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muscular impressions ; animal similar to that of 

 the Unio, but with syphons apparent, short. 



This name is modified from Lasmacampsilis, 

 which signifies flexuolated lamellar tooth, the 

 essential character of this genus. 



SPECIES XIV. Lampsilis cardium (Unio 

 cardium.) 



Shell oval, broad, inclined posteriorly, very 

 ventricose, thick ; apices prominent, heart 

 shaped ; epidermis reddish brown, rugose, black- 

 ish posteriorly ; nacre white, roseate posteriorly. 

 Length f diam. f axis ^ of the breadth. 



A beautiful species, very ventricose ; breadth 

 sometimes six inches ; cardinal tooth striated, 

 crenulated ; lamellar tooth compressed ; animal 

 white, bi-lamdlar appendages broad, exterior la- 

 mellar tooth largest. 



SPECIES XV. Lampsilis ovata (Unio Ovata.) 

 Unio ovatus, SAY. 



Shell oval, regular, attenuated posteriorly, 

 ventricose; apices prominent; epidermis corneous, 

 brown on the posterior depression ; nacre white ; 

 somewhat thick. Length f diam. T 3 ^ axis ^ of 

 the breadth. 



