Prostomium rounded, wider than long, with four eyes with lenses in a trapezoid arrangement. Palps hardly visible dorsally. Median antenna shorter than lateral antennae about twice length of prostomium. Lateral antennae at least 3x as long as the prostomium. Median antenna thicker and longer than lateral ones. Nuchal epaulettes elongated, extending over the first chaetiger.
Dorsal tentacular cirri as long as lateral antennae, ventral not much shorter. Dorsal cirri of first segment the longest, longer than median antenna. Dorsal cirri of second segment much shorter but still 2-3x longer than those on other parapodia. All other dorsal cirri equal in size and shorter than segment width.
Blades of compound chaetae with a large secondary tooth an a smaller terminal tooth. Posterior parapodia from segment 30 and further with an additional needle shaped chaeta.
Pharynx with a twist. Trepan with 9 large and 9 much smaller teeth.
Body up to 25 mm long for 100 segments.
Body dorsally with two purple or dark brown squares on the segments are separated by two white cross lines. Tips of anterior appendages orange- or dark-brown coloured.
Atlantic between Ireland and South Africa, Mediterranean, English Channel, and southern North Sea.