Body relatively short, thorax cylindrical, abdomen tapering.
Tentacular ridge convex, U-shaped with ends pointing forwards. Tentacles numerous and short, comprised of thick furrowed ones, and thin cylindrical ones. Upper lip forming two fleshy, triangular lobes. Lower lip longitudinally and transversely folded. Buccal segment laterally with a pair of large, rounded, thin and flexible lobes, ventrally cushion-like. Three pairs of simple filamentous gills (on segments 2-4).
Fifteen thoracic chaetigers. Notopodial chaetae from segment 6. Uncinigerous tori from segment 6, low, short on anterior part of thorax, long on posterior part of thorax, and again short on abdomen. Notopodial chaetae smooth, straight or slightly curved, with narrow brims. Thoracic uncini with one big and several smaller teeth, with a long shaft, abdominal uncini with one big and several smaller teeth, small.
Pygidium with smooth or weakly scalloped edge.
Up to 30 mm for 70 segments.
A thin layer of secretion encrusted with mud and sand, often fastened to algae or stones.
In life orange with violet tentacles and red gills. In alcohol whitish.
On mud, sand and mixed bottoms; uppermost sublittoral to depths exceeding 2500 m.
Eastern North Atlantic to Liberia, Mediterranean, western North Atlantic, West Greenland, Novaya Zemlya, Kara Sea, Alaskan Arctic, Bering Sea, North Pacific, East and South Africa, southern South America, Subantarctic Islands, Antarctic waters. East Greenland, Svalbard, Iceland, the Faeroes, Shetland, western and southern Norway, eastern Great Britain, Skagerrak, Kattegat, Swedish west coast.