CLASS GASTROPODA 
271 
Range. Unalaska Island, Alaska, to Puget Sound. 
This was described as Cerithiopsis stejnegeri truncata. 
Cerithiopsis fraseri Bartsch, 1921 
Proceedings of the Biological Society of Washington, 34:34. 
Shell elongate-conic, chestnut brown. Nuclear whorls decollated. 
Post-nuclear whorls almost flattened, marked by moderately strong, 
rounded, slightly retractively slanting axial ribs, of which 18 occur upon 
the first, 16 upon the second to fourth, 18 upon the fifth, 20 upon the 
sixth and seventh, 26 upon the eighth and the last whorl. Intercostal 
spaces about half as wide as the ribs. The spiral sculpture consists of 
three strong cords, of which the first, at the summit, is a little less strong 
on the early whorls than the other two, but on the last two whorls equals 
the other two cords. The intersection of the axial ribs and spiral cords 
forms strong tubercles, rounded on the first cord, slightly truncated 
posteriorly on the median cord, and strongly rounded anteriorly and 
strongly truncated on the third cord posteriorly and gently sloping 
anteriorly. The spaces inclosed between the axial ribs and spiral cords are 
well-rounded pits. Suture strongly impressed, the extreme appressed 
portion of the summit appearing as a slender sinuous spiral thread. 
Periphery of the last whorl marked by a sulcus about half as wide as 
that separating the median from the third cord. Base short, well-rounded, 
marked by the feeble continuations of the axial ribs which extend more 
or less threadlike over the base, and two strongly impressed spiral lines on 
the posterior fourth of the base. The space separating the first from the 
second of these spiral lines is about as wide as that separating the first 
from the peripheral sulcus. There is no spiral cord at the insertion of the 
columella. Aperture decidedly channeled anteriorly; posterior angle 
obtuse; outer lip thin, rendered wavy at the edge by the external sculpture, 
which is visible through the substance of the shell; inner lip decidedly 
sinuous, reflected over and appressed to the columella; parietal wall pro¬ 
vided with a thin callus. Length, 6.5; diameter, 2.3 mm. (Bartsch.) 
Type in United States National Museum, No. 340858. Type locality, 
Clayoquot, British Columbia. 
Range. Clayoquot to Victoria and Nanaimo, British Columbia. 
Cerithiopsis willetti Bartsch, 1921 
Proceedings of the Biological Society of Washington, 34:36. 
Shell large, robust, elongate-conic, pale brown. All but the last nuclear 
whorl decollated. This shows, however, that the species belongs to the 
subgenus Cerithiopsina. Post-nuclear whorls crossed by very strong, 
almost sublamellar, rather coarse, rounded, protractively slanting, axial 
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