380 MACTRIN/E. 



The species of Mulinia are principally found on the 

 coasts of North and South America. 



Species of Mulinia. 



angulata, Gray. exalbida, Gray. 



Byronensis, Gray. Patagonica, D'Orb. 



carinulata, Desk. Portoricensis, Shuttl. 



donaciformis, Gray. Rodatzi, Dhr. 



edulis, King. typica, Gray. 



Genus RANGIA, Desmoulins. 



Siphons short, separate. 



Shell ovate, triangular, thick, rather produced behind, 

 covered with a brown epidermis ; beaks often eroded ; mar- 

 gin of valves acute, simple. Hinge with two teeth in each 

 valve, the front one of left valve larger and bifid, the hind 

 one of left and that of right valve equal, small, simple ; 

 lateral teeth elongate, the front dilated and angular above ; 

 ligament internal, in the upper edge of the deep cartilage- 

 pit; cartilage internal. Pallial sinus short, half-ovate. 



Syn. Gnathodon, Gray. Clathrodon, Conrad. 



Ex. R. cyrenoides, Desmoulins, pi. 100, fig. 4, 4, a. 



Ranyia cyrenoides of Desmoulins, or Gnathodon cu- 

 neatus of Gray, is from Lake Pontchartrain in New 

 Orleans, and was formerly an article of diet with the 

 Indians of those parts. The other species are found buried 

 in banks of mud, in brackish water, in the Gulf of Mexico. 



Species of Hangia. 



cyrenoides, Desmoid. rostrata, Petit. 



parva, Petit. trigona, Petit. 



