ILLINOIS BIOLOGICAL MONOGRAPHS 



VOLUME 3 



19o Scatophaga 



s €ter^ 



M;jSC3 



;r 194 



pd sc 



Hydrotaea 



195 



196 



lc/7 Archytas 



206 



ChironomusS 



208 



203 



Bibiocepha'.a 



SP? 



Simultum 





209 



Rhyphus 



\ 



205 



Sciara fl 



^=0 



Psorophora 9 



pd sc 



<c 1 1 Psorophora i 



PETERSOX HEAD AND MOUTH PARTS OF DIPTERA PLATE X 



