37 



SPECIES XXVI. Obliquaria verrucosa (Unio 

 verrucosa.) 



Shell somewhat thick, elliptical; obliquely 

 sloped posteriorly, with verrucose wrinkles ; 

 epidermis reddish brown ; nacre white. Length 

 | axis i of the breadth. 



This species is remarkable for several concen- 

 tric ranges of unequal warts, flattened, often 

 white by rubbing ; found in the Ohio ; breadth 

 three inches ; cardinal tooth one lobe very large, 

 wrinkled, the other small and smooth ; muscular 

 impressions deep and smooth ; lamellar tooth ob- 

 tuse ; ligament horizontal. 



SPECIES XXVII. Obliquaria cuprea (Unio 

 cuprea.) 



Shell thick, elliptical, obliquely sloped poste- 

 riorly ; epidermis black, almost smooth ; nacre 

 copper coloured. Length | diam. f axis ^ 

 of its breadth. 



A very handsome species ; two inches in 

 breadth ; nacre singular, brownish flesh inclining 

 to copper colour, changeable to purple. I found 

 this species in the Monongahela and Potomac ; 



4* 



