48 



narrow ;. epidermis wrinkled, brown ; nacre white. 

 Length % diam. f axis of the breadth. 



Breadth two to three inches. Cardinal tooth 

 large, striated ; fossules visible ; lamellar tooth 

 thick, carinated, somewhat doubled in both valves. 



SPECIES XLIV. Obliquaria sintoxia (Unio 

 sintoxia.) 



Shell thick, ventricose, oblique-oval, without 

 depression ; epidermis black, almost smooth ; 

 nacre roseate. Length T 9 ^ diam. ^ axis f of 

 the breadth. 



Found in the Ohio, rare ; breadth two to 

 three inches ; nearly approaching the Obovaria 

 pachostea, Obliquaria obliquata, and Obliquaria 

 triangularis ; teeth like the latter species ; by its 

 form, makes the transition to the genus Obovaria, 

 which follows. 



SECOND SUB-FAMILY Amblemidia. 



Shell longitudinal ; cardinal tooth under the 

 apex ; lamellar tooth inferior vertical ; axis ter- 

 minal ; wrinkles zonal. 



