 27, FIGURES 20, 23. /\\i','-fi>ui:~elandi(C ;" and cites as a distinct genus 573," Anapa Gray," with Ery- cina Petitiana Recluz as the type. Ei~i'ilia Turton is also included in the family. The next publication by Gray on this subject was his important summary of 1853 (Ann. Nat. Hist, p. 44) in which the " Paphiadce" are divided, by the presence or absence of a pallial sinus, into two groups. In the first, with " a siphonal inflection," are put Mesodesma Desh., with M. novee- zelandice as type ; Taria n. g., with T. Stokesii n. s. as type ; Donacilla Lam., with D. cornea as type; Paphia Lam., with P. glabrata and vcntricosa ; and Ccronia, with C. denticnlata. In the group without a sinus arc included Anapa Gray (1842 and 1847) with an entirely different type from that of 1847, namely A. Smit/iii of Tas- mania ; and Davila Gray, n. g., based on D. polita. The above arrangement is good, but the nomenclature is very faulty, as will shortly appear. It should be mentioned that in the synonymy of Mesodesma no-.: /audits in a catalogue of New Zealand shells, published in Dieffenbach's New Zealand, 1843, Gray had noted that Leach had used the name Macluena for that species in some of his manuscripts, doubtless in allusion to its solen-like form. In the same year d'Orbigny would adopt Donacilla in place of Meso- desma, a course which is impracticable, because Donacille was never Latinized, described, or typified in a sufficient manner by its author. It would have been better, doubtless, if Deshayes had adopted and established this name instead of proposing a new one, but he was quite within his rights in doing what he did. The Adams brothers, Woodward, and others followed Gray in essentials, TRANSACTIONS OF WAGNER QIO TERTIARY FAUNA OF FLORIDA while the last reviser, Fischer, would restrict Mesodesma s. s. to the Donacilla type, use Machcena for M. novceselandice, Eryx Swainson for M. glabratum, in other respects following Gray. Lastly, to close the record of the nomenclature of this group, Ervilia Turton (1822) and C&cella Gray, 1853, may be mentioned, and Conrad's Tri- quctra, 1846, for which he substituted MactropSK in 1854, a genus based on two Claibornian species in which the first stages of submergence of the liga- ment are well exemplified. A number of the names above cited arc not available for reasons which may be stated. Paphia is preoccupied by Bolten, who has precedence of one year. Donacilla was not characterized, but if we adopt M. donaduin Lam. (chilensis Orb.), Deshayes's first species, as the type of Mesodesma, Donacilla can be revived in a sectional sense for the smooth-toothed cuneate species, as was done by- Gray; in which case Ccronia Gray becomes an exact syn- onyme of Mesodesma. Paphies Lesson has precedence of Mach&na for M. novtzzelandice (= M. australis Gmelin). The original Anapa Gray is a synonyme of Lascea (Leach) Brown, and cannot be used for the Tasmanian genus to which Gray later applied it. The family will then stand as follows : Subfamily MESODESMATIN./E. Shells heavy, with a pallial sinus more or less developed ; siphons sepa- rate from their bases ; shell substance porcellanous, epidermis conspicuous ; ligament inconspicuous, generally inserted on the upper part of the posterior border of the " cartilage-pit," if wholly external more or less obsolete ; resilium narrow, oblique ; hinge with an anterior and posterior lateral in the left valve, fitting between laminae in the right valve ; recent species with a single narrow, long left cardinal tooth, with a short posterior arm which crosses the apex of the cartilage-pit ; right cardinal lamellar feeble, obsolete ; Eocene species have the cardinals normal. Genus MACTROPSIS Conrad. Mactropsis Conrad, Proc. Acad. Nat. Sci., vii., p. 30, 1854. Triquetra Conrad, Am. Journ. Sci., 2d Ser., i., p. 217, 1846; not Blainville, 1818. This differs from all the recent forms in that the combined ligament and resilium are very near the dorsal border, and the cardinal teeth are distinct, with subequal arms. The laterals are striated transversely. As the sub- mergence of the resilium progressed in later species, it gradually encroached FREE INSTITUTE OF SCIENCE QI I TERTIARY FAUNA OF FLORIDA upon and nearly destroyed the posterior arm of the cardinals ; but in the two Eocene species upon which this genus was founded the pit does not descend more than half way from the dorsal border to the ventral margin of the hinge- plate. The pallial sinus is small but well marked. The type is M. (cqnorea Conrad, Tert. Fos., p. 42, 1833 (=- Mactra Grayi Lea). M. rectilinearis Con- rad is a somewhat larger species from the same horizon. The intermediate state in which the hinge is found in this genus is good evidence that in America, at least, this family is not likely to be found in earlier than Eocene rocks. Genus ATACTODEA Dall. Papliia Lam., 1801 (,-x pur/,-), not Holten, 1798; I'lrycina Shy., 1822, not Lam., 1804; ,M,-«>tifsniii sp. Desh., 1835 '> /'•'J'-1" Swaiiison, Malacol., p. 370, 1840, not Dauclin in ir Stephens, 1832. Alnclnilt'ii Dall., I "roc. Mai. Sue. Loud., i., p. 213, 1895. Type 1'iT/iliiit gliil/mlii Lam. ; huln-I'acilic region. Shell subtngonal, strong, concentrically sculptured or smooth ; pallial line with a short, well-marked sinus; hinge strong, ligament submarginal, obsolete; cartilage narrow, strong; dorsal areas not differentiated. The group is exclusively old world and especially tropical, extending from the Red Sea to Japan and south to Mauritius. The species are few and mostly very similar in appearance ; the soft parts are unknown. Genus MBSODESMA. Ix-sluiycs. M,-Mi,l,-Miia iK-bh., 1830, Knc. Meth., Vers, ii., p. 442. T\ pe .!/. tlntiitciuni Lam. (- .17. chilcnsf Orb.) ; Chile. Subgenus MESODESMA s. s. Shell donaciform or subtrigonal, inequilateral, solid, with a thick epi- dermis, smooth or concentrically striated, posterior end siibtruncatcci, shorter; dorsal .areas not differentiated; hinge strong, resiliary pit large, deep, with raised margins ; ligament short, chiefly internal ; lateral teeth transversely sulcate, strong, the anterior elongated; pallial sinus well marked. Ceroiiia Gray, 1853, is a synonyme. The species are found in temperate waters of both shores of South America, New Zealand, and the northeastern shore of North America. J/ arctatmii Conrad and M. tlantratitiii Turton are known from the Pleistocene of eastern North America, north of Cape Cod, and M. His/topi White (Powell, Rep. Geol. Uinta Mts., p. 128, 1876) has been described from the western brackish-water Tertiary, but the exact locality TRANSACTIONS OF WAGNER 012 TERTIARY FAUNA OF FLORIDA and age are uncertain. Harris has described a Ceronia Singleyi (Proc. Acad. Nat. Sci. Phila. for 1895, p. 52, pi. 3, fig. 3) from the Lower Claibornian of Lee County, Texas, but the interior is still unknown and the generic position somewhat dubious. Subgenus DONACILLA (Lam.) Philippi. lliiiiiu-illc Lam., Extr. d'un Cours., p. 107, 1812 ; Donacilla Phil. Moll. Sicil., p. 37, 1836; Aiuplii<{i'vihi sp. Lam., 1818; Mcsuiii-siiui sp. Dcsh., 1830; Erycina. sp. Sby., 1822. Type -I/, conicn in I'oli; Mediterranean. Ligament marginal, obsolete; laterals not sulcate, the anterior lateral long, the posterior short, stout, triangular, with the posterior margin of the cartilage-pit raised and thickened like a second tooth ; posterior ventral lamina in the right valve triangular, stout, elevated, vertically directed, the dorsal lamina obsolete, the anterior laminae normal. The group is represented in Europe, Australia, and New Zealand. The shells are mostly small with a horny, often colored epidermis. The Mediter- ranean species is the only member of the subfamily which displays color markings on the shell not pertaining solely to the epidermis. Subgenus TARIA Gray. Taria Gray, Ann. Mag. Nat. Hist., 1853, p. 44. Mesoiii-sniti sp. Dcsh. Type M. Stokcsii Gray (MS. ?) = M. latitm Desh., N. Zealand. Shell subtrigonal, subequilateral ; the hinge concentrated ; the laterals smooth, subequal, short ; the ligament short, strong, mostly internal ; the resilium narrow ; the chondrophore depressed, projecting prominently down- ward ; pallial sinus well marked, sometimes deep. The species occur in New Zealand and on the eastern coast of South America. Subgenus PAPHIES Lesson. Paphies Lesson, Dnperrcy, Voy. Coq., ii., pt. i., p. 424, 1830; .l/,jr//,,y;,r (Leach MS.) Cray, DietT. N. Zeal., ii., p. 252, No. 174, 1843; M<-snifi-sin,i And. ; l',i/>/ii,i llutton, Proc. Lin. Soc. N. S. Wales, x., p. 519, 1884 ; not of Lam. Type M. diislrafis Gmel., (= Mya iwiia-'jcltiniliii' Chcmnitx, I'aplin-s Roissyana Lesson <•/ Mesodesma Chemnitzii Deshayes) ; New Zealand. Shell elongated, subequilateral, subsolenifonn, solid ; hinge concentrated, heavy; laterals smooth or finely granulose, short; ligament short, mostly internal, small; resilium narrow, vertical; the chondrophore. projecting ; pallial sinus very small, angular. Two species are known, from New Zealand. