The Conchologist’s First Book — Edgar A. Poe, 1839 — reading text

toothless, or with two small rudimentary teeth; ligament more or less exterior, placed in a narrow groove ; one very large posterior muscular impression and one very small anterior. Inha- bits the coast of Devonshire. Fourteen species. Avicula nudata. ' Avicula lotaria. A. macroptera. A. heteroptera. A. semi-sagitta. "A. crocea. A. falcata. A. Atlantica. A. Tarentina. A. papilionacea. A. squamulosa. A. physoides. A. costellata. A, virens. 5. Genus Meleagrina. Animal. As above. Shell. Subequivalve, rounded, squamous, a sinus posteriorly for the passage of the byssus, at which place the left valve is notched and narrow ; hinge linear and destitute of teeth; liga- ment marginal, elongated, partly exterior, and dilated in the cen- tre. Inhabits the Indian ocean. Two species, of which our first is the pearl-oyster. Meleagrina margaritifera. Meleagrina albina. FAMILY XVIII. Precrinea. Seven genera. 1. Genus Pedum. Animal. Unknown, but probably byssiferous. CONCHOLOGY. 73 Shell. Subtriangular, inequilateral, inequivaline: with rounded summits, feebly marked, unequal and distant: the right valve inflated, widened at its inferior and posterior edge, sloped ante- riorly, and subauriculated, the left not being so; hinge toothless, anterior or buccal ; ligament inserted in an oblique cavity pro- longed outwardly to the summits, and carried within into a spoon- like cavity. Inhabits the Indian ocean. One species. + . Pedum spondyloideum. 2. Genus Lima. Animal. Body moderately compressed ; a byssiferous abdo- minal appendage; edges of the mantle furnished with tentacular cirrhi in several rows; mouth surrounded with a very thick fringed lip. Shell. Oval, more or less oblique, nearly equivalve, subauricu- lated, regularly gaping at the anterior portion of the inferior edge ; - summits anterior and distant; hinge buccal, longitudinal, tooth- less ; ligament rounded, nearly exterior, inserted in an excavation in each valve; a central muscular impression, divided into three very distinct parts. Inhabits the Indian, Australasian, American, and Mediterranean seas. ‘Six living species. Eleven fossil. Lima inflata. Lima glacialis. L. squamosa. L. fragilis. L, annulata. L. linguatula. | 2. Genus Pecten. Animal. Body more or less compressed, orbicular; mantle furnished with a single row of tentacular papille, and with small oculiform, pedunculated disks, with regular spaces between them ; rudiment of a canaliculated foot, anda byssus ; mouth surrounded with fleshy appendages, irregularly ramified. Shell. Free, regular, thin, solid, equivalve, equilateral, auricu- lated ; summits contiguous ; hinge toothless, a ligamentous mem- brane throughout all its extent, besides a short, thick, ligament, almost altogeth@ internal, and filling a triangular excavation under the summit; a single subcentral muscular impression. 8 74 CONCHOLOGY. Fifty-nine species—and, according to Defrance, fossil. Animal. . Shell. Pecten maximus. P. Jacobeus. P. bifrons. P, zigzag. P. medius. P, Latirentii. . pleuronectes. . purpuratus. P. pailius. . imbricatus. Fr iz B P, asperimus. P. varius. . glaber. P, grisens. . flabellatus. P . quadradiatus. . Tranquebaricus. iy P 1S P. hybridus. P. obliteratus. P. Magellanicus. P. lineolaris. P. nodosus. P. pusio. P. gibbus. P. ornatus. P, florens. P. opercularis. P. tigris. P. histrionicus. Pecten turgidus. P. aspersus, P. plicus. P. rastellus. P. flagellasus. P, flavidulus. P. Japanicus. P. radulus. P. pes-felis. P. sauciatus. P. aurantius. P. sinuosus. P, virgo. P, Isabella. ’ P. flexuosa. P. inflexus. P. miniaceus. P. lividus. P. sulcatus. P. unicolor. P. distans. P. irradians. P. dispar. P. Islandicus. P. sulphureus. P. pellucidus. P. sanguineous. P. senatorius. P. lunatus. P. lineatus. 