Body short and tumid; coxal plate 1 much smaller than plates 2 to 4 and almost completely obscured by plate 2, plate 4 only weakly emarginate, plates 5 and 6 with a conspicuous posterior lobe; epimeral plate 3 about quadrate, posterior angle narrowly rounded. Head very short, lateral lobes only slightly produced with the anterior margin usually weakly sinuous; eyes moderately large and suboval. Antenna 1 peduncle article 1 large, article 2 almost three times as long as article 3, flagellum about 10-articulate; antenna 1 somewhat longer in male than female; accessory flagellum 5-articulate. Antenna 2 about equal in length to antenna 1 in female and about 10-articulate, in male longer than antenna 1 and about 11-articulate with the proximal articles robust and with calceoli. Gnathopod 1 simple, propodus equal to the length of the carpus, posterior margin finely serrate and with three to five small spines. Gnathopod 2 especially elongate and slender, minutely chelate, propodus only about half the length of the carpus, both densely setose. Pereiopods robust, sparsely spinose, merus slightly expanded. Uropods biramous; uropods 1 and 2 spinose, rami about equal in length; uropod 3 outer ramus a little longer than the inner one, with two or three small marginal spines. Telson only little longer than wide, cleft to three-quarters of the length, lobes rather divergent, each with one to three small distal spinules.
Up to 10 mm.
Yellowish or whitish, with a pink or orange colouration on the pereion.
Often found in the branchial cavity of ascidians and in sponges. Depth range from 10 to 600 metres.
North-East Atlantic, North Sea, Mediterranean; European coasts from western Norway to the Adriatic.