Prostomium conical, with two eyes on the posterior half. Prostomium with two dorso-lateral lobes. Anterior two achaetous segments dorsally fused. Achaetous segments are longer than chaetigers.
One pair of long thick palps on the first chaetiger.
Slender filamentous gills, starting at first chaetiger, predominantly on anterior body half.
Chaetae capillary, very finely serrated. Normally from 3rd neuropodium and 6-9th notopodium, 1-3 rarely up to 6-8 smooth, distally bidentate hooks, of which one very small tooth is often hard to recognize.
Up to 40 mm for 140 segments.
Greenish-yellow with yellowish or brown pigmentation.
Australia, North Pacific, eastern North Atlantic up to Mediterranean, Adriatic Sea and Black Sea and English Channel up to the southern North Sea.