CLASS GASTROPODA 
165 
Type in British Museum. Type locality, Santa Barbara, California. 
Range. Monterey to Gulf of California. 
Subgenus Hyalina Schumacher, 1817 
Marginella californica Tomlin, 1916 
Nautilus, 29:138. Arnold, Paleontology of San Pedro, California; PL 4, fig. 9. 
Shell subcylindrical, smooth, vitreous and polished, yellowish-white, 
variously banded with chestnut; spire short and completely glazed over; 
whorls A l / 2 ; aperture narrow, dilated, below; columella sinuous, obliquely 
truncate, with four fairly strong, oblique plaits; outer lip thickened with¬ 
out; suture marked by a narrow white line. Length, 9; diameter, 4.5; 
length of aperture, 7 mm. (Tomlin.) 
Type in the Tomlin Collection, England. Type locality, San Pedro, Calif. 
Range. San Pedro, California, to Puerto Libertad, Mexico. 
This species has been called M . varia, by California collectors. 
Marginella myrmecoon Dali, 1919 
Proceedings of the United States National Museum, 56:308. 
Shell minute, white, smooth, polished, with about three whorls forming 
a blunt spire, widest near the posterior commissure of the aperture, atten¬ 
uated in front, sides moderately convex; suture obscure; aperture narrow, 
outer lip straight, slightly thickened; body with a wash of enamel, pillar 
with three plaits. Height of shell, 3.3 ; max. diam., 1. 6 mm. (Dali.) 
Type in United States National Museum, No. 9440. Type locality, San 
Diego, California. 
Range. Known only from type locality. 
SECTION CYSTISCUS 
Genus CYSTISCUS Stimpson, 1865 
(See description in Appendix, p. 284.) 
Cystiscus politulus (Cooper MS) Dali, 1919 
Proceedings of the United States National Museum, 56:307. 
Shell minute, translucent white, of about two and a half whorls, the 
spire evident but covered with transparent enamel; it is widest posteriorly 
but does not attenuate rapidly enough to become pyriform; the aperture 
is nearly as long as the shell, the outer lip thickened, internally smooth, 
nearly straight; inner lip polished with three oblique plaits. Height of 
shell, 3; max. diam., 1.5 mm. (Dali.) 
Type in United States National Museum, No. 23240. Type locality, 
Catalina Island, California. 
Range. Santa Barbara, California, to Cape San Lucas, Lower Cali¬ 
fornia. 
[165] 
