Pierantoni, 1908
Description:
Tentacles comparatively long, reaching segment 6 when directed backwards. So-called statocysts close together in the anterior part of the prostomium. No eyes. Two nuchal organs narrow transverse depressions, leading to ventral side. Head region with at least 6 or 7 dense, dorsally broadly interrupted, ciliary rings, plus numerous tufts and sensory cilia. Ciliation of segments in form of 2 dorsally incomplete rings per segment and numerous tufts. Salivary glands in the first 11 segments.
Fertile region in males beginning at segment 12 or 13. Lateral organs in segments 7-16, with that of segment 7 only a small rounded pit. Three pairs of spermioducts in segments 13-15; sometimes an additional pair in segment 12.
Size:
Up to 8-12 mm for 35-40 segments.
Colour:
Whitish; pharyngeal region faintly reddish.
Habitat:
Medium to coarse sand sediments in subtidal regions.
Distribution:
English Channel, Skagerrak (Swedish west coast, Gullmarfjord). Mediterranean.