Nucella emarginata (Deshayes, 1839)
Phylum Mollusca, Class Gastropoda, Subcl. Orthogastropoda, Superorder Caenogastropoda, Order Sorbeoconcha, Infraorder Neogastropoda, Family Muricidae
Heavy, low-spired spiral shell to 35 mm; sculpturing varies from irregular, nodulous spiral cords & axial ribs to smooth; siphonal canal short & open; indistinct parietal nub present on inner posterior margin of aperture; shell white, yellow, orange, gray, brown or black.
Common, high to mid-intertidal zones, exposed & protected outer coast; drills into prey (mussels, limpets, barnacles) with radula.
Geogr. Range: Halfmoon Bay, central Calif. to northern Baja
Synonyms: Thais emarginata
Similar species: overlaps with northern Nucella ostrina betwn Halfmoon Bay & Pt. Conception; in zone of overlap, N. ostrina occurs in wave-swept areas; Nucella from Hopkins Marine Station south to Pt. Joe appear to be all N. emarginata with N. ostrina to the south & north.