Prostomium of this scale-worm is somewhat longer than broad, with a median antenna, a pair of lateral antennae, ventrally inserted, and a pair of palps. Two pairs of eyes, the anterior pair on the line of greatest width, the posterior pair near the rear margin. Scales overlap, often leaving a few posterior segments uncovered. The first pair of scales are round, the rest oval to kidney-shaped, at least half of the margins fringed with short papillae, the surfaces with small conical tubercles and larger pointed, conical tubercles that become bigger posteriorly.
Notopodia are small mounds with a ventral acicular ligule and many chaetae. Notopodial chaetae spinose with blunt tips.
Neuropodia well developed with an anterior ligule and chaetae. Neuropodial chaetae spinose with bidentate tips, a few in the lower position with unidentate tips.
Up to 30 mm for 34 chaetigers.
Living animal greenish; in alcohol brownish. Scales with brown spots.
Arctic, North Pacific, North Atlantic to Spain, northern North Sea, Skagerrak and Kattegat.