1910.] NATURAL SCIENCES OF PHILADELPHIA. 87 



At Station 6, about half way up the north side of the limestone 

 ridge, the shells were like those from the cave in size, but somewhat 

 whiter, more calcareous. Near and at the top of the ridge, along the 

 southern side, east and west of station 7, 0. chiricahuana is widely 

 distributed. The shells here are like those from Station 6, but smaller, 

 the largest 10 mm. in diameter. This colony is probably 1,500 feet 

 higher than the cave. The smaller size of the shells from Station 7 

 may probably be correlated with a dryer and hotter habitat. How far 

 down the south slope it extends we did not learn. We found 0. 

 chiricahuana now r here else in Cave Creek Canyon, nor has the typical 

 form been encountered elsewhere. 

 Oreohelix chiricahuana percarinata a. subsp. Fig. 11. 



The shell is larger than typical 0. chiricahuana, whitish, clouded 

 and suffused with flesh color, depressed, with a compressed, projecting 

 peripheral keel, the last whorl excavated, concave above and below 

 the keel, elsewhere strongly convex. Striatum oblique, rather coarse 

 and quite irregular above, sharper and strongly arcuate below. Spiral 



Sfa£Z*>is S 



Fig. 12. — Summit Cross of J Mountain, seen from the mouth of Big Emigrant Can- 

 yon, at X on map, p. 121. Entire range of 0. c. percarinata shaded. At 

 Station 5 and over much of the slope around Station 6, Sonorella optata 

 was found. High granitic spur on left. 



threads few and fine or wanting on the upper surface; on the base 

 there are two to four major spirals at wide intervals, with fine spiral 

 threads over the whole base. The last whorl rarely falls far below 

 the carina at the aperture. Alt. 8, diam. 14 mm. ; whorls 5^. 



Summit of Cross J Mountain near the mouth of Big Emigrant 

 Canyon, Station 5 on map, p. 121. November 12, 1906. This locality is 

 farther north than any other known colony of Oreohelix in the Chiri- 

 cahua range. The Oreohelices were found around the summit, which 

 is probably about 7,500 feet elevation, and along the ridge northward, 

 down about 500 feet, but not in the valley (Station 6), where Sonorella 