4, Genus Plagiostoma. Entirely unknown. Moderately thick, regular, free, subequivalve, sub- ninety-eight auriculated, the two valves nearly equally dilated, both provided with a distinct summit reflexed to the middle of a plane surface, CONCHOLOGY. 73 with a large triangular slope in the middle; articulation trans- verse, straight, and by two distant lateral condyle. Ten species. Fossils only. 5. Genus Piicatula. Animal. Unknown. Shell. Solid, adhering, subirregular, inauriculated, inequivalve pointed at the summit, rounded and subplicated posteriorly ; in- ferior valve without heel; hinge cephalic, longitudinal, provided upon each valve with two strong teeth, entering in corresponding cavities; ligament altogether internal and inserted in a median cavity. Inhabits the American seas. Five species. Plicatula ramosa. Plicatula cristata. P. depressa. P. Australis. P. reniformis. 6. Genus Spondylus. Animal. Body moderately compressed, provided inferiorly with a rudiment of a foot, without byssus; mantle open in all its inferior and superior portion ; mouth surrounded with very thick and fringed lips. Sheil. Solid, adhering, subregular, more or less spined, sub- auriculated, inequivalve; the right or inferior valve fixed, much more excavated than the other, and having posteriorly at the summit a triangular face enlarging, and elongating with age; hinge longitudinal, provided in each valve, with two strong teeth entering corresponding cavities ; ligament short, nearly median, partly exterior; muscular impression single and subdorsal. Found in all the. seas of hot climates, and even in the Mediterranean. » Pour of five fossils are found in France, one in South America. Twenty-one species. *Spondylus Americanus. Spondylus gedaropus. S. candidus. S. arachnoides. S. coccineus. S. multilameliatus. S. spathuliferus. S. crassisquama. S. longitudinalis, S. ducalis. S. costatus, S. violascens. 76 CONCHOLOGY. S. longispinous. S. microlepos, S. regius. S. crocens. S. variegatus. S. radians. S. avicularis. S. aurantius. S. zonalis. 7. Genus Podopsis. Animal. Unknown. Shell. Subregular, somewhat thick, equilateral, symmetrical, inequivalve, adhering by the extremity of the shorter valve; the other terminating in a pointed, reflexed, and median summit. Two fossil species. FAMILY XIX. OsTrackEa. Six genera. 1. Genus Ostrea. Animal. Body compressed, more or less orbicular; edges of the mantle thick, not adhering or retractile, and provided with a double row of short and numerous tentacular filaments; two pairs of elongated and triangular labial appendages ; a subcentral bipartite muscle. Shell. Irregular, inequivalve, inequilateral, roughly foliaceous the left or mferior valve adhering, larger and deeper than the other, its summit prolonged with age into a sort of heel; the right or superior valve more or less operculiform ; hinge oral, toothless ; ligament subinterior, short, inserted in an oblong car- dinal cavity increasing with the summit; muscular impression single and subcentral. Found in all seas near the mouths of rivers. Defrance enumerates one-hundred and twenty species. Lamarck thirty-three fossil, forty-eight living. Ostrea edulis. Ostrea ruscuriana. O. borealis. O. Canadensis. O. cochlear. O. mytiloides. O. gallina. O. trapezina. O. lingua. O. rufa. + % CONCHOLOGY. 77 O. Braziliana. O. gibbosa. O. rostralis. O. elliptica:. O. denticulata. O. deformis. O. cornucopiz. O. plicatula._ O. doridella. O. fusca. O. limacella. O. cristagalli. O. hippopus. O. virginica. O. Adriatica. O. excavata. O. cristata. O. simuata. O. numisma. oe) y ae . tuberculata. O. tulipa. O. magaritacea. O. scabra. O. Australis. O. parasitica. O. haliotidea. O. spathulata. O. fucorum. O. cucullata. O. glaucina. O. rubella. O. turbinata. O. erucella. O. folia. O. labrella. QO. hyotis. O. radiata. O. imbricata. 