1212 THE VOYAGE OF H.M.S. CHALLENGER. 



two points of the front margin, and a group on its decurrent apex ; the fourth joint 

 shorter than the fifth, rather wider above than below, with small spines at three points 

 of each margin ; the fifth joint slightly curved, with small groups of spines at three points 

 of the concave hind margin, spinules at four points of the convex front, and spines at its 

 apex ; the finger short, with a strongly feathered dorsal cilium close to the base. 



Second Perseopods. — The side-plates broader than the preceding pair, the front 

 margin very convex instead of almost straight, the long lower margin straight, the hind 

 margin deeply excavate, the rounded lower portion carrying two spines. The marsupial 

 plates of great breadth, with one margin almost straight, the other very convex, and the 

 distal end somewhat truncate. The limb as in the first pair so far as observed ; the 

 fifth and sixth joints missing. 



Third Perseopods. — The side-plates much broader than deep, the front and hind 

 margins convex, the two lobes very distinct, of about equal depth, the front one with a 

 spine at the front corner, its lower margin rounded, the hinder with an irregularly angled 

 lower margin carrying two spines. The branchial vesicles longer than the first joint but 

 not so broad. The marsupial plates a little smaller than the preceding pairs, with 

 broadly rounded distal margin. The first joint a little longer than broad, the front 

 margin carrying three groups of pectinate spines, the hind margin at the upper part 

 convex, slightly notched for a few setules, below the middle having as it were a 

 triangular piece cut out ; the lower margin sinuous, projecting behind considerably 

 beyond the second joint ; apart from the wing the hind margin on the inner surface is 

 nearly straight and would give a broad joint narrowest at the top and there fringed with 

 several long spines ; the short second joint has some apical spines ; the third joint is 

 much shorter than the fourth, with a narrow neck, then much widened, having on the 

 front two groups of several small spines, and behind three or four large groups, that on 

 the slightly decurrent apex including very many spines ; the fourth joint, with the 

 margins nearly parallel except at the base, has four groups of spines on each, those 

 behind being the longer; the fifth joint a good deal longer and narrower than the 

 fourth, has five groups of spines on each margin ; the finger is short and narrow, not a 

 third the length of the fifth joint. 



Fourth Perseopods. — The side-plates not so broad as the preceding pair, the front 

 margin nearly straight, with a spine at the apex, the lower margin of the front lobe 

 convex ; the hind lobe produced below the front one, with its hind margin straight, its 

 inner nearly so, and the lower angled, carrying two spines. The limb broken, the three 

 remaining joints like those of the third perseopods, but larger, the inner hind margin of 

 the first joint forming an obtuse angle and showing no spines, the third joint having 

 five groups of spines on the hind margin. 



Fifth Perseopods. — The side-plates smaller than the preceding pair. The limb 

 apparently similar to that of the fourth perseopods. A fragment of a limb, probably 



