75 



The striae do not arch forward, in crossing the sides, as is usual 

 in tliis genus, and they are not much interrupted in crossing 

 the obscure corners or the mesial lines on the sides, indeed, it 

 is not easy to determine from our specimen which is the for- 

 ward end of it. The narrow fui'rows are crossed by fine lines or 

 bars and the strife are minutely crenate. There are about fifty 

 transverse striae in an inch in length. 



Our specimen is more or less preserved, for five inches in 

 length, but both ends are broken away so that no correct idea 

 can be formed of the true length of the shell. 



It is distinguished by its great length, rounded form, and 

 surface ornamentation. 



Found in the St. Louis Group, at Spergen Hill, Indiana, and 

 now in the collection of Wm. i''. E. Gurley. 



