CLASS GASTROPODA 
33 
SECTION COLEOPHYSIS Fischer, 1883 
Retusa harpa Dali, 1871 
Plate 2, fig. 3 
American Journal of Conchology, 7:136; PI. 15, fig. 11. 
Shell small, white, of four and a half whorls; tabulate and sharply 
carinate above, characterized by sharp grooves and raised lines, parallel 
with the lines of growth, which extend half over the whorls and become 
obsolete anteriorly. Apex mammillated, minute, globular, prominent, suture 
canaliculated. Anterior portion of the last whorl smooth. Last whorl 
slightly narrower above. Aperture long, narrow, effuse below, with a 
deep narrow sinus at the suture. Columella thickened with a thin layer of 
white callus. Columellar plait obsolete in the adult, rather prominent in 
young shells. Carina intersected by the grooves and slightly dentate. 
Long., .24; lat., .12 in. (Dali.) 
Type in United States National Museum. Type locality, Monterey, 
California. 
Range. Queen Charlotte Islands, British Columbia, to San Diego, 
California. 
SECTION SULCULARIA Dali, 1920 
Retusa xystrum Dali, 1919 
Plate 2, fig. 10 
Proceedings of the United States National Museum, 56:297. 
Shell minute, white, subcylindrical, the aperture as long as the shell, 
whorls involuted, with a deep pit at the apex, slightly wider in front; very 
little constricted around the middle; sculpture of extremely fine, close, 
longitudinal grooves covering the whole surface; the base produced, im¬ 
perforate; the aperture very narrow, outer lip straight, as long as the 
shell, simple, sharp, rounding into the base. Length of shell, 3; max. 
diam., 1 mm. (Dali.) 
Type in United States National Museum, No. 273985. Type locality, 
San Diego, California. 
Range. San Pedro to San Diego, California. 
Genus VOLVULELLA Newton, 1891 
Shell external, subcylindrical or long-oval, tapering at both ends, the 
body-whorl more or less produced in a beak or spine above. Spire con¬ 
cealed ; aperture as long as the shell, very narrow, the outer lip simple, 
[33] 
