CLASS GASTROPODA 
269 
Cerithiopsis ingens Bartsch, 1907 
Proceedings of the United States National Museum, 3:180; PI. 41, fig. 4. 
Shell large, elongate-conic, white. Nuclear whorls decollated. Post- 
nuclear whorls slightly shouldered at the summit, moderately well-rounded, 
marked on the first three turns by three spiral cords. On the fourth turn 
a fourth cord makes its appearance at the summit, rapidly increasing in 
strength until on the last three whorls it is quite equal to the other cords. 
These spiral cords are almost as wide as the spaces which separate them. 
In addition to the spiral cords, the whorls are marked by rather poorly 
developed, rounded axial ribs, of which 14 occur upon the first, 16 upon 
the second, 18 upon the third and fourth, 20 upon the fifth and sixth, 22 
upon the seventh and eighth, and 24 upon the penultimate turn. The inter¬ 
sections of the spiral cords and axial ribs form rather rounded cusps which 
slope more gently anteriorly than posteriorly, while the spaces inclosed 
between are rather shallow, quadrangular pits having their long axes 
parallel with the spiral sculpture. Sutures moderately constricted, showing 
the posterior edge of the first basal cord. In addition to the above sculp¬ 
ture, the entire surface of the spire is marked by very slender lines of 
growth, and, on the last whorl, by very slender, intercalated, spiral lira- 
tions between the cords. Periphery of the last whorl marked by a channel 
equal to the space between the cords on the spire. Base moderately long, 
well-rounded, ornamented with six, strong, spiral keels, which decrease 
regularly in size and spacing from the periphery to the columella. Aperture 
irregularly oval, strongly channeled anteriorly; posterior angle acute; outer 
lip thin, showing the external sculpture within, rendered decidedly wavy 
at the edge by the external sculpture; columella moderately long, somewhat 
twisted, and reflected; parietal wall covered with a thin callus. Length, 
12.5 ; diameter, 4.2 mm. (Bartsch.) 
Type in United States National Museum, No. 32212. Type locality, 
Monterey, California. 
Range. Known only from type locality. 
Cerithiopsis tumida Bartsch, 1907 
Proceedings of the United States National Museum, 33:179; 40: PI. 41, fig. 3. 
Shell medium size, light yellowish-brown, shining. Nuclear whorls 
decollated. Post-nuclear whorls somewhat inflated, well-rounded, separated 
by a constricted suture and ornamented with strong tuberculate axial ribs, 
of which there are 18 upon the second of the remaining whorls and 22 
upon the penultimate turn. In addition to the axial ribs there are four, 
unequally broad, low, spiral ridges between the sutures, which are much 
wider than the spaces which separate them, the latter appearing as strongly 
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