COBYC^OS. 35 



Anterior antennae (PL LXXXIII, fig. 12) 6-jointed, 

 robust, about one third as long as the first cephalo- 

 thoracic segment; fourth joint somewhat longer than 

 any of the rest; setae of moderate length. Posterior 

 antennas 3-jointed (PI. LXXXIII, figs. 13, 14), the 

 basal joint bearing two very strong spine-like setae 

 (a, a) ; the second joint in the male is elongated, sub- 

 quadrangular, has a hooked process (fig. 14 6) at the 

 distal angle of the inner margin, and a row of minute 

 serratures along the middle of the joint) (c) ; in the 

 female (fig. 13) the joint is ovate and destitute of 

 spines and teeth ; the last joint is short, slender, and 

 armed with two pairs of short lateral spines and a 

 large terminal uncinate claw, which in the male 

 reaches beyond the extremity of the basal joint. The 

 inner branches of the first three pairs of swimming- 

 feet (PI. LXXXIY, fig. 12) are 3-jointed, and only 

 about half as long as the outer branches ; the outer 

 branches are armed with strong lancet-shaped spines 

 on the outer margin, the last joint very long, bearing 

 two marginal and two apical spines, the latter being 

 long and marginally ciliated (PL LXXXI, fig. 19). 

 The basal portion (peduncle) of the fourth pair 

 (PL LXXXIY, fig. 13) is elongated and angularly bent, 

 and the inner branch consists of one small bisetose 

 joint; the fifth foot is rudimentary (PL LXXXI, 

 fig. 18), consisting of a single minute joint, to which 

 are attached two long slender setae. The penultimate 

 thoracic segment (PL LXXXIY, fig, 14) is produced 

 into a long hook-like angle (a} ; the first abdominal 

 segment has a small anterior hook at its base (c), and in 



