1176 THE VOYAGE OF H.M.S. CHALLENGER. 



the other ; the fourth joint not quite twice as long as broad, having a slender curved 

 feathered spine at the apex in front, accompanied by stout spines, and a slender spine and 

 spinule higher up, the hind margin having an apical group, in which the spines are broad 

 and curved, and having also a group of three stout spines on the surface near its centre ; 

 the fifth joint narrower, about as long as the third, with four groups of powerful spines 

 along the front margin, and a mixed group at the apex of the hind margin ; the finger 

 short, half the length of the fifth joint, much curved, with a long dorsal cilium near the 

 hinge. 



Fourth Perieopods. — The side-plates much smaller than the preceding pair. The 

 limb larger and longer than in the preceding pair, but similar ; the hind margin of the 

 large first joint slightly convex ; the third joint with spines at six points in front and two 

 behind ; the fourth joint fully twice as long as broad, with three groups in front and 

 two behind ; the fifth joint with five groups of spines on the true front and three on 

 the true hind margin. The fifth and sixth joints in fig. prpA. are reversed, but this is 

 perhaps not their normal position, though no doubt these joints have free play upon 

 the preceding joint. 



Fifth Perseopods missing in the specimen described, but present in a second specimen. 

 The side-plates are small. The limb is similar to the preceding pair, but larger ; the first 

 joint considerably larger in both dimensions, the front margin slightly convex, with eight 

 small spines spaced along it and an apical group, the hind margin very convex except at 

 the oblique upper part, fringed with small plumose setae, serrate, the lower margin well 

 rounded, similarly equipped ; the third joint fringed in front with feathered spines or 

 setse, with strong spines at the apex of this and at three points of the hind margin ; the 

 fourth joint only a little shorter than the third, with three groups of spines in front and 

 two behind ; the fifth joint longer than the third, with five groups of spines in front and 

 three behind ; the finger not half the length of the fifth joint. 



Pleopods. — The peduncles short and stout, shorter than the rami, the coupling spines 

 slender, a little distally bent, with four teeth on one side and three on the other, and the 

 sharp apex apparently also forming a minute hook ; the cleft spines from three to four in 

 a series ; the outer ramus shorter than the inner, but the joints appear to be of the same 

 number, eleven, in each. 



Uropods. — The peduncles of the first pair much shorter than the rami, with some 

 spines on the upper margins, a small one projecting from near the top of the lower 

 margin, and at the apex of this margin one of great length, which added to the base 

 would make the peduncles longer than the rami ; one ramus is rather longer than the 

 other, and has spines at six points of one margin and a group at the blunt apex ; the 

 shorter ramus is similar, but with three pairs of spines on the margin and the apical 

 group ; the second pair shorter than the first, the peduncles shorter than the rami, 

 also with a very long curved spine on the lower apex, the rami broad, and the spines 



