E. Hargreaves 



315 



Spines. In addition to marginal, are four pairs arranged — a long 

 dorsal pair over the anterior end of the mouth-parts; a dorsal short 

 pair on the first abdominal segment ; a dorsal long pair at the anterior 

 angles of the vasiform orifice; a ventral pair beneath the vasiform 

 orifice. 



Dorsal pores. Twelve pairs situated — a pair over the sides of the 

 mouth-parts near the middle line; a pair anterior to the bases of the 

 antennae, and a pair just anterior to them; a pair near each pair of 

 thoracic spiracles; a pair towards the middle of the first abdominal 

 segment; a pair each in the third, fourth, fifth and sixth abdominal 



t t^Hs 



Fig. 26. Fourth instar. 



segments; a pair immediately posterior to the sixth abdominal seg- 

 ment ; a pair at the sides of the vasiform orifice. 



Breathing folds. There is a pair of these folds opening opposite the 

 anterior pair of spiracles, and the lumen of each extends alongside the 

 thorax to the first abdominal segment. I could not find a posterior 

 fold. (See below.) 



Instar IV (Fig. 26). 



This stage, which may be taken to be the equivalent of the 

 pupal stage of other insects, differs very much in appearance from 

 those preceding. When newly emerged there are eleven pairs of 



