Body long, thorax usually thick anteriorly, anterior part of abdomen thick, posterior part slender. Tentacular ridge and upper lip broad. Tentacles numerous, long; thick and thin ones present. Buccal segment ventrally forming a narrow, prominent lower lip. About 9 unpaired, narrow ventral shields followed by 4-5 paired ones, only 4-6 of the anterior unpaired ones distinct. Notopodial chaetae smooth or feathery, starting at segment 2. 17-19 thoracic chaetigers. Uncinigerous tori from first abdominal segment (P. plumosus-detail).
Up to 36 mm for about 100 segments.
In alcohol whitish.
On mixed bottoms of mud with sand; 40-150 m.
The Faeroes, western Norway, eastern North Sea, Skagerrak, Swedish west coast, Irish Sea, South Africa.