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



sizes ; the hind margin, with two small tufts, extends but a short distance before forming 

 a slightly recessed angle which marks the beginning of the long convex palm ; in the 

 recess is planted a group of spines, one of which is much longer than the rest, while 

 recessed in the inner surface of the hand is a second neighbouring group of spines, seven 

 in number, seemingly all of different lengths ; the palm margin carries four spines distri- 

 buted along the earlier part of its course, cilia of different lengths fringing it right up to 

 the finger-joint ; there are also some setae projecting from the surface of the hand ; the 

 finger is slender, curved, and of great length in correspondence with the palm ; it has 

 some minute hairs on the inner margin. 



Second Gnathopods. — Side-plates moderately broad in comparison with their length, 

 not so broad as those of the preceding segment, with two or three spines on the straight 

 hind margin, which is nearly parallel to the front one, lower margin convex. Branchial 

 vesicles as long, but not so broad, as the side-plates. The limb strikingly resembles 

 that of the first gnathopods, the joints being rather longer, and the hand a little more 

 tapering, with the long palmar spine and the four marginal spines somewhat more 

 pronounced. 



First Perwopods. — Side-plates rather narrower than those of the preceding segment. 

 Branchial vesicles small, oval. The whole limb very narrow and elongated ; the first 

 joint reaching much beyond the side-plate, with eight or nine rows of setae near 

 the convex front margin, the slightly concave hind margin fringed with setae, more or 

 less plumose, of different lengths, some of them very long ; the second joint as usual 

 short ; the third shorter than the first, but very long, curved, and little produced below, 

 with four very long thin setae and some setules on the convex front margin, and a variety 

 fringing the concave hinder margin ; the fourth joint is shorter than the fifth, the 

 fifth a little shorter than the third, but both are long and slender, nearly straight, with 

 thin setae and setules at various points ; the finger is slender, very slightly curved, as 

 long as the fifth joint, or a little longer, with a small dorsal cilium near the base, and at 

 a short distance from the apex a row of three or four dorsal setae, the tip forming a very 

 thin nail with a cilium at its base. The finger in each of the peraeopods of this species 

 bears a similarity to the finger of the fifth peraeopods in the (Ediceridae. 



Secoibd PersBopods. — The side-plates not much longer than their greatest breadth, 

 which is above the centre, the hind margin below the excavation running very obliquely 

 forwards, with some slight serrations. The branchial vesicles not as long as the side- 

 plates. The limb closely resembles the first peraeopods. 



Third Peraeopods. — Side-plates small, bilobed, broader than the first joint of the 

 limb, which is oval, but with the hind margin straightened, edged with spinules, the 

 front margin carrying a couple of setules at the top, and small spines round the rest 

 of its course ; the second joint short, overlapped behind by the first ; the third joint 

 shorter than the first, a little longer than the fourth, narrowest at the base, and broadest 



