Prostomium faintly bilobed, with two eyes. Five antennae, indistinctly annulated or smooth. Peristomium three to four times longer than following segments. Apodous segment with two indistinctly annulated cirri.
Gills start on chaetigers 6-10, continuing to near the end of the body, with a maximum of 3-12 filaments. Dorsal cirri as long as gills or longer. Chaetae of four kinds: 1) winged capillary chaetae; 2) comb-chaetae; 3) compound chaetae with stout bidentate hooded hooked blades; 4) stout simple bidentate hooded hooks, which begin on chaetigers 30-41. Aciculae and hooks black (E. norvegica-parapodium).
Two long and two short pygidial cirri.
Mandibles slender, with calcified anterior margins. Maxillae I: hooked forceps; maxillae II: 5-7 teeth each; maxilla III: 7-10 teeth; maxillae IV: 4-7 and 7-10 teeth; maxillae V and VI: unidentate (E. norvegica-jaw apparatus).
Up to 200 mm for numerous segments.
Pinkish, brownish or black spotted with brown.
Lives in an often branched, parchment-like, irregularly bent tube with side openings at the angles. Tube sometimes covered by attached sponges, hydroids, or ascidians. Found on sand, mud, and mixtures of both with gravel, shells, and dead corals. Depths range from about 20 to 1300 m. E. norvegica may be associated with corals (Lophelia , Amphelia , Madrepora , Solenosmilia ), where it lives in a parchment-like sinuous tube which may be entirely surrounded by the coral.
North Atlantic, Mediterranean, northern North Sea, Skagerrak and probably Öresund; eastern North Pacific and Indian Ocean.