6 CRUSTACEA MALACOSTRACA. III. 



part extremely thickened, oblong-oval and as long as the four following slender joints combined (the 



end of flagellum lost). 



Thoracic segments, excepting as to the breadth mentioned, nearly as in the female; the ventral 

 posterior protuberances scarcely as high as in that sex. - The three posterior pairs of legs (fig. i a) 

 with about four long seta on the upper margin of fifth joint, and a good number of very or extremely 



long setae on sixth joint. 



Abdomen posteriorly nearly as produced as in the female, but rather gradually (fig. 6 h), so 

 that the distal third of the lateral margins is flatly and feebly concave, while the end is more narrowly 

 rounded than in the female. — Operculum conspicuously longer than broad; the median lamella a 

 little widened near the end, with the distal outer angle a little produced, triangular, while most of 

 the terminal part of the lamella constitutes a kind of rounded lobe, divided of course in the median 

 line. — Uropods about as in the female, excepting that their peduncles are a little longer. 



Length 2 - i mm. 



Remarks. The female is instantly separated from all other species by the shape of the post- 

 erior part of abdomen, while the male may be distinguished by some features taken together: the 

 breadth of the frontal emarginatiou, the somewhat short antenual squama, the shape of the abdomen 

 and of the median lamella of the operculum. 



Occurrence. Taken by the "Ingolf" at a single deep station in the warm area. 



Davis Strait: Stat. 24: Lat. 63°o6' N., Long. 56°oo' W., 1199 fath., temp. 2-4°; numerous spec. 



(16 J 1 and at least 50?). 



58. Nannoniscus laticeps u. sp. 



(PL IX, figs. 3 a- 3 d|. 



Young Female (with seventh pair of legs not fully developed). -- Body (fig. 3 a) about three 

 and a half times as long as broad. Head and the two anterior segments about two-thirds as broad 

 again as sixth segment and abdomen; third segment not much narrower than the second, and some- 

 what broader than the fourth, which has its lateral margins converging extremely backwards. 



Head (fig. 3 b) fives times as broad as the distance between the anterior ends of the cephalic 

 keels, and the anterior margin of the front area slightly concave. — Anteunulse (fig. 3 c) with first 

 joint a little longer than broad; second joint distinctly longer than the first, somewhat thick, with the 

 terminal protuberances rather short; the process from fourth joint reaches conspicuously beyond the 

 middle of the uncommonly small, oblong vesicle. — Antennal squama marked off, short, much shorter 

 than the diameter of third peduncular joint. 



Antero-lateral angles of second segment terminate in distinct spines (fig. 3 b), while the angles 

 of first and third segments terminate in fine setse. The posterior median part of the ventral side 

 considerably vaulted. 



Abdomen (figs. 3 a and 3 d) conspicuously longer than broad, posteriori}' very broadly rounded, 

 and the lateral margins nearly parallel. - - Operculum somewhat longer than broad, with the posterior 

 margin considerably convex and, besides, almost angular, as a small median part is feebly produced; 

 a spiniform, moderately small process projects on the ventral surface somewhat near the base, and at 



