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Show 362 MOLLUSCA. The external edge of the aperture is crenulated in several species. The animal is more highly ornamented, and is generally furnished with three or four filaments, on each side, as long as its tentacula. The eyes are planted on particular pedicles at the external base of the tentacula; the operculum is round and horny. · A small species, the Trochus tesselatus, L.; A dans., Seneg., XII, 1; List., 642, 33, 34, with a brown shell spotted with whitish, is very abundant on the coast of France( 1 ). PHA.SIANELLA, Lam. An oblong or pointed shell, similar to that of several Bulimi and Lymnrere; the aperture also higher than it is wide, and furnished with a strong operculum; base of the columella sensibly flattened, but no umbilicus. They inhabit the Indian Ocean, and are much sought for by col· lectors on account of the beauty of their colours. The animal is provided with two long tentacula, with eyes placed on two tubercles at their external base, and with double lips that are emarginated and fringed, as well as the wings, each of which has three filaments(2). AMPULLARIA, Lam. A round, ventricose shell, with a short spire, as in most of the He· lices; the aperture higher than it is wide, and provided with an oper· culum; the columella umbilicated. They inhabit t e fresh or brackish waters of hot countries. The animal has long tentacula, and eyes placed on pedicles at their base. In the roof of the respiratory cavity, by the side of a branchial comb, according to the observations of Messrs Quoy and Gaymard, is a large pouch, without an issue, that is filled with air, and which may be consillered as a natatory bladder(3). The LANIST..IE, Montf., are Ampullarire, with a large, spiral, con· ' voluted umbilicus( 4). (1) Add: Trochus labeo, Adans., Seneg., XII, List., 68, 442;-Tro~. P~ nius, List., 637, 25;-Tr. rusticus, Chemn., V, clxx, 164-5, 46,-Tr. mgemmut, lb., 47;-Tr. ZJgyptius, ld., clxxi, 1663, 4;-Tr. viridulus, lb., 1677;-Tr. carneus, lb., 1682;-Tr. albidus, Born., XI, 19, 20;-Tr. asper, Chemn., 1~· clxvi, 1582;-Tr. citrinus, Knorr., Del., I, x, 7;-T,·. granatum, Chemn., v' clxx, 1654-55;-Tr. crocatus, Born., XII, 11, 12;-Turbo atratus, Chemn., ' clxxvi, 1754-55;-Turbo dentatus, Jd., clxxviii, 1767,8, &c. (2) Buccinum tritoois, Chemn., IX, cxx, lOSS, 1036;-Helix salida, Born.,Xlll, 18, 19. (3) Helix ampullacea, L., List., 130;-Bulimus urceus, Brug., List., 125, 2~. (4) .IJ.mpulla carinata, Oliv., Voy. en Turq., pl. xxxi, f. 7, copied lllamv., Malac., xxxiv, 3. GASTEROPODA PECTINJHRANCIITAT A. 363 HEt.ICINA, Lam.(l) Judging by the sheil, the Helicinre are Ampullarire in which the margin of the aperture is reflected(2). When this reflected margin is trenchant, they are the AMPULLINJE, Blainv.; and when it is in an obtuse ridge, the 0LYGIRE, Say. There is one species which is remarkable for a border and stony traverse, on the internal face of its operculum(3). The organs of respiration in these animals are arranged as in the Cyclostomre, and like the latter they can live out of water(4). MELANIA, Lam. A thicker shell; the aperture, higher than it is wide, enlarges opposite to the spire; the columella without plicre or umbilicus; length of the spire very various. The Melanire inhabit rivers, but are not fou11d in France, the ani. mal has long- tentacula, the eyes being on their external side, and at about the third of their length( 5). The RissoA, Freminv.-AoMEA, Hartni. Differs from Melania, because the two edges of the aperture unite above(6). The MELANOPsis, Feruss., Where the form is nearly that of a Melania, differs from it in a callus on the columella, and in a vestige of an emargination near the (1) Montfort has changed the name Helicina into Pitoonilla, but it has not been adopted, and can only be quoted as a synonyme. (2) The Hel. striata, Blainv., Malac., xxxv, iv. (3) The Hel. neritella, List., LXI, 59, copied Blainv., Malac., xxxix, 2. (4) It is from this circumstance that M. rle t~erussac has been induced to class this subgenus with that of the Cyclostomm in an order wbi.ch he names the Pulmonea Operculata. See the Monograph of this genus by M. Gray, Zool. Journ., Nos.l and2. (5) Melanie thiare (Melania amarula, Lam.), Chemn., Tab., 134, f. 1218 and 1219; from the Isle of France and Madagascar. Add: Mel. truncata, Lam., Encyclop., pl. 458, f. 3, a-b;-Mel. coarctata, Id., Encyclop., pl. 458, f. s, a-b., and a great many fossil species, among which are, MeL semi-placata, Defr.;-Mel. Cuvieri, Desh., Coq. Foss., des environs de Paris, tome II, pl. xii, f. 1, 2;-Mel. constellata, Lam. (6) M. de Freminville describes seven species in the Nouv. Bullet. des Sc. Nat. de Ia Soc. Phil., 1814, p. 7, and M. Audouin, three, in the Descr. de l'Eg.: Rias. Freminvillii, Coq., pl. iii, f. 20;-Riss. Deamarestii, lb ., 21 ;-Riss. Orbignii, lb., f. 22. |