1910.] 



NATURAL SCIENCES OF PHILADELPHIA. 



85 



merely a thin film 911 the penultimate whorl. Cuticle .smooth and 

 without "fringes" in young or old, very delicately striated spirally; 

 sculpture of the embryonic whorl delicate, usually worn off. 

 Probably only the first of those measured is mature: 



Alt. 6.1, diam. 13.8 mm. 

 " 6|, " 12 



u 6> u 12 



" 6*, "11 



" -5, " 11 



Found at the Cave Creek Falls in broken rock sprayed by the falls, 

 and near the water's edge, in company with a very small form of 



Fig. 9. — Oreohelix clappi cataracta P. and F. 



Ashmunella chiricahuana. It was also found occasionally among 

 the rocks higher up the slide with 0. barbata and Ashmunella angulata. 

 About 25 were found in two visits to the stations. None were alive, 

 but some perfectly fresh. It is probably a deep burrower. This is the 

 only station where 0. barbata and 0. clappi were found together. 



0. c. cataracta is quite a distinct race. The green, polished base 

 reminds one of Omphalina. It is the smoothest and most depressed 

 form of 0. clappi. 



Oreohelix ehiricahuana Pilsbry. Fig. 10. 



Proc. A. N. S. Phila., 1905, p. 283, pi. XI, figs. 1-3 (shell), pi. XIX, fig. 4 

 (genitalia), pi. XXIII, fig. 24 (jaw). 



The range or this species extends from Emigrant Canyon to Lime- 

 stone Mountain, a distance of about 50 miles. Its range is mark- 

 edly discontinuous towards the north and south ends, but from White 

 Tail to Cave Creek Canyons the colonies are not widely separated. 

 It is always found on limestone, never where the country rock is meta- 

 morphic or igneous. 



The several races differ as follows : 



