6J} CRUSTACEA MALACOSTRACA III. 



good deal longer than broad; the median lamella tapers moderately from somewhat from the base to 

 a little from the end, and reaches beyond the end of the lateral, moderately broad plates. — Uropods 

 only a little longer than in the female, scarcely half as long as the breadth of the abdomen. 

 Length of the male, judging from the parts preserved, 3-6 mm. 



Remarks. H. dentatus is instantly distinguished by the well developed, oblique, lateral pro- 

 cesses on the abdomen from the six species seen by me, viz. H. spinescens Rich., H. granulatus Rich., 

 H. Greeni Tatt. and the three species established later on, which have no vestige of these processes. 

 It agrees with H. Greeni and differs from H. Schmidtii and H.frigidus in having a terminal and a 

 proximal pair of processes on the third joint of the antennae; it agrees with H. spinescens in having 

 the terminal process on third joint of the antennae, but differs in having, besides, the proximal process 

 on that joint. It is somewhat allied to H. Thomsoni Bedd., but in this species the end of abdomen is 

 bifurcate. 



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



South-West of Iceland: Stat. 78: Lat. 6o°37' N., Long. 27°52' W., 799 fath., temp. 4-5°; 4 muti- 

 lated spec. 



42. Heteromesus longiremis n. sp. 



(PI. VI, figs. 2 a— 2 f). 



Female. Only a very mutilated specimen, without head and first thoracic segment, is to hand. 

 — Body finely granulated. Second segment (fig. 2 a) with a minute lateral tubercle and some tiny 

 dorsal protuberances in a transverse row; third segment with similar protuberances but without lateral 

 tubercles. Fifth segment somewhat long, four times as long as broad across its narrowest part, and 

 conspicuously longer than the posterior part of the body; consequently the end of second joint of 

 fourth pair of legs reaches, when directed backwards, scarcely to the end of the corresponding joint 

 of fifth pair, when stretched forwards. — Thoracic legs somewhat long and slender, without sharp 

 granules on second joint, but with the usual short spines on fifth and sixth joints. 



Abdomen (figs. 2 a and 2 b) about oue-third as long again as broad; the part between the uropods 

 moderately produced, with the hind margin forming a portion of a circle. — Operculum (fig. 2 c) about 

 as long as broad, with the posterior margin transverse, very long and slightly convex, excepting at the 

 rounded lateral angles. -- Uropods somewhat long, not fully half as long as the abdomen, straight, acute. 



Length of the preserved part of the body 3-5 mm. 



Male. The single specimen is without head and the four anterior segments. — Fifth thoracic 

 segment (fig. 2 d) long, slightly more than six times as long as broad at the middle, and almost half as 

 long again as the posterior part of the body. — Abdomen, as usual, broader than in the female, only some- 

 what longer than broad (fig. 2 e) ; the produced posterior part with the hind margin forming a portion 

 of a circle; the dorsal longitudinal median area, as usual, narrower than in the female, nearly as 

 broad as one of the lateral areas. — Operculum (fig. 2 f) distinctly broader than long, the median 

 lamella with the proximal part broader, the distal part narrower than in H. dentatus, and scarcely 

 reaching the end of the somewhat broad lateral plates; the distance between the operculum and the 



