AMPHIPODA. 11 
First pereeopods: 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 perzeopods: Like the first, except the side plates (see back). 
Third pereopods: Side plates as deep as the leg is long, widening below, 
the hind margin angulate below, the front rounded. First joimt 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 pereopods: First joint subovate, very obscurely crenate behind. 
Fifth pereopods: 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 uwropods: Rami rather longer than the peduncles, the outer rather the longer, 
with spines on the outer and long setze on the inner margin. 
Telson cleft nearly to its base, reaching to the middle of the rami of the third 
uropods. 
ARISTIAS ANTARCTICUS. (PI. 3, fig. 5.) 
Aristias antarcticus, A. O. Walker, Ann. and Mag. Nat. Hist. XVII. (1906), p. 454. 
W.Q., 28 Feb., 1902, Millurdo Bay, 20 fm., one, length 15 mm. ; D., 5 June, 
1902, one smaller. 
Body moderately compressed, without carinz or teeth. 
Head shorter than the first segment; ocular lobe produced to the end of the first 
joint of the upper antennee, rounded at the apex. yes 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 antennz subequal, scarcely reaching the end of the third segment. 
Upper antenne: 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 antenne : First joint twice as wide as long ; second and third subequal, 
about three times as long as the first ; flagellum ten-jointed. 
