994 THE VOYAGE OF H.M.S. CHALLENGER. 



along the hind margin ; the third joint not elongate, distally rather cup-like, the upper 

 part of the hind margin unarmed, the lower part fringed with long pectinate spines ; the 

 wrist not quite so long as the first joint, much longer and thicker than the hand, the 

 front maro-in smooth, rather irregularly convex, the hind margin nearly straight, fringed 

 with numerous spines, many of them very long ; the hand more than half the length 

 of the wrist, the front margin convex, smooth, the hinder slightly concave, densely 

 fringed with spines which are finely pectinate on two edges ; the finger much curved, a 

 little shorter than the hand, of which it continues the front curvature, close to the 

 smooth inner edge carrying a row of some sixteen submarginal spines, and a couple of 

 cilia, one at, the other near, the base of the nail. The finger is not adapted for impinging 

 against any part of the hand, but evidently hand and finger co-operate to enable the nail 

 to reach the wrist. 



Second Gnathopods. — The side-plates closely resembling the preceding pair. The 

 branchial vesicles longer than the first joint, somewhat lageniform. The marsupial 

 plates longer than the branchial vesicles, not narrow, fringed on both margins with long 

 setae. The limb closely resembling that of the first gnathopods ; the second joint with a 

 large group of spines on the hinder apex ; the wrist much longer than in the preceding 

 pair, widest just below the third joint, then narrowing towards the hand, the upper part 

 of its hind margin more densely fringed than the lower. 



First Perseopods. — Side-plates, branchial vesicles, and marsupial plates as in the 

 preceding pair. The first joint reaching far below the side-plate, widening distally, the 

 front margin serrate below and apically rounded, both margins fringed with very many 

 spines ; the second joint short, with long spines on the hind margin and its apex ; the 

 third joint triangular, twice as long as broad, the apex of the front margin having a 

 group of spines, the hind margin serrate, fringed with long pectinate spines ; the fourth 

 joint longer than the third or fifth, a very narrow oval, attached to the front of the 

 oblique distal margin of the third joint, its front margin smooth, the hinder fringed with 

 long and short pectinate spines, the short continuing quite to the apex ; the fifth joint 

 long, almost linear, with spines at six points of the slightly convex front margin, the 

 hind margin fringed with many pectinate, spines ; the finger short, less than half the 

 length of the fifth joint, with a very small dorsal cilium near the base, the inner margin 

 almost straight, with a very fine decurrent tooth on the inner margin at the base of the 

 nail. 



Second Perseopods. — Scarcely differing from the preceding pair, even in the size of 

 the side-plates. 



Third Pereeopods. — Side-plates broader than the preceding pair, almost as deep in 

 front, much shallower behind, with a sinuous lower margin, but scarcely to be called 

 bilobed. The branchial vesicles and marsupial plates rather shorter than in the two 

 preceding pairs. The first joint of the limb nearly three times as long as broad, with 



