36 



the Kentucky ; resembles the genus 

 Amblema ; ligament horizontal. 



SPECIES XXV. Obliquariafasciolaris (Unio 

 fasciolaris.) 



Shell thick, convex, oval-elliptical, posterior- 

 ly attenuated ; epidermis reddish, almost smooth, 

 with oblique brown bands ; nacre white. Length 

 | axis i of the breadth. 



Var. 1. interrupta bands interrupted. 



Var. 2. fuscata almost entirely brown . 

 bands black. 



Var. 3. obliterata bands almost effaced ; 

 shell very thick. 



Var. 4. longa length f of the breadth. 

 This species is common in the Ohio, Ken- 

 tucky, Wabash, &c. and appears intermediate 

 between the U. interrupta (species 21) and the 

 Unio nasutus of SAY. The animal white, similar 

 to that of the Elliptic . A remarkable character 

 of this species consists in the cavity of the valves, 

 which has some oblique wrinkles. Ligament 

 somewhat oblique ; apices thick, but not promi~ 

 nent ; cardinal tooth wrinkled, thick ; lamellar 

 tooth thick, short ; fossule visible ; muscular im- 

 pressions deep. Breadth sometimes five inches, 