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA Subfamily DAVILINJE. Pallial line simple. Genus DA VILA Gray. />,','i/i! Gray, Ann. Mag. N. Hist., 1853, p. 44. Type />. fioli/ti Gray (MS. ?) = I). f>lnn,t Ilanley, Philippines. Shell compressed, rounded, smooth, with a thin epidermis and simple pallia! line; laterals as in Donacilla ; left cardinal very large and prominent, right cardinal obsolete; ligament small, nearly marginal; cartilage narrow, elongated. There are three or four species, all Indo- Pacific. They are all small and much alike. D. crassnla Desh. (Mesodesma i/in/ufinn GUI.) has color markings near the umbones. Genus ANAPELLA Dall. Aiitipi'llti Dall, I 'roc. Mai. Soc. Loud., I, p. 213, 1895. Aiiiipn Gray, 1853; not Gray, 1X47. (The latter was based upon Jjisirn rnhra, other- wise /''.r\'i tint I'liitiiinti Redux..) Type Anapa Sinil/iii Gray, = ./. /n'l/iii'fm Ilanley, Tasmania. Shell subtrigonal, solid, inflated, concentrically sculptured; dorsal areas obscure; beaks moderate, adjacent, somewhat anterior; valves close fitting; pallial sinus absent, the pallia! line presenting a projecting angle below the posterior adductor; ligament short, partly external between the beaks, partly sunken and attached in a short sinus over the chondrophore, not set off from the resilium by any shelly ridge; chondrophore somewhat below the level of the hinge-plate, strong, its ventral margin somewhat projecting, directed back- ward ; left cardinal strong, narrow, grooved at the apex, with a small obscure accessory lamella ; laterals strong, rather irregular and distant ; right cardinal small, nidi-, its posterior arm walling the pit, its anterior arm short, more prominent, coalesccnt above; lamina? rude, normal, the vcntrals most promi- nent; resilium strong, with its anterior face calcareous. A few species range from Tasmania to the Philippine Islands. They resemble Atactodca except in the absence of a pallial sinus and in having a nitler hinge. Subfamily ERVILIINJE. Shells small, thin, equilateral, concentrically sculptured or smooth ; liga- ment marginal, obsolete, or absent; resilium small; hinge much concentrated; laterals small, dorsal anterior lamina absent, the ventral more or less coales- TRANSACTIONS OF WAGNER Q14. TERTIARY FAUNA OF FLORIDA cent with anterior arm of the right cardinal ; left cardinal large, bifid; pallial sinus well marked. This group has representatives in European seas, the West Indies and southeastern coast of North America, the Red Sea, and Indo- Pacific region. Genus CJECELLA Gray. Cacclla (",niy, 1853, Ann. Mag. N. Hist., p. 43. Type C. Ihi-sJiMii Cray (MS.?); China. Shell large, concentrically striate, white, with a thick brown epidermis, well marked pallial sinus, obsolete marginal ligament, and fluviatile or brackish-water habitat. This genus was referred to the Mactridce by Gray, but a careful study has convinced me that it stands nearest to Ervilla, and if that genus belongs in the Mesodesinatidce so does Ciecclla ; the soft parts of neither being known, their place is not decisively settled. Its distribution is confined, as far as known, to the Indo-Pacific and Austral region. Genus ERVILIA Turtmi. Ewilia Turton, 1822, Brit, liiv., p. 56. Type My a iii/t-iis Montagu ; Britain, South Europe. Shell small, concentrically striate, sometimes brightly colored; pallial sinus well marked; ligament obsolete; epidermis inconspicuous; habitat marine. Er villa chipolana n. s. PLATE 33, FIGURE 10. Oligocene of the lower bed at Alum Bluff and the equivalent marl at McCIellan's marl bed, Chipola River, Calhoun County, Florida; Dall and Burns. Shell small, inflated, pointed behind, the posterior part slightly longer, the anterior end shorter and rounder ; the base evenly arched, the pallial sinus moderately wide, rounded in front, not reaching the vertical of the beaks; umboncs low, not prominent; the sculpture of rather irregular con- centric threads and grooves, absent from the umbones and frequently from a great part of the valves. Lon. 4.5, alt. 3, diam. 2 mm. This species, which is very common in the beds, is readily distinguished from E. concentrica, to which it is most nearly allied, by its more pointed posterior end, its coarser and less regular sculpture, its less conspicuous beaks, and generally smaller size. FREE INSTITUTE OF SCIENCE oi c; TERTIARY FAUNA OF FLORIDA Ervilia triangularis n. s. 1'l.ATK 3J, FlCURK 19. Oligocene of the Chipola beds, at McClcllan's marl bed. Shell small, solid, plump, subtriangular, inequilateral, with steep, nearly straight, dorsal slopes and an evenly arched base ; surface smooth or marked only by rather irregular incremental lines; pallial sinus rounded, falling a little short of the vertical from the beaks; umbones low, calyculate; hinge strong, with the cardinal teeth prominent, and the marginal grooves in the right valve to receive the dorsal edges of the opposite valve long and well marked. Lon. 5.5, alt. 4, cliam. 2.5 mm. This form may prove to be an extreme variety of E. cliipolana, but the specimens so far collected are distinguished by their smoother surface, much more triangular form, and more inequilateral shell. It seems to be compara- tively rare in the marl, and further study is required to settle its systematic value. Ervilia lata n. s. PI.YIK 33, KICURK 20. Newer Miocene of the Natural Well and at Magnolia, Duplin County, North Carolina, Burns ; and of Walton County, Florida, L. C. Johnson. Small, very similar to E. conccntrica, from which it differs by being broader between the beak and the basal margin, with the beaks slightly more equilateral and the dorsal margin behind the umbo usually more im- pressed ; the surface is usually covered with concentric ridges, which are flattened and coarser and less regular than those of E. conccntrica; the hinge-teeth also are less strong than the latter species. Lon. 4.5 ; alt. 3.5 ; diam. 2.2 mm. This form on casual inspection would be referred to E. conccntrica as a mere variety, but when a large number of specimens are examined and the characters above mentioned seem to be fairly constant, I believe it is best to recognize the average differences by a name, than to overlook them by con- solidation with what I regard as probably a distinct species. The Floridian specimens are particularly triangular and small. Ervilia planata n. s. Oligocene sand (Alum Bluff beds) of Oak Grove, Yellow River, Santa Rosa County, Florida ; F. Burns. Shell small, subtriangular, flattened, smooth or obscurely concentrically 23 TRANSACTIONS OF WAGNER 016 TERTIARY FAUNA OF FLORIDA ridged, subequilateral ; the beaks low, calyculate ; the dorsal slopes slightly rounded, subequal ; the base evenly arched, not projecting ; hinge well de- veloped, the marginal grooves in the right valve almost as long as the dorsal margins; pallial sinus small, rounded in front, falling considerably short of the vertical from the beaks. Lon. 3.25, alt. 2.25, diam. 1.5 mm. This small form is distinctly flattened, and looks not unlike the flat valve of some Corbulas. Only a few valves were obtained, but all agreed in this character. The sculpture seems to have been not unlike that of E. chipolana. The horizon is younger than the Chipola marl, but carries, with some peculiar forms, a number of Chipola species. Ervilia polita n. s. PLATE 33, FIGURE 17. Pliocene of the Caloosahatchie and Shell Creek ; Ball and Willcox. Shell inequilateral, moderately full, the anterior end shorter, the ends evenly rounded, the base gently curved ; dorsal slopes gentle, dorsal margins nearly straight, the posterior a little depressed ; surface smooth, polished, marked only by feeble incremental lines; hinge normal, delicate; pallial sinus rounded in front, reaching forward of the vertical from the beaks. Lon. 6.25, alt. 3.75, diam. 2.3 mm. It is somewhat odd that the Pliocene species, which is very abundant in the Caloosahatchie marl, should be more unlike either of the recent species than the forms here made known from the Oligocene. E. polita appears to be a very well-characterized and distinct species. Ervilia oregonensis n. s. PLATE 33, FIGURE 16. Eocene (?) of the Nehalem River, Columbia County, Oregon; J. S. Diller. Shell small, oval, moderately inflated, smooth and more or less polished ; inequilateral, the beaks low, small, closely adjacent ; the anterior end slightly more acute than the posterior end; interior unknown. Lon. 7.5, alt. 5, diam. 3.25 mm. Although this shell is detached from hard rock and the interior cannot be examined, I feel no doubt that it is correctly referred to this genus, and have included it here to complete the list of our fossil species. PLATE XXIII. Fig. i. Solariclla lonisiana Dall ; alt. 5.5 mm. ; p. 407. Fig. I a. The same, from below ; max. diam. 7 mm. ; p. 407. Fig. 2. Solariella turritella Dall ; alt. 5.6 mm. ; p. 408. Fig. 3. Liotia agenea Dall ; diam. 2.5 mm. ; p. 410. Fig. 3 a. The same, from below ; p. 410. Fig. 4. Vaginc/la chipolana Dall, ventral view ; 5.5111111.; p. 431. Fig. 5. The same, in profile ; p. 431. Fig. 6. Teinostoma chipolanum Dall, from below ; 2.3 mm. ; p. 413. Fig. 7. The same, from above ; p. 413. Fig. 8. Teinostoma caloosaense Dall, from below ; 2 mm. ; p. 413. Fig. 9. Teinostoma microforatis Dall, from above ; 4.7 mm. ; p. 415. Fig. 10. The same, from below ; 4.7 mm. ; p. 415. Fig. ii. Teinostoma steiratum Dall ; 2.6 mm. ; p. 415. Fig. 12. Teinostoma pseudadeorbis Dall, from below ; 5.5 mm. ; p. 417. Fig. 13. The same, in profile ; p. 417. Fig. 14. Teinostoma collinus Dall ; 2 mm. ; p. 416. Fig. 15. Teinostoma funiculus Dall, from below ; 2.4 mm. ; p. 417. Fig. 1 6. Cochliolepis striata Stimpson, basal view ; 6 mm. ; p. 419. Fig. 17. The same, from above ; p. 419. Fig. 18. Mdllcria diiplinensis Dall ; 2 mm. ; p. 421. Fig. 19. Neritina chipolana Dall ; 5 mm. ; p. 422. Fig. 20. Calliostoma cyclus Dall, from below ; 5.2 mm. ; p. 403. Fig. 20 b. The same, in profile ; p. 403. Fig. 21. Fissuridca chipolana Dall ; 15 mm. ; p. 426. Fig. 22. Lucapina (Foraminelld) sitffusa Reeve ; 14.75 mm. ; p. 424. Fig. 23 a. Ischnochiton tampa'ensis Dall, central valve, from above ; the fine granulation is not indicated ; lat. 4 mm. ; p. 434. Fig. 23 b. The same valve, from below ; p. 434. Fig. 24. Dentalium caloosaense Dall ; 50 mm. ; the dorsoventral line in the accompany- ing view of the anterior orifice would be horizontal or parallel to the base of the plate, p. 441. Fig. 25. Dentalium cadiiloide Dall ; the same remark applies to the figure of the aperture ; 10 mm. ; p. 442. Fig. 26. Cadulns floridanus Dall ; 9.25 mm. ; p. 446. NOTE. — -As it was necessary to assign numbers to these figures before they could be assembled on the plate, the sequence of the numbers has been broken up. As the figures are of different degrees of magnification, the longest dimension of the specimen — viewed as in the figure — follows the name in the references to this and the other plates, except where otherwise stated. 