CLASS GASTROPODA 263 
spiral cords, the first of which is on the middle of the whorl, and the second 
one about halfway between this and the suture. The early post-nuclear 
whorls have two spiral cords, like the last of the nuclear whorls. Beginning 
with the third turn, a slender, spiral cord appears immediately anterior to 
the summit, increasing rapidly in size until, on the last volution, it is about 
equal to the other two. In addition to the spiral sculpture, the whorls are 
marked by strong, axial ribs equaling the spiral cords in strength. Of 
these ribs, 16 occur upon all but the penultimate turn, which has 18. The 
junctions of the axial ribs and spiral cords form prominent, cusp-like 
tubercles, while the spaces inclosed between them form large, squarish pits. 
Suture strongly impressed. Periphery of the last whorl marked by a strong 
keel, separated from the supraperipheral cord by a sulcus as wide as that 
which separates the supraperipheral from the median cord and, like it, 
crossed by the continuations of the axial ribs which terminate at the 
posterior border of the peripheral cord. Base short, concave, bearing a 
slender fasciole at the insertion of the columella. Entire surface of spire 
and base crossed by numerous fine, incremental lines. Aperture subquad¬ 
rate, very strongly channeled anteriorly; posterior angle obtuse; outer lip 
rendered sinuous by the external sculpture, which is apparent in the 
aperture; columella short, and broad, twisted, the free edge reflected; 
parietal wall glazed with a thin callus. Length, 4; diameter, 1.6 mm. 
(Bartsch.) 
Type in United States National Museum, No. 160079. Type locality, 
San Diego, California. 
Range. San Pedro to San Clemente Island, California, to South Coro¬ 
nado Island. 
Cerithiopsis gloriosa Bartsch, 1911 
Plate 68, fig. 7 
Proceedings of the United States National Museum, 40:353; PI. 36, fig. 7. 
Shell elongate-conic, flesh-colored, variegated with flecks of brown; 
the early whorls are light brown, while the base is dark chestnut. (Nuclear 
whorls decollated. Post-nuclear whorls marked by three strong subla- 
mellar keels, which are not quite as wide as the spaces that separate them. 
The first of these is near to the appressed summit, the third quite a bit 
anterior to the suture, while the second occupies the space midway between 
these two. In addition to these keels, the whorls are marked by slightly 
protractive, axial ribs which are equal to the spiral cords in strength. 
Of these ribs, 16 occur upon the first to fifth, 18 upon the sixth, 20 upon 
the seventh, 22 upon the eighth, 24 upon the ninth, and 26 upon the penulti¬ 
mate turn. The junctions of the axial ribs and spiral cords form strong, 
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