126 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
merited; sinus deep and conspicuous, canal moderately produced and re¬ 
curved, operculum absent; nucleus conic, of a few polished unicarinate 
whorls. (Gabb.) 
Type. Glyphostoma dentifera Gabb. 
Distribution. Japan, west coast of North America. Fossil: Pliocene 
and Pleistocene of California. 
Glyphostoma conradiana Gabb, 1869 
Paleontology of California■, 2:7; PL 1, fig. 12. 
Shell small, robust, broadly fusiform; spire high; whorls seven and a 
half, the first smooth and round, the remainder angulated; concave above, 
convex on the side; suture very indistinct. Surface marked by ten or 
twelve large, rounded, radiating ribs, crossed by square elevated ribs, 
with sometimes smaller ones interposed; on the upper or concave portion 
of the whorl are six or seven fine linear revolving ribs; of the large re¬ 
volving ribs, three or four only appear on the upper whorls, the body 
volution showing about fourteen. Aperture narrow; inner lip thinly 
incrusted; outer lip acute on the edge, thickened behind; posterior sinus 
narrow, deep, oblique, bordered by a thickened rim and almost adjoining 
the suture. (Gabb.) 
Length inch. 
Type locality, Post-Pliocene of Santa Barbara, California. 
Range. San Pedro, living; Pliocene and Pleistocene, California. 
Glyphostoma adria Dali, 1919 
Proceedings of the United States National Museum, 56:52; PI. 17, fig. 5. 
Shell small, slender, acute, whitish with the aperture more or less 
tinged with brown; nucleus white, glassy, with a minute globular apex 
and four subsequent whorls changing abruptly into the sculpture of the 
six subsequent whorls; the first of the latter has a peripheral keel chang¬ 
ing on the next whorl to two and on the later whorls to three equidistant 
prominent cords with a smaller one behind and another in front of and 
close to the suture; on the last whorl the latter is obsolete and on the 
base there are 9 or 10 cords with interspaces widening toward the periph¬ 
ery, of which cords the more prominent are minutely nodulous or 
swollen when they cross the axial riblets; there is a wide concave anal 
fasciole in front of the suture with arcuate striation; the whorls at the 
suture somewhat appressed; axial sculpture is composed of about a dozen 
rather feeble ribs extending from the anal fasciole forward to the suture, 
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