918 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXIII. PLATE XXIV. Fig. l. Gemma purpurca var. Tottcni Stm., from above ; 3.5 mm. Fig. 2. Gemma purpurca Lea, right valve, from above; 2.8 mm. Fig. 3. Gemma purpurca var. Tottcni Stm., side view ; 3.5mm. Fig. 4. Gemma purpurca Lea, side view ; 2.8 mm. Fig. 4b. Gemma purpurca Lea, interior of right valve ; 2.8 mm. Fig. 5. Carolia floridana Dall, view of the cardinal region showing valves in juxta- position ; p. 777. Fig. 6. Carolia floridana Dall, from above ; no mm. ; p. 777. Fig. 6 b. Carolia floridana Dall, profile of part of the lower valve showing scar of foramen and profile of chondrophorus ; p. 777. Fig. 7. Carolia fl.oridana Dall, view of the same from above. Fig. 7 b. Carolia floridana Dall, showing interior of upper valve, cardinal areas, liga- mentary and adductor scars ; 1 10 mm. ; p. 777. Fig. 8. Aligena aquata Conrad, sp., Miocene of Virginia; interior of the left valve; 5 mm. Fig. 8 a. Aligena a-quata Conrad, sp., showing exterior of left valve ; 5 mm. Fig. 8 b. Aligena cequata Conrad, sp., showing interior of right valve ; 7 mm. Fig. 9. Plcurodon Adamsii Dall, interior of right valve ; 3.25 mm. ; Florida Strait ; figured for comparison ; p. 60 1. Fig. 10. Pleitrodon Woodii Dall ; 2.75 mm. ; p. 600. 919 TRANSACTIONS WAGNER FREB INSTITUTE OF SCIENCE PLATE XXIV. PLATE XXV. Fig. i. ~\Arca {Cucullaria} tceniata Dall, inner and outer view of left valve; Ion. 52 Fig. i a. J mm. ; p. 631. \ Coralliophaga elegans Dall ; Ballast Point silex beds ; Ion. 19 mm. Fig. 2 a. J Fig. 3. Sportella lancea H. C. Lea ; Caloosahatchie beds ; Ion. 10 mm. Fig. 3 a. Sportella compressa H. C. Lea; Caloosahatchie beds ; 7.2mm. Fig. 4. Sportella constricta Conrad ; Caloosahatchie beds ; right valve ; 9 mm. Fig. 4 a. Sportclla constricta Conrad, left valve ; 9 mm. Fig. 5. Unio caloosaensis Dall, profile ; 45 mm. ; p. 688. Fig. 6. Bornia lioica Dall; Caloosahatchie beds ; Ion. 9.5 mm. Fig. 7. Leda multilincata Conrad, valve in profile showing teeth ; 20 mm. ; p. 588. Fig. 8. Bornia Mazyckii .Dall ; Caloosahatchie beds ; 11.5 mm. Fig. 9. Lucina {Here) ainabilis Dall ; Caloosahatchie beds ; interior of right valve- showing sunken lunule ; alt. 1 5. 5 mm. Fig. 9 a. Lucina {Here} ainabilis Dall, front view ; alt. 15.5 mm. Fig. 10. Psammobia {Gobreeus} IVagneri Dall ; Caloosahatchie beds ; 77 mm. Fig. II. Leda multilincata Conrad ; 20 mm; p. 588. Fig. 1 1 b. Leda multilincata Conrad, from above, in profile ; 20 mm. ; Fig. 12. Scintilla Kurtsii Dall ; Caloosahatchie beds; Ion. 8.25 mm. Fig. I2b. Unio caloosaensis Dall, viewed from above ; 57 mm. ; p. 688. 920 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATH XXV. 2 la lib 4a 12b 12 PLATE XXVI. Fig. I. Pecten expansus Dall, view of right valve ; lat. 147 mm. ; p. 706. Fig. 2. Pecten coosensis Shumard, view of right valve ; alt. 100 mm. ; p. 700. Fig. 3. Pecten deminrgus Dall, view of right valve ; alt. 71 mm. ; p. 718. Fig. 4. Pinna caloosa'ensis Uall, interior view of part of left valve near apex ; Ion. 120 mm. ; p. 660. Fig. 5. Pecten Stearnsii Dall, view of right valve ; alt. 71 mm.; p. 706. Fig. 6. Pecten Aladisonius var. Sayanus Dall, view of right valve ; lat. 135 mm. ; p. 725. Fig. 7. Pecten fucamis Dall, view of mold of left valve ; alt. 85 mm. ; p. 704. 92I TRANSACTIONS WAGNKR FREE INSTITUTE < >[• SCIENCH PLATE XXVI. PLATE XXVII. Fig. i. Mactra (Mactrotomd) fragilis Gmelin, right valve from below, showing the pro- file of the hinge-teeth : a, anterior ventral, and b, anterior dorsal lamina ; c, accessory lamella of, if, anterior arm of the right cardinal tooth, and f, posterior arm of the same ; the space between the teeth a, c, d, c and the edge of the chondrophore is the ventral sinus, that between a and b is the anterior sinus ; f, septum between the ligament (attached to the shell at if) and the rcsilium ; // and / are the ventral and dorsal posterior lamina' respectively ; about 60 mm. ; p. 876. Fig. 2. Spisula (Hcinimactra) citrlidcns Dall, outline of young shell traced from incre- mental lines on broken larger valve ; 35 mm. ; p. 898. f'S- 3- Spisula (Hfiniinactni) subpotlderosa Orbigny, profile of hinge from above, left valve : a, anterior lateral ; /;, cardinal tooth ; c, accessory lamella ; d, spur with part of the cavity for the sagittate ligament below it ; c, scar of attach- ment of ligament ; f, posterior lateral lamina ; 70 mm. ; p. 878. Fig. 4. Mactra (Mactrotoma) fragilis Gmel., part of right valve showing hinge: a, anterior dorsal lamina ; f, anterior ventral lamina ; b, accessory lamella of, f, anterior arm (t, posterior arm) of the right cardinal ; d, septum between the resilium and ligament ; -c, ligamentary scar ; p. 876. Fig. 5. Teinosloma (Solariorbis) jloi'idannin Dall, 1 895, 'upper surface ; 1.6 mm. Fig. 6. The same, lower surface ; Pliocene of the Caloosahatchie beds. Fig. 7. Spisula (Mactnuncris) dodona Dall, exterior of right valve ; Oak Grove, Florida ; 50 mm. ; p. 896. Fig. 8. Mactra (Alactrotoina) Jragilis Gmel., left valve, profile of hinge-plate : a, anterior lamina ; /;, accessory lamella ; c, cardinal tooth ; d, septum ; f, posterior lamina ; p. 876. . Fig. 9. Teinosloma (Solariorbis) Jloridanuin Dall ; 1.6 mm. Fig. 10. Teinosloma (Solariorbis) undiila Dall, 1895 ; from Natural Well of Duplin County, North Carolina ; 2.5 mm. Fig. II. The same, from above ; Miocene. Fig. 12. Teinostoma (Solariorbis) ihiplincnsc Dall, 1895; Miocene; from below ; 2mm. Fig. 13. Spisula (Mactroineris) dodona Dall, hinge-plate of left valve ; 30 mm. ; p. 878. Fig. 14. Mactrclla alata Spengler, hinge-plate of left valve : a and /;, posterior lamina- ; f, scar of ligament above septum ; d, spur ; posterior and anterior sides of cardinal tooth are supported by, e, septal buttresses ; s, anterior sinus ; /, anterior lamina ; 57 mm. ; p. 877. Fig. 15. Teinostoma (Solariorbis) duplinense Dall, from above ; diam. 2 mm. Fig. 16. Spisula (Hciniinaitra) stikpondcrosa Orbigny, hinge-plate of left valve : a, dorsal, and c, ventral posterior lamina: ; b, ligamentary scar not separated from the pit below by a septum ; c, spur ; /", accessory lamella ; /, petaloid cardinal tooth ; d, anterior lamina with s, absorption scar, from ventral lamina of opposite valve ; 70 mm. ; pp. 878, 899. Fig. 17. Teinostoma (Solariorbis) itndiila Dall, from below ; 2.5 mm. Fig. 18. Mactra {Mactrotoma) fragilis Gmelin, hinge-plate of left valve : a, posterior lamina ; b, ligamentary scar with septum below it ; c, spur, roofing the pit ; d, cardinal tooth with e, accessory lamella, and f, anterior lamina ; p. 876. Fig. 19. Mactra chipolana Dall, hinge-plate of left valve : -a, dorsal, and c, ventral posterior lamina ; b, ligamentary scar ; c, spur ; f, anterior arm of cardinal tooth ; d, anterior lamina ; the septum is not shown very clearly, being seen on edge ; p. 892. Fig. 20. Labiosa (Racta*) a/fa Conrad, exterior of right valve ; 65 mm. ; p. 907. Fig. 21. Tcinostoiiui (Solariorbis) duplinense Dall ; 2 mm. Fig. 22. Spisula (Hcniimactra~) dcnsa Dall, exterior of left valve ; Oak Grove, Florida ; 14 mm. ; p. 900. Fig. 23. Labiosa (Racta) alta Conrad, hinge-plate of left valve : f, anterior lamina ; c, ligament scar with septum below it ; /', cardinal tooth with one arm project- ing over the chondrophore ; a, anterior lamina ; 33 mm. ; p. 907. Fig. 24. Spisula (Hcmiinactra) curtidcns Dall, hinge-plate of right valve : a, dorsal, and e, ventral anterior lamina; ; b, anterior arm of cardinal tooth ; c, ligament scar, without septum below it ; d and f, posterior lamina} ; 44 mm. ; p. 878. Fig. 25. Spisula (Mactroineris) dodona Dall, hinge-plate of right valve ; 30 mm. ; p. 896. Fig. 26. Spisula dcluinbis Conrad ; Suffolk, Virginia ; interior of right valve ; 96 mm. ; p. 897. Fig. 27. Gyrodisca diiplincn sis Dall, 1895; Upper Miocene ; 3.6111111. /^ Fig. 28. Modiolus tainpacnsis Dall ; from liallast Point silex beds ; interior of right valve ; 22.5 mm. ; p. 793. Fig. 29. Spisula ma^nol/ana Dall, interior of left valve ; 19 mm. ; p. 899. 922 • TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXVII. PLATE XXVIII. Fig. i. Liicina (Milthd) caloosaensis Dull, right valve ; 55 mm. ; Pliocene. Fig. 2. Diplodonta acclinis Conrad, interior of right valve ; from the Caloosahatchie beds ; 23 mm. Fig. 3. Lima caloosana Dall ; 33 mm. ; p. 767. Fig. 4. 