Body cylindrical, long and thin.
Prostomium broadly oval, without an encircling rim. Nuchal slits semicircular, posteriorly opened. laterally with up to 10 ocelli.
66 chaetigers. Anterior and posterior chaetigers short; in mid-body long, some 5x as long as broad. Anterior glandular bands on almost all segments; some segments with glandular areas posterior to parapodia.
Anterior 4-14 segments with spines on neuropodia; the rest of neuropodia with normal hooks. Posterior 3-6 segments without chaetae.
Pygidium relatively short, cylindrical to conical.
Up to 500 mm for 66 and more chaetigers.
Covered with mud, fine sand and foraminiferans.
Diameter outside 1.5 mm, inside 0.5 mm.
Anterior body half with irregularly distributed yellow or red-brown to purple stains. Parapodia posteriorly more or less clearly with single or more, half to complete, cross-bands.
The vertical distribution extends from upper sublittoral down to 2000 m deep.
Arctic, North Atlantic up to Skagerrak, Kattegat, the Belts and northern Öresund.