Pacific Ocean: central and southern California (USA). [details]
Pacific coast of North America: from Alaska to central California. [details]
Sandy mud beach, and coarse sand at shelf depths (50-79% sand; 18-41% silt; 4-9% clay). [details]
In sandy mudflats and sand flats, in bays and estuaries. [details]
Pleijel (1991: 234) examined holotypes of C. splendida and Eulalia nigrimaculata, and concluded they were synonyms. ... [details]