CRUSTACEA MALACOSTRACA. IV. 



second joint, with about 4 spines on the inner margin; second joint has a single long spine and about 5 minute 

 spines on the inner margin, a long and thick spine and an extremely long seta on the end; exopod a little or 

 somewhat shorter than the endopod, with very few setae excepting some at or near the distal end. 



Length of a female with marsupium from Stat. 24 3.8 mm., of an ovigerous female from Stat. 36" 

 4.1 mm. 



Remarks. This species is allied to L. siphonatits Calm., but differs in several particulars. Pseudo- 

 rostrum is considerably longer and scarcely curved ; the dorsal edge and the anterior margin of the carapace 

 have more teeth ; some of the thoracic segments have marginal teeth ; in second thoracic legs the carpus is 

 still more elongated than in L. siphonatits, while in the uropods the endopod is conspicuously longer than the 

 exopod. — The rather mutilated adult female from the cold area differs from the specimens from the warm 

 area only in having 5 instead of 2 or 3 small teeth on the dorsal edge of the carapace behind the interruption. 

 — It may be noted that many of the teeth, f. instance on the lower margin of the carapace, are frequently 

 difficult to count. 



Occurrence. Taken by the "Ingolf" at three deep-sea stations in the warm and one station in 

 the cold area. 



Davis Strait: Stat. 25: Lat. 63°3o' N., Long. 54°25' W., 582 fath., temp. 3. 3 ; 1 small specimen. 

 Stat. 24: Lat. 63°o6' N., Long. 56°oo' W. , 1199 fath., temp. 2.4 ; 5 specimens (1 



adult ?). 

 Stat. 36: Lat. 6i°5o' N., Long. 56°2i' W., 1435 fath., temp. 1.5 ; 2 specimens (1 



adult ?). 

 South of Jan Mayen: Stat. 117: Lat. 6q c i3' N., Long. 8°23' W., 1003 fath., temp. — i.o°; 2 spec- 

 imens (1 adult $). 



B Species with the branchial siphon reaching at most a little beyond pseudorostrum. 



a. Endopod of the uropods longer than, or at least about as long as, the exopod. 



5. Leucon tener n. sp. 

 (PI. I, figs. 2 a — 2c.) 



Female (with marsupium). Carapace oblong, half as long again as deep, and when pseudorostrum 

 is included twice as long as deep, about as long as the free segments combined. The serration on the dorsal 

 edge occupies only about its anterior third, and in this third even a long interruption is found, as two teeth 

 are seen anteriorly, then comes a smooth part and behind it 3 or 4 teeth. Pseudorostrum is considerably 

 upturned, long, nearly - 5 of the whole length of the carapace, with the narrow end obtuse and the upper margin 

 slightly concave, while the lower margin is nearly straight and has two saw-teeth a little before the base 

 of the antennulae. The frontal lobe on each side with two teeth, one towards the dorsal edge, the other a little 

 above the lower margin. The antenna! notch is feebly developed, as the antero-lateral corner of the carapace 

 is slightly produced, terminating in a small tooth, above which two minor teeth are seen; the lower margin 



The Ingolf-Expedition. III. 6. 2 



