REPORT ON THE AMPHIPODA. 869 



First Pers;opods. — Side-plates similar to the preceding pair. Branchial vesicles 

 expanding from a narrow neck so as to be widest distally, as long as the first joint, and 

 almost as wide as long. First joint extending a little below the side-plate, second joint 

 very short, third longer than fourth or fifth, with some setae on the hind margin and apex 

 of front ; fourth a little longer and much broader than fifth, with setae on both margins ; 

 fifth not broad and not tapering, with setae on both margins, those on the straight hind 

 margin short ; the finger very short, with short cilia near the hinge and near the nail ; 

 the nail with a pointed projecting cap. 



Second Perseopods. — Side-plates not much longer but very much broader than the 

 preceding pair, the excavation behind descending a very small distance. The first joint 

 not reaching the end of the side-plate, the limb in other respects scarcely diff"ering from 

 the preceding pair. 



Third PersBopods. — Side-plates broad but not deep, the hind lobe less broad than the 

 front, of about the same depth, crenulate and ciliated round the lower part of its hind 

 margin. The first joint large, oblong, oval, rather broader below than above, with small 

 setae in the crenulation of the hind rim, and longer setae on the front margin ; second 

 joint very small ; third of great size, nearly as long as the first joint, much broader than 

 the fourth, somewhat decurrent, with setae, some of which are spiniform, along both 

 margins ; the fourth joint longer and much broader than the fifth, with setae on both 

 margins ; the fifth not so long as the straight, slender finger, with setas on both margins, 

 and at the front apex close to the hinge of the finger a group of spines, two short and 

 stout, and a third half the length of the finger, of great strength ; the finger tapering, 

 minutely pectinate in front, the nail spine-like, with a cilium at its base, and sheltered 

 by a long cap, the peak of which projects beyond it. 



Fourth Peneopods. — The hind lobe of the side-plates produced much below the 

 front one. The first joint more rounded than in the preceding pair, rather broader, but 

 rather shorter, especially behind; the other joints similar but longer, the third and 

 fourth also wider, the third more strongly armed with spines. 



Fifth Perwopods. — Side-plates small, not bilobed. Branchial vesicles small, ovate, 

 a little larger than the side-plates. First joint broader and behind much longer than 

 that of the preceding pair ; the third joint large, broad, and strongly spined ; fourth joint 

 longer than in the preceding pairs, with spines as well as setae on the front margin ; the 

 fifth joint equal in length to the finger, the dorsal cilium of which in this, as in the two 

 preceding pairs, is very small. 



Pleopods. — Groups of setae on the peduncles, two hooked spines both apically sharp, 

 one with three, the other with two retroverted teeth, the opposite margins with backward 

 serrature ; the rami with fourteen joints to the inner, sixteen to the outer ; the first joint 

 of the inner with three cleft spines at the upper part, some plumose setae below, and 

 groups of setae on the opposite margin. 



