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

flat valves, the valves contiguous and unequal; the lower lateral ones the largest: the whole of them united and kept together by means of their mem- branes. Inhabits the British seas. Six species. Anatifera levis. Anatifera dentata. A. villosa. A. striata. A. vitrea. A. Aculeata. ~~ & CONCHOLOGY. 33 8. Genus Pollicipes. Pl. V.- Animal. Body covered by a shell, and supported on a tabular, tendinous, scaly peduncle; with many tentacular arms. Shell. Compressed at the sides, multivalve, contiguous, unequal in number, with numerous small valves situated at the base ; peduncle covered with embricated scales, lower ones rounded and turned upward. Inhabits the European seas. Five species. Pollicipes cornucopia. Pollicipes mitella. P. scalpellum. P. peronil. P. homii. a 9. Genus Cineras. Pl. V. Animal. Body pedunculated, and encased in a membranous tunic, which is swollen above, with an opening below the summit, from which protrude many ciliated articulated arms. Shell. composed of five testaceous oblong valves, two at the sides of the aperture and three on the back, not covering the whole of the body ; supported by a peduncle of a greenish color, with several longitudinal stripes. Inhabits the British coast, One species. Cineras vittata. 10. Genus Otion. Pl. V. Animal. Body pedunculated, enveloped in a2 membranous tunic, which is ventricose above; two horn-like tubes, directed backwards, truncated, and open at their points, and situated in the apex of the tunic ; having a lateral opening, with many articulated and ciliated arms. Sheil. Composed of two testaceous valves, attached near the lateral opening, the centre aperture admitting the animal’s tenta- cule, the singular form of which prevents its being blended with the genus cineras without a further examination of its structure. In- habits the North seas. Two species. Otion Cuvieri. Otion Blainviilii. 34 CONCHOLOGY. CLASS III. CONCHIFERA. Animals. Soft, inarticulated, always fixed in a bivalve shell, without head or eyes, having the mouth naked, concealed, and without any hard parts; a large mantle enveloping the whole of the body, forming two laminiform lobes, the edges detached or sometimes united in front. Gills or respiratory organs external, situated on each side between the body and the mantle; circula- tion simple, the heart with one ventricle ; some few ganglions of the different nerves, but no knotted medullary cord. Shell. Always bivalve, enveloping the animal entirely or par- tially, sometimes free, sometimes affixed; the valves most fre- ‘quently united on one side by a hinge or ligament, sometimes attached to the shell, are testaceous accessory pieces. ‘Twenty families. FAMILY I. Tusicota. Six Genera. 1. Genus Aspergillum. PI. V. Animal. Entirely unknown. Shell. Oval, somewhat elongated, striated longitudinally, conic, club-shaped, open at its attenuated extremity, and terminated at the other by a convex disk, pierced by a number of small perfo- rations, and encircled by a dilated margin of papyraceous tubes, resembling a plaited ruff, smaller extremity always open. This is a well known, but rare shell, found in sandy places in low water in the Indian ocean. Four species. Aspergillum Javanum. Aspergillum Nove Zelandie. A. vaginiferum. A. agglutinans, 2. Genus Clavageila. Pl. VI. Animal. Unknown. Shell. A tubular a? lin attenuated, and open before ; CONCHOLOGY. 30 terminating posteriorly in an oval, sub-compressed club, rough- ened by spiniform tubes. Inhabits the Indian seas. One species. Clavagella aperta. 3, Genus Fistulana. Pl. VI. Animal. Provided with two protuberant calcareous tubes, cover- ing parts of its body at the open end of the tube, each of which is terminated with from five to eight cup-shaped calcareous, or corneous appendages. It inhabits the sand, and perforates wood, stones, and sometimes shells. Shell. Lamarck asserts that the tube and shell ef this genus are quite distinct. They have the shell free and detached within the sheath, and neither of the valves fixed into the partition of the tube, which is most generally testaceous, closed, and retort-shaped at the posterior extremity. Inhabits the Indian seas. Four species. Fistulana clava. Fistulana gregata. F. corniformis. F. lagenula. 4, Genus Septaria. Pl. VI. Animal. Unknown. Shell. _ A very long testaceous tube, gradually attenuated to its upper end, and divided internally by vaulted divisions seldom complete, the extremity of which is terminated by two slender tubes without interior partitions. Specimens of this genus have been found five feet long. Found in sand on the shores of the Indian sea. ‘I'wo species. Septaria arenaria. Septaria maculata. 5. Genus T'eredina. Pl. VI. A fossil genus; consisting of a testaceous cylindrical sheath, the posterior extremity closed, and exhibiting the two valves of the shell it encloses ; the anterior end open. ‘Two fossil species. 