'Mulinia caloosaensis Dall, profile ; 22 mm. ; p. 902. Fig. 5. Spisula marylandica Dall, interior of right valve ; 92 mm. ; p. 897. Fig. 6. Mulinia CdlooSO/insis Dall, dorsal aspect ; 22 mm. ; p. 902. Fig. 7. Mulinia sapotilla Dall, interior of an elevated young right valve ; 18 mm. ; p. 880. Fig. 8. Mitlinia sapotilla Dall, dorsal aspect ; 12 mm. ; p. 902. Fig. 9. Mulinia sapotilla Dall, interior of adult left valve, showing elongation ; 29 mm. ; p. 880. Fig. 10. Mactra (Afyctrotoma) //'///< vuv'/ Dall, interior of right valve ; 45 mm. ; p. 894. Fig. n. Mactra (Mactivtoma) M'illcoxii Dall, exterior of left valve ; 45 mm. ; p. 894. Fig. 12. Mactra (Aficromac(ra) undula Dall, interior of left valve ; 42.5 mm. ; p. 893. Fig. 13. Diplodonta acclinis Conrad, exterior of right valve ; 23 mm. Fig. 14. Mulinia sapotilla Dall, exterior of valve figured above at fig. 7 ; 18 mm. ; p. 902. Fig. 15. Afactra multilineata Dall, exterior of left valve ; from the Caloosahatchie beds ; 49 mm. Fig. 16. Donax 1-jiimonsi Dall, 1892; Miocene of North Carolina ; profile; 10 mm. Fig. 17. Donax aqtrilibrata Dall, 1892 ; Miocene of North Carolina ; profile ; 18 mm. 923 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXVIII. PLATE XXIX. Fig. i. Pcctcn /loii'iit-iu-iisis Dall, exterior of left or flat valve ; hit. 36 mm. ; p. 713. Fig. 2. Pcctcn oca/anus Dall, left valve ; lat. 36 mm. ; p. 756. Pig. 3. Pec ten Gabbi Dajl, right valve ; lat. 53 mm. ; p. 717. .Fig. 4. I'cctcn \yi//c7i.tfi Dall, right valve ; alt. 19111111.; p. 737. Fig. 5. I'cctcn cborens var. scncscens Dall, left valve ; lat. 63 mm. ; p. 751. Fig. 6. Pcctcn opuntia Dall, left valve ; alt. 33 mm. ; p. 707. Fig. 7. Pinna c/uadrata Dall, exteVna* view of anterior portion of internal cast ; Ion. 56 mm. ; p. 660. Fig. 8. Pfctcn subvcntricosus Dall, left valve ; lat. 63 mm. ; p. 707. Fig. '9. Pcctcn c/iipolanus Dall ; lat. 25.5 mm. ; left valve ; p. 733. Fig. 10. Pcctcn Kavi-iifli Dall, right or convex valve ; lat. 48 mm. ; p. 721. Fig. I I. Alrina Harrisii Dall, exterior of decorticated right valve ; alt. 150 mm. ; p. 663. Fig. 12. J'cctcn caloosaensis Dall, right valve ; alt. 64 mm. ; p. 731. 924 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXIX. PLATE XXX. Fig. i. Spisula duplinensis Dall, interior of right valve ; Miocene, Duplin County, North Carolina; Ion. 58 mm. ; p. 898. Fig. 2. Modialus graintitatus Dall ; Ballast Point silex beds; Ion. 20 mm. ; p. 794. Fig. 3. Lima smirna Dall; Oligocene ; Ballast Point silex beds; alt. 31 mm. ; p. 766. Fig. 4. Ostrea falco Dall, inner face of upper valve; Zeuglodon bed; alt. 55 mm.; p. 682. Fig. 5. Ostrea podagrina Dall ; Oligocene of Suwanee River, Florida; interior of upper valve ; alt. 1 10 mm. ; p. 682. Fig. 6. The same, external view ; p. 682. Fig. 7. Tellina dodona Dall ; Oligocene, Oak Grove marl ; Ion. 16 mm. Frg. 8. Pododesmus scope/us Dall ; Rock Bluff marl ; inner face of attached valve ; lat. 57 mm. ; p. 779. Fig. 9. Mytilits pandionis Dall ; umbonal view ; p. 787. Fig. 10. Mytiltts pandionis Dall; White Beach, Osprey, Florida; internal cast of right valve ; Ion. 122 mm. ; p. 787. Fig. II. Ostrea falco Dall; alt. 55 mm. ; external view; p. 682. 925 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXX. PLATE XXXI. Fig. I. Area (Scapharca) dodona Dall ; Oak Grove marl; umbonal view; Ion. 40 mm. ; p. 640. Fig. 2. Area (Scapharca) santarosana Dall ; Oak Grove marl ; umbonal view ; Ion. 37 mm. ; p. 641. Fig. 3. Area (Scapharca) campyla Dall ; Caloosahatchie beds ; side view ; Ion. 37 mm. ; p. 644. Fig. 4. Area (Scapharca) campyla Dall, umbonal view, showing tortuosity of the valves ; Ion. 37 mm. ; p. 644. Fig. 5. Area (A nadara) alciina Dall ; Caloosahatchie beds ; Ion. 30111111.; p. 635.- Fig. 6. Area (Anadara) rustica Tuomey and Holmes; Caloosahatchie beds; Ion. 54 mm. ; p. 653. Fig. 7. Area (Anadara) aleima Dall ; Caloosahatchie beds ; view of interior of left valve; Ion. 30 mm. ; p. 635. Fig. 8. Area (Scapharca) dodona Dall ; Oak Grove marl ; profile view of left valve ; Ion. 40 mm. ; p. 640. Fig. 8 a. Enlarged view of posterior rib sculpture of the same ; p. 640. Fig. 9. Area (Anadara) rustica Tuomey and Holmes, umbonal view ; Ion. 54 mm. ; P- 653- Fig. 10. Area (Scapharca) santarosana Dall ; Oak Grove marl ; profile view of left valve ; Ion. 37 mm. ; p. 641. Fig. n. Area (Scapharca) stamina/a Dall ; Chipola marl ; Ion. 27 mm. ; p. 641. Fig. 12. Area aquila Heilprin ; Caloosahatchie beds ; Ion. 33.5111111.; p. 621. Fig. 13. Area (Scapharca) staminata Dall; Miocene, Walton County, Florida; Ion. 37 mm. ; p. 641. Fig. 14. Area (Noetia) litnula Conrad; Caloosahatchie beds; umbonal view; Ion. 60 mm. ; p. 631. Fig. 14 b. Area (Noefia) limula Conrad, profile view of left valve ; Ion. 60 mm. ; p. 631. 926 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXXI. 11 13 12 14b xxxii. Fig. i. Yoltiia fritter Dall ; Oligocene of Oak Grove, Florida; exterior of left valve; 13.5 mm. ; p. 596. Fig. 2. Lcda hypsoina Dall; Miocene, Duplin County, North Carolina; 5.5 mm.; p. 589. Fig. 3. Li'iia acala Dall ; Eocene of Wood's Bluff, Alabama ; 15.5 mm. ; p. 586. Fig. 4. Leda trochilia Dall ; Miocene of Alum Bluff, Florida ; 9.5 mm. ; p. 590. Fig. 5. Leila peltclla Dall ; Oligocene of Bowden, Jamaica ; 8 mm. ; p. 579. Fig. 6. Lcda dodona Dall ; Oligocene of Oak Grove, Florida ; 9.2 mm. ; p. 589. Fig. 7. Xuiitla sinaria Dall ; Oligocene of Oak Grove, Florida ; 4.5 mm. ; p. 575. Fig. 8. Leila pharcida Dall ; Eocene of Wood's Bluff, Alabama ; 34 mm. ; p. 587. Fig. 9. Niteula priinieola Dall; Miocene of Plum Point, Maryland; 6 mm. ; p. 576. Fig. 10. Nucula ehipolana Dall; Oligocene of Chipola, Florida, marl ; 3.6 mm.; p. 575. Fig. II. Area initiator Dall; Oligocene of Chipola, Florida, marl ; 5.5 mm. ; p. 634. Fig. 12. Leda trochilia Dall ; Miocene of Alum Bluff, Florida ; 8.5 mm. ; p. 590. Fig. 13. Lcda catasarcn Dall; Eocene of Wahtubbee Hills, Mississippi; 5.5 mm.; p. 588. Fig. 14. Xiiiiila taphria Dall ; Miocene of Duplin County, North Carolina, Natural Well ; 3.8 mm. ; p. 576. Fig. 15. Area latidentata Dall ; Oligocene of the Chipola marl ; 18 mm. ; p. 638. Fig. 1 6. Area Spcnecri Dall ; Pliocene of Tehuantepcc ; hinge of right valve ; 16 mm. ; p. 652. Fig. 17. Trinacria Meekii Dall ; Oligocene of Oak Grove, Florida ; 4 mm. ; p. 604. Fig. 18. Area ovalina Dall ; Oligocene of Bowden, Jamaica ; 3.2 mm. ; p. 630. Fig. 19. Area (Cucullaria) Aldrichi Dall ; Eocene of the Claiborne Sands ; 8.2 mm. ; p. 630. Fig. 20. Area eatasarea Dall , Pliocene of Alligator Creek, Florida; 55 mm. ; p. 654. Fig. 21. Area eampsa Dall ; Miocene of Alum Bluff, Florida ; 41.5 mm. ; p. 656. Fig. 22. Area campyla Dall, var. (cretea Dall; Pliocene of Shell Creek, Florida; 34 mm. ; p. 645. Fig. 23. Area Virginia Wagner ; Miocene of Virginia ; 84 mm. ; p. 627. Fig. 24. Area Spenceri Dall; Pliocene of Tehuantepec ; restored left valve; 18 mm. ; p. 652. 927 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXXII. PLATE \XX\l\. Fig. I. Area hypainela Dall ; Oligocene of Chipola, Florida ; 50 mm. ; p. 637. Kiy. 2. Area arcs/a Dall ; Miocene of Alum Bluff, Florida ; 41 mm. ; p. 655. Fig. 3. Area pkalarea Dall ; Oligocene of Oak Grove, Florida ; 23 mm. ; p. 626. Fig. 4. Area areitla Heilprin ; Oligocene of Tampa silex beds ; 47 mm. ; p. 624. Fig. 5. Area irregularis Dall ; Pliocene of the Caloosahatchie marls ; 52 mm. , p. 623. Fig. 6. Area triphera Dall ; Caloosahatchie Pliocene; 1 8 mm. ; p. 648. Fig. 7. Area tolcpia Dall ; Oligocene of Bowden, Jamaica ; dorsal view ; 28 mm. ; p. 649. Fig. 8. The same, side view ; p. 649. Fig. 9. Area (Itathyarea) llcnilersvni Dall ; Oligocene of Howden ; 2 mm. ; p. 653. Fig. 10. Ervilia eliipolana Dall ; Oligocene of the Chipola beds; 4.2 mm. ; p. 914. Fig. n. Area earolinensis Wagner; Miocene of North Carolina ; 56 mm. ; p. 639. Fig. 12. Area frixwdeniatM Dall ; Oligocene of Bowden, Jamaica ; II mm. ; p. 622. Fig. 13. Area donacia Dall ; Oligocene of Bowden, Jamaica; 6.5 mm. ; p. 649. Fig. 14. Area paratina Dall ; Chipola marl; 28 mm. ; p. 621. Fig. 15. Area aeainpsa Dall; Oligocene of Alum Bluff, Florida ; 20 mm. ; p. 648. Fig. 16. Emilia vreifoneiisis Dall; Nehalem River, Oregon; 7.6 mm. ; p. 916. Fig. 17. Emilia polita Dall; Caloosahatchie Pliocene; 6.3 mm. ; p. 916. Fig. 1 8. Ali£cna piislnlnsa Dall; Oligocene of Oak drove, Florida; 6.5 mm. Fig. 19. Eniilia, triangularis Dall ; Oligocene of the Chipola beds ; 5.7 mm. ; p. 915. Fig. 20. Ervilia fata Dall ; Miocene of Duplin County, North Carolina ; 5 mm. ; p. 915. Fig. 21. Carolia jainaiccnsis Dall ; Eocene of Cambridge beds, Jamaica ; 48 mm. broad ; p. 776. Fig. 22. Aligcna pustulasa Dall; Oligocene of Oak drove, Florida; view of interior; 6.5 mm. Fig. 23. Mactra (Mactrotoma) cymata Dall; Oligocene of Oak drove, Florida ; 31 mm. ; p. 893. Fig. 24. Area haliiionata Dall ; Oligocene of Bowden, Jamaica ; 56 mm. ; p. 646. Fig. 25. Area clisia Dall ; Miocene of Virginia; 56 mm. ; p. 657. Fig. 26. Area actinophora Dall ; Oligocene of Monkey Hill, Panama Railway ; 46 mm. ; p. 647. 