Liljeborg, 1855
Description
Female body considerably shorter and more robust than in the type species, with the tail scarcely exceeding in length the anterior division. Carapace rather deep, and about the length of the exposed part of the trunk, dorsal crest extending to the hind edge, frontal lobe moreover armed on each side with three small denticles, two successive subdorsal, and one lateral, pseudorostral projection much shorter than in Leucon nasicus, horizontal and obtusely truncated at the tip, its terminal edges being cut off into four denticles, infero-lateral corners but slightly produced.
Adult male much more slender than the female, and having the carapace smooth, with only two small successive denticles close to the end of the frontal lobe; pseudorostral projection transversely truncated, with only two denticles on the terminal edges below, infero-lateral corners obtusangular. Superior antennae smaller than in the type species, with the last joint of the peduncle shorter than the second. First pair of legs comparatively feebler in structure, wile the penultimate joint much shorter than the antepenultimate one. Second pair of legs with the last joint about the length of the antepenultimate one, and armed with several rather unequal spines, which are not ciliated. Third pair of legs in male with two subequal, narrow lanceolate appendages of the ischial joint.
Uropods with the rami subequal in length, and somewhat longer than the basal part, the inner one without any ciliated setae outside, its distal joint not nearly attaining half the length of the proximal one, and carrying about six ciliated spines gradually increasing in length distally; outer ramus with only a very limited number of setae.
Size
Length up to 6 mm.
Colour
Whitish, with a faint yellowish tinge.
Ecology
Shelf to bathyal.
Depth range
Down from 20 to 100 m.
Distribution in the North Sea
Northern North Sea, Skagerrak.
World distribution
North Atlantic and Arctic Oceans.
Remarks.
This form is easily distinguishable by its much shorter and more robust body, the fuller development of the dorsal crest of the carapace, and the shorter pseudorostral projection. In the structure of the several appendages also, well-marked differences are found to exist.
[After Jones, 1976]