792 STUDIES IN AUSTRALIAN NFUROPTEKA, vii., 



again rests for some days, and tlien undergoes its first ecdysis. 

 This appears to bn fatal to many of tlie larvye, cbietiy owing to 

 the great difficulty experienced in removing the head from the 

 very hard shell of the cuticle enclosing it. 



Second Larval Instar. (Plate Ixxix., fig.4; Text-ti<5,3). 



At the tirst ecdysis, there is a great increase in the size of the 

 head of the larva, which now becomes about 14 mm. long in an 

 average-sized larva. (There is considerable variation in the sizes 

 of individual specimens, and this is not rectified in the imagines, 

 which also vary greatly in size). The head becomes more de- 

 finitely trapezium-shaped than before, owing to the increased 

 definiteness of the four angles; its colour is a rich brown. An 

 extra joint is added to the antennse, which are now nine-jointed, 

 and to the labial palps, which become five-jointed. The man- 

 dibles and maxill?e are almost as long as the head, shaped as in 

 the first instar, but of stronger build. The ocelli become more 

 plainly marked, each set of five being placed upon an irregular 

 darkened area just behind the base of the antenna. 



Text-fig. 3 shows the cast skin of the head of the larva at the 

 end of this instar. The armature of the head is very remarkable, 

 consisting of numerous raised papillae, from each of which a tiny 

 hooked hair projects: these are especially conspicuous upon the 

 sides of the head, and upon the projecting triangular labrum. 

 The figure shows very plainly the mid-dorsal and lateral splits 

 which take place in the cuticle at ecdysis. 



As at hatching, so also at the beginning of the second instar, 

 the three thoracic segments are approximately equal in size, the 

 prothorax being somewhat longer and narrower than the other 

 two. After a meal, the meso- and metathorax swell up, like the 

 abdomen. But the prothorax can only swell up posteriorly, the 

 neciv-constriction remaining unchanged; so that this segment 

 soon becomes much narrower than the other two. The legs 

 remain small, and formed as in the first instar, with un jointed 

 tarsi. 



The abdomen is at first fairly slender and tapering towards 

 the anus. As the larva feeds, it swells up rapidly, and assumes 



