47 



lamellar tooth thick carinated ; muscular, impres- 

 sions andfossule deep. 



SPECIES XLII. Obliquaria scalenia ( Unio 

 scalenia.) 



Shell thick, ventricose, triangular; sides almost 

 straight, especially the posterior, which is trun- 

 cated ; angles rounded ; no depression ; epidermis 

 smooth, reddish brown, with some oblique longi- 

 tudinal brown lines ; nacre white. Length 

 diam. axis -^ of the breadth. 



Found in the Kentucky, &c. ; breadth about 

 two inches ; cardinal and lamellar teeth furrow- 

 ed, confluent ; lines narrow, radiated, distant. 



Sixth Sub-genus SINTOXIA. 



Shell oblique-oval; lamellar tooth and ligament 

 curved. 



SPECIES XLIII. Obliquaria lateralis (Unio 

 later alis.) 



Shell thick, ventricose, oblique-oval ; with a 

 slight depression, oblique longitudinal, curved, 



