The species of Spionidae herein described were collected by the author from the littoral of California between Fort Bragg, Mendocino County, and Pacific Grove, Monterey County, California, including the estuarine and brackish waters of San Francisco Bay and lake Merritt, Oakland. More specific localities are given in the descriptions.
Holotypes are to be deposited in the United States National Museum, paratypes in the University of California and the California Academy of Sciences.
