Plate 1 issued from : J.M. Bradford & J. Wells in Polar Biol., 1983, 2. [p.4, Fig.3].
Stage V male (from Antarctic: Ross Ice Shelf): a, habitus (lateral); b, rostrum; c, urosome (lateral); d, idem (dorsal); e-h, P1 to P4; i, P5.

A1 extends well beyond posterior border metasome. Pedigerous segments 1 and 2, also 4 and 5 separate. Posterolateral margins of metasome triangular in lateral view, extending to posterior border of urosome. Urosome 4-segmented, segments 2, 3 and caudal rami with surface spinules: ventrally and laterally on segments 2, ventrally on segment 3 and caudal rami. Mouth parts similar to those of X. harpagatus except that teeth on gnathobase reduced, and large spine on lobe 4 of Mx2 more weakly constructed than large spine on lobe 5.Swimming legs ornamented, differ from those of X. harpagatus chiefly in that P1 endopod narrow, P3 basipod 1 with posterodistal row of spines, and terminal spine on exopod with coarse serrations; P5 uniramous asymmetrical, incipiently 4-segmented on both sides.