928 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATE XXXIII. PLATE XXXIV. Fig. i. Pec ten coccy in f fits Dall, left valve ; alt. 30 mm. ; p. 741. Fig. 2. Pecten cactaceits Dall, right valve, the cars restored from a smaller one ; alt. 28 mm. ; p. 716. Fig. 3. Pcctfn indecism Dall, right valve ; alt. 16.5 mm. ; p. 744. Fig. 4. Pecten scissuratus Dall, left valve ; lat. 30111111. ; p. 715. Fig. 5. Pecten compactus Dall, right valve ; lat. 26 mm. ; p. 707. Fig. 6. Glycymcris dnplincnsis Dall, interior of left valve ; alt. 10 mm. ; p. 613. Fig. 7. The same valve, exterior view ; p. 613. Fig. 8. Pcctcn Hiirnsii Dall, right valve ; lat. 19 mm. ; p. 720. Fig. 9. Pecten watftubbeanus Dall, left valve ; alt. 17.5 mm.; p. 736. Fig. 10. Pcctcn aliimensis Dall, left valve; alt. 8.5 mm. ; p. 740. Fig. ii. The same, right valve ; p. 740. Fig. 12. Pcctcn Gnppyi Dall, right valve ; p. 718. Fig. 13. The same, left valve ; lat. 5 mm. ; p. 718. Fig. 14. Pcctcn condyloniatus Dall, left valve ; lat. 24 mm. ; p. 729. Fig. 15. The same in profile, showing undulations ; p. 729. Fig. 16. Oryctoinya clailwi-ncnsis Dall, left valve ; Ion. 27 mm. Fig. 1 6 a. The same, pustular sculpture enlarged; Claibornian ; Nautilus, xi., p. 135, April, 1898. Fig. 17. Area callicestosa Dall, sculpture magnified ; p. 638. Fig. 18. The same, exterior of left valve ; 32 mm. ; p. 638. Fig. 19. Thracia Dilleri Dall ; from Eocene of Oregon ; Ion. 48 mm. ; Arago beds near Coos Bay, Oregon. Fig. 20. Yoldia psammotcea Dall, left valve ; Ion. 21 mm. ; p. 596. Fig. 21. Pecten centrotus Dall; lat. 19.5 mm. ; p. 733. Fig. 22. Pecten cugrammatus Dall, right valve ; lat. 20 mm. ; p. 712. Fig. 23. Pcctcn cocihiiuis Dall, left valve ; alt. 23.5 mm. ; p. 738. Fig. 24. Pcctcn Harrisii Dall, left valve of a slightly distorted specimen ; lat. 31 mm. ; p. 742. 929 TRANSACTIONS WAGNF.R FREE INSTITUTE OF SCIENCE PLATE XXXIV. PLATE XXXV. Fig. I. Julia ftoridana Dall, outside of right valve ; Ion. 3.7 mm. ; p. Si I. Fig. 2. The same, inside view. Fig- 3- The same, inside view of left valve. Fig. 4. Limcca solida Dall, inside view ; alt. 3. 5 mm. ; p. 769. Fig. 5. The same, outside view. Fig. 6. Crcnclla ditplincnsis Dall, inside view ; alt. 2.5 mm. ; p. 804. Fig. 7. Anomia floridana Dall, inside of upper valve ; Ion. 29 mm. ; p. 783. Fig. 8. Dimya grandis Dall ; Ion. 33 mm. ; p. 764. Fig. 9. Sphcnia attcniiata Dall, inside of left valve; Ion. 9.5 mm. ; p. 860. Fig. 10. Tugoniopsis compacta Dall, inside of left valve; Ion. 7 mm. ; p. 860. Fig. II. Anomia niicrograiniiiata Dall ; Ion. 22mm.; p. 783. Fig. 12. Modiolaria carolincnsis Dall ; Ion. 6.5 mm. ; p. 806. Fig. 13. Congeria lamcllata Dall, inside of right valve, the lower margin imperfect ; alt. 11.5 mm. ; p. 809. Fig. 14, Congeria lamcllatii Dall, inside of left valve ; alt. 17 mm. ; p. 809. Fig. 15. The same, seen in profile to show projecting lamina. Fig. 16. Modiolus Guppyi Dall ; Ion. 9 mm. ; p. 794. Fig. 17. Modiolus pugctcnsis Dall; Ion. 17 mm. ; p. 792. Fig. 1 8. Lima tampaensis Dall; alt. 20 mm. ; p. 766. Fig. 19. slnomia liinatulii Dall, outside of upper valve ; with one of the hollow calcareous byssal plugs of the same species affixed to the surface ; lat. 70 mm. ; , P- 785. Fig. 20. Lima vicksburgiana Dall, from a cast; alt. 31 mm. ; p. 7^5. Fig. 21. Lima carolincnsis Dall ; alt. 16.5 mm. ; p. 767. Fig. 22. Creiit'lla iinnuscula Dall ; 2 mm. ; p. 803. Fig. 23. Fistulana oca/ana Dall, cast ; Ion. 55 mm. ; p. 826. Fig. 24. Lima costulata Dall, fragment ; Ion. 18 mm. ; p. 766. Fig. 25. Spondylus rotundatus Heilprin, outside of young upper valve ; alt. 57 mm. ; P- 759- Fig. 25 a. The same ; profile of one of the foliations. Fig. 26. Modiolus (Gregariella) minimus Dall, pseudomorph in silica, from above, show- ing traces of original shell ; Ion. 7 mm. ; p. 797. Fig. 27. Lit/iopliaga nuda Dall, silicious pseudomorph, dorsal view, showing traces of shell, the posterior end defective ; Ion. 50 mm. ; p. 800. 930 TRANSACTIONS WAGNER FREE INSTITUTE OF SCIENCE PLATH XXXV. INDEX. For the purposes of this index subgenera and varieties are treated as genera and species, but the species of any genus will usually be found assembled under the generic and not the subgeneric name. Names of groups and species first published in this work are in italics. The page number indicating the place where a diagnosis or synonymy is given, or where important information is to be found, is in italics; a single reference or casual mention is indicated by Roman numerals. Acar (sec- Area) 615, 616, 629. Acesta 765. Achatina 572. Achatium 572. Acila 372, 573. castrensis 572. Cobboldiie 573. ( 'onradi 573. corJata 573. ducisa 573. ilivaricata 572 Krraani 572. Fultoni 572. insignis 572. jafonica 572. Lyalli 572. mirabilis 572. Schomburgki 573. truncata 573. tuberculata 573. Actinomya 832. Adesmacea 812. Adrana (ste Leda.) jSo, 592. Adula 799. Enigma 772. /Equipecten 6yj, 696, 705, 713, 7'4, 732. 733. 734- Agina 834, 836, 837. purpurea 834. Alectryonia 672. Aligena 928. x'quata 928. fustulosa 928. Aloidis 836, SjS, 843, 844, 845, 846, 849, 850, 852, 853. guineensis 838. Amphidesma 908, 912. Amusium 692, 693, 6yS, 699, 744, 745, 755- Dalli 698. Amusium, cont'ii. Lyoni 693, 698, 745, 7/9. magnum 726. Mortoni 718, 719. ocalanttm 745. papyraceum 718. squamulum 757. testiulinarium 726. Amussiopecten 699. Amygdalum 790. dendriticum 790. Anadara (see Area) 617, 618, 6/y, 636, 6J3, 65*. Anapa 909, 913. Smithii 909, 913. tri<[uetra 913. Anapella 913. Anatifera 572. Anatina 837, 906. pellucida 906. Anatinacea 827. Anatinella Syo, 891. dilatata 890. nicobarica 890. Sibbaldii 890. Anatinellina; 874, 890, 891. Anatium 572. Anisorhynchus 836, Sjy, 840. Anisothyris 836, 837, 839, 840, 853, 854, obliqua 839. Anomalocardia 619,636, 643, 658. Anomalomya 810. Anomia 769, 772, 773, 774, 775, 781, 782, 783. acontes 784. aculeata 779, 784. zenigmatica 774. Conradi 784. delumbis 785. Anomia, tont'ii. electrica 784. elyros 774. ephippioides 781, 782, 783. i-pliippitim 774, 784. JloriJana 783. glal>ra 784. g^yphus 673, 67.1. iiijfdsa 783. jugosa 782. lampe 785. limatula 785. lisbonensis 781. macroschisma 780. McGeei 782. mitrogrammata 783. navicelloides 782. placenta 772. Ruflini 182, 783. simplex 784. squamula 784. subcostata 780, 783. umbonata 783. Anomiaceie 769. Anomiidas 769, 776, 779. Anomya 781. Anonica 668. Anticorbula 839. Area 6fj, 616, 864. actinophora 647. Adamsi 615, 629, 659. a-quicostata 644. / 645. alcima 635. AMrichi 630. americana 650, 651 , 652, 659. antillarum 636. antiquata (117, 619. aquila 621. 931 932 TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA Area, confd. arata 643, 644, 645. arcula 615, 624. aresta 638, 653. aspera<>l5, 625. asperula 659. auriculata 649, 655, 659. aviculajformis 619, 620. barbata 614, 615, 659. bicops 636. bisulcata 617, 659. Bonaczyi 621. bowdcniana 622. braziliana 635. brevidesma 644. buccula 643, 644. caelata 615, 629. Caillati 631. callicestosa 638. callipleura 639, 655, 657. campechensis 6jo, 651, 659. campsa 656. campyla (144, 645. canalis 658. cancellata 658. Candida 615, 626, 659. carolinensis 615, 632, 6jy. catasarca 654. celox 616. centenaria 615, 628. centrota 617. Chemnitzii 636, 659. chiriquiensis 642. clathrata 629. clisea 657, 658. complanata 627. congesta 658. Conradi 615. consobrina 646, 647. contraria 633. crassicosta 653. cuculloides 615, 624, 625. cumanensh 633. declivis 650. Deshayesii 659. devineta 658. dipleura 658. divaricata 629. dodona 640. domingensis 629. donacia 649. donaciformis 615. elegans 633. elevata 642. Area, cont'd. filicata 636. filosa 632. floridana 636, 637, 647. gigantea 658. glomerula 653, 659. glycymeris 607. gracilis 631. gradata 629. grandis 642. granulifera 658. halidonata 646. hatchetigbeensis 622. Ilclblingii 626, 659. hemicardium 617. Hendersoni 653. heterodonta 615, 616. liians 615, 627. Holmesii 651, 652. hypomila 637, 647, 648. idonea 6jy, 640. imbricata 621. improceva 643, 644, <>.|i>. inxquilaturalis 647. incile 632, 633. incongrua 618, 633, 634, (13-;, 659; inequivalvis 617, 618. initiator 634. inornata 658. irregularis 623. jaraaicensis 626. lactca 629. Larkini 659. latidentata 638, 647. Lesueuri 625, 643. lienosa 633, 636, 637, 638. lima 615, 624. litnatula 659. limula 617, 631, 659. lineolata 644. lintea 615, 659. Listen 621. lithodomus 615. Martini! 617. morylandica 615, 623, 624. maxillata 658. microtlonta 658. mississippiensis 615, 625, 626, 643. modiolus 795. multilineata 658. nose 613, 620. nodosa 635. Area, confd. nodulosa 659. nucleus 571. obispoana 658. occidentalis 620, 622, 659. Orbignyi 636. oronlensis 658. ovalina 630. ovalis 650. ovata 627. paratina 621, 623. patricia 642, 658. pectinata 612. pectunculoides 619, 653, 659. pectunculus 607. PennelH 658. [icxala 618, 649, 650, 6jf, 659- phalacra 626. pilosa 607. platyura 632. plicatura 643, (<.//. polycyma 659. pouderosa 617, 632, 6_;j, 659. profundicola 659. propatula 615, 627. protexta 632, 633. protracta 615, 621, 6-'?. pulchra 658. reticulata 629, 659. reversa 616, 617. rlioinbica 636. rhomboidella 625. Rogers! 646. Rogersiana 646. rubrofusca 616. rustica 653, 655. sagrinata 659. santarosana 641, 642. scalarina 634. scalaris 634. scapha 650. schizotoma 659. secticostata 636, 637, 659. senilis 618. Spenceri 652. squamosa 629. staminata 641, 642. staminea 642, 657, 658. stillicidium 639. sublineolata 644. subprotracta 621, 622, 627. subrostrata 655. subsinuata 645. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA 933 Area, coiil'tl. sulcicosta 659. tie ni nl a 631. tenuicardo 655. tolfpia 6jy, 652. tortuosa 616. transversa 643, 644, d.fj, 646. 659. trapezia 617. trigintinaria 658. trilineata 658. trinitaria 617, 658. Irifhera 648. triquetra 642. umbonata 620,' 622, 659. velata 659. Virginia' 62f, 628. Wagtttriana 619. zebra 620. Arcacea 603. Arcida,1 604, 6117. AiviiKr 613. Arcinulla 835. iis 780, 787. 