The genus
Hipponoa [sic, for Hipponoe] (Polychaeta, Amphinomidae) is monotypic.
Hipponoa gaudichaudi Audouin & Milne-Edwards, 1830, probably represents a highly specialized species whose affinities to amphinomids has been questioned. As part of an on-going study of Amphinomida, both the genus
Hipponoa and species
H. gaudichaudi are redescribed and emended. Affinities with other taxa of the order are briefly discussed.