Fo BRITISH COPEPODA. 
seventh is again more prominent and convex dorsally ; 
the last abdominal segment has a sharp spine at the 
postero-dorsal angle. The second, third, and fourth 
segments are sometimes deeply tinged with purplish or 
bluish black. The male (fig. 2) has a strongly gibbous 
thorax, the outline of the animal when seen laterally 
being not unlike a note of interrogation (?). 
Anterior antenna 4-jointed (fig. 3), in the female the 
third joint is the longest, the first jomt has two small 
spines, and the second, one very large and stout spine, 
while the third and longest joint bears a row of several 
small denticulations on the under margin; the distal 
half of the antenna is densely setose. In the male 
(fig. 4) the same spines appear, but that of the second 
joint is not so strongly developed; the fourth joint 
forms a vesiculiform swelling, and the limb is clawed 
at the apex. The inner branch of the posterior an- 
tenna is attached to the middle of the first joint (fig. 
5), 18 very small, 1-jointed, and bears four sete. The 
mandible (fig. 6) is small, bluntly toothed at the apex, 
and has a small 1-joited palp to which are attached 
four sete. The posterior foot-jaw (fig. 8) is slender, 
having an elongated subtriangular hand and a long 
slender claw, which is quite as long as the hand itself. 
The peduncle of the first pair of feet (fig. 9) is 2- 
jointed, the outer branch very slender, 3- or sometimes 
2-jointed (the last two joints being often coalescent) 
and only half as long as the first joint of the inner 
branch; the inner branch is very stout, and armed 
with a strong falcate terminal claw. The second, 
third, and fourth pairs have the outer branch (fig. 10) 
