1056 THE VOYAGE OF H.M.S. CHALLENGER. 



fourth joint, longer than the fifth or the two preceding united, has five strong spines on 

 the front margin and a dozen smaller ones, besides some spinules ; at the apex behind, 

 on the slope of the lower margin, there is the usual group, including eight stout spines 

 and three or four that are very slender ; the serrate convex front margin of the fifth 

 joint has eleven strong spines besides those on the produced apex ; there are two on the 

 hind margin ; the upturned finger has two or three dorsal teeth. 



Fifth Perseopoch. — The shallow side-plates seem to be quite coalescent in front with 

 the segment which on its lower border carries some spinules ; the lower margin of the 

 side-plate is convex, fringed with slender spines, and forming an angle with the straight 

 upper margin. The front margin of the first joint is nearly straight, set with spinules, 

 and having some small spines at the apex ; the lower margin crosses the top of the second 

 joint, then descends nearly to the end of the third, whence with a much-rounded angle 

 it ascends again, forming a continuous curve with the hind margin, from which it is 

 probably to be distinguished by the commencement of the fringe of plumose setae and 

 spines which ends at the lowest point of the joint ; the width of this joint is much less 

 than its length, it is greatest a little above the apex of the front margin ; the second 

 joint is very short, with some apical spines in front ; the third is longer, especially 

 behind, where the apex is far decurrent ; the front margin has two or three setules and 

 an apical spine ; the hind margin is fringed with thirteen long plumose setas and some 

 spinules ; the front margin of the fourth joint is rather shorter than the hind margin of 

 the third ; it has four groups of spinules, the lower two having each a spine also ; the 

 hinder apex has spines and a long seta ; the fifth joint is laminar, longer than the fourth, 

 with smooth margins, except at the apices which have the usual short spines ; the finger 

 is lanceolate, shorter than the preceding joint, marked like it within the hinder margin 

 as if for the insertion of setae, the nail or its equivalent abruptly tapering, having at its 

 base a setule. 



Uropods. — The peduncles of the first pair rather longer than the rami, the lower 

 ramus rather longer than the upper, each with the apex acute, curved ; the peduncles of 

 the second pair rather longer than the rami, the upper ramus a very little longer than 

 the lower, on which the denticulate spine near the apex is only moderately elongate ; the 

 marginal spines are numerous ; the peduncles of the third pair shorter than the rami, the 

 lower margin apically produced, the upper carrying a prominent spine ; the rami very 

 broadly lanceolate, equal in length, the inner margin of the inner ramus nearly smooth, 

 the other margins, except at the upper part, carrying numerous long plumose setae, the 

 outer margin of the outer ramus showing also a series of spines, and a strip of its surface 

 being coated with denticles. 



The Telson a little longer than the peduncles of the third uropods, nearly twice 

 as long as broad, cleft four-fifths of the length, the sides converging to two almost 

 acute, not dehiscent, apices, each furnished with a spine and feathered cilium, the 