2. Genus Gryphea. Animal. Unknown. Shell. More finely lameilated than in the Ostrea, free, or slightly adhering, subequilateral, very inequivalve; the inferior valve very concave, with a summit more or less recurved in a hook ; the superior opiculiform and much smaller; hinge toothless ; ligament inserted in an elongated and arcuated cavity ; a single Habitation unknown. One species. , Gryphea angulata. muscular impression. ‘ 3. Genus Vulsella. Animal. _ Body elongated and compressed ; mantle much pro- longed posteriorly, and edged with two rows of very close tuber- cular papilla ; a moderately-large abdominal foot, proboscidiform, canaliculated, without byssus; a very large transversal mouth -with well-developed triangular labial appendages; branchiz nar- row, very long, and united in nearly all their extent. Qe 78 + CONCHOLOGY. “Shell. Subnacred, irregular, flat, elongated, subequivalve, inequilateral, with summits anterior, distant and flexed inferiorly ; hinge oral and toothless; ligament undivided, thick, inserted in a round pit excavated in a projecting apophysis upon each valve ; a moderately large subcentral muscular impression, and two very small ones altogether anterior. Inhabits the Indian and Austral- asian seas. Six living species. One fossil. Vulsella hians. Vulsella lingulata. V. rugosa. V. mytilina. cas VY. spongiarum. V. evata. 4, Genus Placuna. Animal, Entirely unknown. Shell. Free, subirregular, very fine, almost entirely translucid, flat, subequivalve, subequilateral, slightly auriculated; hinge alto- gether internal, formed upon the snperior valve, which is the smaller, by two elongated, unequal, oblique, crests ; converging to the summit, at the internal side of which a ligament is attached in the form of a V., a single, small, subcentral muscular impression. Inhabits the Indian seas. Two fossils in France. Three living species. , Placuna sella. Placuna papyracea. P. placenta. 5. Genus Anomia. Animal. Much compressed ; edges of the mantle very fine; not adhering, and furnished exteriorly with a row of tentacular filaments; contractile muscle thick, divided into three parts, the largest of which passes partially across a slope of the inferior valve , and often contains a calcareous substance or small bone, adhering to marine bodies. Sheil. Adhering, irregular, inequivalve, inequilateral, ostrace- ous; inferior valve a little flatter than the superior, divided at the summit into two sloping branches, whose approxmiation forms a large oval hole; the superior valve, which is the larger, has an oval excavation under the summit ; a subcentral muscular impres- y CONCHOLOGY. * TY > sion, divided into three parts. Inhabits the British coasts. Nine species, Anomia ephippium. Anomia cepa. A. patellaris. _ A. electrica. A. pyriformis. A. membranacea. A. fornicata. _ A. squamula, A. lens. FAMILY XX. ¥ Bracuiopopa. Three genera. 1. Genus Orbicula. Animal. Body much compressed and rounded; mantle open throughout its whole circumference ; two ciliated tentacular appen- dages. 7 Shell. Orbicular, much compressed, inequilateral, very inequi- valve; inferior valve very thin, adhering, imperforated, the superior patelloid, with the summit more or less tmclined towards the posterior side. Inhabits the Norwegian seas. One living species, Two fossil. Orbicula Norwegica. 2. Genus Teredratula. Animal. Depressed, circular or oval, more or less elongated, with two long pectinated labial tentacula. Shell. Thin, inequivalve, regular, subtrigonal; one of the valves larger and more dilated than the other, which is sometimes operculiform; hinge condyloid, in a straight line and formed by two oblique articular surfaces in one valve placed between corres- ponding projections in the other. Inhabits the sea at the Zetland Islands. Twelve living species. Thirty-seven fossil. Terebratula dilatata, Terabratula globosa. T.