254 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Cerithiopsis pedroana Bartsch, 1907 
Plate 72, fig. 2 
Proceedings of the United States National Museum, 33:181; 40: PI. 38, fig. 2. 
Shell small, slender, dark brown. Nuclear whorls three, yellowish- 
white, smooth. Post-nuclear whorls strongly differentiated from the nu¬ 
clear ones, showing the sculpture characteristic of the adult shell from 
the very beginning. This sculpture consists of three equally spaced tuber- 
culate spiral keels between the sutures, the posterior one of which is 
slightly smaller than the other two. These keels are separated by deep 
rounded channels almost as wide as the keel. In addition there are many 
low, rather broad axial ribs, the intersections of which with the keel form 
the tubercles. About 20 of them occur upon the first, 22 upon the fifth, 
and 30 upon the penultimate post-nuclear turn. The connection between 
the tubercles, both spiral and axial, are about equal, inclosing deep, 
squarish pits. In addition to the above sculpture the entire surface is 
marked by fine spiral lines and lines of growth. Sutures strongly marked, 
constricted, showing the peripheral keel in the later whorl. Periphery 
marked by a broad, low, rounded keel. Another of equal width is located 
upon the middle of the base. The sulcus which separates these keels, and 
the supraperipheral sulcus are of equal width; both are crossed by the 
weak continuations of the axial ribs, which gradually weaken as they pass 
toward the columella. The basal keel is separated from the columella by 
broad, shallow grooves. Aperture irregularly oval, decidedly channeled 
anteriorly, outer lip thin, rendered sinuous by the external keel; columella 
stout and somewhat twisted, with a strong callus on its inner edge that 
extends over the parietal wall. Length, 5.2; diameter, 18 mm. (Bartsch.) 
Cotypes in United States National Museum, No. 109512. Type 
locality, Terminal Island, San Pedro, California. 
Range. San Pedro, California, to Point Abreojos, Lower California. 
Cerithiopsis berryi Bartsch, 1911 
Plate 69, fig. 8 
Proceedings of the United States National Museum , 40:339; PI. 39, fig. 8. 
Shell small, elongate-conic, brown. Nuclear whorls four, well-rounded, 
separated by constricted sutures, smooth, forming a mucronate apex to the 
shell. Post-nuclear whorls strongly sculptured, having three spiral cords 
between the sutures, of which the one at the summit is much smaller than 
the rest of the early whorls; the other two are subequal in strength, the 
second one being close to the one at the summit, while the third is almost 
halfway between the second and the suture. On the last whorl, the cord 
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