8o CRUSTACEA MALACOSTRACA. II. 



The two anterior abdominal segments with the ventral tubercles wanting or rudimentary; 

 third and fourth segments with the tubercles either rudimentary or rather low and triangular; fifth 

 segment (fig. yh) with the tubercle high and posteriorly produced into a very long, acute process pro- 

 jecting horizontally backwards and reaching the middle of sixth segment; in a single specimen (from 

 Stat. 102) the tubercle of fifth segment is rudimentary with the process very short, being undeveloped 

 from one reason or another. Pleopods with the setae almost twice as long as the rami. - Uropods 

 as in the majority of the preceding species, not fully as long as the two posterior segments combined; 

 peduncle somewhat less than twice as long as deep; proximal joint of the endopod not quite as long 

 as the peduncle and about as long as or a little longer than the distal joint (fig. 7g); exopod scarcely- 

 half as long as first joint of the endopod. 



Length of the females without marsupium 2.5 2.8 mm . 



Remarks. The differences between L. hastata and the two following species are pointed out 

 in the "Remarks" on these species. 



Occurrence. L. hastata has been taken by the "Ingolf" at two deep-sea stations in the 

 cold area. 



East of Iceland: St. 102: Lat 66 23' N., Long. 10 26' W., 750 fm., temp. -4- 0.9; 2 spec. 



North of Iceland: 81125: Lat. 68 08' N., Long. i6O2' W., 729 fm., temp, -f- 0.8; i spec. 



50. Leptognathia armata n. sp. 

 (PI. VIII, figs, i a if.) 



Female (without marsupium) and subadult Male. This species is so closely allied to L, 

 hastata that it is nearly sufficient to point out the differences. -- The antennulae of the female almost 

 as in L. hastata. The antennulae of the subadult male (fig. la) five-jointed, very thick; first joint a 

 little shorter than the other joints combined, a little more than twice as long as deep, at the end 

 somewhat less deep than somewhat beyond the base; second joint a little more than half as long as 

 the first, somewhat more than half as long again as deep and considerably produced above; third joint 

 short and thick; fourth and fifth joints combined somewhat shorter than the upper margin of the 

 second, and fourth joint considerably deeper than long. 



The chelipeds have the carpus two-thirds as long again as deep and its distal part is very 

 moderately expanded downwards with the corresponding lower margin somewhat convex (fig. ib) 

 thus the carpus is conspicuously longer in proportion to depth and less expanded downwards than in 

 L. hastata. The chela is slightly shorter than the carpus and a little more than twice as long as 

 broad, otherwise as in L. hastata. 



Second and third pairs of legs (figs, i c and i d) nearly as in L. hastata, but the denticles on 

 the posterior margin of sixth joint are very distinct, in the female specimen (fig. i d) besides developed 

 on fifth joint. Three posterior pairs (fig. i c) with the setiform denticles on seventh joint scarcely as 

 long as in L. hastata. 



Four anterior abdominal segments (fig. i f) with the ventral tubercles strongly chitinized, rather 

 large and varying in shape, either subconical or a little obliquely and somewhat broadly truncate. 



