OF THE FAMILY OF NAIADES. 435 



Hab. Ohio. T. G. Lea. 



My Cabinet. 

 Cabinet of T. G. Lea. 

 Cabinet of Prof. Vanuxem. 

 Diam. -8, Length 1.3, Breadth ( 2 inches. 



Shell elliptical, inequilateral] ventricose; substance of the 

 shell thin, the rays being very visible through the nacre; 

 beaks prominent and slightly undulated; epidermis bright 

 olive yellow, with numerous green rays passing from the 

 beaks to every part of the margin : slightly wrinkled, smooth 

 and glossy: cardinal tooth double in both valves aiul deeply 

 cleft; lateral tooth lamelliform. nearly straight, higher near 

 the termination, termination abrupt : anterior cicatrices dis- 

 tinct: posterior cicatrices confluent; dorsal cicatrices situated 

 on the under part of the cardinal tooth, and within the margin 

 of the cavity of the beaks : cavity of the beaks huge and round- 

 ed : nacre pearly white and iridescent, thin, showing the rays 

 very distinctly through it. and presenting a wide margin. 



Remarks. — This beautiful shell resembles most the young 

 cariosus of the Ohio and other western waters. It diffi re, 

 however, in being much less ponderous, possessing more mi- 

 nute rays, being rather more ventricose. having more elevated 

 teeth and more prominent beaks. 



S. Unio Occident Plate X. fig. 16. 



.Testi'i avb-ellipticd, ineequUaterali, trantvend, ventricosd; valvulis 

 crassis : natibus sub-umlnlittis, raro deeorticatia ; ligamento aub-brtvi 

 crussoquc; dentibus elcrcttis ; margaritd albd. 



Shell inequilateral, Bab-elliptical, transverse, ventricose ; valves thick : 



beaks slightly undulated, rarely decorticated; ligament rather sli<>ri and 



thick; teeth elevated ; nacre white. 



Hab. Ohio. T. G. Lea. 



My Cabinet 



VOL. III. — 5 s 



