Body long, thorax cylindrical, abdomen tapering.
Tentacles numerous. Upper lip very low and broad, enclosing mouth dorsally and laterally. Lower lip prominent, cushionlike. No eyespots or gills.
Long lateral lobes, distinct on segments 2 and 3, less distinct on segment 4. Anterior thoracic segments distinct also on the dorsum. 10 ventral shields on thorax. Notopodial chaetae from segment 4. 16 chaetigerous thoracic segments with capillary chaetae on the notopodia of 3 kinds: anteriorly capillaries with wings; posteriorly, long and short capillaries with teeth. Uncinigerous tori from segment 6, long on thorax. Uncini in double rows on segments 11-19. All uncini with one big and several smaller teeth (P. graffii-chaetae).
Pygidium with wavy edge.
Up to 42 mm for 49 segments.
In life brownish. In alcohol pale yellow.
On mixed bottoms of clay or sand with stones and shells, also on rocky surfaces with some sediment; shallow sublittoral.
Eastern North Atlantic to Madeira, Black Sea, Trondheimfjord, Oslofjord, Swedish west coast, Skagerrak.