REPORT ON THE AMPHIPODA. 1289 



more than half the length of the hand, its hind margin nearly straight, armed with a few 

 small teeth, the front margin convex, the apex acute. 



Second Grnathopods. — The side-plates rather deeper than in the preceding pair. The 

 branchial vesicles oval, narrowed at each end, about as long as the first joint. The first 

 joint longer than in the first gnathopods, but less wide, sinuous, widest distally ; the 

 second joint short, with a distal spine ; the third joint longer than the second, five-sided, 

 with two spines on the apex of the joint, and two others just below the end of the hind 

 margin ; the wrist longer than the hand, being produced behind it in a slightly divergent 

 process, of which the oblicrae distal or inner margin is denticulate with about twenty teeth ; 

 the hand and finger are as in the first gnathopods, but the hand is a little narrower. 



First Peraeopods. — Side-plates much broader than deep, rather deeper behind than in 

 front. Branchial vesicles as long as the first joint, and broader. The first joint a little 

 sinuous, the front margin for the most part concave, and the hinder convex ; the second 

 joint a little longer than broad; the third considerably longer than the fourth, which 

 is narrower than the third but broader than the fifth ; the fifth nearly as long as the 

 third, a little curved, the lower part of the concave hind margin pectinate, the apex also 

 infinitely pectinate ; the finger slender, not strongly curved, acute, not half the length of 

 the fifth joint, its inner margin a little pectinate. 



Second Perseopods very similar to the first, but the third joint more decidedly longer 

 than the fifth. 



Third Peraeopods. — Side-plates with the hinddobe deeper than the front. Branchial 

 vesicles of irregular form. The first joint pretty evenly expanded, at no part widely ; 

 the second joint about as broad as long ; the remaining joints slender ; the third much 

 longer than the fourth, the front apex pectinate ; the front margin of the fourth pectinate, 

 but less strongly than the apical margin ; the fifth joint not shorter than the third, the 

 slightly concave front margin closely pectinate ; the finger nearly straight, not nearly 

 half the length of the fifth joint, with the upper part of its inner or concave margin 

 pectinate, as in the other perseopods, the lower teeth of the pectination being much the 

 longest. 



Fourth Perseopods similar to the third, but th e side-plates less broad, with the hind- 

 lobe much deeper than the front, the branchial vesicles longer, the first joint rather longer 

 and broader, the third and fifth joints rather shorter, and the fourth joint as strongly 

 pectinate as the fifth. 



Fifth Peraeopods. — Side-plates not bilobed, a little broader than deep. First joint 

 wider than in the preceding pairs, wider above than below, the front margin straight 

 except at the top, the hind convex, slightly crenate, produced with rounded apex below 

 the front ; the second joint short, not reaching below the hind lobe of the first joint ; the 

 third joint twice as long as the second, widening from the base, both margins and the 

 apices minutely serrate or pectinate ; the fourth joint abruptly narrower than the third 



(ZOOL. CHALL. EXP. — PAET LXVII. — 1888.) Xxs 162 



