OCR Text |
Show 334 MOLLUSCA. More commonly there is one in that portion of the apet·ture which is closed by the penultimate whorl(l). It is frequently observed inside of the external edge(2). CnoNnnus, Cuv. The aperture, as in the last mentioned Pupre, indented on the side next to the spine by the preceding whorl and bordered with salient laminre or teeth; but the form is more ovoid, like that of a common Bulimus. Some of them have teeth on the margin of the apet·ture(3). Others are furnished with more deeply seated lamin~( 4). Here terminate that series of terrestrial Helices, the adult shells of which have a tumid margin round the aperture. SuoOINEA, Drap. Shell oval; the aperture higher than it is broad, as in Bulimus, but larger in proportion; margin of the aperture not tumid, and the side of the columella almost concave. The shell will not receive the cntit·e animal, and it might almost be considered as a large· shelled Testacella. Its inferior tentacula are very small, and it lives on the plants and shrubs which line the banks of rivulets, a cit·cumstance which has caused the genus to be considered as amphibi· ous(5). CLAUSILIA, Drap. These Mollusca formerly belonged to the genus Turbo of Linnreus, from which it has been found necessary to sepat·ate them, in order to approximate them to the terrestrial Helices. The shell is long, (1) Turbouva, L., Martini, IV, cliii, 1439;-Tm·bomttscorum, L. (Pupamargi· nata, Drap., Ill, 36, 37, 38);-Pupa muscorum, Drnp., Ill, 26, 27 (Vertigo cylindrica, Feruss. );-Pttpaumbilicata, Drap. III, 39, 40;-P. doliolum, lb., 41, 42. (2) Hel. vertigo, Gm., (Pttpa vertigo, Drnp., HI, 34, 35);-Pupa antivettigo, lb., 32, 33;-Pupapygmma, lb., 30, 31;-Bulimus ovula1'is, Oliv., Voy., XVli, 12, a, b. (3) Bulimus zebra, 01., XVU, 10;-Pupa tridens, Drap., lll, 57;-Pupavaria· bilis, lb., 55, 56. (4) Bulimus avenaceus, llrug., (Pupa avena) Drap., HI, 47, 48;-P. secale, lb., 49, 50;-P. frumentum, lb., 51, 52;-Bulimus similis, llrug. ;-P. cinerea, Drap., lb., 53, 54;-P. polyodon, IV, 1, 2;-llelix quadridens, (Pupa q1tadr., Drap.) lb., 3. (5) Succinea amphibia, Drap., IV, 22, 23 (Helix putris, L· );-S. oUlonga, lb., 24. -The genera Cocnr.onYDllA, l~cruss., LucJNA, Oken, T.ASSADE, Huder, correspond to the Succinca:. M. Delamark at first styled themAllu>ninur.nu. The .ll.mphib· ulime encapuclwnne, Lam., Ann. du Mus. VI, lv, l, may n.lso form a Testacella. GASTEROPODA PULMONEA. 335 slender an~l pointed, the last whorl, in the adult, narrowed, compressed, sl~~htly d~tac;ed, and terminated by a complete aperture with a tumt m~rgm, requently dentated or furnished with Iaminre. In th: contractiOn of the la~t whorl we usually find a little plate bent wto an S, th. e use of wluch to the livin.g an1'n1al 1· s un k nown. The spec1es are very small, living in mosses at the foot of trees, &c. A great many of them are reversed(l). AcnATINA, Lam. Necessarily separated from the Bullre of Linn-"n"' us and p1 a cec1 h et·e. Th: apet·tur~ o~ the oval or oblong shell is higher than it is broad, as m the Buhm.t, but wants the tumid margin; the extremity of the col~mella also IS tru.ncated, the first indication of the emarginations whtch we shall find 111 so many marine Gasteropoda. These Achati? re are large Helices, which devour trees and shrubs in hot countries( 2). Montfort distinguishes those, in the last whorl of which we find a callus or peculiar thickening,-LIGuus, Montf.(3); this whorl is proportionably lower in them than in the others: And those in which the extremity of the columella is curved towards the inside of the aperture-PoLYPHEMus, Montf.( 4); the last whol'l is higher. The PULMONEA AQUATICA Have but two tentacula, as already stated; they are continu~ lly compe11ed to rise to the surface for the purpose of breathmg, so that they cannot inhabit very deep water .; they are usually found in fresh water or salt ponds, or at least in the vicinity of the sea coast and of the mouths of rivers. Some of them have no shell, such as . (l~ Turbo perversus, L., List., 41, 39;-T. bidens, Gm., Dra.p., IV, 5, 7;-T. paptllaru, Gm., Drap., I b., 13; and the other Clausilia: of Drap., figured on the same plate;-Bulimusretusus, Oliv., Voy., XVII, 2;-Bul. injlatus, lb., 3;-Bul. teres, lb., 6;-Bul. torticollis, lb., 4, a, b;-Turbo tridens, L., Chemn., IX, :xii 957·- 0lauailia collaris, Feruss., List., 20, 16. ' ' (2~ Bulla zebra, L. Chemn., IX, ciii, 875, 876; cxviii, 1014-1016;-Brllla achatma, lb., 1012, 1013;-Bulla pttrpurea, Ib ., 1018;-Bulla dominicensis, Id., CXVIJ, 1011;-Bulla stercus pulicum, CXX, 1026, 1027;-Bulla jlammea, Id., CXIX, 1021-1025;-Relix tencra, Gm., lb., 1028, 1030;-Bulimus bicarinatus, Brug., List., 37;-Melanie buccinoi'de, Oliv., Voy., XVH, 8. (3) Bulla virginea, L., Chemn., IX, cxvii, 1000, 1003; X, clxxiii, 1682, 3. (4) Bulimus glans, Brug., Chemn., IX, cxvii, 1009, 1010. |