370 PROCEEDINGS OF THE ACADEMY OF [June, 
a little recurved below; the margins approaching, parietal callus 
short, thin except in old shells. 
Alt. 11.25, diam. 19.5, alt. aperture 10.5, diam. 9.25 mm. 
baie ei + eee tees . iia. "ar Oaeow sts 
Back dusky, tentacles dark, sole pale yellowish, with faint longi- : 
tudinal lines, demarking the areas, near the tail. 
Genitalia (Pl. XI, figs. 4, 4a, No. 103,093, from Station 29).— 
The penis is large, cylindric, encircled by a small muscular sheath 
at the contracted base, its retractor muscle inserted upon the apex 
of the penis and the base of the epiphallus. The walls of the penis 
are thin. Papilla (fig. 4a) nearly as long as the penis, stout, cylin- 
dric, having obliquely longitudinal corrugation near the end, the 
apex being obtusely conic with terminal pore. The flagellum is 
longer than usual. Epiphallus is about equal to the penis in length. 
The vagina is decidedly shorter than the penis. The duct of the 
spermatheca is very long. 
Length of organs in mm.: 
No. 103,093.—Penis, 10; epiphallus, 10; flagellum, 1.3; papilla, 
8; vagina, 6; spermatheca and duct, 39. 
No. 103,094.—Penis, 11; epiphallus, 9; flagellum, 1.3; papilla, 
7; Varma, 7. 
The jaw is highly arched, with five broad, unequal ribs. 
Dragoon Mountains. Types from Station 28, Bear Canyon, No. 
103,094, A. N.S. P., collected by Ferriss and Daniels, November, 1910. 
Also at Station 29, south of the Huzzar Mine, in the same vicinity. — 
This species is related to Dos Cabezas species by the position of 
the insertion of the penis-retractor, the cylindric penis-papilla and 
the short vagina. It differs from all of these in its very large and 
differently sculptured penis-papilla, and the thin shell, with rounded 
aperture and minute granulation and hairs on the neanic whorls, 
and a different pattern on the embryonic whorls. It is not closely 
related to any species of the ranges further west. 
Other specimens, topotypes, from Station 28 measure,,, 
Alt. 11, diam. 21 mm. 
CHa eels 14 
“cc 10.8, ce 19 ce 
Oe 2 eis ek ayp es 
Specimens from Station 29 measure: 
Alt. 10.9, diam. 20 mm. 
cc 10.3, ce 18 cc 
cc 10, “ 20 “ 
ce 9, (a9 17/83 “ 
- oe em Stu de ra ie a 
: rey 
