Genus diagnosis (from Blake 1996). Prostomium wedge-shaped, elongate or blunt, usually with eyes; peristomium with 2–3 annulations. Two or more grooved tentacular filaments arising from a single anterior segment. Branchiae first present from same chaetiger as tentacular filaments, occurring singly, continuing over most of body to posterior end. Parapodial rami well separated. Chaetae including capillaries and acicular spines.