336 



ARTICULATA : INSECTA. 



abdomen has two long-jointed appendages. The May- 

 flies or Ephemeridae (Fig. 455), are very short-lived, 

 living in the imago state scarcely more than a day, al- 



FIG. 456. 



FIG. 455. 



May-Fly, Ephemera. 



Stone-Fly, Pteronarcys regalis, Newman. 

 Much reduced in size. 



FIG. 457. 



Dragon-Fly, Libellula trimaculata, DeGeer. 



though their larva and pupa state extends through several 

 years, all of which they pass in the water. 



