1915.] NATURAL SCIENCES OF PHILADELPHIA. 397 
Station 2, at the base of bluffs southeast of Station 1 and somewhat 
higher, afforded a few similar shells (Pl. IX, figs. 5, 5a, 5b). One 
preserved in spirit differs from S. walkeri by having a decidedly 
longer penis, penis-papilla and epiphallus. There is no flagellum, 
and no penial retractor muscle was found. (Fig. 5.) These differ- 
ences, if confirmed by further dissections, in our opinion, indicate 
a distinct species; but to direct attention to it we now rank the 
race as a subspecies of S. walkeri. The diameter at Station 2 runs 
from 22.35 to 24 mm. The elevation of this Station is between 
4,100 and 4,200 feet, according to the topographic map. 
Sonorella clappin.sp. Pl. IX, figs. 8, 8a, 8b. 
The shell is umbilicate (umbilicus contained about 8 times in the 
diameter), thin, depressed, semimatt, cinnamon, the base paler, 
fading to olive-buff in the middle, and with a chestnut-brown shoulder 
band having paler borders. Embryonic shell of 12 whorls, the 
initial } whorl smooth, the rest densely and evenly reticulate-granu- 
lous, having an indistinct zigzag pattern in some places, but without 
the spirally descending threads of the hachitana type. Subsequent 
whorls are lightly striate and microscopically wrinkle-granose, this 
sculpture becoming weaker on the base. Whorls 43, the last descend- 
ing in front, rounded peripherally. Aperture rounded-oval, the 
peristome thin, narrowly expanded. 
Alt. 10.8, diam. 19 mm.; umbilicus 2.4 mm. (type). 
erelUsoct hy LS ‘‘ (globose topotype). 
ri Meds ‘17.7. “ — (depressed topotype). 
Genitalia (Pl. XII, figs. 6, 7).—-Penis slender throughout, with a 
thick, short basal sheath and a long papilla. Epiphallus and vas 
deferens slender, the former terminating in a minute flagellum, the 
retractor muscle inserted close to its base. Vagina shorter than 
the penis. Measurements in mm. follow. 
| Sperma- 
St | Penis | Penis- | Epiphal- | Flagel- | Vagina. | theca 
tion. |. | papilla. lus:, | lum. and duct. 
| 
| 
8 8.5 | 6 8.5 Minute yc WN ag CRee eee ct 
i 6.5 eatin toa 8 Minute 3 25 
Santa Rita Mountains: Station 8, Madera Canyon, type No. 
112,163. Also taken at Station 16, Madera Canyon; 6, 12, 13, 14 
near the head of Agua Caliente Canyon; abundantly at Station 5, 
