92 



anterior side slightly contracted or furrowed from 

 beak to base; basal margin slightly emarginate; epi- 

 dermis straw-coloured, polished; within white; car- 

 dinal teeth double in each valve; lateral teeth slightly 

 arcuate. 



SYNONYME. 



U. stramineus, Nob. New Fresh Water Shells, pi. vii. fig. 3. 

 Cab. A. N. S. t No. 20420. 



OBSERVATIONS. 



Inhabits brooks or mill streams in Greene county, 

 Alabama. 



This species may be compared to some varieties 

 of siliguoideus, but is sufficiently distinct, being desti- 

 tute of rays on the disk, and having remarkably 

 prominent lines of growth. The siliqaoideus has not 

 been found in Alabama. 



UNIO PATULUS. 



Plate L. Fig. 2. 

 DESCRIPTION. 



Shell ovate; convex anteriorly, and compressed 

 and cuneiform posteriorly; substance of the shell thick 

 on the anterior and thin on the posterior side; beaks 

 not terminal, prominent, undulated, almost contigu- 

 ous; umbonial slope undefined or obtusely rounded; 

 epidermis brownish-yellow, with broad interrupted 

 green rays composed of fasciculi of hair like lines; 

 within white; cardinal teeth, in the left valve pro- 



