Body robust; coxal plates 1 to 5 elongate, distal margins with long setae; plate 1 tapering distally; plate 2 in male with the posterior margin excavate. Head with short lateral lobes, apex subacute; eyes small, rounded. Antennae moderately robust and setose; antenna 1 about half the body length, peduncle article 3 about equal or longer than article 1, flagellum with about eight articles. Antenna 2 peduncle articles 4 and 5 about equal in size, flagellum about 8-articulate. Female gnathopod 1 similar to male except that the palm is less deeply sculptured, propodus longer than the carpus, oval, palm oblique, weakly sinuous, delimited by a slender spine. Male gnathopod 1 moderately setose, propodus robust, much larger than the carpus, very broad distally, palm deeply emarginate. delimited by a prominent angle and a slender spine. Female gnathopod 2 larger than gnathopod 1, generally similar except propodus broader and palm rather more strongly sinuous, palmar angle rounded with a slender spine. Basis of male gnathopod 2 robust with a small anterodistal lobe, ischium also with a distal lobe, carpus with a slender setose posterior lobe, propodus broad and very robust, palm strongly excavate and sculptured, delimited by a slender process, palmar margin crenulate with 2 prominent rounded tubercles. Pereiopods robust; pereiopods 3 and 4 with long plumose setae, carpus about two-thirds the length of the propodus; pereiopods 5 to 7 sparsely setose. Rami of uropods 1 and 2 with small marginal spines; peduncle of uropod 3 little longer than the outer ramus, outer ramus with 2 to 3 marginal setae. Telson short, triangular, apex truncated.
Length up to about 5 mm.
Greyish white, with transverse light brown bands.
Depth range about 5-200 metres; constructs tubes of mud attached to hydroids.
An arctic-boreal species; very widely distributed. North Atlantic, American and European coasts; North Pacific; Arctic Ocean; North Sea.