CRUSTACEA MALACOSTRACA. III. 



97 



least in my single specimen it is directed nearly horizontally backwards. — Uropods with the exopod 

 distinctly more than half as long as the endopod; that the rami are uncommonly robust may probably, 

 at least to some degree, be due to the young stage of the animal. 



Length of the young specimen 14 mm. 



Remarks. The extreme breadth of the head and two anterior segments as compared with the 

 posterior segments renders it impossible to refer this specimen to any of the other species of this 

 section (viz. forms with a ventral process on the female operculum), even if we suppose that a part 

 of the difference may be due to age. Furthermore it differs materially in the shape of the operculum. 



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



North of Iceland: Stat. 126: Lat. 6j°ig' N., Long. i5°32' W., 293 fath., temp. -=-0-5°; 1 spec. 



59. Nannoniscus reticulatus n. sp. 

 (PI. IX, figs. 2 a— 2 1). 



Female (without marsupium). The body has the upper surface nearly everywhere adorned 

 with a most conspicuous reticulated network (fig. 2 c); it is from somewhat less to somewhat more 

 than three and a half times as long as broad, and the two anterior thoracic segments are somewhat, 

 though not much, broader than the sixth or the seventh segment. 



Head (fig. 2 c) about four times as broad as the distance between the anterior ends of the 

 cephalic keels, and the anterior margin of the front area is rather deeply concave. — The antennulse 

 (fig. 2 d) differ from those in N. oblongits in having second joint somewhat thicker, and the process 

 from fourth joint shorter, scarcely reaching the middle of the pyriform vesicle. — Antenna; lost, except- 

 ing the proximal joints; squama oblong-triangular, much shorter than the diameter of third joint. 



Second thoracic segment (fig. 2 c) with the lateral parts produced considerably forwards, the 

 end cut off and armed with a proportionately long spine, while first and third segments have their 

 lateral parts much less produced, and on their angles at most short setse. Median ventral part of the 

 three posterior segments very characteristic, especially when seen from the side (fig. 2i); fifth segment 

 raised in a thick, high, distally rounded protuberance; seventh segment vaulted as a very high pro- 

 tuberance having a kind of incision in the posterior half, which is lower than the anterior half, and 

 the latter is cut off and angular, with its posterior angle even sometimes produced a little backwards; 

 the protuberance of sixth segment is somewhat lower than that of the seventh, subcorneal, with the 

 end obtuse. — Legs normal; first pair (fig. 2 e) distinctly thicker than the following pairs, with two 

 well developed spines on fifth and on sixth joints, and the accessory claw slender; the six other pairs 

 have only some few spines, and the three posterior pairs no natatory setse. 



Abdomen (figs. 2 h and 2 i) as long as, or a little shorter than broad, posteriori}- feebly or 

 scarcely produced, with the margins outside the uropods straight or slightly convex, and the posterior 

 end rounded. — Operculum slightly longer than broad (fig. 2 h), posteriorly at the middle feebly, but 

 distinctly, produced in a broad angle; its proximal part, seen from the side (fig. 2 i| much vaulted and 

 produced in a process of a very moderate size, curved horizontally backwards, acute. — Uropods normal; 

 exopod distinctly more than half as long as the endopod. 



The Ingolf-Expedition. III. ;. 13 



