Notes on certain Terrestrial Mollusca. 165 



Helix sportella, Gould. 



In a paper on land and fresh-water shells collected by Dr. J. 

 G. Cooper in the Rocky Mountains, etc. {Annals vii. 366, 

 1861), it is remarked that this species differs from H. Yancou- 

 verensis Lea "in having the incremental striae more or less 

 decussated by revolving lines, giving it a granulated appear- 

 ance ;" also that in some individuals " the decussation is to a 

 great extent obsolete, or confined to the upper whorls only, and 

 it seems to us that the two species cannot be separated." 



Since the publication of that paper, I have received from Dr. 

 Newcomb a specimen of H. sportella agreeing with Dr. 

 Gould's description, and believe that it should be considered a 

 distinct species. 



In the larger specimens of H. Yancouverensis from Oregon 

 (as in H. concava Say), microscopic spiral lines may be detected, 

 and in the smaller forms found near San Francisco, those lines 

 are sometimes more deeply indented, intersecting the striae of 

 growth, and giving more or less of a granulated character to 

 parts of the surface of the shell, especially of the upper whorls. 

 Dr. Newcomb observes {Amer.Jour. of Conch, i. 235) that the 

 smaller forms referred to " have been distributed under the 

 erroneous name of H. sportella Gould." 



In H. sportella, not only are the incremental strias more 

 coarsely and regularly developed than in Vancouver ensis, but 

 the whole surface of the shell, both above, save the apicial 

 whorls, and below, even within the umbilicus, is very distinctly 

 decussated by the revolving lines, and consequently granulated. 

 In the former the whorls are more flattened above, and the 

 umbilicus is somewhat smaller. 



H. Yoyana Newc. of California (Amer. Jour, of Conch. 1. c.) 

 is an extremely interesting species of the same group. From 

 the general character of the sculpturing, it seems more allied to 

 H. sportella than H. Yancouverensis. 



