1915.| NATURAL SCIENCES OF PHILADELPHIA. 415 
and weakly annular. The vagina is slender and long. Free vas 
deferens very long. The organs of two individuals measure: 
Penis. Papilla. Epiphallus. Vagina. 
3.2 2.5 5.5 5.5 mm. 
3 2.0 7 5.5 mm. 
Baboquivari Mountains, at Station 24, on the west side of the 
ridge, close to the summit, a half-mile south of Baboquivari Peak. 
Type No. 111,554, A. N. 8. P., topotypes in collections of Ferriss 
and Daniels. Also on the north side of the highest peak of the 
Qui-i-tomoc Hills, J. C. Blumer. 
This species is readily distinguished from S. baboquivariensis by 
the wider umbilicus, smaller aperture, the shorter, steeper descent 
of the last whorl to the aperture, and the absence of distinct sculpture 
on the embryonic whorl; also by the very different genitalia. 
By the small penis and slender, tapering penis-papilla, S. vespertina 
is closely related to S. twmamocensis and S. eremita. In shell charac- 
ters it comes very close to S. sitiens, which differs by the form of its 
penis-papilla. 
S. vespertina was found at our only collecting station west of the 
summit of the range, but it occurred there in considerable abundance. 
Over 100 living individuals and numerous ‘‘bones”’ were taken by 
two of us in about three-quarters of an hour, in the course of our 
tramp from camp in Oro Fino Canyon to the peak and down to camp 
in Sycamore Canyon. 
The specimens taken in the Qui-i-tomoc Hills have not been dis- 
sected, but we cannot distinguish the shells from the Baboquivari 
vespertina. 
Sonorella baboquivariensis n. sp. Pl. X, figs. 1 to 2b. 
The shell is very narrowly umbilicate, globose-depressed, thin, 
glossy, cinnamon or sayal brown, fading or whitish around the 
umbilicus and on both sides of the broad chestnut-brown shoulder 
band. First third of a whorl smooth, the following whorl with 
sculpture of irregular radial wrinkles, over which run spiral, slowly 
descending, irregular threads; later whorls marked with fine growth 
lines as usual. Whorls 43, the last very wide, its last fourth slowly 
and rather deeply descending. The aperture is very large, strongly 
oblique. Peristome narrowly expanding throughout, the columellar 
margin brown-edged, broadly dilated and reflexed half over the um- 
bilicus. The parietal callus has an opaque, pale brown edge. 
Height 13.2, diam. 21 mm. 
Genitalia (Pl. XIII, fig. 1).—The penis is long, the distal fourth 
