1418 THE VOYAGE OF H.M.S. CHALLENGER. 



spine ; the fourth joint not wider than the third, about twice as long, nearly as long as 

 the first joint, the front margin hairy, fringed with eight spines, the hinder margin 

 having spines at the apex and two or three higher up ; the fifth joint slender, longer than 

 the fourth or the first, with a very slight curve, the front margin carrying five spines, and 

 at first hairy, the hairiness passing into strong pectination towards the apex ; the finger 

 slender, smooth, distally a little curved, about a fourth the length of the fifth joint ; in 

 the specimen specially examined, the fifth joint in one of these limbs was not so long as 

 in the other, so that the finger was more than a quarter of the length. 



Fourth Perseopods not differing much from the third, the first joint about as long but 

 rather less widened below, with four spines on the lower part of the front margin, the 

 third joint as long but less widened distally, the fourth joint much shorter, scarcely once 

 and a half the length of the third, with five unequal spines along the hairy front margin, 

 the fifth joint nearly as long as the third and fourth together but shorter than in the 

 preceding pair, with spines along the front margin, others more slender on the inner 

 surface, and two or three on the hind margin, the front hairy near the base, but pectinate 

 for almost the whole length ; the finger nearly a third of the length of the fifth joint. 



Fifth Perasopods similar to the fourth, the first joint a little longer, with three spines 

 on the lower part of the front margin, the straight outer hind margin with only a single 

 indent, the inner hind margin having as usual some spines near the apex ; the third joint 

 rather longer and narrower, the fourth rather shorter and narrower, than in the preceding 

 pair; these two with little spinules at intervals along the otherwise smooth front margin, 

 the fourth joint not once and a half as long as the third, with six unequal spines projecting 

 from the inner surface ; the fifth joint as long as or a little longer than the third and 

 fourth together, the hind margin smooth, the front armed only with little spinules, but 

 with five unequal spines projecting from the inner surface ; the finger between a third 

 and a fourth of the length of the fifth joint. 



Pleopods. — Coupling spines with three pairs of retro verted teeth below the half-moon- 

 shaped apex ; cleft spine placed below the middle of the first joint of the inner ramus, 

 the serrate arm the longer, the subapical dilatation of the other arm small ; a single 

 plumose seta on the outer margin of this joint in the third pair ; two such setse in the 

 first and second pairs ; the first joint of the outer ramus has three or four seta? on the 

 bulging part of the outer margin ; each ramus has eleven or twelve joints. 



Uropods. — Peduncles of the first pair scarcely longer than the inner ramus, the outer 

 ramus much shorter than the inner, the adjacent margins strongly pectinate, bulging near 

 the base so as to overlap one another, but contracting a little below the base, the other 

 margins smooth ; the peduncles of the second pair broader but shorter than those of the 

 first, not so long as the inner ramus, the apex of the inner margin acutely produced ; the 

 outer ramus little more than half the length and less than half the breadth of the broadly 

 lanceolate inner ramus, the adjacent margins of the two rami strongly pectinate; peduncles 



