LIMNZA. 95 
cannot be specifically separated from reflexa ; 
it might, however, retain its name as a beauti- 
ful variety. The species appears to extend 
through all the north-western States, but does 
not inhabit the waters flowing into the Pacific 
Ocean, being there replaced: by an allied, but 
distinct species, L. Rowellii. 
10. LIMNAA ATTENUATA, Say. 
Hald. Monog. 28, t. 9, figs. 1, 5. 
11. LIMNAA ROWELLII, Tryon. 
Plate 17, fig. 1. 
Shell elongate, narrow, consisting of six 
rather obliquely revolving whorls; spire some- 
what attenuately lengthened; apex acute; 
suture not much impressed; aperture not half 
the length of the shell, oblique; columella 
with a distinct fold, turned to the left below, 
and appressed to the body the whole distance; 
surface rather smooth and polished; texture 
fragile. 
(69) 
