(McIntosh, 1869)
Description:
Body small and slender.
Prostomium as long as broad, bluntly conical, with a pair of eyes. Antennae short, indistinctly annulated; palps long with a short terminal section. Peristomium and apodous segment a little longer than following chaetigers.
Parapodium quite long, cylindrical, with equal chaetal lobes. Dorsal cirrus short, ovoid, present on all chaetigers. Ventral cirrus also ovoid. Supra-acicular chaetae of two kinds: (1) stout forked chaetae with subequal smooth branches; (2) 1-2 finely toothed capillary chaetae. Subacicular chaetae compound, with bifid, finely toothed stout hooked blades (P. kefersteini-detail).
A pair of short and a pair of longer annulated pygidial cirri.
Mandibles short, X-shaped, with finely toothed anterior margins. Maxillary carriers fused posteriorly, V-shaped. Maxillae: two upper rows and two lower rows of fine teeth; the basal plates of upper rows fused posteriorly, those of lower rows free (P. kefersteini-jaw plates).
Size:
Up to 15 mm for numerous segments.
Colour:
Dorsal surface bright red or orange.
Habitat:
Mostly on sandy substrata, less commonly on mud; but also under stones, among sea grasses and algae, and in empty tubes of serpulid polychaetes. Occurs in the lower intertidal and the shallow subtidal zones.
Distribution:
North Atlantic to North Sea and English Channel, Mediterranean and Black Sea.