Carapace of female very large and tumid, almost globose in form, and perfectly smooth, with the upper margin boldly vaulted, pseudo-rostral projection distinct, though rather short, sub-rostral incisions well marked; that in adult male much less deep and more evenly vaulted above, pseudo-rostral projection less prominent, antero-lateral corners blunted. First pedigerous segment not visible at all; second segment well developed; the three succeeding ones narrowing abruptly. Tail exceedingly slender and elongate, much longer than the anterior division, all the segments contracted in their anterior part; last segment nearly as long as the preceding one, gradually widening distally, and considerably produced behind.
Eye wholly absent.
Superior antennae with the sensory filaments of the outer flagellum extremely elongate; those in male with an additional bundle of such filaments at the base of the flagellum. Palp of anterior maxillae with a single apical seta. Second pair of maxillipeds with the basal joint unusually large, lamellar, and coarsely denticulated in the distal part of the outer edge. Third pair of maxillipeds with the basal joint strongly developed being more than twice as long as the succeeding joints combined, and angularly bent in tile middle; terminal expansion very large, reaching beyond the meral joint. First pair of legs exceeding the carapace in length, basal joint large and lamellarly expanded in the middle, terminal part very slender, with the propodal joint the longest; second pair longer than the succeeding pairs, and terminating in four diverging spines.
Uropods in female scarcely longer than the last segment, basal part very short and perfectly smooth, rami twice the length of the former and sub-equal, both terminating in a sharp point, the inner one without spines or setae; those in adult male considerably more slender, basal part much longer than in female, and carrying inside seven ciliated bristles, inner ramus armed inside with a dense row of small, ciliated spinules.
Telson long, postanal part narrowed, with several pairs of lateral spines.
Length of female reaching to 8 mm of male 7 mm.
It is a true deep-water form, only found in depths of more 200 m.
Down from 200 to 2750 m.
Distribution in the North Sea
Spanish coast and in the North Atlantic.
N. Atlantic, Mediterranean, Azores.
[After Sars, 1900]