Urosome segment 1, dorsal margin with prominent angular keel, posterior margin of keel often concave; epimeral plate 3 quadrate, distal angle rounded. Head with lateral lobes broadly rounded; eyes very large, elongate. Antenna 1 peduncle article 1 large, articles 2-3 strongly compressed, flagellum up to about 11-articulate; accessory flagellum slender, up to 6-articulate. Antenna 2 in female only slightly longer than 1, flagellum up to 13-articulate; in male antenna 2 about twice length of 1. Antenna 1 and 2 in male with calceoli. Gnathopod 1 propodus narrowly rectangular, equal to length of carpus, palm oblique, minutely toothed, dactylus with large tooth on inner margin. Gnathopod 2 propodus much shorter than carpus, oval, minutely subchelate, palm minutely toothed. Pereopods 5-7 basis broadly expanded, posterior margin finely toothed. Uropods 1-2 weakly spinose, rami subequal; uropod 3 inner ramus slightly longer than article I of outer ramus, outer margin of outer ramus with few small spines; in male inner margins of both rami with few long setae. Telson triangular, cleft to three-quarters length, each lobe with 2-3 lateral and 1 apical spines.
Up to 7 mm.
Depth range from 50 to 900 metres, typically a deeper water species.
Arctic Ocean; North Atlantic, American and European coasts; North Sea.
Source: Lincoln, 1979.