332 PROCEEDINGS OF THE ACADEMY OF [May, 



abundant at the summit near and north of the small stone "monu- 

 ment" or cairn which marks the summit, on and under stones. Also 

 on the precipitous western slope at Station 10. 



The species is very uniform in all its characters. The size varies 

 from 14 to 16 mm. diameter, and in some shells the last whorl descends 

 more than in others. Very few have the parietal callus thickened 

 and a little raised. It differs from all forms of 0. strigosa by its 

 convex, radially costellate embryonic whorls, but in many adult 

 shells this sculpture is effaced. 0. ferrissi is probably the most 

 nearly related species, though very different. 

 Oreohelix hachetana cadaver n. subsp. Plate VI, fig. 2. 



The shell is larger than hachetana, the periphery rounded in adults 

 except near the aperture in front, where it is distinctly angular. 

 Umbilicus smaller, one-sixth the diameter of the shell. 



Alt. 11.5, diam. 18.5 mm.; barely 5 whorls. 



Station 5, below the cliffs on the north side of the summit of 

 Daniels Mountain, Daniels and Pilsbry, August 22d, 1910. 



Only a few long-dead shells were found in this thirsty place, where, 

 at the base of the cliffs there are a few small pinyon pines, mostly 

 dead or moribund. Holospira and Ashmunella mearnsi live here in 

 abundance. 



A young shell, long dead, found at Station 6, may belong to the 

 same variety. 

 Oreohelix (Radiocentrum) ferrissi n. sp. Plate VI, figs. 4 to 5d. 



The shell is openly umljilicate, umbilicus conic, over one-fourth 

 the total diameter; slightly convex above, base strongly convex; 

 thin, light dull brown. The embryonic shell of 1| convex whorls 

 is finely lamellose striate radially (fig. 5d). Post-embryonic whorls 

 have the surface densely lamellose along growth-lines, the lamellae 

 rising in triangular cuticular processes where they cross the spiral 

 ridges of the shell. When denuded, the shell has a blunt, projecting 

 peripheral carina; the upper surface has a wide, somewhat angular 

 spiral ridge upon all the post-embryonic whorls, sometimes with one 

 or two minor ridges; the lower surface has three to five low spiral 

 ridges and some minute, weak spiral striae; the whole shell being 

 closely thread-striate along growth-lines. The last whorl usually 

 does not descend in front. Aperture oblique, irregularly rounded, 

 lip simple, the margins rather widely separated, parietal callus thin. 

 Shells denuded of the cuticular processes measure: 



Alt. 6.5, diam. 14.5 mm.; 4^ whorls. 

 " 6, " 15 " 4^ " 



