128 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
from Glyphostorns by smaller size, less brilliant surface, less fusiform 
profile, less contracted mouth and different nucleus. (Dali.) 
Type. Pleurotoma bicolor Risso. 
Distribution. California to Gulf of California. 
Philbertia canfieldi Dali, 1871 
American Journal of Conchology, 7:101; PI. IS, fig. 9. 
Shell solid, elongated, turreted, of five or six whorls; apex pointed, 
nucleus small, hyaline, of one whorl, smooth, subsequent whorls more 
or less shouldered or carinated above, or rounded, suture impressed rather 
deep. Aperture less than half and more than a third as long as the shell, 
rather narrow; outer lip thickened, very effuse, internally ridged with 
from three to six elevated lines terminating in tooth-like nodules. Canal 
short, rather wide. Sinus somewhat below the suture, deep and prominent 
with the portion between it and the suture, forming a tooth-like projec¬ 
tion on the upper part of the inner lip. Columella smooth in the young, 
with from one to four crenulations or nodules in the adult, near the anterior 
end. Upper portion smooth. Sculpture consisting of revolving rounded 
even ridges, sixteen or less on the last whorl, crossed on the upper part 
of the whorl by numerous indistinct longitudinal plications, which vanish 
on the lower half of the whorl. One of the revolving ridges near the 
suture is sometimes stronger than the rest, giving a carinated shoulder 
or tabulate appearance to the upper portion of the whorls. Color yellow¬ 
ish-white with three purplish bands often absent, wholly or in part, one 
on the lower, one on the middle and one on the upper portion of the whorl. 
These are only apparent on the last whorl in most cases. Long., .32; lat., 
.14 in. (Dali.) 
Type in United States National Museum. Type locality, Monterey, 
California. 
Range. Crescent City to Laguna Beach, California. 
Philbertia affinis Dali, 1871 
American Journal of Conchology, 7:102. Proceedings of the California Academy of 
Sciences, 5; PI. 2, fig. 7. 
Shell resembling the last, but smaller, though with as many whorls. 
Sculpture similar, but much coarser and stronger, with the longitudinal 
plicae represented by strong rounded ribs, which pass clear over the whorls, 
which are more inflated than in the last. Aperture smaller and narrower 
than in the last, less than one-third as long as the shell. Canal very short 
and narrow. Outer lip internally lirate, much thickened with two strong 
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