394 PROCEEDINGS OF THE ACADEMY OF (June, 
body. It has a basal sheath, and a slender, conspicuously annulated! 
papilla, one-third the length of the penis or longer. The flagellum is 
well developed for Sonorella. The penial retractor is inserted at the 
apex of penis and base of epiphallus. The vas deferens is slender 
throughout. Measurements of the organs in mm. follow. 
: : Penial | Sperma-| Diam. 
Sta- -_| Penis- | Epiphal-| Flagel- . Pp 
. Penis. . 5 retrac- | Vagina. theca of 
pune papilla. lus. lum. | tor. andduct. shell. 
| 
5 Sere (hs ce es 22, 1.5 14 29 28 23 
5 40 13 Dia dl Soe 3, oh al aoe 5 YE os i 22:3 
12 IT ee ar 26 1.8 15 Doi AVF 23.5 
Dal OMe a| Pen ok ener ekg 18 cree MR a 20 
10 41 Wr 18+ 2 15 36 27 22.5 
Specimens from Station 11, and numerous others from Station 5, 
opened but not measured, were sufficiently examined to show that 
the specific characters—great length of penis and vagina—are con- 
stant. 
S. santaritana differs from other species of the same range by its 
wider umbilicus, the more approaching ends of the lip, and especially 
by the great length of penis and vagina. In the characters of the 
genitalia it is nearest to S. rinconensis P. and F. (these PROCEEDINGS: 
for 1909, Pl. XXII, fig. 5). That species differs by having a still 
longer vagina, and a more capacious shell with larger aperture and 
relatively smaller umbilicus. S. dalli and S. virilis are somewhat 
related, but differ in characters of both genitalia and shell. 
This is the most abundant and widely distributed Sonorella of 
the part of the Santa Rita Range which we explored. 
In size, specimens from Walnut Canyon (PI. IX, figs. 1-2b) measured 
from 19 to 25.8 mm. diameter, but only in one colony were such 
small ones found, the minimum size in other colonies is about 21.5 
mm. 
In Stations 10, 11 and 14 they run from 20.4 to 22.5 mm. In 
other stations the size is about typical. 
A beautiful albino (PI. IX, fig. 3) was taken at Station 5. It shows. 
very faint traces of the shoulder band and the embryonic shell is 
faintly buff, but otherwise it is pure white. Genitalia as in the 
colored form. 
Sonorella walkerin.sp. Pl. IX, figs. 4, 4a, 46. . 
The shell is umbilicate (the width of umbilicus contained about 
9 times in the diameter of the shell), rather solid, pale cinnamon, 
