Body up to 2 mm long in female, 1 mm in male; more or less parallel-sided in female and noticeably constricted in the middle of the pereion in male. Eyes much larger in the male than in the female. Antenna 1 in male attaining almost one third the length of the body and inclining ventrally; proximal article of flagellum very short and, like the two following articles, with a dense bunch of aesthetascs. Maxilliped of female with long seta arising from just below articulation of palp.
Chelipeds similar in males and females.
Pereiopods 4 to 6 with the bases broader than in pereiopods 1 to 3.
Uropod biramous; the exopodite slightly shorter and narrower than endopodite; each ramus with 2 articles.
This species has a vertical distribution from the littoral down to 100 m. It is often found in kept holdfasts and offshore among hydroids and in muddy sand and gravel.
This species has been recorded from the Shetlands, the east and west coasts of Scotland, east and south-west coasts of England, western Ireland, Isle of Man and the Channel Islands. On a world-wide level records exist for the Mediterranean, the Atlantic coast of France, the Faroes, Norway and south of Iceland.