302 DISCOVERY REPORTS 



complete anteriorly (Fig. 7). The remaining thoracic somites are very broad, and the 



coxal plates correspondingly short: those of the third, fourth and fifth somites are 



separated from them by sutures. The third, 



sixth, and seventh somites are sub-equal, the 



fourth and fifth slightly longer. The coxal 



plates of the seventh somite are not much 



more produced than those of the sixth, and 



extend backwards almost to the level of the 



base of the uropods. 



The first three abdominal segments are 

 sub-equal, not much narrower than the last 

 thoracic somite. The pleural plates of the 

 second and third segments are broad, and 

 produced backwards beyond the coxal plates 

 of the seventh thoracic somite ; those of the 

 second extend almost to the posterior end 

 of the terminal segment, those of the third 

 beyond it, reaching nearly to the level of the 

 outer distal angle of the protopodite of the 

 uropod. The terminal segment is about as 

 broad as long. It is almost circular in out- 

 line, but with the postero-lateral regions 

 slightly excavated for the reception of the Fig- 7- Serolis elliptka, n.sp.,$: x 22. 



uropods, so that the posterior extremity appears to be broadly rounded. A median dorsal 

 carina is present and the outer margins of the coxal and pleural plates are fringed with 

 delicate plumose setae. 



The antennule is short, about one-half the length of the antenna. The first peduncular 

 joint is small ; the second is twice as long as the first, broad, with rounded distal end ; 

 the third joint is the longest, but is narrower than the second; the fourth is a little 

 shorter than the third. The flagellum consists of seven joints of which the terminal and 

 penultimate are short, together equal to the fifth. A sensory seta is present at the tip of 

 the terminal joint and at the anterior distal angle of the fourth, fifth and sixth joints. 



The antenna consists of a peduncle of five and a flagellum of nine joints. The first 

 peduncular joint is short, the second and third are a little longer: the inner margin of the 

 second is fringed with short hairs and at its inner distal angle is a stout, densely plumose 

 seta. The fourth and fifth joints are longer and sub-equal and their anterior margins 

 bear groups of long setae between which is a fringe of shorter ones. 



The mouth-parts are of the type usual in members of this genus. The primary cutting 

 edge of the left mandible is rounded distally and sHghtly produced a Uttle to one side 

 of the middle ; its secondary edge is in the form of two spines, one of which is slender, 

 while the other is large and flattened distally to form a finely toothed blade. The primary 

 edge of the right mandible is also rounded, with a single notch towards one side; the 



