REPORT ON THE AMPHIPODA. 1473 



beyond the apex of the preceding joint ; the succeeding joint is about half as long and 

 broad, with two or three apical filaments, and followed by a minute terminal joint. 



Lower Antennae (in the male). — The third (first free) joint of the peduncle moderately 

 thick and long, slightly curved, narrowing distally ; the fourth joint very slender, very 

 much longer than the preceding, thickening distally ; the fifth joint similar to the fourth, 

 subequal in length, less thickened distally ; the first joint of the flagellum is longer than 

 the third joint of the peduncle, thinner than the fifth, and about two-thirds of its length; 

 the second joint of the flagellum is almost as thick and long as the first. 



Mandibles. — The small cutting edge has an oblique finely dentate margin, that of the 

 one mandible more oblique than that of the other ; the secondary plates similar to the 

 primary, but not quite so large ; the palp is set far back, with the first joint longer than 

 the second or third, but not equal to both together, the third is about equal in length to 

 the second, but narrower. 



First Maxillse with three little teeth close-set on the inner margin near the apex. 



Second Maxillse broader than the first, with narrow apex. 



Maxillipeds. — The inner plate is very short, rather broad ; the outer plates are 

 broad, the outer margins very convex, the inner sinuous ; the apices narrowly rounded. 



First Gnathopods. — Side-plates small, the lower front corner forming a somewhat 

 acute angle, nearly bisected by a ridge on the under side. The first joint reaching much 

 beyond the side-plate, widening till near the distal end, then narrowing, the front margin 

 convex, carrying a few setules, the hind margin more convex than the front, with a 

 setule a little above the apex; the second joint short, with one or two setules on the hind 

 margin ; the third joint longer than the second, distally widened, with three setules on 

 the lower half of the front margin, and one at the apex of the hinder ; the wrist not wider 

 than the third joint, but longer even without the triangular process at the end of the 

 slightly sinuous, finely denticulate, hind margin ; the narrow, curved, somewhat tapering 

 hand is longer than the front, but shorter than the hind, margin of the wrist, less than 

 twice the length of the process, its front margin convex, its hinder slightly concave, and 

 like the margin of the process which faces it scarcely denticulate ; the finger is very short 

 and slender, less than a third of the length of the hand. 



Second Gnathopods. — The side-plates with the lower front corner rounded. The 

 branchial vesicles large, of very thin texture. The first joint rather longer than in the 

 preceding pair, with the front margin concave except at the two ends, the hind margin 

 very convex ; the other joints are nearly as in the first gnathopods, but the third joint is 

 a little longer and narrower, with several setules along the hind margin, the wrist has 

 the front margin shorter, the hind margin longer and straighter, with two or three setules 

 on the proximal half, and forming a longer process, serrate on both edges. In the first 

 joint there are gland-cells, in both pairs of gnathopods. 



First Peraeopods. — The side-plates similar to the preceding pair. The branchial 



(zool. chall. exp. — pakt lxvii. — 1888.) Xxx 185 



