1918. 



NATURAL SCIENCES OF PHILADELPHIA. 



289 



It lives in relatively dry rock slides, with the smooth SonoreUa 

 marmorarius, high on ]\Iarble Peak and its flanks, thus differing in 

 habits from ^S. odorata. The shell is readily separable from odorata, 

 and perhaps it should be considered a separate species. It has the 

 same peculiar odor. 



SonoreUa sabinoensis n. sp. PI. IV, figs. 1 to 5d. 



. The shell is rather narrowly umbilicate (width of umbilicus con- 

 tained 8 times in that of shell in the type specimen), rather soUd; 

 cinnamon-buff, broadly zoned with white (or whitish) on both sides 

 of the chestnut-brown band above the periphery. The surface is 

 glossy; embryonic whorls having the usual sculpture of the hachifana 

 group, granular, with divaricating protractive threads below and 

 retractive above; subsequent whorls delicately marked with growth- 

 lines. Suture descends moderately in front. The aperture is large, 

 oblique, rotund-oval. Peristome narrowly expanded, dilated at the 

 umbilical insertion. 



Alt. 12, diam. 21.2 mm.; aperture 12x13 mm.; 4| whorls. 



Santa Catalina mountains, Arizona, in Sabino canyon (type loc. 

 Station 16, 1913) and its tributaries. Sycamore canyon and Mt. 

 Lemon Fork, from about 3000 to 6000 feet elevation. Also Rock 

 and Vantana canyons, west of Sabino, and Bear canyon eastward. 



It is a species of the dry, sun-baked rock-slides, living ones found 

 only deep in the crevices, in the lower levels of desert vegetation. 

 The Sabino Basin, Sycamore and Bear canyon localities are below 

 the pine belt, in arid country, with some oak, juniper and sj'camore. 

 The species is not known to occur in the humid upper forest. 



Genitalia (fig. 3, a-d) resembling those organs in S. marmorarius. 

 The penis is thin, not swollen basally. The penis-papilla is slender 

 and corrugated, as in the other species, and nearly as long as the penis 

 (fig. 3a). The flagellum is either minute or wanting. 



Type, fijj;. 3r. 



Fig. 3(/. 



Fig. 3a, h. 



Shells from the type station measure from 20 to 24 mm. diameter. 

 The relative size of the aperture also varies within rather wide limits. 

 In the type specimen (pi. IV, figs. 2-26) the width of aperture is con- 



