53S 



ARCINiE. 



ends more- or less oblique or longitudinal; ligament exter- 

 nal ; ligamental area narrow. Pallial impression entire. 



E.v. S. insequivalvis, Bruguiere, pi. 1.25, fig. 3, 3, a. 



In Scapharca the valves of the shell are inequivalve 

 like those of Cucullaea. The species are met with in the 

 seas of most warm climates. 



Species of Scapharca. 



ambigua, Reeve. 

 angicostata, Reeve. 

 anomala, Reeve. 

 bifrons, Cpr. 

 bisulcata, Lam. 

 Brasiliana, Lam. 

 Cayenensis, Lam. 

 cepoides, Reeve. 

 chalchanthium, Reeve. 

 cistula, Reeve. 

 clatlirata, Reeve. 

 compacta, Reeve. 

 concirma, Sotv. 

 corbicula, Gruel. 

 cornea, Reeve. 

 cymbseformis, Reeve. 

 disparilis, Reeve. 

 emarginata, Sow. 

 globosa, Reeve. 



gubernaculum, Reeve. 

 inaequivalvis, Brag. 

 incongrua, Say. 

 Japonica, Reeve. 

 labiata, Sow. 

 labiosa, Sow. 

 loricata, Reeve. 

 myristica, Reeve. 

 mix, Sow. 

 obesa, Soio. 

 occidentalis, Phil. 

 occlusa, Reeve. 

 ovata, Grnel. 

 pertusa, Reeve. 

 pilula, Reeve. 

 rhouibea, Bom. 

 rufescens, Reeve. 

 transversa, Say. 



Genus PARALLELEPirEDUM, Klein. 



Shell sub-quadrangular, suh-equivalve, twisted, the left 

 valve the larger and more twisted, with the hinder slope 

 more or less keeled ; surface of valves covered with a 

 paleaceous epidermis. Hinge with the teeth divided into 

 large oblique plates broader at the outer ends ; ligament 



