92 PROCEEDINGS OF THE ACADEMY OF [VOL. LXXIV 



The canyons inhabited by this snail are generally noteworthy 

 for their growth of the palm, Neowashingtonia, but the palms 

 occur principally in close proximity to the creek bed, while the 

 snails inhabit the immediately adjacent slopes. 



Micrarionta xerophila new species. Plate X, figs. 1-4. 



Shell strongly depressed, of moderate weight; whorls convex; 

 sutures distinct; last whorl strongly descending behind peristome. 

 Umbilicus of moderate width, being contained about seven times 

 the diameter of the shell, funicular, permeable. Aperture strongly 

 oblique, its deflexion about 45°. Peristome distinctly thickened, 

 its margin somewhat reflected, especially near the umbilicus, 

 the circular outline of which, however, is scarcely affected. Nuclear 

 whorls heavily covered with elongate, moderately crowded papillae, 

 more or less distinctly ranked in oblique, forward slanting lines; 

 subsequent whorls showing gradually smaller, more granular, and 

 less crowded papillae, which finally become practically obsolete 

 on the body whorl both above and below. Spiral sculpture wanting. 

 Periostracum, except for the papillae and numerous fine lines of 

 growth, smooth, thin, lustrous. Shell moderately to conspicuously 

 encircled by a narrow band, 0.5-1.0 mm. wide, varying in color 

 from deep brownish vinaceous in light toned shells, to liver brown 

 in darker ones, this band bordered above and below by very light 

 bands about twice as wide, which vary from white to light ivory 

 yellow; base of shell pale grayish vinaceous to avellaneous; region 

 below suture pale grayish vinaceous to deep brownish vinaceous; 

 shell on living animals pale olive buff, passing to cinnamon drab 

 near suture, often much mottled or clouded. Body of animal 

 varying from slate black to black, shading slightly lighter toward 

 margin; mantle neutral gray to slate gray, without conspicuous 

 pigment patches; sole of foot deep neutral gray, shading rather 

 abruptly to blackish slate at margin. 



Maximum Minimum Diameter Number of 



Diameter Diameter Altitude Umbilicus Whorls 



mm. mm. mm. mm. 



hiratvpe (dead shell ). . 17.0 14.0 10.1 2.4 4% 



Paratype, Smith Coll... 16. S 13. S 9.3 2.3 4% 



Paratype (dead shell) . . 16.3 13.5 10.3 2.3 4% 



Type 16.7 13.5 9.2 2.3 4Y 2 



Paratype 14.0 11.7 8.2 2.0 4Y 2 



Type: Berry Collection Cat. No. 4,888. Paratypes in the 

 museum of The Academy of Natural Sciences of Philadelphia, 

 the California Academy of Sciences, and tin; private collection of 

 Allyn G. Smith. 



Type Locality. Station VII; in crevices and under stones on 

 slope on Ocean to Ocean Highway, 5 miles west of Indian Well, 

 Riverside County, California; alt. 400-000 ft.; April 2, 1920, 4 



