Four new species of polychaetes belonging to the Nereididae, Hesionidae, and Nephtyidae are described from the Santa Maria Basin off central California, and
Glycera nana is redescribed based on new material from the same area. The specimens are part of the collections from the California Outer Continental Shelf Monitoring Program that was conducted between 1983 and 1990 for the United States Minerals Management Service. The newly described species are
Nereis ligulata,
Gyptis plurisetis,
Podarkeopsis perkinsi, and
Nephtys signifera.