Body slender, posteriorly tapered.
Prostomium much longer than broad. Eyes medium-sized, situated near the posterior margin of the prostomium. Median antenna very small, situated just anterior to the eyes, often deeply sunken and difficult to see. Proboscis covered with diffusely distributed conical papillae. Terminal ring of about 12 papillae.
Tentacular cirri of segment 1 reaching about segment 4. Dorsal tentacular cirri of segment 2 reaching about segment 5; ventral tentacular cirri flattened, reaching about segment 4, with chaetae arising from anterior side of cirrophores. Dorsal cirri of median segments inflated, oval. Parapodial lobes rounded, with 5-10 chaetae. Terminal end of chaetal shaft with rather long teeth, decreasing in size proximally. Blades of medium length. Capillaries may occur on posterior segments. Ventral cirri similar to dorsal cirri but smaller.
Pygidial cirri with rounded ends, about twice as long as broad. A small median pygidial papilla present (P. limbata-detail).
Living relaxed specimen 14 mm long for 90 segments.
Living animals transparent, yellowish. Females with light green eggs, males whitish. Eyes bright red. Preserved animals yellow to brown, with darker dorsal and ventral cirri. Small spots often present dorsally and ventrally near parapodial bases on median and posterior segments. Spots also occasionally present mid-ventrally on each segment.
Sand, shell gravel, kelp holdfasts, among stones and shells. Intertidal to at least 50 m.
North-east Atlantic to Mediterranean, English Channel, North Sea, Skagerrak.