69 



land river, and it seems chiefly confined to the waters 

 of Tennessee — I saw none in Alabama. The figure 

 is from a specimen in the cabinet of Mr. Feather- 

 stonhaugh. 



UNIO GREENIL 



Plate XXXVIII.— Fig. 2. 

 DESCRIPTION. 



Shell sub-triangular; disks slightly flattened; ante- 

 rior side not very short, margin rounded, not very 

 obtuse; umbo flattened, not elevated; beaks eroded; 

 umbonial slope straight, subangulated; ligament short, 

 ligament margin forming with the posterior margin a 

 nearly regular arcuate line; extremity obtusely round- 

 ed or subtruncated; basal margin slightly arcuate; 

 epidermis wrinkled on the margins, with narrow 

 green rays on the posterior slope and interrupted 

 rays on the umbo; within white; cardinal teeth slightly 

 oblique; lateral teeth oblique and very slightly curved. 



SYNONYME. 



IT. greenii, Nob. New Fresh Water Shells, p. 32, pi. iv. fig. 1. 

 Cub. A. N. S. No. 20413. 



OBSERVATIONS. 



Dedicated to my friend Jacob Green, M. D., Pro- 

 fessor of Chemistry in Jefferson College, a gentleman 

 well known as a contributor to Conchology. Inhabits 

 the head waters of Black Warrior river, Alabama; 

 not uncommon. 



