(M. Sars, 1861)
Body cylindrical with 19 chaetigers. The first segments are relatively short, but mostly longer than broad.
Prostomium rounded, rim with a notched margin. Nuchal slits semicircular.
The seven most anterior segments are bi-annular and as long as prostomium-peristomium. The following segments are much longer than broad, posterior ones again short.
First chaetiger enlarged into a collar.
Notopodial chaetae are capillaries, on anterior segments they are winged and with long tips; on posterior segments also feathery chaetae present. Hooks present on neuropodia starting on 2nd chaetiger. 1 or 2 posterior segments without chaetae (C. biceps-detail).
The three anterior segments with a complete glandular band, the 5 next ones with ventral glandular areas, the rest with glands on neuropodia.
Pygidium with oval to rounded anal plate, with deep incisions.
Up to 180 mm for 19 chaetigers.
Cylindrical and thin. Diameter outside 4-4.5 mm, inside about 2 mm.
Anterior irregularly dark-brown pigmentation. Posterior paler. In alcohol yellowish with whitish glandular bands.
In mud, sometimes in mixed bottoms with sand and shells. The vertical distribution extends from the upper sublittoral, 45 m down to 1000 m deep.
Arctic, North Pacific, North Atlantic up to Mediterranean and Adriatic, Northern and middle North Sea, Skagerrak, Kattegat, possibly to eastern Baltic Sea.