Prostomium rounded rectangular, as long as broad or somewhat longer. Acicular lobes slender, triangular. Prechaetal lamellae rudimentary, broadly rounded. Postchaetal lamellae of the notopodia unequally bilobed, as long as or shorter than the acicular lobe; those of the neuropodia shorter, simple, oval or broadly rounded. Neuropodia without accessory cirrus. Gills start at chaetiger 8-15 and are absent from the last 14-40 parapodia. Proboscis with 14 longitudinal rows of 10-20 papillae.
Up to 120 mm for 90 segments.
In alcohol reddish to brown.
Arctic, North Pacific, Atlantic, Mediterranean, Red Sea, Indian Ocean, northern North sea to the Skagerrak.