ILLINOIS BIOLOGICAL MONOGRAPHS 



VOLUME 3 



251 



Psorophora 



<c*ib Dolichopus 



""— ^ =^ ar -^^j^s. sc ar / Sarcophaga 



227 oecoihca ( vyO I 244 



Sapromy/a 



248 



249 Ollersia Bibiocrphala* 



PETERSON" HEAD AND MOUTH PARTS OF DIPTERA PLATE XI 



