1910.] 



NATURAL SCIENCES OF PHILADELPHIA. 



105 



shorter than in A. p. emigrans or A. duplicidens, but this may be an 

 individual character. 



A. f. albicauda is found in White Tail Canyon almost everywhere 

 on the southern side, but not on the opposite slope of the canyon. Speci- 

 mens were taken at Stations 1 to 5, 9, 12, 14, on the south side of the 

 Box Canyon and on the south side below Indian Creek, ranging from 

 about 20 feet above the creek bed (at the last place) to about 7.500 

 feet elevation on the rim southward, where indeed it was taken at 

 Station 3, which lies across the acute divide and on the Pinery side. 

 Not one single specimen was found on the north side of the canyon, 

 where A. lepiderma replaces it, coming down to the bottom of the 

 canyon. 



The range of A. fissielens in the Pinery and Pinery Canj^on is un- 

 known. The great Pinery Valley lay before us in splendid panorama 

 from the ridge south of White Tail Canyon and again from the ridge 

 north of Barfoot Park. Probably its ravines are inhabited by fissidens 

 and perhaps forms connecting that with A. proxima. It may be noted 

 that the large Sonorella of White Tail Canyon is a race of S. virilis, 

 of Barfoot Park, etc. 



At all stations in White Tail Canyon where many shells were taken, 

 the same variations in height of spire noted under .4. duplicidens were 

 noticed. Otherwise there is variation in the size of the outer lip-tool h 

 and especially in that of the inner tubercle of the basal tooth. The 

 parietal tooth may be either straight at its axial end or abruptly 

 curved inward, and, when turned inward, a low ridge usually runs to 

 the outer end of the lip, making the parietal tooth V-shaped. 



Ashmunella fissidens pomeroyi n. subsp. Fig. 20. 



In Hand's Pass, head of Jhu Canyon, Ferriss and Pomeroy collected 



Fig. 20. — Ashmunella f. pomeroyi P. and 1'.. Hand's Pass. 



