152 



HALP HOURS WITH E^SECTS. [Packard. 



was the so-called sub-imago ; after a few hours, if it had not 

 been placed in the collecting bottle, it would have thrown 

 off a thin pellicle, and then been sexuall}^ mature. It then 



Fig. 116. 



Fig. 117. 



Fig. lis. 



Larva and Pupa of Sialis. Larva of Palingenia. 



May Fly. 



la^-s its eggs in a round mass and dies. Some of the larvae 

 live in burrows at the bottom of ponds, while others swim 

 free. 



Coming, lastly, to the family of Dragon flies, we find 

 among the larvae the most diverse means of respiration. In 

 the young of Agrion (Fig. 119 ; a, respiratory leaf of larva) 

 the body ends in three large leaves, through the middle of 

 which runs a trachea which sends off a number of smaller 

 branches. These larvai when quite small are beautiful ob- 



24 



