1536 THE VOYAGE OF H.M.S. CHALLENGER. 



with the rounded front apex below the hinder apex ; at the top of the slit rises the short 

 second joint, partially overlapped by a third process ; the third joint is long, with the 

 front margin longer than the hind one, strongly pectinate, forming a triangular process 

 with smooth hind margin nearly halfway along the front of the much narrower fourth 

 joint, which is pectinate with much smaller teeth ; the fifth joint is minutely pectinate, 

 narrower and shorter than the fourth, the two together equalling the length of the 

 third ; the finger is quite minute, sharp, no doubt retractile within the pectinate apex 

 of the fifth joint, not nearly reaching to the base of the first joint. 



Fifth Perseopods. — Side-plates rather deeper than broad, deeper behind than in front. 

 The first joint a good deal more than half as long, and less than half as broad as the 

 first joint in the fourth perseopods, the front margin nearly straight, the hinder at first 

 parallel, then sinuously sloping to a very narrow apex ; there is a ridge nearer to the 

 front than the hind margin, and nearly parallel with it, reaching below the middle of the 

 joint ; the second joint is minute, with slightly convex front margin ; the third joint is 

 about as long, but scarcely so broad as the second ; it curves backwards, with convex 

 front and nearly straight hind margin. 



Pleopods. — The two coupling spines are small, with the usual caps; in the cleft 

 spine the subapical dilatation is very small ; the joints of the rami number ten and eleven. 



Uropods. — The first pair have the peduncles scarcely so long as the rami, the rami 

 long, lanceolate, reaching a little beyond the second pair, and not quite so far as the 

 apices of the third, the margins cut into teeth, those on the inner margin being rather 

 longer than those on the outer, and not approaching quite so closely to the acute 

 apex, the outer ramus like the peduncles three-edged ; the peduncles of the second pair 

 are shorter than those of the first, but reach as far back, with the inner apex acutely 

 produced ; the rami are not much shorter than those of the first pair, the inner longer 

 and considerably broader than the outer, with both margins cut into teeth, the outer 

 with only the inner margin so ornamented ; the peduncles of the third pair are very 

 short, broader than long, the slightly produced inner apices of the two peduncles nearly 

 meeting ; the rami are shorter than the preceding pairs, the outer scarcely shorter, 

 but considerably narrower than the inner, having the lower two-thirds of its inner 

 margin cut into long teeth, more than twenty in number, the apex narrowly rounded ; 

 the inner ramus is oval, but with a flattened base and the greatest width near the base ; 

 the edges are smooth ; the inner ramus of one pair partially overlaps that of the other 

 pair. 



Telson small, about as broad as long, about half an oval with a slightly convex 

 base ; the distal portion overlaps the upper inner corners of the inner rami of the third 

 uropods. 



Length. — The specimen in the position figured, measured, in a straight line from end 

 to end, one-fifth of an inch. 



