Fig. 24 



Fig. 25 



Fig. 26 



Fig. 24 — A Black-fly (Simulium sp.). (From Kellogg's Amer. 

 Insects.) 



Fig. 25 — Screw-worm fly (Chrysomyia macellaria). 

 Fig. 26 — Blow-fly (Calliphora vomitoria). 



