AMPHIPODA. 11 



First perseopods : Side plates narrow, widening distally, curved. Coxopodite 

 distinct, about one-third the length of the side plate. First joint subequal to the next 

 two, widening distally ; third joint rather wider at the distal end than the first at the 

 same point ; second, third, and fourth setose, fifth spinous on the hind margin. 



Second perseopods : Like the first, except the side plates (see back). 



Third perseopods: Side plates as deep as the leg is long, widening below, 

 the hind margin angulate below, the front rounded. First joint wider than 

 long, with the hind margin excavate and setose above and obscurely crenate below ; 

 hind margin of the third joint produced to the middle of the next and terminating in a 

 spinous point ; the front margin of all the joints except the first is armed with short 

 spines. 



Fourth perseopods : First joint subovate, very obscurely crenate behind. 



Fifth perseopods : First joint much wider than that of the fourth pair, the hind 

 margin distinctly crenate in the middle. 



First and second uropods : The peduncles as long as the outer rami, the inner 

 rather shorter. 



Third uropods : Eami rather longer than the peduncles, the outer rather the longer, 

 with spines on the outer and long setae on the inner margin. 



Telson cleft nearly to its base, reaching to the middle of the rami of the third 

 uropods. 



Aristias antarcticcjs. (PI. 3, fig. 5.) 



Aristias antarcticus, A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (1906), p. 4.54. 



W.Q., 28 Feb., 1902, Millurdo Bay, 20 fm., one, length 15 mm. ; D., 5 June, 

 1902, one smaller. 



Body moderately compressed, without carinse or teeth. 



Head shorter than the first segment ; ocular lobe produced to the end of the first 

 joint of the upper antennae, rounded at the apex. Eyes large, dark, expanded 

 below. 



Body-segments increasing in length backwards. First four side-plates about as 

 deep as the segments, the first concealed by the second ; the fourth moderately pro- 

 duced behind ; the fifth much wider than deep. Posterior angle of the third pleon 

 segment produced backwards, acute. First urus segment depressed in front ; second 

 and third almost concealed by the first, and perhaps coalesced. 



Upper and lower antennae subequal, scarcely reaching the end of the third segment. 



Upper antennse : First joint rather longer than the second and third, the lower 

 margin projecting distally ; second twice as long as the third, lower margin projecting. 

 Flagellum ten-jointed, the first joint setose, as long as the next three joints, which are 

 distally setose. Appendage five-jointed, the first the longest, the rest subequal. 



Lower antennse : First joint twice as wide as long ; second and third subequal, 

 about three times as long as the first ; flagellum ten -join ted. 



