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. 0,24 inch; lat 0,12 inch. (Dall.)

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 mammilated, 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 ami slightly dentate. Lon. 0,24, lat. 0,12 in.
Habitat, Monterey, California; adhering to the tentaculae of Actinias; three specimens.
This pretty and very distinct species is unlike any other from the coast, and is readily recognized by the characteristic grooves.

Queen Charlotte Islands, British Columbia, to San Diego, Cali fornia.