CLASS GASTROPODA 
253 
Type in United States National Museum, No. 106505. Type locality, 
Point Abreojos, Lower California. 
Range. San Pedro, California, to Point Abreojos, Lower California. 
Cerithiopsis carpenteri Bartsch, 1911 
Plate 72, fig. 9 
Proceedings of the United States National Museum, 40:334; PI. 38, fig. 9. 
Shell broadly elongate-conic, dark chocolate brown. Nuclear whorls 
three, smooth, well-rounded, separated by a slender suture, forming an 
elongate-conic spire. Post-nuclear whorls well-rounded, marked by three 
strong, broad, spiral bands which are as wide as the spaces that separate 
them. Of these, the first and widest is at the summit, the next is median, 
while the third is a little posterior to the suture. In addition to the spiral 
keels, the whorls are marked by slender, rounded, axial ribs, which are 
about half as wide as the spiral cords. Of these ribs, 20 occur upon the 
first and second, 22 upon the third to fifth, 24 upon the sixth and seventh, 
28 upon the eighth, and 30 upon the penultimate turn. The junctions of 
the axial ribs and spiral cords form strong, elongated tubercles, having 
their long axis parallel with the axial sculpture. The tubercles at the 
summit are well-rounded anteriorly and posteriorly; those of the median 
series are a little more suddenly rounded anteriorly than posteriorly; while 
those belonging to the supraperipheral cord are truncated suddenly pos¬ 
teriorly and slope gently anteriorly. The spaces between the spiral 
cords and axial ribs are small, moderately rounded, well-impressed pits. 
Suture constricted, showing a portion of the basal cord. Periphery of the 
last whorl marked by a deep, spiral groove as wide as that separating the 
first supraperipheral cord from the median spiral cord and, like it, crossed 
by the continuations of the axial ribs. Base short, well-rounded, marked 
by a broad, spiral cord which is truncated posteriorly and slopes gently 
anteriorly toward the shallow, well-marked groove which separates it 
from the base proper. Entire surface of spire and base marked by nu¬ 
merous, very slender, incremental lines. Aperture irregularly oval, very 
strongly channeled anteriorly; posterior angle obtuse; outer lip thin, show¬ 
ing the external sculpture within, rendered decidedly sinuous at the edge 
by the external sculpture; columella stout, moderately long, the edge 
reflected; parietal wall glazed with a thin callus. Length, 8.1; diameter, 
2.8 mm. (Bartsch.) 
Cotypes in United States National Museum, No. 109510. Type lo¬ 
cality, Terminal Island, San Pedro. 
Range. San Pedro, California, to South Coronado Island. 
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