REPORT ON THE AMPHIPODA. 911 



pectinate, more coarsely near the middle, at which part it is easily seen that the pectina- 

 tion is on two edges ; the inner margin of the finger is produced into a, tooth at the base 

 of the nail ; the dorsal cilium near the base of the finger is small. 



Second Gnathopods. — Side-plates with the front margin convex, its lower portion 

 senate and spined, its lower angle rounded and crenulate as in the preceding pair. The 

 branchial vesicles oval, broadest below, reaching much beyond the side-plates ; in the 

 specimen examined one of the pair was distally bilobed. Marsupial plates long and rather 

 broad, longer than the branchial vesicles, the edges finely crenate for the long setse. 

 The limb like that of the first gnathopods, but all the joints longer, especially the hand 

 and wrist ; the armature similar, except that the hand is more simply adorned. 



First Perieopods. — Side-plates broad, the front corner and much of the lower margin 

 crenate and spined. The branchial vesicles long and broad. The marsupial plates long, 

 not broad except near the middle. First joint, as in the preceding and the following pair, 

 having its base close to the lower border of the side-plate, long, and nearly evenly broad, 

 with many spines on both margins, those near the base very slender, some very long ones 

 on the hinder margin, also with several submarginal groups on the surface near it ; the 

 short second joint has spines at three points of the hind margin, some of which, as in the 

 preceding joint, are long and plumose. 



Second Pereeopods. — Side-plates very similar to the preceding pair, a little broader, 

 the hind corner a little drawn down, as in the preceding pair with numerous spines on 

 the lower part of front and hind margins, only a small part of the lower margin being 

 without spines or crenulation ; there are also many setae on the inner surface of the 

 plate in this and the three preceding pairs ; the branchial vesicles large. The marsupial 

 plates long and slender. Limbs like those of the first pair but a little shorter ; the third 

 joint longer than the next two united, with six groups of spines at the hind margin, and 

 three on the front ; the fourth joint much shorter than the fifth, like the fourth somewhat 

 dilated distally, with two groups of spines on the hind margin, the front smooth except 

 at the apex ; the fifth joint with four groups of stout spines on the hind margin, the 

 front slightly convex, smooth except at the apex ; the finger strong, curved, longer than 

 the fourth, shorter than the fifth joint, with two setules at the base of the strong curved 

 nail ; a small dorsal cilium near the base of the finger. In the Plate the last four joints 

 are drawn facing the wrong way. 



Third Peneopods. — Side-plates with the front lobe much narrower and deeper than 

 the hind one, of which the lower margin is sinuous ; both have the lower portion set 

 about with spines. First joint pear-shaped, broader above than below, the hind margin 

 fringed with curved spines, the expanded part serrate, the front margin with numerous 

 groups of slender setae or setiform spines, the lower margin squared, neither lobed nor 

 decurrent ; the second joint short ; the third shorter than the first, longer than the fourth, 

 not expanded, sparingly spined ; the fourth longer than the fifth, with spines at three 



