LEAF-HOPPERS. 



81 



Family Psyllidae. These leaf -hoppers commonly live in all stages 

 on the under surface of leaves, some of them forming galls. They 



FIG. W.Psylla tripunctata. After Riley. 



are generally conical, with a broad head, with long, 10-jointed an- 

 tennaj and short legs, the hinder ones adapted for springing ; the 



FIG. 68. Seventeen-year Cicada. A. larva ; o, pupa; b, its cast skin split 

 the back; e. eggs; d, gashes made for them in a twig. All except A natural 

 size. After Riley. 



6 



