72 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 joint 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), is very small, 1 -jointed, and bears four setse. The 

 mandible (fig. 6) is small, bluntly toothed at the apex, 

 and has a small 1 -jointed palp to which are attached 

 four setae. 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) 



