CRUSTACEA MALACOSTRACA. IV. 19 



feebly oblique, with 6 or 7 teeth. Antero-lateral corner of the carapace much produced, so that the antennal 

 notch is deep and the terminal tooth on the corner long and strong ; the lower margin of the notch with a couple 

 of minute teeth. The lower margin of the carapace in my adult female with about 10 teeth. The abdomen is 

 moderately slender, about as long as cephalothorax without pseudorostrum. 



The antennula? are very short (figs. 6 a — 6 b), in horizontal position their end is vertically below the 

 apex of pseudorostrum; second joint of their peduncle is very thick and distinctly longer than third joint, 

 which is rather robust and a little longer than the outer flageUum; the inner flagellum is short. Third maxilli- 

 peds (fig. 6c) with a row of small teeth on somewhat less than the proximal half of lower side of second joint; 

 fourth joint, the merus, seen from below with 3 strong, acute teeth at the terminal margin, and one large, 

 acute tooth distally on the outer margin ; carpus with two slender teeth on the outer margin and one tooth 

 on the lower side at the end. First pair of legs cannot be fully described, because only a single leg was moder- 

 ately preserved, while the other five legs in the 3 specimens had lost their distal half; in an immature male 

 the second joint has a longitudinal row of 6 very strong, oblong teeth on the distal part of the lower side, 

 while in the adult female (fig. 6d) only 3 real and rather feeble teeth are found; in the last-named specimen 

 the distal half of the leg was uncommonly slender and its dactylus as long as the propodus, but somewhat 

 shorter than the carpus. Second pair of legs with the dactylus as long as the carpus. -- The uropods (fig. 6e) 

 have the peduncle slightly shorter than the exopod, with about 4 spines along the inner margin; the exopod 

 has 3 shorter setae on the proximal part of the outer margin of second joint, while the end and the distal part 

 of the inner margin possess the usual long setae; the endopod is much shorter than the exopod; its first 

 joint, which is nearly half as long again as the second, has 5 or 6 spines at the inner margin and one long 

 spine at its end; second joint with 4 spines on the inner margin and 2 terminal spines, the outer as long as, 

 or somewhat shorter than, the joint. 



Length of an ovigerous female 4.9 mm. 



Remarks. Norman established his L. serratus on a single female specimen measuring 6 mm. 111 

 length, thus somewhat larger than the single adult female examined by me. His description was published 

 as early as in 1879, without figures, and though seemingly good has its defects. Thus the relative dimensions 

 of the carapace stated by him had scarcely been measured with a micrometer and are therefore not accurate, 

 as I do not think the depth of the carapace is "subequal" to its length in any species of Leucon. Furthermore 

 his expression on the carapace: "antero-lateral corner produced forwards and outwards in wing-like form" 

 is certainly somewhat unfortunate. In order to remove these and other difficulties as to the determination 

 of my specimens I wrote to my able and always very helpful friend Dr. W. T. Caiman, asking him to examine 

 Norman's type preserved in the British Museum (Natural History) as to certain points, and I enclosed calk- 

 ings of my figures for comparison. He answered the questions and added sketches of the carapace, of first leg 

 and of an uropod. He says that "the antero-lateral angle of the carapace is not conspicuously everted", and 

 "there is no tootli on the side of the frontal lobe", an important character. His sketch of the carapace shows 

 that the dorsal edge of the type is somewhat more convex towards the middle, so that the carapace is distinctly 

 shorter in proportion to length than in my adult female, though without pseudorostrum decidedly more than 

 one-fourth as long again as deep ; furthermore he figures only 4 teeth on the lower margin of the carapace. 



