1915.] NATURAL SCIENCES OF PHILADELPHIA. 403 
Except for the specimens of S. twmamocensis, 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, 8a, 8b. 
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. twmamocensis. Subsequent whorls are lightly marked 
with growth lines. Whorls 4%, 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 (Pl. 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, slowly tapering, indistinctly annulate. 
The slender epiphallus bears the retractor muscle and terminates 
in avery minute flagellum. Female organs as usual. Jaw (fig. 6) has 
five ér 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. 
apes ie Oro) < erat ae Oe ie 
Black Mountain, near the mission of San Xavier del Bac, in the 
Papago Indian Reservation, Pima Co., about 9 miles south of Tucson. 
Types No. 112,16], 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. 
