398 PROCEEDINGS OF THE ACADEMY OF [June, 
Walnut branch of Agua Caliente; and Stations 17 and 173, Camperel 
Canyon, on the eastern slope of the mountains, at about 6,500 feet. 
This is a smaller, thinner shell than other Santa Rita Sonorellas, 
and readily distinguished by its microscopic granulation and the 
beautiful sculpture of the embryo. It is variable in degree of eleva- 
tion of the spire, size of umbilicus and color. In Madera Canyon 
the shell has a russet hue. 
In Walnut Branch of Agua Caliente the color ranges from almost 
chamois in the thicker old individuals to nearly water green in those 
barely grown to full size. The microscopic granulation is sometimes 
typically developed on the last whorl, but more often more or less 
obsolete, sometimes only visible in a few places; and most specimens 
show incised spiral lines on the last whorl, occasionally quite distinct 
and numerous. Around the head of Agua Caliente Canyon the color 
is similar to the Walnut Branch lot. 
S. clappi resembles the Huachucan 8S. granulatissima and S. 
danielsi in the embryonic sculpture and the general appearance, but 
in those species the aperture is more oblique than usual in S. clappi 
and the genitalia are conspicuously different. Having dissected a 
good many individuals of all of these species, I feel confident that 
the genitalia afford the most reliable specific characters. S. clappi 
is very much like S. walkeri in genitalia. 
A couple of shells from Station 173, Camperel Canyon, on the 
eastern slope of the range, resemble the Agua Caliente form in being 
light colored. One from Station 17, in the same canyon, is the 
darkest of all, being nearly a sorghum-brown color, more vinaceous 
where the cuticle is worn off. The genitalia (Pl. XII, figs. 4, 4a) 
differ from typical S. clapp: by the longer penis and penis sheath, 
and the shorter vagina. Length of penis 13, penis-papilla 10, epi- 
phallus 10, flagellum 1, vagina 43 mm. 
A bleached Sonorella, No. 105,385, U. 8. N. M., collected, or at 
least sent to Dr. I. Lea in 1860, by H. C. Grovenor, is labelled “Santa 
Rita Mountains, 6,000 feet above the sea.” It is very thin and 
appears under the lens to have been granular. The lip-ends con- 
verge, as in S. clappi, from which this shell differs by its larger size 
and less depressed shape; diam. 20.5 mm. It is probably a distinct 
species related to S. clappz, but it is not in condition for description. 
The spire is broken. 
Sonorella granulatissima occidentalis n. subsp. Pl. IX, figs. 7, 7a, 7b. 
Similar in sculpture to S. granulatissima, but differmg by the 
narrower last whorl, which is less convex above; the light borders of 
the chestnut-brown band, and the less depressed spire. 
