UNIO LAPILLUS. 



SPECIFIC CHARACTEU. 



Very small, thick, radiated 5 teeth very thick. 



SYNONYM. 



U. LAPILLUS, Noh. Tiwisylvania Journal of Medicine- 

 Vol. 4. p. 528. 



DESCIllPTION. 



>S'Ae// transversely suboval, thick, obscure yellowish, with 

 very numerous dark green radiating lines : posterior mar- 

 gin not very short, rounded: beaks but little elevated, 

 simple : lunule fusiform, very obvious : hinge margin and 

 anterior margin a little depressed, declining graduallly in 

 an arquated line : anterior basal margin rounded : basal 

 margin nearly rectilinear in the middle : ivithin pearly 

 white ; cardinal teeth direct, thick ; lateral teeth thick, 

 oblique with respect to the base : cicatrices very deep and 

 rounded ; cavity of the beaks almost obliterated, with a sc- 

 ries of small cicatrices, extending downwards and back- 

 wards. 



OBSERVATIONS. 



The robust teeth and the thickness of the whole sliell, 

 have induced many, and myself amongst the number; to 



