Body rather slender, especially in the male, with the tail unusually narrow and scarcely as long as the anterior division.
Carapace in female about the length of the exposed part of the trunk, dorsal crest well developed, extending beyond the middle, and reappearing for a short distance in the hindmost part; pseudorostral projection not much produced, almost horizontal, and obtuse at the tip, terminal edges cut off into o denticles; anterolateral corners somewhat produced.
Carapace of male quite smooth, with only a single small denticle at the end of the frontal lobe; pseudorostral projection obtusely rounded at the tip, with the terminal edges smooth; antero-lateral corners blunted. First pair of legs rather feeble, with several plumose setae outside the terminal part, penultimate joint nearly as long as the antepenultimate; second pair with the last joint about the length of the two preceding joints combined, and linear in form, with about eight unequal spines. Third pair in male with two comparatively short, falciformly curved appendages of the ischial joint.
Uropods rather slender, with the rami much narrower than in the two preceding species, the inner one with the distal joint scarcely shorter than the proximal one, and armed with five or six spines, the outermost very much elongated; outer ramus with scattered setae.
This form, in the fresh state, is at once recognised by its beautiful bright orange or fulvous colour, a character which has indeed given rise to the specific name. The species is also otherwise easily distinguishable from the two preceding ones, both as regards the general form and the structure of some of its appendages, especially that of the uropods.
Length of adult female scarcely 5 mm, of male 5.5 mm.
Bright fulvous, somewhat lighter in male.
Shelf to bathyal.
Down from 10 to 20 m.
Distribution in the North Sea
This northern species may reach the northern North Sea.
North Atlantic and Arctic Oceans.
[After Sars, 1900]