(Peach, 1847)
Description
Column elongated and worm-like, divided fairly distinctly into scapus, a short capitulum, and a physa which is often inflated and bulbous; up to 70 mm in length and 6 mm diameter. Freshly collected specimens usually have sand grains stuck to the adhesive papillae on the lower part of the column, which are not otherwise conspicuous.
Tentacles: Tentacles 12, moderate in length although short for an athenarian.
Colouration: Disc usually with a pattern of various shades of brown on a white, yellowish, or cream ground; sometimes the pattern is lacking or present only on the tentacles, with the disc being plain white, brown or yellow. Column white, buff, pink or yellow, longitudinally striped by the translucent insertions of the mesenteries.
Habitat
Burrowing in mud, sand or gravel, often in the region of eel-grass (Zostera) beds, occasionally under stones. From the lower shore around LWST to depths of about 100 m offshore.
Distribution
All coasts of the British Isles and north-west France. If, as seems likely, this species is conspecific with H. duodecimcirrata (Sars, 1851) its range extends throughout most of northern Europe and the Atlantic coast of North America.