CKISTACEA MALACOSTRACA. III. 



99 



similar spine is found on each angle of third segment, while no spine or seta exists on the angles of 

 first segment. Median ventral part of the posterior segments (fig. 4 f) considerably vaulted, but without 

 any protuberance or process. - - Legs of first pair (fig. 4 c) very considerably thicker and shorter than 

 second pair (fig. 4d); especially fifth joint is thickened with six strong spines, the third and the fourth 

 long; sixth joint somewhat thick with two spines of moderate size; accessory claw slender. Second 

 (fig. 4d) to fourth pairs are slender; fifth joint with six or seven spines; sixth joint with about four 

 spines; seventh joint with claw slender, and the accessory claw very small. The three posterior pairs 

 (fig. 4 e) with some spines 011 fifth joint; seventh joint with claw very slender, and the accessory claw 

 very short and thin; furthermore the fifth joint has along the half of the upper margin about seven 

 very long seta:, and above on the sixth joint a row of extremely long natatory setae. 



Abdomen (fig. 4 f) nearly as long as broad; the lateral margins converge feebly from before the 

 middle to the posterior margin, which consequently is long; each half of this margin is scarcely or 

 feebly concave, as the median part of abdomen is posteriorly slightly produced backwards with the 

 terminal margin somewhat convex. — Operculum about as broad as long, without any ventral process 

 or protuberance; the posterior margin is straight. — Uropods with the rami slender and somewhat 

 long; the endopod almost twice as long as the exopod. 



Length of a large female with marsupium 3-3 mm. 



Remarks. N.inermis, which is the largest species known, is in general aspect, excepting as 

 to the posterior part of abdomen, somewhat similar to N. analis, but it is easily separated from this 

 species by the shape of the posterior part of abdomen, and by having no process on the operculum. 

 Besides, it is distinguished from all species of the genus by the elongate vesicle of the antennulae, by 

 the spines on first pair of legs, and finally by the fact that the female has natatory setae on fifth and 

 sixth joints of the three posterior pairs of legs, a feature otherwise only found in males. 



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°; 3 spec. (?). 



61. Nannoniscus aequiremis n. sp. 



(PI. IX, figs. 5 a- 5 h). 



Female. Body about three and a half times as long as broad; second, third and fourth seg- 

 ments are rather a little broader than the posterior segments, consequently the animal is a little more 

 slender than N. oblongus, but otherwise similar in aspect. 



Head (fig. 5 a) nearly more than eight times as broad as the distance between the anterior ends 



of the cephalic keels, and the anterior margin of the front area is considerably concave. — Antennulae 



(fig. 5b) somewhat thick; first joint somewhat longer than broad; second joint scarcely longer than 



the first, with the distal part rather thick, the process at the outer side somewhat large, nearly longer 



than thick and somewhat longer than the inner process; third joint scarcely discernible; fourth joint 



thick, with the process short and thick, reaching about to middle of the vesicle, which is pyriform 



and only a little longer than broad. — Antennal squama somewhat small, triangular, slightly longer 



than broad, acute. 



13* 



