46 



any of the large rivers. It is common in Bayou 

 Teche, Louisiana, and has been found in the Ohio 

 canal near Louisville, whence Mr. Hyde has received 

 it. 



UNIO BLANDINGIANUS. 



Plate XXIII. Fig. 2. 



DESCRIPTION. 



Shell subtrapezoidal, rather thin, ventricose; ante- 

 rior margin very obtusely rounded; ligament margin 

 much elevated, slightly arcuate, angulated at tip, pos- 

 terior margin long, oblique and rectilinear; extremity 

 subtruncated or obtusely rounded; beaks slightly ele- 

 vated, eroded; umbonial slope rounded, very distant 

 from the margin; epidermis finely wrinkled; within 

 purplish, with green stains; cardinal teeth small, single 

 in the right valve and compressed; widely bifid, and 

 rather obtuse in the left; lateral teeth distant from 

 the cardinal teeth, and arcuate; anterior muscular 

 impressions marginal. 



SYNONYME. 



U. blandingianus, Lea. Trans. Amer. Philos. Soc. new series, 



vol. v. p. 101, pi. xv. fig. 44. 

 Cab. Ji. N. S. No. 1859. 



OBSERVATIONS. 



A species allied to complanatus and declivis, but 

 differing from both in the elevated ligament margin 

 and inflated disks. The anterior lunule resembles 



