I02 CRUSTACEA MALACOvSTRACA. III. 



63. Nannoniscus minutus n. sp. 



(PL IX, figs. 7 a- 7 h). 



Female. Body (fig. 7 a) about four times as long as broad ; first segment slightly broader 

 than the second and half as broad again as seventh segment, which is at least as broad as the front 

 end of fifth segment; the major part of the lateral margins of fourth segment converge moderately 

 backwards. 



Head (fig. 7 b) about three times as broad as the distance between the anterior ends of the 

 cephalic keels, and the anterior margin of the front area a little convex. Antennulse (fig. 7 c) with 

 first and second joints nearly as in N.plebcjus; fourth joint with the process long, reaching conspicu- 

 ously beyond the middle of the pyriform vesicle, which is about half as long again as broad. An- 

 tennae in a female with young in the marsupium reaching about the anterior angle of third thoracic 

 segment; the two distal peduncular joints proportionately short and moderately thick; flagellum much 

 longer than sixth peduncular joint, 8-jointed, but its first joint is nearly as long as the three following 

 joints combined, and somewhat thickened; squama small, triangular, acute. 



First thoracic segment (fig. 7b) with an uncommonly long and moderately strong spine on 

 each antero-lateral angle; second segment with minute spines, and third segment with short, stiff setae 

 on the angles. Median ventral part of seventh segment vaulted and produced into a strong, long, 

 very curved, acute, almost hook-shaped process (figs. 7g and 7111. First pair of legs (fig. 7 d) some- 

 what robust, while the other pairs (fig. 7 e) are slender; fifth joint of first pair with a feeble spine at 

 the middle of its lower margin, and a more developed spine at the end ; the accessory claw somewhat 

 slender on all pairs; the three posterior pairs without natatory setae. 



Abdomen (figs. 7 f , 7 g and 7 h) somewhat longer than broad; the second third parts of the 

 lateral margins converge a little to a point outside and slightly before the base of the uropods, where 

 each margin suddenly is incised, forming a very conspicuous, sharp angle or even a low, triangular 

 tooth; the posterior margin, which is moderately broadly rounded at the end, runs to the bottom of 

 each incision. - Operculum (figs. 7 g and 7 h) a little longer than broad, posteriorly very broadly 

 rounded, with the proximal half moderately vaulted and without any tubercle or process. - Uropods 

 somewhat slender; endopod not quite twice as long as the exopod. 



Length of a female with young in the marsupium 1-5 mm. 



Remarks. N. minutus is a small species easily separated from all northern forms by the 

 incisions in the margin of the abdomen. In this respect it agrees with the antarctic form N. bidens 

 Vanh., which has been insufficiently described and figured, but so much can be seen, that this species 

 is much larger than N. minutus, and its antennae proportionately much longer than in our form. 



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



Davis Strait: Stat 25: Lat 633o' N., Long. 5425' W., 582 fath., temp. 3-3; 3 spec. (?). 



64. Nannoniscus armatus n. sp. 



(PI. X, figs, i a i f|. 



Young Female (last pair of legs only half developed). -- Body (fig. i a) somewhat less than 

 four times as long as broad, with the anterior half and especially first and second thoracic segments 



