Webster & Benedict, 1887
Description:
Body is long and cylindrical, divided in three regions.
Prostomium is conical, rounded at the tip, with two eyes and two anterior nuchal slits. Mouth ventral.
A single, very long gill inserted on the hind margin of chaetiger 2 or on the 3rd chaetiger.
Parapodia are rudimentary.
Thorax of 16-21 short segments, abdomen like a string of beads, with a marked constriction between segments. 20-40 abdominal chaetigers.
The preanale region with 8-10 short segments.
Anterior two and posterior two segments achaetous.
All chaetae finely toothed capillaries.
Pharynx eversible
Pygidium with three cirri.
(Coss. longocirrata-detail).
Size:
Up to 19 mm for 85 segments.
Colour:
Colourless.
Habitat:
Usually in mud, sometimes in muddy sand. 7 to 900 m deep.
Distribution:
Arctic, North Pacific, North Atlantic, Skagerrak, Kattegat and Öresund.