1300 THE VOYAGE OF H.M.S. CHALLENGER. 



the rami of that pair ; the outer the shorter, with a little serration of the outer and 

 not much more of the inner margin, the apex acute ; the inner ramus also similar, 

 a little more strongly armed ; the peduncles of the third pair set wide apart, a little 

 shorter than those of the first pair, much longer than the rami, the inner apex acute ; 

 the rami shorter than those of the second pair, the outer the shorter, the margins only a 

 little denticulate. 



The Telson much broader than long, very short, triangularly rounded, its base 

 occupying the space between the third uropods. 



Length, outstretched, about a quarter of an inch. 



Locality.— March 9, 1876, South Atlantic, surface; lat. 37° 47' S.,long. 30° 20' W.; 

 surface temperature, 64° # 5. One specimen. 



Remarks. — The specific name is given out of respect to Sir J. D. Hooker, among 

 whose numerous unpublished drawings of Amphipoda there is one representing a species 

 of this genus ; the colouring represents the head as almost black, evidently occupied 

 almost entirely by the eyes, the body a deep blue, the antennse a lighter shade of the 

 same colour, and the legs light red. In Cyllopus armatus, Bovallius, the first flagellum 

 joint of the upper antennaa is drawn out to a much greater extent, there is a much 

 greater disproportion between the second and third pereeopods, the rami of the second 

 uropods are more nearly ecpial to those of the third, the telson is differently shaped, 

 and the size of the animal much greater. Cyllopus magellanicus, Spence Bate, has 

 the rami of the third uropods " scarcely one-fourth of the length of the peduncle," the 

 telson cylindrical, and the body of the animal "thickly covered with coarse stellate 

 spots of black pigment," whereas the Challenger specimen was colourless except as to 

 the eyes. From Cyllopus magellanicus, Dana, if the figures of that species can be trusted, 

 the present species is distinguished by having the fifth and sixth segments of the pleon 

 coalesced instead of free, by having the peduncles of the second uropods much shorter as 

 compared with those of the first, and by having the first joint of the fifth perasopods of 

 greater breadth ; to these marks of distinction might be added the fact that the telson 

 is free, not, as in Dana's figure, coalesced with the preceding segment, but the figure 

 cannot perhaps be relied on for so minute a detail. 



Dr. v. Willemoes Suhm, in a letter from Cape York, September 1874, 1 refers to the 

 capture of a species of Cyllopus, but a mounted specimen so named, in his handwriting, 

 with his monogram attached, and labelled as taken on the voyage from " Api to Cape 

 York," belongs not to Cyllopus but to Paraphronima. 



1 See Note on v. Willemoes Suhm, 1SV5 (p. 452). 



