REPORT ON THE AMPHIPODA. 1017 



Third Persaopods. — The front lobe of the side-plates produced below the hinder part, 

 of which the lower margin is almost straight, The branchial vesicles like the preceding. 

 The first joint long, with the hind margin strongly serrate, nearly straight, the front a 

 little convex, with spines, the apical one long ; the second joint short, almost completely 

 overlapped by the rounded lower hind margin of the first joint ; the third joint longer 

 and much broader than the fourth or fifth, most expanded just below the narrow base, 

 with spinules on the slightly convex front margin, five spines on the hind margin, below 

 the fifth forming a short triangular decurrent apex ; the fourth joint with the upper part 

 broader than the lower, spines at five points of the front margin, one group about the 

 middle of the hind margin and another at its apex including a long spine ; the fifth joint 

 slender, as long as the fourth, a little widened distally, with a single spine arid four 

 groups of spines on the front margin, and a group of long ones at the apex behind ; the 

 finger as in the preceding pair ; the dorsal cilium near the base. 



Fourth Perteopods missing. 



Fifth Perseopods. — Side-plates with the front margin ciliated, deeper behind than in 

 front. The first joint broader but not longer than that of the third perseopods, broader 

 above than below ; the third joint a little longer than in the third pair, of more even 

 breadth, with spines at four points on each margin, the triangular apex behind having 

 two little cilia; the fourth joint subequal in length to the third, but shorter than the 

 fifth, with three groups of spines, besides sjnnules, on the front margin, and two groups 

 behind ; the fifth joint with spines at six points in front, and some spinules behind ; the 

 finger similar in shape to that of the third perseopods, but larger. 



Pleopods. — Coupling spines very slender except at the base, with one large lateral 

 tooth, and seven denticles including the apex ; there is a simple spine beside the two 

 with hooks ; the cleft spines from three to four, placed far down the joint ; the joints of 

 the rami eighteen in number, the peduncles long, apparently grooved, with an apical 

 process on the outer side, folded to assist in coupling the two rami ; on the third pair 

 one of the edges of the peduncles proved to be serrate below and spined. 



Uropods. — Peduncles of the first pair longer than the rami, with spines on the 

 margins, and a larger one on the produced outer apex, the outer ramus rather shorter 

 and less broad than the inner, both with few marginal spines, and each with a group 

 inserted in the apical cavity ; peduncles of the second pair about as long as the outer 

 ramus, this being a little shorter than the broad inner one, which has several marginal 

 spines ; each ramus with an apical group ; the edge of the inner ramus in this and the 

 preceding pair is finely pectinate, possibly also that of the outer ramus ; peduncles of the 

 third pair much shorter than the rami, which are moderately broad, lanceolate, subequal in 

 length, with serrate margins carrying spines, and tipped with spines, the length of these 

 rami equalling that of the inner ramus of the first pair, and reaching back a little 

 beyond it. 



(zool. CHALL. EXP. — part lxvit. — 18S7.) Xxx 128 



