REPORT ON THE AMPHIPODA. 1345 



long as the third and fourth together of the first pair; the fifth joint also considerably 

 longer than the fifth in that pair. 



First Perxopods like the preceding gnathopods except in size and in having the 

 extremities of the first four joints unarmed or almost so. The branchial vesicles larger 

 than the preceding pair in proportion to the greater size of the limb. The first joint 

 wider than in the preceding pair, especially at the distal end ; the fourth joint longer 

 than the third and fourth together of the preceding pair, and much wider, its front 

 margin convex, the hinder nearly straight, the distal minutely pectinate ; the fifth joint 

 as long as the fourth joint of the first gnathopods, having, as in the gnathopods, some 

 small setules about the apex ; the finger very small. 



Second Peraeopods similar to the first, but a little longer. In the female specimen, 

 the second perceopods have the first joint longer, but the fourth and fifth joints shorter, 

 than the corresponding joints of the first pair. 



Third Peraeopods. — Side-plates rather broader and branchial vesicles larger than in 

 the preceding pairs, the limbs similar to the preceding pairs but both longer and broader. 

 The first, fourth, and fifth joints are very considerably longer than the corresponding 

 joints in the second peraeopods ; the fourth joint is but little shorter than the first; the 

 fifth is much narrower than the fourth, and a little over half its length ; the finger 

 minute and slender, very little curved, the basal part squared. 



Fourth Peraeopods. — Side-plates and branchial vesicles similar to the preceding pairs, 

 the limbs shorter. The first joint is a little shorter and above slightly broader than in 

 the third peraeopods, the second and third joints similar, the fourth much shorter, not 

 narrower ; the fifth shorter and rather broader, the finger similar. 



Fifth Peraeopods similar to the fourth but shorter, the side-plates not so broad. 

 The first joint not shorter than in the preceding pair, and decidedly wider just below 

 the neck ; second and third joints similar, fourth and fifth each much shorter but not 

 narrower ; finger similar. 



Pleopods. — Peduncles strong, in the first and second pairs longer than the rami, in 

 the third pair about equal to the rami ; the coupling spines form a series of from eight to 

 twelve on each pleopod, each spine having only the apical pair of retroverted hooks ; 

 there is no cleft spine, this being probably not needed when the coupling spines 

 are so numerous ; the first joint of the inner ramus is fringed with the ordinary 

 plumose setae ; the joints of each ramus are eleven or twelve in number, the terminal 

 joints not lengthened. In the female specimen the coupling spines did not exceed five 

 on any pleopod, and the joints of the rami were only six or seven in number. 



Uropods. — The peduncles of the first pair are a little longer than those of the third, 

 but not quite so broad ; they widen gradually to the distal end ; the lanceolate equal 

 rami are about half the length of the peduncle, and where widest about half its 

 greatest breadth ; the peduncles of the second pair are shorter than those of the third 



(ZOOL. OHALL. EXP. — PART LXVII. —1888.) Xxx 169 



