46 



ins, Raf. has most resemblance to it in habit. Witli 

 age the posterior extremity becomes slightly pro- 

 duced. 



Inhabits Flint river in Georgia. 



UNIO OVIFORMIS. 



Plate 111.— Fig. 6. 



DESCRIPTION. 



Shell ovate, convex, thick anteriorly, thinner pos- 

 teriorly; anterior margin rather obliquely rounded; 

 posterior margin obliquely truncated; extremity an- 

 gulated; beaks prominent, not decorticated, with 

 three or four strong interrupted undulations; lunule 

 ovate; umboniai slope rounded; epidermis light yel- 

 lowish olive, with broad crowded green rays, widely 

 interrupted; cardinal teeth direct; within pearly 

 white, highly iridescent posteriorly. 



OBSERVATIONS. 



A beautiftil species, allied to U. scalenms, Raf. 

 It differs in not being sinuous or compressed; and in 

 having undulated beaks. It is not oblique. 



It inhabits rivers in Tennessee, but I know not the 

 exact locahty. It was presented to me some years 

 since by Mr. Brewster, of Mount Pleasant, Ten- 

 nessee, to whom I am indebted for the finest speci- 

 mens of certain species which have reached our cabi- 

 nets. 



