REPORT ON THE AMPHIPODA. 933 



Upper Antennse shorter than the lower. Peduncle short, first joint once and a half 

 as long as broad, not equalling the length of the next two united ; third a little shorter 

 than the second; flagellum of thirty joints, the first longer than the next two united, 

 carrying three groups of cylinders ; many of the other joints with cylinders longer than 

 the joints ; the secondary flagellum one-jointed, minute, not half the length of the first 

 joint of the principal flagellum, with a long seta inserted in the tip, and two or three 

 cilia or hairs. In the young extracted from the mother's pouch, the flagellum of the 

 upper antennse consists of six long joints. 



Lower Antenna'. — First three joints very short, subequal, gland-cone short, decurrent ; 

 fourth joint longer than the preceding three united ; fifth joint rather narrower but longer 

 than the fourth ; flagellum of thirty-three joints, the first six rather thick, the first as long 

 as two or three together of those that follow. In the young the flagellum is of eight or 

 nine joints. 



Upper Lip. — The distal border with a small non-central emargination, the cilia 

 facing one another on either side of it rather stout and tooth-like, those more remote as 

 usual hair-like. 



Mandibles. — Cutting plate divided into seven teeth, of which the lowest three are 

 the largest ; secondary plate of left mandible distally widened and divided into five 

 teeth, the lowest of which is the largest ; secondary plate of the right mandible slight in 

 structure, showing only two terminal teeth, the hinder of which is much the longer ; 

 spine-row on the left mandible of nine curved pectinate spines, the first broader than the 

 rest, with oblique denticulate apex ; the right mandible showed only six spines, without 

 a specially broad one ; close to the spine-row T is the molar tubercle with strongly dentate 

 crown ; above it a blunt-headed process, and above this the strong palp, the first joint a 

 little expanded distally, as also is the second, which has on the surface near the inner 

 margin about a dozen spines, slightly plumose, those near the apex the longest ; the third 

 joint is subequal in length to the second, the outer margin convex, with two long spines 

 on the outer surface near the base, many short spines along the inner margin and four 

 longer ones at the apex ; the outer surface almost covered with adpressed cilia. In the 

 young there appeared to be only three short spines at the apex of the third joint, with 

 none alonoj the inner margin. 



Lower Lip. — Principal lobes rather broad and deep, little dehiscent, strongly ciliated 

 round the distal and inner margins ; inner lobes broad and thick and short ; mandibular 

 processes short, squared at the ends. 



First Maxilla?. — Inner plate small, with five (in a second specimen only four) plumose 

 setse on the oblique distal margin, followed by four setules, two of which are upon the 

 slightly produced apex, and two upon the inner side of it ; outer plate carrying eleven 

 spines on the truncate margin, the outermost long and straight, slightly denticulate, set 

 among some long cilia ; the next shorter, with a long apical tooth on the inner side or 



