1909.]} NATURAL SCIENCES OF PHILADELPHIA. 517 
A NEW SONORELLA FROM THE RINCON MOUNTAINS ARIZONA. 
BY H. A. PILSBRY and J. H. FERRISS. 
The Rincon Mountains lie near the western border of Cochise County, 
Arizona, north of the Whetstone Mountains, which are north of the 
Huachuca range. 
In 1907 one of us (Mr. Ferriss) visited the range and procured 
specimens of a large Sonorella, the first mollusk known from these 
mountains. 
Fig. 1. Sonorella rinconensis. Cotypes, nat. size. 
Where visited the range is rather dry. The rock is granitic, of 
pre-Cambrian age.* Besides Sonorella rinconensis only a few shells 
were taken, minute forms common to the region. Sonorella rincon- 
ensis was found sticking to large rocks and boulders, a habit not 
hitherto noticed in the genus. They are rare, the biggest bag made 
being six in one day. 
Sonorella rinconensis n. sp. Pl. XXII, figs. 1-4, 7. 
The shell resembles S. ashmuni Bartsch in shape. It is pale brown 
fading to white around the umbilicus, with a broad chocolate shoulder- 
band, widely whitish-bordered above and below. The surface is 
smoothish, marked with delicate growth-lines, and under the lens some 
faint spiral lines may be traced on the last whorl near the suture. The 
embryonic whorls have sculpture of the S. hachitana type. The 
whorls increase rather slowly to the last, which is much widened, and 
well rounded peripherally. It descends a little in front. The aper- 
ture is rotund-lunate; peristome slightly expanded, dilated at the 
columella as usual. Umbilicus about as in S. ashmunt. 
Alt. 16, diam. 26.5, width of umbilicus 4 mm. ; whorls fully 9. 
The penis is extremely long and slender, and contains a very long 
papilla. Its lower end is enveloped in a sheath. The retractor 
1C7. W. P. Blake, Some Salient Features in the Geology of Arizona, with 
Evidences of Shallow Seas in Paleozoic Time, American Geologist, Vol. 27, 1901, 
p. 160. 
