THE CANADIAN ENTOMOLOGIST. 



133 



of rectUi7i€a on the other hand show apparently a marked tendency to 

 obsolescence, and we possess several Illinois specimens in which we can 

 detect but the merest trace of white on the veins ; in fact, were it not for 

 locality, they might easily be mistaken iox phyllira. Continued breeding 

 will be necessary to decide the question as to whether the above mentioned 

 larval distinction holds good. 



In the accompanying sketch we give a diagram of the position of the 

 primary tubercles in the first stage oi phyllira ; this is apparently typical 



Fig. 



4. Prothoracic plate. 



5. Small plate. 



for the genus Apaniesis, at least it holds good for all the species that are 

 discussed in this present paper. On the meso- and metathoracic segments 

 tubercles I and II coalesce forming a single wart with two seta^ ; on the 

 abdominal segments, I and II are separate, the former being minute ; III 

 contains two setœ, a typical Arctian feature ; IV is immediately behind the 

 spiracle, V directly below IV, each one with seta ; VI is absent and VII 

 is represented only on those abdominal segments which bear no prolegs 

 as a minute seta ; on the thoracic segments VII is a more prominent wart 

 with two setae. On the prothorax and 9th and loth abdominal segments 

 considerable reduction of the tubercles takes place. In the following 

 descriptions if no reference to the position of the tubercles is made, it 

 may be taken for granted that they correspond with the above diagram. 



Ovum. — Conical from a flat base ; yery slightly sculptured ; pale 

 yellow, shiny, with no colour change until just previous to emergence 

 when it becomes blackish ; deposited promiscuously on the ground. 



Stage I. — Head black with sparse setae ; body pale greenish brown 

 with blackish tubercles and large black thoracic plate, this latter contain- 

 ing 8 black setae arranged in an anterior and posterior row of four. On the 

 thoracic segments the setae of tubercles I, II and III are black, the others 

 being white ; on the abdominal segments I-IX tubercle II contains a 



