Pereion and pleon segments without posterodorsal teeth, pleon weakly keeled dorsally with a small notch marking the posterior end of the keel. Head with a short curved rostrum, lateral lobes weakly sinuous; eyes large, especially in male, kidney-shaped. Coxal plates 1 to 4 small in male, much longer and broader in female, distal margins weakly setose, also with small setules on the surface of the plates. Epimeral plates 1 to 3 distal angle with a small tooth, posterior margin convex. Female antenna 1 about one-third of the body length, peduncle articles 1 and 2 about equal in length, article 3 very small, flagellum up to about 25-articulate. Female antenna 2 little longer than antenna 1, peduncle article 5 much longer than article 4, flagellum up to about 25-articulate. Male antenna 1 peduncle article 2 longer than article 1, tapering distally, flagellum very slender and much longer than in female. Male antenna 2 peduncle more robust than female, article 4 tapering distally; confronted margins of peduncle articles in male with many tufts of short fine setules. Gnathopod 1 basis robust and densely setose, propodus much longer than the carpus, oval, palm oblique, almost straight, delimited by a pair of slender spines, palmar margin with several small spinules; merus, carpus and propodus strongly setose, setae stout, some setae pectinate. Gnathopod 2 basis robust, less densely setose, propodus a little longer than the carpus, subrectangular, palm strongly oblique, almost straight, delimited by a pair of slender spines; merus, carpus and propodus with stout setae, some setae pectinate, but less dense than in gnathopod 1. Pereiopods 3 and 4 dactylus small; in female basis densely setose, other articles spinose but almost devoid of setae; in male, basis, merus, carpus and propodus with long marginal plumose setae. Pereiopods 5 and 6 basis expanded, distal margin prolonged, angular; pereiopod 7 basis with the posterior margin coarsely dentate, distal angle rounded. Coxal gills deeply pleated. Uropod 3 rami three times the length of the peduncle; in male the margins with small spines and many long plumose setae; in female spines larger but with a few short plumose setae. Telson a little longer than wide, truncated distally, cleft to three-quarters of the length, lobes slightly overlapping medially, each with one or two apical spines.
Up to about 10 mm.
Whitish, with brown patches on the dorsal surface and the coxal plates.
Depth range from the lower intertidal to about 50 metres. Locally common.
North Atlantic; American and European coasts; Arctic Ocean. European coasts from northern Norway to the western Mediterranean; North Africa to Senegal.