LIMN^A. 113 



tures impressed ; whorls six, slightly convex ; 

 aperture narrow-elliptical. 



Length 17-5, diam. 6-3 mill. 



Poland, Ohio; Nebraska. 



35. LIMN^A LANCEATA, Gould. 

 Plate 18, fig. 11. 



Shell moderate, thin, diaphanous, horn-col- 

 ored, delicately reticulated with incremental 

 and revolving stria3 ; 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. aftenuaia and L. refiexa, from both of which 



it differs in the flatness of its whorls, in its 



(87) 