792. Arcoptera (see Area) 614, 619. Argina 617, 6iS, 619, bjq, 657. Argyromya 832. Asaphis 836. Aspidopholas 821. Astarte 864. Conradi 88 1. Atactodea gif, 913. Atrina 6fy, 66 I. alamedensis 665. argcntea 662, 663. chipolana 662. Harrisii 663. jacksoniana 662. muricata 659, 661. nigra 659. rigida 659, 663, 664. serrata 659, 663, 664, 665. venturensis 665. Avicula (see Pteria) 668. aluco 670. atlantica 670. Candeana 668. cardiacrassa 669. chloris 670. communis 670. heteroptera 670. liirundo 670. inacroptera 670. Avicula, coiit'd. multangula 669. nitida 670. pteria 670. serniaurita 666. smaragdina 668. slrix 670. tarentina 670. vitrea 670. Aviculopecten 701. Aximva (see Glycymeris). bellasculpta 607. duplistria 607. filosa 607. inequistria 607. intercostata 607. intermedia 608. Axineoderma 607. Azara 836, 837, 839. contracta 856. lialanus 780. Barhatia (s?t Area) 614, 616, 619, 623, 624, 625, 626 627, 628. Barnea 815, 816. alatoidea 817. Aldrichi 817. arcuata 8 1 6. costata 816. Levesquei 817. spinosa 815. truncata 816. Barreltia 776. Basterotia 861, 862. Bathyarca (see Area) 616, 6iy, 632. Batissa 776. Bentharca (set Cucullaria) 616. Berthelinia 810. Bicorbula 836, 838. Blainvillea 883. Bornia lioica 920. Mazyckii 920. Bothrocorl>uia 836, Sjy, 850, 85 1 , 852. viminea Sjo, 851, 852. Botula ft)2, 797, 801. Botulina 791. Brachidontes 791. Brachydontes /<;/, 794, 795, 805. clava 795. liainatus 7X1). modiolus 796. Byssoarcu 614, (123, 643. liyssomia petricoloides 801. Cacophonia 883. Cadmusia 818. Gucclla 910, 9/4. Horsfieldii 914. Callitriche 786. Callitrichodenna 786. Calloarca 6jj, 6*3, 624, 625, 626. Camptonectes 692, 697, 751, 753. Cardilia 890. Carolia 770, 771, 772, 774, 77j. floridana 774, 777. jamaicensis 771. placunoides 774. Cassidea 572. Cassis 572. Cepa 781. Cercomya ledreformis 579. Ceriun 572. Cerium 572. Ceronia 909, 911. denticulata 909. Singleyi 912. Chicna 823, 826. cuneiformis 825. Chama glycymeris 571. Clienopea 832. Chlamys 690, 692, 693, 699, 705, 707, 7'5, 7«6, 724, 725. 728, 734, 737, 743, 744- Cibota 614. Cladodon 904. Clathrodon 903, 904. dementia 883. Cmsterium 595. Ccelomactra ^75, 891. Columbia 903. Congeria SoS, 809, 810. cochleata 809. Gundlachi 809. lamcllata 809. leucophseata SoS, 809, 810. Rossmassleri 809, 810. Sallei 809. Conus 689. Coralliopliaga elegans 920. Corbula Sj6, 837, 838, 860. alabamiensis 841, 842, 848. akufonnis 840. Aldrichi 841, 842, 843, 848. aliformis 839, 846. alia 838, 846. aniara 839. amazonensis 840. 934 TRANSACTIONS OF WAGNER TKRT1ARY FAUNA OF FLORIDA Corbula, cont'd. ariitifera 840. Barrattiana 849, 856. biangulata 836, 838. bicarinuta 846. Bradley! 850. Burnsii 847. caloosfE 853. caribeea 855. carinata 840. carinifera 856. Churchisonii 84.3. complanata 836. compressa 842, 843. concentrica 840. concha 841. Conradi 842 contracta 838, 852, 854, Sjj. cubaniana 848. cultriformis 840. cuneata 840, 853, Sj.f, 856. curta 852. densata 842. diegoana 856. Dietziana 856. disparilis 849, 852, $5 j. duminicensis 847. elevata 852. Englemannii 840. engonata 841, 846, Stf, 856. erecta 840. Evansana 840.. extenuata 844. ferruginosa 856. filosa 844, 846. fluviatilis 839. fossata 844. Gabbi 840. gallica 836, 837, 838. galvestonensis 852. gibba 837. gibbosa 843, 845. gregaria 840. Gregorioi 841, 842, 843. ffarrisii 855. Mauxwelli 840. heterogtnca 850. Hornii 840. idonea 852. ignota 843. ima 841, 842. inajqualis 853, 854. intastriala 846. interstriata 846. Corbula, cont'ii. laqucata 844, 845, 852. Lavalleana 848, 849. lechiTormis 840. levata 852. lutcola 856. mactriformis 840. margaritacea 837. mediterranea 836. miliuin 845. Murchisonii 843, 844. nasuta 841, 842, 843, 854. nasutoides 846. nncleata 855. obliqua 840. oniscus 843, 844, 845, 846, 852. ovata 840. paillis 840. pearlensis 846. perdubia 844, 852. perundata 840. prmia 846. priiuorsa 840. priscopsis 8sj. pyriformis 836, 839, 840. t'adiatllla 851. rugosa 843. snrJa 847. seminella 848. sericea 848. smithvillensis 843. sphenia 847. sphetiiclla 840. subcompressa 841. subcontracta 849, 854. subengonata 841. subnasuta 841. subtrigonalis 840. sulcata 836, 837, 838. Swiftiana 855. syttarmoifes Sfo, 851. tecla 842. tenelhi 851. tenuis 840. texana 845. vieta 841), 850. viminea 836, 839, Sja, 851. IVailesiana 846. WhilfulJi 849. WilleoxiiQl. Corbulamella 840. gregaria 840. Corbulida; 836, 861. Corbulomya 836, 837. Crassatella 874, 908, 909. cygnea 874. Crassatellites 871. Crassostrea 677, 672, 675. Crenella 798, So/, 805. aequilatera 577. concentrica 803. costata 803. decussata 803. divaricala Soj, 804. ilitplinensis 804. faba 804. glandula 804. isocardiotdea 803. lateralis 807. latifrons 79$, 803. margaritacea 802, 803. ininusciila 803. pulcherrima 802. sericea 802. tenuis 803. Crenellodon 802, 803. Cryptodon 885, 906. Cryptomya 859. calilurnica 859. ovalis 859. Ctenoconcha 581. Ctenodonta 583. CteiioilontiilLV 583. Ctenoidcs 765, 768. Ctenolium 691. Cubitostrea 671. Cucullcea 603, 604, 840. concamerata 603. gigantea 603. lev is 603. maconensis 605. macrodonta 603. onocliela 603, 658. Rogers! 646. Rogersiana 646. Saflbrdi 603. transversa 603. Cuculloearca 624, 643. Cucullaria (see Area) 604, 615, 6 1 6, 630. heterodonta 616. Ciicurbitula 824. Cunearca (see Area) 6iS, 6jj, 634, 635, 636. Cuneocorbula 836, SjS, 841, 842, 843, 846, 847, 848, 849, 853-6. FREE INSTITUTE OF SCIENCE TliRTlARY FAUNA OF FLORIDA 935 Cuspidaria 602, 846, 859. Cyclomactra 875. Cyclopecten 697, 752. Cymbophora 869, Sf<), 891, 896. Cymbulostrea 671, 678. Cyphoxis 614. Cypricia 906. Cyrena 864. C.'yrilla 598, 600, 601. decussata 59^- nuinita 602. sulcata 6oi, 602. Cyrtodaire 835. Cyrtodaria Sjj, 870. Kurriana 835. siliqua 835. Cyrtopleura 815, 816. Cytherea dariena 895. Dactylina 814. Daphne 614. Daphneodeima 614, 615. Daprmodenna 615. Dai Mia ,V,Vy, 891. declivis 890. Kingii SSy. soleiioiilcs S&9. Davila 909, yij. crassula 9 13. plana 913. polita 909, 913. Davilina.' 913. 672. '^ia 607. Deshayesia 607. Dili, I-KS 799, 801. Dimya 764. argentea 764. grandis 764. Dimyacidae 764. Diplodonta acclinis 923. Diploschiza //./, 781. Donacilla 909, 910, 912, 913. cornea 909. Donacille 908, 909, 912. Donax xquilibrata 923. Kninionsi 923. 1 Ireissena 808. americana 808. leucopha-ta 808. . recurva 789. Riisii 808. Dri-issensia 808, 809, 810. lluviatilis 808. Massei 809. Dreissensia, confd. polyraorpha 808. Dreissensiida; 807. Dytluilmia danubii 808. Kastunia SSf, 891. ajgyptiaca 887. ' nicobarica 887. rugosa 872. SHmpseni 887. Kbunieupccteii 697,751. Kchion 781. Ecliionoderma 781. Electroma 668. Enocephalus Soj, 808. Entolium 698. Ephippium 769, 770, 771, 773, 774, 775. 777- papyraceum 775. sella 769. Erodina 836. Erodona 836, Sjy, 840, 853 niacti'oidcs 836. Ervilia 909, 910, iy/./. chipolana . dolabriformis 876. elegans 877. fragilis 876, 886, 894, 895. fragosa 900. glabrata 908. Grayi 911. incrassata 900. lateralis 901. macescens 894. mendica 880. nasuta 894. Nuttallii 906. oblonga 894 oblongata 894. ovalina 894. ovata 866. papyracea 906. parilis 896, 902. pellucida 876, 886, 887. plicataria 877. polynyma 878. ponderosa 899. prsetenuis 893, 896. pygmasa 896. Reevesii 877. rectilinearis 896. recurva 906. rostrata 901. rugosa 887. silicula 894. solida 878. solidissima 878. Spengleri 863, 865, 880. striatella 879. stultorum 874. subponderosa 899. triangularis 879. trigonalis 901. triquetra 901. tristis 867. I "mid:! 875. turgida 875. tindula 893. vclata 875. violacea 875. virginiana 897. vitrea 877. Willcoxii 894. Mactracea 862. MactrellaS77, 879, 880, 884, 891, 895- Mactrida; S^3, 874, 885, 886, 891. Mactrinrc 57,?, 881, 891, 893. Mactrinula £77, 894. Mactroderma 875, 876, 891. Mactrodesma 878. ponderosa 899. Mactromeris 878, 896, 899. Mactropsis 870, qio. requorea 911. rectilinearis 911. 4 Mactrotoma 576, 891, 892, Syj. fragilis 894, 895. Malletia jS/, 595. chilensis 581. Norrisii 581. obtusa 581. Malletina: 581,597. Mantellum 765, 767, 769. Margarita 668. Margaritaria 832. Margaritifera 668. margaritifera 668. radiata 668. Margaritiphora 668. Martesia 819. clausa 820. cuneiformis 820. Dalli 820. elongata 820. intercalata 820. obtecta 821. ova/is 820. sphccroidalis 820. striata 820. texana 820. Megayoldia 595. Meleagrina 668. Melina 663, 666, 667. maxillata 667. montana 668. Mulleti 667. mytiloides 667. torta 667. Melinidse 665. Merope 887. Mesodesma 908, 909, 910, gi i, 912. arctatum 911. australis 910, 912. Bishopi 911. Chemnitzii 912. chilense 910, 911. confraga 900. confragosa 900. corneum 912. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA 939 Mesoclcsmn, con/'ii. deauratum 911. donacia 908. donacium 910, 911. glabratum 910. latum 912. mundum 913. novaszelandiix; 909. Quoyi 908. ventricosa 908. Mesodeimalidee 869, 896, 9117, 914. Mesndesmatina: 910. Metabola 888. Micromactra 876, 8(13, 894. Microyoldia 584. regularis 584. Miltha 92 3. Miorangia SSr, 891, 905. Modiella 791. Modiola (see Mudiolus) 790. anlillarum Soo. appendiculata Sol. caribwa 800. castanca 805. caudigera 800. corrugata 799- cretacea 792. elliptica 807. hamatus 789. houstonia 798. lignea 805. mtiltiradinta 789. papuana 790. polita 791. pulex 788. rhombea 805. sulcata 791, ./, 805, 806, 807. alabamcnsis 806. rarolinensis St>6. discors 807. discrepans 805. lateral is 806. raarmorala 807. nigra 807. subpontis 805. trauslucida 807. virginica 806. Modiolus (>6S, 786, 79(>. alabamensis 796. Modiolus, cont'if. capax 793. Chemnitzii 796. cinnamomeiis 792, 797. citrinus 794, 795, 805. contractus 796. cretaceus 792. curtultis 794. demissus 79^, 795. Ducatelii 793. . filosus 792. flabellatus 793. fuscus 797. g'gas 793- grammatits 794. Guppyi 794. houstonius 798. inflatus 793. minimus 797. mississippiensis 796. modiolus 791, 793. multiradintus 797. opifex 797. ornatus 796. p'etagnoe 791. pictus 791. plicatulus 794. potomacensis 796. pugctcnsis 792. rectus 793. Safibrdi 796. semicosta 795. semicostalus 795. silicalus 793. spiniger 798. subponlis 798. sulcatus 79', 796. tenuis 798. texanus 796. tidipus 793, 805. Monia 770, 777, 772, 773, 771, rfo. macrochisma 771. Monothyra 814. Mulinea (see Mulinia). Mulinia 864, 8j2,SSo, 891, 899, 900. caieosaftttit 902. caroliniana 902. congesta 900. crassidens 901. edulis 880. lateralis 901. Milcsii 902. Mulinia, t~ont'rupta 830, 858. acuta 857. alba 857. anatina 860. arctica 833, 834. arenaria 857, 858. bilirata 858. byssifera 834. corpulenta 857. crassa 858. crispata 817. erodona 836. glycymeris 827, 830. Hemphillii 857. intermedia 857. labiata 836, 839. mercenaria 857. montereyana 858. nitcns 914. norvegica 832. novtezelandiiE 908, 909, 912. ovalis 857. picea 835. plicata 835. ]>r.i.