DESCRIPTION OF SPECIES 353 



by a small blunt spine : the posterior margin of these prominences is better defined than 

 the anterior. The eyes (Fig. 21) are about half the length of the head, reniform in shape, 

 rather narrow in proportion to the size of the head, and containing black pigment. 



The lateral or coxal portion of the second thoracic somite, which is fused with the 

 head, is divided into an anterior and a posterior portion by a transverse ridge. This 

 ridge commences on either side at a point approximately midway along the length of 

 the eye, and runs at first transversely and then obUquely backwards and outwards, finally 

 disappearing near the lateral margin. The posterior margin of the second thoracic 

 somite is produced backwards as a small median dorsal spiniform process. The third, 

 fourth and fifth thoracic somites are sub-equal ; each is produced backwards in the mid- 

 dorsal line into a small spiniform process which increases in length from before back- 

 wards. The sixth and seventh thoracic somites are together equal in length to one of the 

 preceding somites ; the terga of these two somites are fused with each other and with the 

 tergum of the first abdominal segment for a short distance on either side of the mid- 

 dorsal hne. In this character the species agrees with S. bouvieri, Richardson, and with the 

 Australian species S. australiensis, Beddard, S. elongata, Beddard, and S. longicaiidata, 

 Beddard. In the female the position of the suture between the sixth and seventh somites 

 is indicated by a slight groove. 



Well-developed coxal plates are present on each of the third to seventh thoracic 

 somites ; these are closely applied together for their whole length in the female, but in 

 the male the tip of each projects slightly beyond that of the preceding one. The coxal 

 plates of the third, fourth and fifth are marked off by distinct sutures from their re- 

 spective somites ; just within these sutures the lateral portion of the somite on each side 

 is raised into a low eminence and similar raised areas are present in corresponding 

 positions on the remaining somites. The coxal plates of the seventh thoracic somite are 

 longer than those of the other segments and, in the male, extend backwards beyond the 

 pleural plates of the second and third abdominal segments to a point level with the distal 

 end of the protopodite of the uropod ; in the female they are somewhat shorter and 

 extend to a level equal to that reached by the pleural plates of the third abdominal 

 segment. 



The posterior margin of each of the three free abdominal segments is produced into 

 a median dorsal spiniform process similar to those of the thoracic somites ; the posterior 

 border of the sternum of each of these segments is produced backwards into a median 

 spine ; these increase in size from before backwards, and are considerably larger in the 

 female than in the male. The pleural plates of the third abdominal segment are longer 

 than those of the second and extend backwards to the level of the articulation of the 

 uropod. 



The terminal segment (Fig. 21) is broader than long, terminating posteriorly in a 

 slightly up-turned trifid extremity, the middle projection of which is formed by the 

 extension backwards of a low median dorsal keel. Anterior to this keel is a strong median 

 dorsal spine, whilst on either side of it, in a lateral position, is a short ridge ending in 

 a spiniform process at about the level of the articulation of the uropod. Slightly posterior 



