396 MOLLUSC A. 



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 Limse 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(l). 



Pedum, Brug. 



The oblong and oblique shell with small ears, of the Limsej 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(2). 



Certain fossils may be placed here which have the hinge, 

 ligament, and central muscle of the Ostrese, Pectines, and 

 Lirase, but are distinguished by some of the details of the 

 shell. 



HiNNiTA, Defr. 



The Hinnitse appear to be Ostrea or Limae with small ears, and 

 adhering, irregular and very thick shells, the convex valve in parti- 

 cular. A depression is observed on the hinge for the ligament(3). 



(1) Add: Ostrea glacialis, Chemn,, VII, Ixviii, 652, 653; Os^r. excavatu, lb., 

 654; OsM fragilis, lb., (>5Q-0str. Mans, Gualt., LXXXVIII, FF, G. For the 

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



and Sowerb., Min. Conch. 



(2) Ostrea spondyloidea, Gm., Chemn., VIII, Ixxxii, 669, 670. 



(3) Some living species have very lately been referred to the genus HiifNiTA, 

 Defr. M. Gray, Ann. of Phil., August 1826, describes one by the name o{ Hin- 

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

 corallina; finally, M. Deshuies refers the Ostrea sinuosa, L , to this genus, and de- 