-cisa 857. prtelonga 858. producta 858. rertexa 858. siliqvia 835. simplex 858, 862. subsinuala 858. truncata Sj7, 872, 885, SS6. uddevallcnsis 857. Myacea 823, 840. Myacidre 857, 861. Myalina 8(>I. Myoconcha 789, 790. incurva 789, 790. Myoforceps 798, 799, 800. Myinnaclra 889. Myoparo 802, 803. costatus 802. Mytilacea 785. Mylilastcr 786. Mytiliconcha 787, 789. 940 TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA Mytilidne 785. Mytilina 808. Mytillus lateralis 807. striatus 789. Mytiloconcha 787, 789. incrassata 787, 790. Mytiloides 808. Mytilomia 808. Mytilopsis 807, 808. leucophseatus 808. Mytilus 785, 787, 823. arista! us 800. ascia 789. attenuatus 801. bidens 788. bifurcatus 789. borealis 788. carolinensis 789. californianus 789. caudigerus 800. cinnamominus 797. citrinus 795. clava 795. Condoni 789. Conradinus 787.'' cubitus 796. decussatus 801. demissus 794. dichotomus 789. discors 804, 805. / domingensis 788. edulis 786, 787, 788, 789, 809. exustus 787, 788, 795. flavicans 795. fluviatilis 808. galloprovincialis 788. hamatus 789. hesperianus 790. hirundo 668, 670. humerus 789. impactus 804. incrassatus 787, 790. incurvus 787, 789, 790. inezensis 789. inflatus 793. leucophasatus 808. lithophagus 798, 800. magellanus 795. Mathewsonii 789/ Middendorffii 789. minganensis 788. modiolus 786, 790. notatus 788. Mytilus, cont'd. pandionis 787. pectinatus 786. pedroanus 789. pellucidus 788. petagnoe 791. pholadis 834. plicatulus 795. recurvus 789. striatulus 788. wolgn; 808. Mytulus 786. Naiadacea 688. Nassa 572. Nassaria 572. Navicula 614. aspera 625. aspersa 615, 625. Nesera gibbosa 845. ignota 843. nasnta 841. perdubia 844. prima 846. Neilo 581. australis 581. Cumingii 581. gigantea 581. Neilonella 582. corpulenta 582. Nemodon (see Area) 615. Nettastomclla 819. Nodipecten 695, 710, 717, 724, 725, 728, 729, 730. Noetia (see Area) 6ib, 617, 63 r, 632, 633. 6S8- Nucinella (see Pleurodon). miliaris 597. Nucula (sec Acila) 377, 572, 573.57^.577. scquilatera 577, 803. antiqua 577. nntiquata 575. baccata 577. carinifera 577. chipolana 575. concentrica 588. crenulata 575, 577. cuneiformis 577. decussata 575. delphinodonta 576. diaphana 577. dolabella 577. exigua 577. expansa 577. Nucula, cont'd. inflata 577. Irevis 596. limonensis 577. magnifica 576. mediavia 576. meridionals 577. miliaris 597. monroensis 577. obliqua 574. ovula 576. pectuncularis 577. proxima 574. prunicola 576. rostrata 572. Sedgwickii 577. Shaleri 575. sinaria 575. spheniopsis 577. taphria 576. tennis 577. tenuisculpta 577. trunculus 574. vicksburgensis 577. vieta 577. Nuculacea 571. Nuculana (see Lecla) 571, 572, 577- Gabbii 585. Nuculidse 571. Nuculina (see Pleurodon) 581. miliaris 597, 598. Nuculites 583. Nuculoeardia 802, 803. divaricata 802. Oopecten 699. Orthoyoldiaj^, 596. Oryctomya claibornensis 929. Ostracea 671. Ostramm polyleptoginglymum 667. Ostrea 677, 780. alabamiensis 6jS, 679. alepidota 680. angulata 671, 674. athyroidea 688. Attwoodii 681, 685. bellovacina 679. borealis 687. Bourgeoisii 684. californica 685. canadensis 687. carolinensis 686. cerrosensis 685. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA 941 Ostrea, confd. cinnabarina 735. claibornensis 679. compressirostra 671), 6S2. conchaphila 687. conspersa 747. contracta 676, 683. crenulata 687. crenulimarginata 677. cretacea 679. cristagalli 672. cymbula 671. demissa 708, 735. denticulifera 677. disparilis 679. divaricata 677. echinata 759. edulis 671, 687. ephippium 665, 666. equeslris 672, 687. eversa 672, 681. falcata 686. falciformis 677. falco 682. florida 710, 747. folium 687 fimclata 687. gallus 685. georgiana 6Sj, 684, 685, 687. gibba 745. glacialis 768. glauconoides 677. grandis 726. guttata 747. haitensis 685. haytensis 685. lleermanni 685. Helen iana 684. isognomon 665, 666. Johnson! 680. laeta 678. lateralis 681. lima 765, 767. Iragaa-canis 678. lingua-felis 677. lurida 687. lut,-:l 745. nwgellanica 726. mauricensis 679, 684, 687. maxima 689. megodon 685. meridionalis 686. Morton i 682. nodosa 728. Ostrea, confd. nucleus 747. palmula 687. panda 682. pandreformis 688. panel ir<>rmis 679. pansa 683. pan/ana 683. ptutcipli. subjecta 68 1. subtrigonalis 682. sylviurupis 683. Tayloriana 679, 684. thirsiv 677, 6Sn, 6Si. titan 683. triangularis 687. trigonalis 680, 6Si, 683, 686. Tryoni 684. tumidula 677. Tuomeyi 679, 6Sj. Ostrea, confd. turgida 747. Veatchii 685. veleniana 684. vermilla 678. vespertina 685. vicksburgensis 682. virginiana 686, 687. virginica 671, 674, 675, 676, 679, 684, 685, 687. vomer 672. Ostreidre 671. Ostrenomia 761, 764. carolinensis 761. Ostreola 672. Oxyperas 879. Pachydon 836, 837. obliqua 836. Pacyodon 836. Paleoneilo 583. I'alliohun 697. Pallium 696. estrellanum 701. Panomya 832. ampla 833. norvegica 832, 833. 1'anopsea (see Panopea). Panopea 827, 828, 858, 872. abrupta 830. alabama 828. Aldrovandi 830. americana 830. arctica 833. Basteroti 829. bitruncata 832. I Bivona? 832. cymbula 829. dubia 832, 859. elongata 828. Faujasi 829. floridana 831, 832. generosa Sjo, 831, 832. ghbosa 831. glycimeris 833. Goldfussii 829, 830. margaritacea 832. Menardi 829, 830, 831, 832. Middendoriiii 833. nana 833. navicula 831, 832. norvegica 832. oblongata 828. porrccta 829. porrectoides 828. 942 TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA Panopea, coiifd. reflexa S'9, 830, 831. Rudolphii 829. soHrfa 831. Spengleri 832. ll'hitfieldi 829. Panopia 827. Paphia 908, 909, 912. glabrata 908, 909, 911. ventricosa 909. Paphiada: 909. Paphies 908, 912. Roissyana 912. Papyrina 877. Parallelodon 604, 616. Parallelodontidne 603. Paramusiuni 698. Paramya S6i, 862. subovata 861. Paranomia 773. Parapholas 819, 820. californica 819, 820. Kneiskerni 820. Parviamusium 698. Patinopccten 695, 699, 700, 706. Patro 774. Peclen 572, 689, 690, 691, 694, 780. abyssorum 697. aciileatus 697. zequisulcatus 694, 698, 706, 7/7. affinis 721. alaskensis 777, 752. alabamcnsis 737, 758. altiplectus 700. altiplicatus 700. alumeiisis 740. amplicostatus 745, 747- anatipes 73°- anguillensis 7/5, 732. angusticostatus 713, 714. anisopleura J-fo, 761. antillarum 715, Jjr. argenteus 732. aspersus 709. bellis 704, 706. bellus 704., 706. Benedict! 743, 744. biformis 720. boreal is 745, 747, 748. bowdetiensis 713. brunneus 726. burdigalensis 699. Pecten, cont'd. Burnsii 720. cactaceus 716. caloosaensis 731. calvatus 752, 753. cancel latus 698. carolinensis 722, 736. catilliformis 700. caurinus 695, 699, 700, 710. centrotus 733. cerinus 753. cerrosensis 705. chipolanus 711, 734- choctavensis 733, 735, 753. cinnabarinus 708. circularis 710, 745. claibornensis 752, 753. Clarkeanus 739. clavatus 697. clintonensis 726. Clintonius 695, 703, 722, 723, 727. coccymelus 741. cocoanus 738. comatus 711. compactus 707. comparilis694, 707,718, 749, 75°- conccntricus 748. condylomatm 729. coosaensis 700. coosensis 700. corallinus 728. corneus 697. costellata 735. crassicardo 701, 703. cretatus 742. cristatus 698, 699. darliiigtonnisis 75°- decemnanus 741. demiurgus 718. dentatus 701, 706, 707. deserti 7; 695, 71(1. ofuntia 707. ornatus 715, 716, 736, 743. oxygomun 713, 716, 717. pabloensis 703, 705. pallium 696. I'ecten, confd. panamensis 696, 717. papyraceus 719, 755, 757 Parmeleei 708. Pealeii 708, 735. Peckhami 705. pedroanus 705. peedeensis 729. pernodosus 728. perplanus 719, 732, 733, 734, 739, 740. pesfelis 697, 707. phrygium 734, 735. pleuroncctes 698. plica 696. pomatia 710. Poulsoni 707, 7/9, 720, 732. precursor 755, 756 princeps 726. principoides 726. propatulus 699, 704, 710. pseudamusium 697. pulchricosta 730. purpuratus 696, 702, 745- pyxidatus 71 1- radula 767. rastellinum 708. Kaveneli 721. Rigbyi 736. Rogers! 730, 753. rotundatus 699. rubicundus 745- rubidus 708, 735. nulls 718. Sayanus 723, 724, 725. Schrammi 746. scinlillatus 697, 752, 753. scissuratus 715. sentscens 751. septemnarius 722. sepicnarius 703, 722. solarioides 7411, 750. soror 712. Snvcrbii 745. Sowcrbii 709. Spillmani 732. sulvinatus 609. quinqiieriigattis 6lo, 6ri transversus 609, 611. tricenarius 609, 611. tumulus 609, 611. undatus 610. virgini^e 609. Pedalion 665. Penitella 819. Peplum 697. Perissodon 903, 904, 905. Perlamater 668. Perna 665, 666, 786. Conradi 667. cornelliana 668. cretacea 792. inflata 793. maxillata 667. raodiola 796. plicatula 795. semiaurita 666. Soldani 667. texana 796. torta 667, 826. Pernidae 665. Perrisonola 580. Petricola 835. carditoides 835. Phaseolicama 810. Phcnacomya 823. cuneata 823. petrosa 823. Mauryi 823. Pholadacea 814, 858. Pholadidae 814. Pholadidea 818, 819, 820, 822. Conradi 819. Darwini Srg. Loscombiana 818, 819. melanura 819. ovoidea 820. penita 819, 820. spelsea 820. Pholadinae 814. Pholadomya abrupta 832. cuneata 823. Pholadomya, cortt'd. Mauryi 823. Pholameria 819, 820. T'holas 814. acuminata 816. alatoidea 817. arcuata 816. bifrons 817. campechiensis Srj, 816. Candeana 815. Candida 815, 816. clavata 819. concamerata 819. costata 8 1 6. crispata 817. dactylus 814. hians 825. Janellii 819. lamellata 8iS. Memmingeri Srj, 817. oblongata 814, 815. orientalis 814. ovalis 820, 821, 823, 826. pacifica 817. papyraceus 818. parva 817. penita 819. petrosa 823. producta 815, 816. rhomboidea 812, 821. Roperiana 817. semicostata 818, 822. scutata 821. striata 819. tri(juetra 820. truncata 816, 817. tugon 860. virginianus 816. Wilson! 