1915.] NATURAL SCIENCES OF PHILADELPHIA. 403 



Except for the specimens of S. tumamocensis, taken by Mr. Blumer 

 at Cat Mountain, the Tucson Range, about 25 miles long, is not 

 explored for shells. 



Sonorella papagorum n. sp. PI. VIII, figs. 8, 80, 86. 



The shell is depressed, umbilicate (the umbilicus contained about 

 9 times in the diameter of the shell), rather thin, somewhat glossy, 

 light pinkish cinnamon, fading to whitish around the umbilicus, and a 

 trifle pale at the edges of a dark chestnut-brown band at the shoulder. 

 Apical sculpture is of the hachitana type, but very weakly developed, 

 the initial half-whorl smooth, the rest of the embryonic shell similar 

 to that of S. tumamocensis. "Subsequent whorls are lightly marked 

 with growi;h lines. Whorls 4f , convex, the last descending slowly 

 in front. Aperture oblique, rotund-oval. Peristome slightly' ex- 

 panded above, the outer and basal margins well expanded, thin; 

 columellar margin broadly dilated, partly covering the umbilicus. 



Alt. 14, diam. 23 mm.; aperture, alt. 11.8, diam. 13.6 mm.; width 

 of umbilicus 2.7 mm. 



Genitalia (PI. XIII, fig. 4). — Penis small and slender, about equal 

 in length to the vagina and of equal calibre throughout. A short, 

 loose sheath envelops its base. The penis-papilla is nearly as 

 long as the penis, very slender, slowl.y tapering, indistinctly annulate. 

 The slender epiphallus bears the retractor muscle and terminates 

 in a very minute flagellum. Female organs as usual. Jaw (fig. 6) has 

 five or six strong, unequal ribs, or in one specimen four unequal 

 weaker ribs. It is quite variable. 



Fig. 6. — Jaw of Sonorella papagorum. 



The shells show but little variation, excepting size. 



Alt. 13.8, diam. 23.5 mm.; aperture 12 x 13.3 mm. 

 " 12, " 20.5 " " 10x11.7 " 



Black Mountain, near the mission of San Xavier del Bac, in the 

 Papago IncUan Reservation, Pima Co., about 9 miles south of Tucson. 

 Types No. 112,161, A. N. S. P., collected by Pilsbry and Daniels, 

 October 5, 1910. 



This shell is less solid than S. eremita, with a narrower umbilicus 

 and far weaker apical sculpture. 



