410 PROCEEDINGS OF THE ACADEMY OF [June^ 



mocensis, but the enlargement is largely concealed by the overhanging 

 and dilated columellar lip. It is light pinkish cinnamon, fading to 

 white around the umbilicus, usually with a white streak on the last 

 whorl, left by a former resting stage, and with white bands above 

 and below the rather wide chestnut-brown shoulder band. The 

 apical sculpture is of the sitiens type, but some interrupted, descend- 

 ing spiral threads are visible on the best examples; subsequent 

 whorls are lightly marked with growth lines. The aperture is 

 larger than in S. tumamocensis, but less ample than that of *S. vesperus. 

 The peristome expands cUstinctly, though narrowly. 



Alt. 10.1, diam. 18, longest axis of aperture 10.1 mm. ; 4f whorls. 

 " 10.8, '' 19, " " " " 11.5 " 4f " 



" 9.7, " 17.4, " '' " " 10.3 " 4| " 



Comobabi Mountains, at the base of a cliff on the north side of 

 the highest part of the range, elevation about 4,000 feet. Type and 

 paratypes No. 112,252, A. N. S. P., other paratypes in Ferriss col- 

 lection. Also taken in the Cababi Hills, about 10 miles westward, 

 in a slide of volcanic rock on the north side of the highest peak, 

 about 3,000 feet elevation. All were collected by Mr. J. C. Blumer, 

 of Tucson, in the course of botanical exploration. 



About 120 specimens were collected, some of them showing the 

 surface and color unimpaired, though all were dead shells. We are 

 therefore unable to give any information on the soft parts. The 

 shell is very much like S. sitiens of Las Gijas, further south, and east 

 of the Baboquivari Range; but on account of the wide separation of 

 the localities, it is likely to be subspecifically or even specifically 

 distinct. 



The Comobabi Mountains form a short range, about 75 miles 

 west of Tucson. The Cababi Hills, immediately west, and the 

 Qui-i-tomoc Hills, a short distance south, are parts of the same 

 group. It is evidently rich in shells, as Mr. Blumer found *S. s. 

 comobahiensis on the highest peaks (near the south end) of both 

 Comobabi and Cababi, and a form which we cannot distinguish 

 from S. vespertina on the north side of the largest peak of the Qui-i- 

 tomoc Hills. Somewhere in the Cababi Mountains, the exact location 

 not given, Mr. Frank Cole collected two forms, which we provision- 

 ally refer to *S. ashmuni as varieties; one of them is the largest 

 Sonorella known. 



Sonorella ashmuni capax n. subsp. PI. X, figs. 7, 7a, 7b. 



The shell is umbilicate, the umbilicus very narrow within, but 

 in the last half -whorl widening to about three times its former width, 



