LIMNAA. 1138 
tures impressed; whorls six, slightly convex ; 
aperture narrow-elliptical. 
Length 17:5, diam. 6°3 mill. 
Poland, Ohio; Nebraska. 
35. LIMNAZA LANCEATA, Gould. 
Plate 18, fig. 11. 
Shell moderate, thin, diaphanous, horn-col- 
ored, delicately reticulated with incremental 
and revolving striz; whorls six, flattened, 
quite oblique, the last equaling three-fourths 
of the shell’s length; aperture narrow, almost 
equaling one-half the shell’s length, acute pos- 
teriorly; columella fold conspicuous, acute, 
scarcely spiral; labrum with a submarginal 
chestnut band. 
Length 20, diam. 6 mill. 
Lake Superior. 
Next to L. gracilis this is the most delicate 
species we have. It may be compared with 
L. attenuata and L. reflexa, from both of which 
it differs in the flatness of its whorls, in its 
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