70 

 UNIO SHEPARDIANUS. 



Plate XXXIX. 

 DESCRIPTION. 



Shell profoundly elongated, sinuous, compressed, 

 tapering to the posterior extremity, which is trun- 

 cated; valves rather thin, with concentric lines, pro- 

 found over the umbonial slope, which is slightly ele- 

 vated; a carinated line passes between the umbonial 

 slope and posterior dorsal margin; beaks very small, 

 hardly raised above the dorsal line; within purple; 

 lateral teeth long and rectilinear, somewhat dilated 

 or thickened near the anterior termination. 



SYNONYME. 



U. shepardianus, Lea. Trans. Amer. Phil. Soc, new series, vol. 



v. p. 95, pi. xiii. fig. 38. 

 Cab. A.N. S.No. 20411. 



OBSERVATIONS. 



This is perhaps the most elongated, proportionally, 

 of any known Unio, except the Grayanus, and differs 

 chiefly in this respect from U. angustatus, which is 

 the species most nearly related to it. 



Inhabits Alatamaha river, near Hopeton and Da- 

 rien, Georgia. 