819. Plioleobia prrecisa 834. Phragmopholas 814. Pinctada 668. colymbus 670. Pinna (see also Atrina) 659, 660. alamcdensis 665. aleutica 665. alta 663, 664. argentea 662, 663. bullata 66l. caloosaitisis 66 1. carnea 659, 66f. carolinensis 663. degenera 661. D'Orbignyi 663, 664. Pinna, cont'd. flabellum 659, 66l. muricata 664. nobilis 661, 663. pectinata 663. pernula 661. qttadrata 660. rnmulosa 664. rudis 659, 660, (>6i . seminiula 663, 664, 665. squamosissima 665. subviridis 663, 664. vavicosa 66 1. venturensis 665. Pinnidre 659, 664. Placenta 770, 771, 772, 773, 77^, 775, 777- orbicularis 774. placenta 770. Placopecten 6yj, 724, 725, 728. Placuna 772, 773. papyracea 775. scabra 773. solida 773. Placunanomia 770, 771, 774, 775. abnormalis 779. alope 780. cepio 780. Cumingii 771, 774. echinata 779. fragosa 778, 781. Gouldii 779. Harfordi 779. inornata 780. lithvbh-ta 778. macroschisma 780. plicata 778. rudis 770, 779. Saffonli 773. Placunema 774. Placunomia 778. Plagiarca 615. Pliigioctfiiium (x)6, 703, 707, 710, 717, 718. Plagiostoma 705, 745. annulatum 705. duinosum 758. pedroanuni 705. truncalum 705. Planimodiola 791, 805. Plalyodon SjS. cancellatus 838, 885. Pleurodon 581, 584, 597, 598, 601. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OF FLORIDA 945 Pleuroilon, ftiiit'J. Attamsii 599, 601, 602. calabnu 600, 602. tniliaiis 598, 599, 6oa, 602. niunita 599, 602. ovalis 597, 598, 600, 602. Rcussii 600, 602. Segnenzie 601, 602. ;/;«,/// 599, 600, 602. Pleurudoiite 597, 598, 603. I'kunmeclia 698, 755. Lyoni 719. papyracea 718. I'leurotoma 572. Plicatula 676, 690, 761, 762, 763, 764, 772. conccntrica 762. cristata 763. densata 761, 763. lilainrllt<»a 761, j6j. gibbo.sa 7(11, 764. Mnntilli 762. marginata 764. /i/ii/iit/ii 762. plil"lta 7(12. ramosa 701. nulls 704. vrxillata 763. Pododesmus 770, 779, 782. decipiens 779. macroschisina 774, 780. ruilis 774, 779. scopelus 779. 1'ulynema 615. Portlandia 581,595, 596. Potamuniya 836, 837, 839. Prasina 810. borbonica 810, 811. Prasinia 810. Prasinidie 810. Praxis 808. Prionodesmacea 571. Prupcamusium 6yS,ji I, 757,762. Psammobia Wagneri 920. Psimmophila 883. 1'seudaniusium 697, 718, 731, 751. 752- Pseudwardium 878. Pseudoghmus 582. Pseiidomalletia 581. Pteria (see also Avicula) 668. animal d(«). argcntra (it*;, 670. ctiipoliina 669. Pteria, cont'd. claibornensis 669. colyrabus 670. birundo 670. inornata 669. limula 669. multangula 669. trigona 669. vitrea 670. Ptcriacea 659. Pteriida; 6C8. Pteropsidina; 873, 88 1 , 891 , 906. Pteropsis 864, 868, SSi, 89 1 , 906. papyria 896. Pycnodonta 672. Radula 765. Raeta 869, SSi, SSi, 891, t)o(>. Abercrombiei 883. alta 907. orecla 907. i lit/if, i SS-', 8X3. liulchclla 882, 8,S ; rostralis S8j, 883. tennis 882, SSj, Ractclla SS-', 891. Raetina 882. Ralela 836. Rangia 864, 870, 872, SSu, 891 , 9°J> 9°4, 90S- clathrodonta 904. cuneata 880, 904, cyrenoides 880, 904. Johnson! 905. minor 905. Rangianella 880. Rastellum 672. Resania 889, 891. lanceolata 889. Rliomboidella 805. Rocellaria 823. antiqua 826. hians 825. ovata 824. Roxellaria 823. Rupellaria 824. Sarepte 5^,584. speciosa 583. Sareptin;x; 583. Saturnia 582. Saxicava 827, 832, Sjj, 834, 835. abrupta 835. arctica 833, Sjj. bilini'.tt.i 8 ; |. distorla 834. Saxicava, cont'ii. gallicana 834. gronlandica 834. incita 834. insita 834. lancea 835. Icgumen 835. inya'formis 835. parilis 835. pectorosa 835. protexta 834. rhomboides 834. rubra 834. rugosa 833, 834. striata 834. ungana 834. Saxicavella 835. Saxicavid;c 827, S6r. Scapharca6/7, 618,619, 628, 6jj 6j6, 637-42. Scuphula 616. Scapluira 616. Sclii/.odesnia 865, 875, i'A'n, Niii. aliscissa 880. Si-lii/.ollin.-rus 885, 8S(>. Scintilla fCurtzii gto. Scissodesma 880. Scobina 816, 817. Sctiti^ora 821. SiYphomyti 822. Sellaria 773. Semimodiola 791. Seitiiplicatula 773. Scnilia 617, 6lS. Septifer 786, 787, 807, 810. bifurcatus 789. dichotomus 789. Serpula 813. Seipalidae 812. Silicula fragilis 584. Simomactra 876. Solariorbis 918. Soleinya 870. Solen 870. crispus 817. niinutus 834. Solcnella 581. Spcngleria 824. Sphxna 859. Spliicnia 859. californica 859. Splicna 859. Splicnia 832, 858, Sjp, 861, 862 allcrnata 859. 946 TRANSACTIONS OF WAGNER TERTIARY FAUNA OF FLORIDA Splienia, confd. atteintala 860. bilirata 859. liingliaini 859. californica 859. dubia 859, 860. ornatissima 859. Swainsoni 857. Sphcenia 859. S|>issula 895. Spisula S?S, 879, 880, 885, 887, 891, 892, Sys- albirupiana 896. Ashburneri 879. confragosa 900. fiirti Jens 898. delumbis 897. densa 900. dodona 896. ditplineiisis 898. fragilis 894. funerala 896. inu|llilateralis 89(1. magnoliana 81)11. inaryliindica Sift, 898, 899. medialis 900. mississippiensis 896. . modicella 892, 893, 900. ovalis 896. polynyma 878, 898. 'ponderosa 878, 892. quadricentenninlis 905. Raveneli 901. similis 885, 898, 901. solicla 878. solidissima 868, 878. Spengleri 880. slriatella 879. subcuneata 900. subparilis 900. subponderosa 899. triangularis 879. Spisulina 895. Spizula 895. Spondylida: 758. Spondylus 690, 740, 738. americamis 759, 760. amussiopse 761, 762. arachnoides 760. armatus 759. aurantiacus 759. avicularis 760. bifrons 758. bostrychites 758, 759. r Spondylidoe, cont'il. chipolatnts 758, 759. crassis(|iiama 760. croceus 759. •ligitatus 760. dominicensis 759. dumosus 75$, 761. echinatus 759. crinaceus 760. cslrallensis 761. estrellanus 702. 761. folidbrassicse 760. grederopug 758, 760. gilvus 760. ( 'lussoni 761. ictericus 760. imbutus 760. inornatus 761, 763. longispina 760. longitudinalis 760. mix 760. plic.il us 761. ramosus 760. rotundatus 759. spathuliferus 760. uslulatus 760. vexillum 760. Spoitella 835. comprcssa 920. constricta 920. lancea 920. Stalagmium 802. margaritaceum 802. Standella 876, SS6, 887, 891, 894. congesta 901. lateralis 901. Stavelia 786. Striarca (see Area) 615, 628. Sutura 665. Syncyclonema 697. Tagelus 870, 884. Taria 909, §>/.?. Stokesii 909, 912. Tedinia 779. Teinostoma cluplincnsc 918. floridanum 918. undula 918. Teleodesmacea 812. Tcllina amazonensis 840. dodona 925. Teredina 818, 822, 823. bowdcniaiiit S22. personata 822. Teredinidae 812. Teredininoe 822. Teredo 812, 813, 821, 822. calamus 813. circula 813. clava 826. cmacerata 8 1 2. fistula 813. incrassata 813. mississippiensis 812. navalis 812. pugetcnsis 812. simplex Sf2, 813. sim])lexopsis 813. substriata 813. virginiana 813. Thovana Sr.f, 815. Thracia 872. Dillcri 929. my;vformis 831;. pliascolina 872. Thmlosiu 817, SiS. Thyas 614. Tichogonia 808. Tindaria 579, 581, 582. acinula 582. seolata 582. ngathiila 582. amabilis 582. arata 581. callistiformis 582. cuneata 582. cytherea 582. pusio 582. Smithii 582. virens 582. Tindariina: 583. Tindariopsis 582. Tiza 838, 839, 846. Tomala 836. Trapezium 823. Tresus 858, SSj, 886, 891. Nuttallii 885. Tridacna 572. Tridachne 572. Trigonarca 603, 605. corlniloiilcs 606. decisa 606. declivis 606. ellipsis 606. perplanus 606. Trigonella 874, 875. Trigonoarca maconensis 605. Trigonocxlia 604. Trigonocaslix 604. FREE INSTITUTE OF SCIENCE TERTIARY FAUNA OK FLORIDA 947 Trinacria 603, 6oj, 606. Baiuloni 605. carinifera 604. cuneus 604. dccisa 658. ledoidea 604. Mcekii 604. mixta 605. pectuncularis 577i 604, 606, 607. Triquelra 910. Trisidos 616. Trisis 616. Tuceta 607. Tugonia S6o, 890. Tugoniapsis 860. coinpacta 860. Turritella 780. gatunensis 895. Unio 572, (>SX, "89, 857. liuckleyi 6SS. caltotatnsis <>S8. I inoniiUe 688. Unioiuim 57-!, (K..S. Vanganella 889. Taylori SN •,. Variainubium OyS. Veleila 878. Hntea 879. Venericla- 908. Volsclla 786. striata 797. ll'iikullina 77^, 774, 777. Xylopliaya S-'t, NJJ. ilorsalis S2I. inississi|)|iicnsis S2I. Xylupliagus 812, 821. Xylotomea 821. Xylolrya palmulata 813. YuMia 580, /(y, 594. abrupta 5<)4- albaria 585, 586, 594. Aldrichiana 594. angularis 594. arctica 593, 594, 595- claibornensis 594, 596. Cooperi 594. corpulentoidea 594- Crosbyana 594. eborea 594. Jraler 596. glacialis 593, 594. 595. 5'ji>. liypcrliorca 594, 595. inipressa 594. Kiiullci 594. Uevis 594, 595, /•/>, 597- lanceolata 595. limatula 594, 596, 597. Yoldia, confii. lucida 595. iiHintcreycn>is 595. nastita 594. oval is 594- poinpllul) \ 582. porllanclica 593, 594. prolexta 585, 586, 594. psammottea 596. sapotilla 597. scapania 580. scapina 595. scissurata 595. serica 594. tarpixia 597. thraciaiformis 594, 595, 596. truncata 594, 595. Yoldiella 595. Xcnatia SS8, 891. acinaces 888. IVshayesii 888. zelanilica 888. Zenotiime .v/,-, ,v,y,v, 891. 7.irfca8l5, S/7, 818. crispata SiJ, 818. dcnlata 818. Gabbii 8 1 8. plana 818, 820. (see Zirfiua). FINAL NOTE. The manuscript of this paper was sent in for publication April 3, 1898, anil the printing com- pleted October 15, 1898. The plates of higher number than Plate XXXV., to which a few references appear in the text, will be issued with Part V. ERRATA. Page- 571, line 13, for " Colonnianum" read Calonniammi. 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