6. Genus Teredo. Pl. VI. Animal. Body very much elongated, vermiform : mantle very fine, tubular, opening only at front and below for the issue of a teat-shaped foot; mouth small; very short, distinct tubes; the in- 36 CONCHOLOGY. ferior or respiratory one somewhat larger than the superior ; labial appendages short and striated; branchie very long, narrow, united, and prolonged throughout the extent of the tubular cavity of the mantle; only one large contractile muscle between the valves ; at the point of junction of the mantle and tubes is a muscular ring, in which is implanted a pair of corneo-calcareous appendages. Shell. Thick, solid, very short or annular, open before and behind; valves equal, equilateral, angular and trenchant before, only touching each other by the opposite edges; no hinge; a considerable spoonlike cavity ; only one feeble muscular impression, Tube more or less distinct from the substance in which the animal lives, cylindrical, straight or winding, and closing with age at the bucal extremity so as to envelope the animal and its shell; at the other end it is always open, and divided internally into two syphons by a partition in the middle. Inhabits the European seas in timber. Three species. Teredo navalis, Teredo palmulata. Teredo gigantea. FAMILY II. Puorrpania. ‘Two Genera. ®, 1. Genus Pholas. Pi. VI. Animal. Without a tubular sheath, projecting anteriorly into two united tubes, frequently surrounded by a common skin, and the posterior extremity provided with a short muscular foot, flattened at its extremity. Shell. Multivalve, equivalve, transverse gaping at both ends, with various accessory pieces either on the hinge or below it. Inhabits Indian seas and American shores. Thirteen species. Pholas dactyla. Pholas silicula. P. orientalis. P. costata.* P. candida. P. callosa. P. dactiloides. P. clavata. P. papyracea. P. ovum. P. tuberculata. P. lancellata.* . crispata. CONCHOLOGY. 37 2. Genus Gastrochena. PI. VI. Animal. Unknown. Shell. Equivalve, somewhat cuneiform with a very large oval and oblique aperture anteriorly ; posterior extremity nearly closed ; hinge linear; marginal and without teeth. Three species. Gastrochena cuneiformis. Gastrochena mytiloides. G. modiolina, FAMILY III. SoLenrpa. Four genera. I. Genus Solen. PI. VI. Animal, Body cylindroid, much elongated; the mantle in form of a canal open at both ends, closed in the rest of its extent by a thick epidermis which surrounds it; a cylindroid anterior foot. Shell. Equivalve, extremely inequilateral, the summits very small, and entirely at the commencement of the dorsal line; one or two teeth in the hinge. Inhabits the seas of America and Eu- rope. Nineteen species. Solen vaginus. Solen vaginoides. S. corneus. S. siliqua. S. ensis. S. cultellus. S. pygmeus. S. planus. w S, ambiguus. S. minutus. S. dombeii. S. constrictus. S. javanicus. S. coarctatus. S. caribeus. S. rostratus. S. antiquatus. 8. violaceus. S. giganteus. © 2. Genus Panopea. PI. VI. Animal. Unknown. Shell. Regular oval, elongated, gaping at both ends, equivalve, inequilateral; summit little marked and anterodorsal; hinge com- plete; similen formed by a conical primary tooth, before a short, compressed, ascending callosity, ligament exterior, attached to the 5 > 38 CONCHOLOGY. callosity; two muscular impressions. Inhabits the Mediterranean sea. One species. Panopea aldrovandi. 3. Genus Solecurius. Pl. VI. Animal. Unknown. Shell. Oval, elongated, equivalve, subequilateral, with edges nearly straight and parallel, the extremities equally rounded, and, as it were, truncated; summits but little marked ; hinge without teeth, or formed by some rudimentary primary teeth, ligament projecting, affixed to thickened callosities; two distinct rounded muscular impressions. Mediterranean sea. Three species. Solecurtus radiatus. Solecurtus strigilatus. S. legumen. 4. Genus Glycimeris. Pl. VI. Animal. Unknown. Shell. Covered with epidermis, slightly irregular, elongated, gaping at both ends, equivalve, exceedingly inequilateral ; sum- mits little marked; hinge toothless; a longitudinal callosity. Ligament exterior, affixed to very projecting callosites on the shortest side of the shell; two distinct muscular impressions. Inhabits the north seas. ‘Two species. Glycimeris margaritacea. Glycimeris siliqua. FAMILY IV. Myarra. Two genera. I, Genus Mya. Pl. VI. Animal. Subcylindrical, enveloped in a mantle pierced only with one interior and inferior hole for the passage of a very small and conical foot; the tubes very considerable, and com- pletely united; a tolerably large mouth, oval, and with simple lips ; very small labial appendages ; branchial lamine inconsider- able ; the external very short, the internal united with that of the opposite side. Sheli. Surrounded with a thick epidermis, which is prolonged upon the tubes and the edges of the mantle of the animal ; tolera- CONCHOLOGY. 39 bly solid, with fine trenchant edges; the summits very little marked ; hinge dissimilar ; one or two oblique cardinal folds, diver- gent, behind a horizontal spoon-shaped hollow upon the left valve, corresponding with a hollow; horizontal and cardinal in the right valve; two distinct muscular impressions. Inhabits the British coast. Four species. Mya truncata. Mya erodona. M. arenaria. M. solenimyalis. 2. Genus Anatina. Pl. VI. Animal. Unknown. | Shell. Transverse, subequivalve, gaping at both vaives, or m one only ; no cardinal teeth; one broad primary tooth in both valves, projecting interiorly ; a lateral plate running obliquely under the primary teeth. Sometimes there is a fissure extending from the apex, giving the appearance of a second plate or rib Inhabits the British seas. Ten species. Anatina laterna. Anatina trapezoides. A. truncata. A. rugosa. A. subrostrata. A. imperfecta. A. longirostris. A. myalis. A. globulosa. A. rupicola. FAMILY V. Mactracea. Seven genera. 1. Genus Lutraria. Pl. VI. Animal. Body oval, much compressed, or subcylindrical ; the mantle enclosed only in the half of its inferior side: foot small and projecting but little beyond the abdominal mass, tubes long, distinct or united. Shell. Oval or elongated, regular, equivalve, more or less inequilateral, sometimes but slightly gaping ; edges always simple and trenchant ; summits feebly marked ; hinge subsimilar, formed by two very small divergent cardinal teeth; two very distinct muscular impressions united by a palleal impression profoundly sinuous to the rear. Inhabits the seas of Europe. Eleven species. 40) CONCHOLOGY. Lutraria elliptica. ]., papyracea. L. Plicatella. L. crassiplica. L. complanata. L. candida. Lutraria solenoides. L. rugosa. L.