Body extremely broad; pereion segments not keeled; pleosome segments distinctly keeled dorsally; the keel is produced at the last segment to a somewhat upturned tooth; urosome in female smooth above, in male segment 2 and 3 each armed with a small dorsal projection. Coxal plate 1 obtusely truncated distally, anterior margin rounded; coxal plates 2 and 3 with the anterior corner produced to an acute point; coxal plate 4 tapering distally, with a deep emargination in its upper part; coxal plates 5 and 6 with a small posterior lobe. Posterodistal angle of epimeral plate 2 with a small tooth. Posterodistal angle of epimeral plate 3 with a big tooth. Head with a large rostrum, deflexed and obtusely rounded at the tip, lateral lobes broadly rounded; eyes an irregular path of chalky white pigment, only visible in living specimens. Female antenna 1 peduncle little longer than flagellum; flagellum 8-articulate; accessory flagellum small, 2-articulate; in male antenna 1 scarcely longer but with flagellum article 1 elongate and setose; accessory flagellum 3-articulate. Antenna 2 in female somewhat longer than antenna 1, flagellum much shorter than the peduncle and 7-articulate; in male antenna 2 much longer, about as long as the body, flagellum 12-articulate. Gnathopod 1 slender, simple, carpus longer than the propodus, setose, propodus small, dactylus slender. Gnathopod 2 carpus little longer and more slender than in gnathopod 1. Pereiopods 3 and 4 very slender, setose. Basis of pereiopod 7 little expanded, posterior margin smooth, merus and carpus robust. Inner ramus of uropod 3 somewhat longer than the outer one, twice the length of the peduncle. Telson twice as long as broad, tip minutely bidentate.
Up to about 6 mm.
British Isles and Norwegian coast.