CLASS GASTROPODA 
175 
quite deeply impressed; aperture long, narrow, oblique; outer lip slightly 
arcuate anteriorly, smooth interiorly; inner lip smooth; columella spirally 
lined externally. Long., 9.5; lat., 3.9; body-whorl, 6.5; aperture, 4.5 mm. 
(Arnold.) 
Type in United States National Museum. Type locality, Lower San 
Pedro, series at Deadman Island, San Pedro. 
Range. Living, Santa Rosa Island, California. Fossil: Pliocene of 
San Pedro, and Pleistocene of Santa Barbara. 
Family FASCIOLARIIDAE 
Genus PTYCHATRACTUS Stimpson, 1871 
Shell fusiform, spirally striated; aperture with a moderate canal; 
columella plicated as in Fasciolaria. (Tryon, Manual of Conchology .) 
The shell of this genus unites the form of a Sipho with the folds of 
a Fasciolaria; its small size, color, and northern habitat will distinguish 
it from the latter, even without taking into account the very diverse den¬ 
tation ; yet without the latter difference it would scarcely have been advis¬ 
able to have separated the single species upon which the genus was founded 
from Fasciolaria. (Tryon, Structural and Systematic Conchology.) 
Type. P. ligatus Mighels and Adams. 
Distribution. Boreal Atlantic and Pacific. 
Ptychatractus occidentalis Stearns, 1871 
Plate 7, fig. 1 
Conchological Memoranda, 7:1. Bulletin 112, United States National Museum; PI. 6, 
fig. 3. 
Shell elongated, fusiform, rather slender, whitish, traversed by narrow, 
revolving, brownish threads and much wider intervening spaces; suture 
distinct, spire tapering; aperture oblong-oval, about half the length of 
the shell; within white, polished; canal short, nearly straight; columella 
obliquely plicated. Length about in. (Stearns.) 
Type in United States National Museum. Type locality, near Attou 
Island, Aleutian group, Bering Sea. 
Range. Bering Island to Shumagin Islands, Alaska. 
Ptychatractus californicus Dali, 1903 
Bulletin, Museum of Comparative Zoology, 48 :299. 
Shell small, fusiform, white, with a pale straw-colored periostracum 
and about five whorls; suture distinct, not appressed, whorls turgidly 
[175 1 
