ILLINOIS BIOLOGICAL MONOGRAPHS 



VOLUME 3 



oe.p 



oe.p 



Hypothetical 



493 



TabanusS 



494 



Tabanus* 



495 



Tabanus $ 



496 



Simulium 



497 



Psorophora? Psorophora 



504 505 



Geranomyia 



506 



Limnobia 



507 



ep 

 Rhyphus 



508 



Rhyphus 



509 



PETERSON HEAD AND MOUTH PARTS OF DTPTERA PLATE XXI 



