Levensteiniella kincaidi, n. gen., n. sp. and
Macellicephala galapagensis, n. sp., in the Macellicephalinae, and
Harmothoe macnabi, n. sp., in the Harmothoinae, from the hydrothermal vent areas on the Galapagos Rift and off the East Pacific Rise at 21°N are described, as well as a deep-water pelagic macellicephalin,
Natopolynoe kensmithi, n. gen., n. sp., from the Santa Catalina Channel. A summary of the polynoid polychaetes collected during
Alvin dives by the Galapagos Rift Biology Expedition in 1979 and the OASIS Expedition to the East Pacific Rise in 1982 is included, along with a key to the species.