244 Part III. — Nineteenth Annual Report 



apical setae, the two outer sub-apical setae are small, but the other two are 

 moderately stout and unequal in length, the inner one being the longest, 

 both are feathered on the distal half (fig. 23). Each foot of the fifth 

 pair consists of a single uniarticulated branch, elongated and somewhat 

 slender and spine-like ; this pair, instead of being situated on the ventral 

 aspect, which is the usual position in the majority of Copepods, are placed, 

 well round towards the back, and are probably utilised for supporting 

 between them the egg-sacs which combine to form a globular mass on the 

 dorsal aspect of the genital segment of the abdomen. This globular mass 

 is easily detached, and would be even more so were it not supported and 

 kept in position by the fifth feet (fig. 15). 



The first segment of the abdomen is of moderate size, but the other 

 segments are small ; the caudal furca are very short and somewhat 

 divaricate. 



Description of the male. — The male is about half the size of the female, 

 being only *825 mm. (about the -j^- of an inch) in length. The cephalo- 

 thorax is distinctly segmented, and of a somewhat oval outline, the 

 cephalic segment is moderately large, being equal to about two-fifths the 

 entire length of the cephalothorax, but the thoracic segments are small. 

 The genital segment of the abdomen is somewhat dilated, and equal to 

 about half the entire length of the remaining segments and the caudal 

 furca combined, the posterior portion of the abdomen is composed of what 

 appear to be seven or eight distinct articulations, but with the exception 

 of the ultimate segment they are for the most part very small ; the caudal 

 furca, which are scarcely equal in length to the last abdominal segment, 

 are each provided with a small seta near the base of the outer margin in 

 addition to a few short apical setae (fig. 16). 



The antennules are very short and four-jointed, the first joint is mode- 

 rately large and somewhat inflated, numerous delicate hairs spring from 

 its rounded upper surface, as shown in the drawing (fig. 24). The 

 remaining joints are small, the second one and the last are furnished with 

 several delicate hairs similar to those on the first joint. 



The thoracic feet. — The first four pairs of thoracic feet are all two- 

 branched, and the outer branches are all three-jointed and armed on their 

 exterior margins "with strong sabre-like spines, the first and second joints 

 being each furnished with one of these spines, and the third joints with 

 three, except that the third joints of the first pair carry four spines ; in all 

 the outer branches the terminal spines are considerably larger than the 

 others. Moreover, in the outer branches of all the four pairs, the inner 

 margins of the first joints appear to be devoid of spines or setae, but the 

 second joints are each provided with one plumose seta on the inner 

 margin ; on the other hand, the third joints of the outer branches of the 

 first pair have only four plumose setae on their inner margin, while on 

 the inner margin of the third joints of the next three pairs there are five 

 plumose setae, so that though the outer branches of the first pair have 

 one spine more than the other three pairs, the number of setae is corres- 

 pondingly fewer. 



But although all the four pairs of thoracic feet are somewhat similar as 

 regards the structure and armature of the outer branches, a considerable 

 divergence is observable when the inner branches are compared. In the 

 first pair of feet the inner branches are composed of a single small but 

 somewhat tumid joint bearing one or two claw-like spines (fig. 25). In 

 the second and third pairs the inner branches are three-jointed, but con- 

 siderably shorter than the outer branches ; in each of the inner branches 

 the first joint bears one and the second and third two moderately elon- 

 gated plumose seta?, in addition to two small sabre-like terminal spines 



