86 MOLLUSC A. 



valves, one brown, the other white, and internal ribs, fine as 

 hairs, approximated two by two*. 



Lima, Brug. 

 The Limse differ from the Pectens in the superior length of their 

 shell in a direction perpendicular to the hinge, the ears of which are 

 shorter, and the sides less unequal, thus forming an oblique oval. 

 The ribs of most of them are relieved with scales. The valves_ can- 

 not join during the life of the animal, whose mantle is furnished 

 with numberless filaments of different lengths without tubercles, and 

 more internally, with a large border which closes the opening of the 

 shell, and even forms a veil in front. The foot is small and the bys- 

 sus trifling. The Limte swim with rapidity by means of their 

 valves. 



One species, the Ostrea lima, L. ; Chemn., VII, Ixviii, 651, 

 of a fine white, inhabits the Mediterranean. It is eaten f . 



Pedum, Brug. 



The oblong and oblique shell with small ears, of the Limse ; but 

 the valves are unequal, and the one only that is most convex has a 

 deep emargination for the byssus. The animal is similar to that of 

 a Lima, but its mantle is only furnished with a single range of small, 

 slender tentacula. Its byssus is larger. 



But a single species is known; it inhabits the Indian 

 Ocean %. 



Certain fossils may be placed here which have the hinge, 

 ligament, and central muscle of the Ostreae, Pectines, and Limae, 

 but are distinguished by some of the details of the shell. 



HiNNiTA, Defr. 



The Hinnitpc appear to be Ostreae or Limae with small ears, and ad- 

 hering, irregular and very thick shells, the convex valve in particular. 

 A depression is observed on the hinge for the ligament §. 



* Add the ninety-one species of Ostrea, Gmel. ; we must remember, however, 

 that some of them are far from established on a solid foundation. For the fossil 

 species, consult Sowerby (Mineral Conchology), and Brongniart, App. Cuv., Oss. 

 Foss. tome II, Env. de Paris. 



t Add, Ostrea glaciuUs, Chemn., VII, l.xviii, 652, 653 ; — Ostr. excavata, lb., 

 654 ■^—Oslr.fragilis, lb., 650 •,—Ostr. Mam, Gault,, LXXXA^II, FF, G. For the 

 fossil species, see Lamarck, Ann. du Mas., VIII, p. 461 ; Brocchi, Conch. Foss., 

 and Sowerb., Min. Concb. 



+ Ostrea spomhjloulea, Gm., Chemn., Vlll.lxxxii, 669,670. 



§ Some living species have very lately been referred to the genus Hinnita, 

 Defr. M. Gray, — Ann. of Phil., August 1S26, — describes one by the name of Hin- 

 nita gigantea; Sowerby, — Zool. Journ. IX, p. 67, adds a second by that of H. 

 roraUina; finally, M.Deshayes refers the Ostrea siniiosa, L., to this genus, and de- 

 scribes a fourth living species under the name of Hinnita Defrancii; M. Defrance 

 also admits two fossil species, the H. Cortesii, Blainv., Malac, pi. Ixi, f. 1, and the 

 //. Dulntissonii. 



