Body large and thick with up to 150 chaetigers.
20-40 pairs of radioli, webbed to over two-thirds of their length, with long filamentous tips without side-branches. Two short, thick palps.
Upper lip thick with two lobes. A short collar with two small dorsal lobes, incised laterally and ventrally with a large triangular flap.
Peristomium with two groups of ocelli.
Thorax with 7-9 chaetigers. The first chaetiger with thin, long capillary chaetae on notopodia. The rest of the thoracic notopodia bear numerous long, thin, winged capillaries. They are difficult to see, the presence is indicated by small circular pads on each side of each segment.
Thoracic hooks with a long shaft and a strong tooth at the bent tip; sometimes with a second small tooth above (old specimen loose these hooks).
Abdominal capillaries resemble those on thorax. Abdominal uncini are truncated. They form nearly complete girdles in a groove around each abdominal segment.
One or more ocelli with lenses behind the parapodia.
Pygidium wit eyespots.
Up to 200 mm for over 150 segments.
Transparent, gelatinous, thick (up to 30 mm diameter); carrot-shaped and easily renewable.
Body yellow or orange, crown brown or violet.
In mud or muddy sand; eulittoral to 500 m; polyhaline.
Arctic, North Pacific, North Atlantic to Mauritania, Namibia and South Africa, North Sea to Öresund, Australia.