Notes on 13 species of Polychaeta selected from collections made on, or near, the coasts of California and Mexico during 1958 and 1959 are recorded. Of these one (
Eurythoe complanata var.
mexicana) is a new variety, three (
Paraeurythoe americana,
Halla parthenopeia,
Asychis amphiglypta) are new records for the eastern Pacific, three (
Perinereis obfuscata,
Nereis oligohalina,
Polyophthalmus pictus) involve new records of swarming forms, and two (
Glycera robusta,
Aphrodite falcifera) are extensions of distribution. The remainder deal with species having miscellaneous features of some other interest.
