1916.] 



Fauna of the Chilka Lake : Terrestrial Isopoda. 



467 



ist — 5th segments there is a slight furrow just in front of the posterior margin. In 

 the pleon the granulations are smaller and less evident. . The posterior border of the 

 first segment is transverse, not being produced backwards at the postero-lateral angle. 

 In the succeeding segments this angle of the side-plate is produced more and more 

 backwards until in the seventh segment it forms an acute point reaching as far back 

 as, or further than, the posterior border of the third segment of the pleon ; the first 

 and second segments of the pleon are short and without side-plates ; the third, fourth 

 and fifth have well-developed side-plates produced back into acute points, that of the 

 fifth reaching about half way to the end of the terminal segment. The terminal seg- 

 ment is much broader than long, its lateral margins end acutely posteriorly and the 

 posterior border is produced at the centre into an acute point as already described 

 (fig. 20, p. -472). 



Fig 

 Fig. 12 



Ligia exotica, Roux. 

 11. — First leg of male, with terminal portion more highly magnified. 



-Second leg of male. 



Antenna 1 (fig. 1, p. 463) is very small, as usual for this genus and is not visible 

 in a dorsal view of the head ; the first joint is nearly as broad as long, and about two- 

 thirds the length of the second, and its margins are almost free from setae; the 

 second is nearly three times as long as broad and is thickly covered on the distal 

 portion with short fine setae, some of them almost scale-like, and there are a few 

 longer setae at the extremity and on the lower margin ; the third joint is very short, 

 almost minute, and rounded at the end. 



Antenna 2 (fig. 2, p. 463) is, in most cases, fully as long as the body, though the 

 length varies with the development of the animal ; the first two joints of the peduncle 

 are short, and slightly grooved on the outer side to receive the third joint when reflexed ; 

 the third joint is about as long as the first and second together and bears near the 

 inner distal angle a single, stout seta and is also grooved on the outer side towards 

 the distal end; the fourth joint is about twice as long as the third, but shorter than 



