Aeverrillia armata (Verrill, 1873)

This ctenostome species is readily identified by the arrangement of zooecia along the stolon in oppositely attached pairs. An additional identifying characteristic is the presence of four short prominences at the distal end of each zooid. Each prominence bears a bristle or spine. A. armata is common in harbors along the temperate coasts of the western Atlantic, and has been reported from New Zealand. Our records of its occurrence in bottom trawls from San Francisco Bay appear to be the first for the northeast Pacific.