24 



SYNOPSIS OF 



Til 



O 



w 



Eh 



i< 



;>^ 



Oh 



o 



OVAL. 



W 



§-< 



to 



altilis, Cow. 



multiradiatus. Z^ea. 

 Unio fasciola? -ffa/ 

 Unio fasciolus. Con. 

 Unio ligamentina. Desh. 



perovalis. Con. 



capsseformis. Lea. 



Greenii. Con. 



pictus. Lea. 



taeniatus. Con. 



interruptus. Lea. 



venustus. Lea. 



crassus. Say. Bar.* 

 Unio ellipticus. Bar. 

 Unio carinatus. Bar. 

 Unio ligamentina. Lam. 

 Mya gravis. Wood. 

 Unio fasciatus. Con.\ 



* Mr. Barnes made eleven varieties of crassus ; most of which were no 

 doubt distinct species, some were plicate. 



f Mr. Conrad thinks the crassus of Say is fas data of Mr. Rafinesque. An 



