Four species of Polynoidae, found in colonies of the bryozoan Schizoporella unicorns (Johnston), are here described. Among these Scalisetosus gracilis is a new species for science, and Halosdna glabra Hartman and Harmathöe macginitiei Pettibone, cited by the first time for Brazilian coast. Lepisdonotus caeruleus was the most abundant species of the family. Scalisetosus gracilis sp. nov. is characterized by the elytra with long and bifid papillae scattered on the surface as well as on external borders and distinct notosetae and neurosetae.