Tentacles extend to segment 3 if directed posteriorly (550-650 µm long). Two so-called statocysts; no eyes in adult individuals. Nuchal organs large, oval, dorsolateral grooves. Prostomium with transverse ciliary bands, one behind each nuchal organ. Two well-developed, segmentally arranged, transverse, incomplete rings of ciliary tufts; additional scattered tufts. Females with lateral ciliary bands in segment (8) 10-14; not observed in animals from Helgoland. Epidermis with numerous glands, especially of the bacillary type, distributed most densely ventrally and ventrolaterally. Two well-developed, adhesive pygidial lobes that resemble those of Protodrilus adhaerens . Salivary glands in anterior 10-12 segments of males and in 18-20 segments of females.
Fertile region in males begins in segment 10 or 11, in females in segment 12. Four pairs of spermioducts in segments 11-14. Lateral organs extending from segment 7 to 15; in segment 7 only ciliary pits. No oviducts.
Up to 4-7 mm for 35-50 segments.
Transparent; without colour except for the faintly reddish pharyngeal region.
Intertidal and subtidal shell gravel, and fine to coarse sediments.
North Sea (Helgoland), English Channel, Skagerrak (Swedish west coast, Gullmarfjord), Mediterranean (Naples).