266 



POPULAR CONCHOLOGY. 



the attached valve is very convex, the other flat, having a 

 small pointed tooth fitting 

 into a corresponding pit 

 in the former ; and there 

 is a long recurved testa- 

 ceous appendage, called 

 the clavicle, connected by 

 a cartilage at both ends to 

 a deep cicatrix under each 

 umbo; the muscular im- 



p ,-• , i • Chamostrtea albida. 



pression of the mantle is 



entire, and the ligament is external.* Animal unknown. 



Stutchbury first observed the curious testaceous ap- 

 pendage in the interior; the only species is C. (Chama) 

 albida Lam. from New Holland. 



Family U.—LUCINACEA. 



The animal has the mantle open before ; behind, there 

 are two simple openings for the passage of the water, 

 which has been through the gills; tubes sessile, or of 

 varied form; the foot also varies in the genera. The 

 shell is roundish, seldom much longer than broad, equi- 

 valve, closed ; the pallial impression has no sinus. — 

 Found in the seas of all zones. 



Lucina. Brug. — Shell nearly round, equivalve, in- 



Lucina divaricata. 



* Reeve's Cou. Sys. 



