LIMNEUS UMBROSUS. 



DESCRIPTION. 



Shell horn colour, tinged with reddish brown: spire 

 elongated, tapering, acute : whorls six or seven, slightly 

 convex, wrinkled across: body whorl measured at the 

 back, more than half the total length : suture moderately- 

 indented : aperture less than half the length of the shell : 

 labium with calcareous deposite, the fold of the columella 

 is very slight. 



SYNONYM. 



Limneus elongatus, Nob. Journ. Acad. Nat. Sc. Vol. 2, 

 p. 167. 



OBSERVATIONS. 



It inhabits in considerable numbers, the ponds and tran- 

 quil waters of the Missouri, in the vicinity of Council 

 Bluft, and Dr. Bigsby obtained specimens in Rainy lake 

 and Seine river of Upper Canada. 



I am under the necessity of changing the name which I 

 first applied to this shell, that of elongatus being preoccu- 

 pied by Draparnaud for a very different species. 



PI. 81. 



