202 TROCEEDINGS OF THE ACADEMY OF [Oct., 



The dead shells from Station V on the Arctic side of the Divide 

 are not typical of the race as here described. The same would prob- 

 ably be true of those taken at Station VI, were any of them adult. 



Thysanophora ingersoUi (Bland). 



I do not recall having seen Thysanophora reported from so far 

 north. However no special peculiarities have been detected in these 

 specimens. 



Pyramidula cronkhitei (Newcomb). 



Not found as commonly as would naturally have been expected. 



Punctum californicum Pilsbry. 



This determination is due to Mr. Vanatta. The specimens are 

 distinctly smaller, are much darker brown in color, and appear 

 somewhat more coarsely striate than any Californian specimens of 

 the species before me, and further, although the embryonic whorls 

 are in both instances weakly spirally striate, they are much less 

 distinctly so in the Montana form. 



Zonitoides arborea (Say). 



Found commonly only in McDonald Creek Canyon; scattering 

 specimens elsewhere. 



Euconulus fulvus alaskensis Pilsbry. 



Wherever we went in the Park Euco7iulus was foimd not only to 

 be ubiquitous but abundant. 



Mr. Vanatta referred the shells sent him to typical fulvus rather 

 than to alaskensis, but I am unable to effect a satisfactory separation 

 of the remainder of the specimens from other Rocky Mountain 

 Euconulus referred unquestioningly to the subspecies. Under a 

 fairly high power (82 diameters), I can discover no trace of spiral 

 sculpture on the earlier turns as in specimens of fulvus s. s. from 

 Unity, Maine. Also there is "about one whorl more in shells of 

 similar size"^ for the Maine form, the color is noticealjly paler, the 

 axial sculpture finer, and the luster brighter. 



Polita binneyana (Morse). 



This was found principally in connection with the same peculiar 

 plant association as Oreohelix cooperi apiarium, and attention to this 

 fact should lead to its discovery at many other Stations than those 



2 Cf. PUsbry and Ferriss, :10, p. 132. 



