REPORT ON THE AMPHIPODA. 939 



about throe times as long as the wrist, broad at the base, narrowing almost to a point at 

 the hinge of the finger, the front margin smoothly convex, with short setae at the apex, 

 the hind margin gently sinuous, without any definite palm ; the long, slender, slightly 

 curved linger, about half the length of the hand, closes over the concave part of the 

 hand's hinder margin, so as to leave a narrow cavity ; its tip touches the margin between 

 two pairs of setae; between the lower of these two pairs and the hinge there are on 

 the margin six setules and another pair of setae. 



Second Gnathopods. — Side-plates oblong, with the corners rounded, longer than 

 the preceding pair, but not so broad below. The limb a rather elongated replica of 

 that of the first gnathopods. 



First Pcrxopods. — Side-plates in general like the preceding pair, but longer, the 

 hind margin very straight, its lower corner scarcely rounded. Branchial vesicles small 

 and narrow. Marsupial plates elongate, considerably exceeding the length of the first 

 joint, narrow above, a little expanded below. First joint reaching a little beyond the 

 side-plate, fringed along the front margin with many setae, on the hind margin carrying 

 a croup of very long setae at the centre, two groups of short ones below it, and spines 

 at the apex ; second joint short, a spine at the hinder apex; third joint longer than the 

 fifth, much longer than the fourth, a little decurrent in front, with an apical spine, the 

 hind margin having three groups of setae ; the fourth joint has a small apical spine 

 in front, and at six points of the hind margin setas, more or less plumose, of greater 

 length successively towards the apex ; the fifth joint narrowing a little distally, with 

 spines at four points of the nearly straight hind margin, the front margin a little 

 convex, with setules at the apex ; the finger slightly curved, more than half the 

 length of the fifth joint, the margins smooth, except for a very small dorsal cdium near 

 the hinge. 



Second Per&opods. — Side-plates broader than the preceding pair, not very deeply 

 excavate, hind margin below the excavation sloping very slightly forwards. Branchial 

 vesicles like those of preceding pair, but rather larger. The limb not materially 

 different from that of the first pe"raeopods. 



Third Perseopods. — The hind lobe of the side-plates deeper but narrower than the 

 front one. Branchial vesicles not reaching below the hind lobe of the side-plate. 

 Marsupial plates also short and narrow. First joint almost as broad as long, and of 

 nearly ecpial breadth throughout, the hind margin with a few serrations and cilia in the 

 notches, the front margin carrying several setae and spines, a long spine at the apex ; 

 a group of long setae on the inner surface ; second joint short, with an apical spine in 

 front ; third joint longer than the fourth, a little decurrent, with spines at four points 

 in front, at three behind ; fourth joint with spines at three points in front and at the 

 apex behind ; the fifth joint subequal in length to the third, with spines at five points 

 in front ; one group of setules at the apex of the hind margin, and another a little 



