REPORT ON THE AMPHIPODA. 1569 



length of the fifth joint, shaped as in the gnathopods, but without setule or interruption 

 of the concave part. 



Second Perzeopods like the first, but with the third, fourth, and fifth joints longer. 



Third PersBopods. — Side-plates with convex front and hind margins and a narrow 

 tongue-like backward-directed process on the inner side. • Branchial vesicles shorter than 

 the first joint and not broader. The first joint slightly channelled behind, about three 

 times as long as broad, fully as long as the three following joints together, its sides 

 nearly straight ; the second joint longer than broad, the third considerably longer than 

 the second, the fourth than the third, and the fifth than the fourth ; the fourth joint 

 straight, very finely pectinate along the front margin ; the fifth much narrower, scarcely 

 curved, still more minutely pectinate ; the finger as in the preceding pairs, but much 

 smaller, about a sixth of the length of the fifth joint. 



Fourth Perseopods.— Branchial vesicles shorter than the preceding pair. The first 

 joint much longer than all the remaining joints together, little shorter, but in the upper 

 part much broader than, the first joint of the third pereeopods, the lower end of the broad 

 oval much narrowed and smoothly rounded ; the second joint very small, scarcely capable 

 of reaching the apex of the first ; the third joint longer than the remaining joints 

 together, its front margin pectinate with retroverted teeth, the apical prolongation 

 narrow, almost acute, not quite reaching the middle of the next joint ; the fourth joint 

 much longer and broader than the fifth, armed like the third except at the narrowed 

 apical portion ; the fifth joint slender, nearly straight, with a setule at the apex of the 

 hind margin, the lower part of which is a little concave ; the finger small and blunt, 

 abruptly narrower than the fifth joint, and about a sixth of its length. 



Fifth Perseopods very feeble, the narrow first joint a little curved, about half the 

 length of the" first joint of the fourth peraeopods, and a fifth or a sixth of its greatest 

 breadth ; the hook-like appendage obscurely divided into four joints of which the second 

 forms the bend, the terminal one having a rounded apex. 



Pleopods. — Peduncles produced downwards at the inner angle ; coupling spines very 

 short, with the usual apical cap ; one arm of the cleft spine having a long narrow dilata- 

 tion, the other arm nearly equal ; inner ramus with five joints, outer with six. 



Uropods. — Peduncles of the first pair longer than the rami, three-edged, the outer 

 margin pectinate below ; the outer ramus longer than the inner, three-edged, the outer 

 margin more strongly pectinate than the inner ; the inner ramus laminar, its margins 

 less strongly pectinate than those of the outer ramus ; peduncles of the second pair 

 rather shorter than the outer ramus ; the outer ramus three-edged, almost smooth on the 

 outer margin,- the inner pectinate; the inner ramus rather shorter than the outer, 

 coalesced with the peduncle, both margins pectinate ; peduncles of the third pair shorter 

 than the outer ramus ; the outer ramus considerably shorter and narrower than the 

 inner, the outer margin smooth, the inner pectinate ; the inner ramus coalesced with the 



(zool. CHALL. EXP. — PART LXVII. — 1888.) Xxx 197 



