Prostomium pointed, with four or without eyes, with a small median antenna. Caruncle reaching chaetiger 1 or 2.
Notopodial postchaetal lobes in segment 1 tiny, in the following segments completely fused to the gills, later with a free tip and in posterior segments small and oval. Neuropodial postchaetal lobes in anterior segments broadly rounded to oval, in posterior segments becoming smaller.
Anterior parapodia with capillary chaetae only, absent in the first notopodium, from neuropodium 14-18 onwards also up to 14 hooded hooks present. These in profile with two or three accessory teeth, that may be split. No notopodial hooks (S. korsuni-detail).
Pygidium with two lobes.
Over 21 mm for more than 51 segments.
Arctic, northern North Sea.