39 



Breadth from two to four inches. Animal of a 

 deep or orange yellow colour, with a large cir- 

 cular foot ; in other respects it resembles Ellipta. 

 Shell almost yellow when young ; the lamellar 

 tooth carinated, thin ; cardinal tooth striated 

 over the whole surface; ligament oblique, re- 

 sembles the unio lineolata, which perhaps ought 

 to be placed here. 



SPECIES XXIX. Obliquaria Cyphia (Unio 

 Cyphia.) 



Shell thick, ventricose, hunched ; edge flexuous, 

 sloping posteriorly ; epidermis chestnut brown ; 

 tubercles with flexuous wrinkles; nacre white. 

 Length f diam. f axis f- of the breadth. 

 Breadth two to three inches. 



Shell thickest anteriorly, with large wrinkles, 

 and some oblong tubercles; a large oblique longi- 

 tudinal hunch, or boss ; cardinal tooth thick, 

 striated ; found at the falls of the Ohio. 



SPECIES XXX. Oliquaria metanevra (Unio 

 metanevra.) 



Shell thick, ventricose, hunched, with two 

 marginal sinuses ; one posterior and the other 



