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Show 4~0 'MOLLUSCA. Some of them al·e found in t h e san c.1 at the mouths of rivers in France( 1). In the MYA, Lam., . llecl one valve is furnished with a h M Properly so ca ' . . Or t e ya . . h ther and this latter wtth a CaVlty. h. h . Jects mto t e o ' plate w tc P1 0 f this cavity to that plate. The ligament stre~ches ro~ d in the sand along the coast of Some spectes are loun France(2). ANATINA, Lam. . k h uld be approximated to the preceding Tl1 ~ atm~ ofLamarc s o . 'd . h e .. n . 1 h small projecting plate ms1 e Wit M ~ Each of the1r va ves as a Y • d'n from one to the other. the ligament exten 1 g . l thin species is known, the valves 0 blong and excessive Y f ne o . d b an internal ridge(3); and another o of which are supporte y a squarer form without the ridge( 4).· In the SoLEMYA, Lam. . n the outside of the shell, part of it re· The ligament 15 seenho .· tal internal cuilleron on each valve. . . ttached to a ot1zon . mammg a 1' 1 t th and a thick epidermis proJects There is no other car< ma oo ' beyond the edge~ of the s;~~l.' togata Poli II, xv: 20, is found in One spectes, the .1. e tna ' ' the Mediterranean( 5). GLYOYMERIS, Lam.-CYRTODARIA, Daud. . . h h'nge but a simple cal· Neither teeth, plates, nor cavtttes on t e 11 r' ment The ani· lous enlargement, behind which is an externa tga • mal resembles that of the My~. . . L . Chemn. XI, 193, The most common species-Mya 81.hqua, ., f. 194, is from the Arctic Ocean. ( 1) Mactra lutraria, List., 415, 259; Chemn., V I , x xiv , 240 'f2i 41,· -.M ya oblonga, Id lb. ii 12;-Acosta, Brit. Conch., XVII, 4; Gualt., 90~ A, g 3 · ~m. .(,2 ) M' ya' truncata, 1 •. , Ch emn., VI? 1 · , 1 ' 2'· -M. arenana, lb., • · (3) Solen anatinus, Chemn., VI, VI, 46- 48· . 'd la cuv. An. sans (4) Encyc., 230, 6, under the name of Corbule;-An. htspl uf ~ de' Bellevue .. f 8 I t that the Rul'ICOLE o · f vert., Egyp. Coq. pl. Vll, . • suspe: Th live in the ioterioro (Voy. Uoissy, VI, 440) must approach thls subgenus. ey stones like the Petricolre, Plwlades, &c. l' Lam ( 5) New-Holland furnishes a second species, the Sol. austr(L ~s, . ACEPHALA TEST ACEA. 421 PANOPEA, Mesnard, Lagr. A stout tooth, anterior to the callous enlargement of the preceding subgenus, and immediately under the summit, which decussates a similar one on the opposite valve, a character which approximates the Panope~ to the SoJens. A large species is found in the hills at the foot of the Appenines in so high a state of preservation, that it has been mistaken for a recent sea-shell( 1 ). There is another fossil species, which may perhaps be separated from it, that is completely closed at its anterior extreinity(2). After these various modifications of the My~, we may place the PANDORA, Brug. In which one valve is much flatter than the other; the internal ligament is placed transversely, accompanied in front by a projecting tooth of the flattened valve. The posterior side of the shell is elongated. The animal withdraws more completely into its shell than the preceding ones, and its valves shut more closely-its habits however ar·e the same. But a single species is well known; it inhabits the seas of Europe(3). Here also we find a group of some sma11 and singular genera, such as BvssoMIA, Cuv. Wher·e the oblong shell, which has no marked tooth, has the opening for the foot at about the middle of' its edge and opposite the summits. The Byssomi~ also penetrate into stone, corals, &c. A species which is provided with a byssus, abounds in the Arctic Ocean( 4). HIATELLA, Daud. The shell gaping, to allow the passage of the foot, near the middle (1) Mya glycimeris, L., Chemn., Vl, iii. A neighbouring, but shorter species inhabits the Mediterranean. Another, fossil species is found near Bourdeaux. (2) Panope de Faujas, Mesnard, Lagr., Ann. du Mus., IX, xii. Here should be the place of the SAXIC.AVA of M. F. de Bellevue, small Testacea Which perforate stones. See Roiss., VI, 441. (3) TeUina i~quivalvi8, Chemn., VI, xi, 106, and for the animal, Poli, II, xv, 7. (4) Mytilus pholadis, Mull., Zool., Dan., lxxxvii, 1, 2, 3, or Mya byasifera, Fabr., Green}. |