88 PROCEEDINGS OF THE ACADEMY OF [Feb., 



lives. This slope of the mountain is limestone, becoming cherty 

 above, but the summit is angular, friable quartzite (?), among the 

 fragments of which the Oreohelices live. None were found on the 

 ridge running toward the mouth of the canyon, which is composed 

 of a disintegrating, coarse-grained granitic rock. There is little vege- 

 tation of any kind on the upper part of Cross J Mountain. The 

 station is rocky, barren and exposed. The snails are moderately 

 abundant, though living ones are hard to get. 



Paradise Canyon. On the south side, about two miles below the town 

 of Paradise, Oreohelix was found in some abundance, but owing to the 

 snow which covered the ground at the time we camped there (November 

 20) but few living examples were taken. The form is almost identical 

 with that of Cross J Mountain, the adult differing only in having the 

 radial striation on the base a little more regular, and the major spirals, 

 of w T hich there are three or four, often somewhat stronger, though in 

 some shells they are hardly noticeable. In young and half-grown shells 

 a thin cuticular thread runs along the summit of each of the striae, 

 and at the intersections of the major spirals these threads rise in 

 short triangular processes. This feature was not observed in the 

 shells from Cross J Mountain. 



Another similar lot was taken on the northern slope of the canyon. 

 These places are probably not far from the 6,000 feet contour, being 

 thus much lower than Cross J Mountain. 



The separation of these colonies from the Cross J Mountain colony 

 of 0. c. percarinata probably indicates independent evolution of 

 the same characteristics, since an area occupied by 0. chiricahuana 

 obsoleta lies between Big Emigrant and Paradise Canyons. 



Oreohelix ohiricahuana obsoleta n. subsp. Fig. 13. 



In White Tail Canyon, this form of 0. chiricahuana was taken at 

 Stations 1, 2, 3, 6, 7, 8, 12, 14 — all on the southern side except 3, 

 which is just over the crest of the ridge on the Pinery side. The 

 sculpture is rather rude and blunt, the striation less sharp than in 

 the Cave Creek form, being effaced or subobsolete especially on the 

 base where spiral lines are wanting or rarely weakly indicated, while 

 Cave Creek chiricahuana has sharp, subregular striation and distinct 

 spirals. Two or three inner whorls are brown, the rest being white 

 with some faint gray streaks and scattered dots. Whorls 5| to 5| 

 (4^ in typical chiricahuana), the last carinated as in chiricahuana. 

 The shape varies from typical to decidedly more elevated, and the size 

 everywhere exceeds that of Cave Creek shells. A series from the 

 typical Station 14, where it is abundant, measures: 



