Amphipoda with notes on a species of Isopoda. 441 
Side-plates of the thorax presenting no special features but much as in the re- 
maining species of the genus ; the first side-plate somewhat expanded ; side-plates 
1-4 fringed with setae on their lower margins and with a specially strong spiniform 
seta on the posterior margin where the second joint of the limb comes off. The first 
three segments of the pleon have the lower hinder corners rounded and are without 
spines or setae. 
First antenna (pi. XVIII, fig. 11) about equal to or slightly longer than the 
peduncle of the second antenna, first joint of the peduncle about as long as the second 
but considerably stouter, third joint shorter than the second, fiagellum shorter than 
the peduncle, composed of 9-10 joints. In the male the second and third joints of the 
peduncle are shorter and stouter than in the female and the fiagellum is composed of 
about 12 joints but there is no special development of sensory hairs. 
Second antenna (pi. XVIII, fig. 12) in the female about one and a half times as long 
as the first, last joint of the peduncle elongate and slender about one and a half times 
as long as the preceding joint, iiagellum longer than the last joint of the peduncle 
and composed of about 11-12 joints. In the male the fiagellum is composed of about 
20 joints. 
Mouth parts and first thoracic limbs (maxillipedes) as for the genus. 
Second thoracic limbs (first gnathopods) (pi. XVIII, fig. 13) rather slender and 
elongate, second joint long and narrow, very nearly as long as the rest of the limb, third 
and fourth joints short, fifth joint with the carpal process very long and narrow extend- 
ing to the margin of the palm of the hand, sixth joint long and oval in shape, at least 
three times as long as broad, palmar margin longer than the hind margin of the joint, 
from which it is defined by a slight angle armed with a small spine, palmar margin 
furnished with long setae. 
Third thoracic limbs (second gnathopods) (pi. XVIII, fig. 14) longer and somewhat 
more slender than the second, second joint longer than the rest of the limb, carpal pro- 
cess of the fifth joint very long and narrow, reaching to the margin of the palm of the 
hand, sixth joint smaller than the corresponding joint on the second thoracic limbs, 
long and almost linear in form, about three times as long as broad, palm about as 
long as the hind margin of the joint, defined by a slight angle furnished with a spine, 
and armed with long setae. 
PI. XVIII, fig. 15 shows the form of the fifth pair of thoracic limbs. The fourth to 
the seventh pairs resemble this figure in general structure. In all the carpus is about 
equal to the propodus and the nail long and well developed and only slightly shorter 
than the propodus. 
In the sixth and seventh pairs the second joint is furnished with long plumose 
setae. 
Eighth thoracic limbs (pi. XVIII, fig. 16) very elongate, second joint somewhat 
pyriform in shape, posterior margin fringed with short setae and having the lower 
distal corner produced into a lobe as long as the third joint, which is quite short ; 
fourth to the seventh joints long and successively narrower, the propodus slightly 
longer than the merus, carpus and dactylus, which are subequal in length. 
