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 2.5 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. S. 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. haboquivariensis 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. timiamocensis 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. PI. X, figs, l 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 4^, the last very wdde, 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 refiexed half over the um- 

 bilicus. The parietal callus has an opaque, pale browm edge. 



Height 13.2, cham. 21 mm. 



Genitalia (PI. XHI, fig. 1). — The penis is long, the distal fourth 



