100 PROCEEDINGS OF THE ACADEMY OF [Feb., 



smaller than in other places, about 4x10.3 mm.; but a few are as 

 large as 11.5 mm. diameter and many as small as 9.5 mm. The 

 scale-like sculpture is especially well developed in shells from this 

 station. In some colonies the cuticular scales are minute, sparse or 

 even wanting in adult shells. 



At Hand's Pass, at the head of Jhu Canyon, this species reappears. 

 The surface is regularly very minutely pustulate, some perfectly fresh 

 shells having minute cuticular appendages on the pustules in places. 

 There are also some cuticular spiral hair-lines on the base. Alt. 5, 

 diam. 12 mm., whorls 6. This colony is separated from the type 

 locality by the whole southern slope of White Tail Canyon, where 

 lepiderma certainly does not occur. We have considered the possi- 

 bility that the Hand's Pass form may be an independent convergent 

 modification of the proxima stock; but in the absence of alcoholic 

 material permitting a full comparison this hypothesis must remain in 

 abeyance. 



Ashmunella proxima Pils. Fig. 17. 



Ashmunella levettei proxima Pils., Proc. A. N. S. Phila., 1905, p. 242. 



This species was described from "Sawmill Canyon," otherwise known 

 as Rigg's or Pine Canyon, where the senior author collected it in 1904. 

 We did not find it there in 1906, but our search was impeded by snow. 

 We found it near Fort Bowie in company with Sonorella bowiensis. 

 The exact locality Is a little thicket of long-leaved scrub oaks, just 

 below a low rock-wall, somewhat more than half-way up "Quartzite 

 Hill." on the side facing Dixon's house, shown at (1) in the sketch on 

 p. 67. This is about a mile from Old Fort Bowie. 



Similar shells were also taken at Crook's Peak (Ferriss and Daniels) 

 in 1907; only two specimens. 



In ranking A. proxima as a subspecies of A. levettei, a wrong estimate 

 was made of its affinities. It is related to A. fissidens and duplicidens, 

 but differs from both by having two distinctly separated teeth on the 

 basal lip. A. levettei angigyra stands very near proxima in shell-charac- 

 ters, but the lower end of the tooth within the outer lip runs inward in 

 angigyra, while in proxima the free edge of this tooth rims parallel with the 

 peristome. In angigyra the outer-basal and outer lip tooth are usually 

 closer together than are the two basal teeth. This is not the case in 

 proxima, in which the three teeth are about equally spaced. In soft 

 anatomy the two are quite distinct. A. I. angigyra has a far longer 

 penis of different shape and a shorter epiph alius and vagina than 

 A. proxima; moreover, angigyra has a radula with more teeth, and 



