1898. Pyramidula (striatella) cronkhitei Pilsbry, Nautilus, vol. 12, pp. 85- 



86. 



1905. . Pyramidula cronkhitei Dall, Land and Freshwater Moll. Alaska, 



pp. 9, 50. 



Material Examined 



Dall (1905, p. 50) referred all his Albertan and British Columbian 

 montane forms to striatella ( = anthonyi Pilsbry) , his British Columbian coastal 

 forms t > cronkhitei. Vanatta (1906, p. 95) likewise has reported anthonyi 

 from Field and Banff. Nevertheless, since it is difficult to detect depend- 

 able differences, other than perhaps their rather consistently smaller size, 

 between the shells from the Canadian Rockies and those from Montana, 

 Colorado, and other more southern localities which are usually referred with- 

 out much question to cronkhitei, it is probably advisable for the present to 

 call them all cronkhitei s.s., rather than attempt their reference to the 

 eastern subspecies, anthonyi. When even so competent an authority as 

 Pilsbry has within a few years allocated the same Arizona shells to both 

 anthonyi and cronkhitei, a less experienced student is not likely to feel infallible. 

 The (ruth is, we do not know the real boundaries of the distributi nal 

 areas of either form, or even whether any clear-cut limits either in shell 

 characters or in distribution actually exist. Thorough and critical study 

 of an abundance of material will alone enable the precise identification of 

 particular specimens. The following table briefly summarizes the results 

 of a comparison of specimens from various localities with material of anth- 

 onyi from Unity, Maine. 



