11 



There is an affinity between this and the preceding 

 species;, but besides the difference in the coloured 

 markings, this has the superior valve less convex than 

 the superior. 



I found this species upon the coast of South Caroli- 

 na, and on that of the Gulf of Mexico, near Mobile 

 Point. Mr. Hyde suggested its identity with Pecten 

 purpuratu8 \ and a comparison of the Florida speci- 

 mens with a fine series from South America, has con- 

 firmed his observation. 



This shell has a very extensive range, occurring on 

 the coast of Panama, and in Coquimbo Bay, in Chili, 

 where the natives, who eat the animal, procure it 

 abundantly in the surf. In this locality it occurs much 

 larger than on the coast of Florida, and becomes thick- 

 er and more ponderous than is usual in the genus. 



The largest specimen I have seen measures about 

 four inches in length. 



PECTEN PEALIL 



Tab. II, jig. ^ "X. 



SPECIFIC CHARACTER. 



Shell ovate ; dull red, varied with cinereous ; ribs 

 about 26, elevated, very rugose, and divided at the 

 base by a longitudinal sulcus; interstices with each a 

 scaly longitudinal stria; ears unequal. 



Cabinet of the Acad. Nat. Sciences, No. 1400. 



