UNIO VIRIDIS? 



Plate IX.— Fig. 1. 

 DESCRIPTION. 



Shell ovate, thin, inflated over the umbonial slope; 

 anterior side slightly compressed; beaks with angu- 

 lar transverse ridges; colour ochraceous, with green 

 rays; basal margin straight or slightly contracted in 

 the middle; cardinal teeth small, compressed, divided 

 into three lobes, the posterior lobe situated directly 

 under the beaks; lateral teeth much compressed; 

 within bluish-white, iridescent. 



Unio VIRIDIS? Raf. Monograph of the bivalve 

 shells of the river Ohio, &c., p. 19. 



OBSERVATIONS. 



Inhabits Schuylkill river; Juniata river; creeks in 

 Lancaster co.. Perm., Mr. Hyde. Kentucky river, 

 Mr. Rafinesque. 



The viridis of Rafinesque was found in Kentucky, 

 and the shell I have described in the Atlantic streams; 

 they may therefore be different species, as I have not 

 seen a good specimen of Ihe former. I propose in 

 that case to call the present shell subviridis. 



