Abstract
Examination of all the specimens collected from deep hydrothermal vents in the eastern Pacific allowed us to describe two new species and one new subspecies belonging to the genus Paralvinella Desbruyères and Laubier, 1982: P. pandorae sp.n., P. palmiformis sp. n., and P. pandorae irlandei ssp. n. Alvinella pompejana is split into two species, A. pompejana and A. caudata sp.n., based on to morphological and biochemical data. The six species and subspecies of Alvinellinae (Polychaeta: Ampharetidae) are well separated from all other terebellomorph species by the absence of differentiation between thorax and abdomen. We propose here the erection of a new family, Alvinellidae, which seems to be primitive within the order Terebellida. All known alvinellids are strictly associated with deep hydrothermal vent phenomena.