Body very short, cylindrical.
Tentacular membrane smooth, with round lobes in the median part. Lateral cirri on segments 2 and 3 simple or with forked tips. Paleae numbering 9-11 on each side. Dorsal brim smooth. Segment 3 ventrally with notched anterior margin. Segment 4 midventrally with a pair of big papillae. Segments 4 and 5 each bearing a pair of lamellate lateral gills.
Seventeen segments with dorsal chaetae, the posterior fourteen also with ventral uncini.
Bristles of the first three chaetigers short, thin and straight. Chaetae of the following segments longer and stouter, subdistally bent and denticulate. Uncini with two large teeth (P. pusilla-detail).
Scaphe not distinctly set off from body, short and round. Dorsolateral edge of scaphe with six pairs of papillae, the anterior pair long, the rest short and triangular. One small anal papilla, near this two small eyespots.
Worm up to 15 mm long, tube up to 32 mm long.
Nearly straight, only slightly conical masonry of relatively large sand and shell particles.
In life pale, yellowish to orange, according to Fauvel (1927) iridescent. In alcohol pale.
On sand or mixed bottoms; in Norwegian waters from 15 to 200 m.
Eastern North Atlantic to the Congo, Mediterranean. The Faeroes, Kattegat, northern Öresund, Swedish west coast, Norwegian coast to Lofoten.