Technical Series, No. 22. 



U. S. DEPARTMENT OE AGRICULTURE, 



BTJRE^TIT OF lCiSrTOM:OI-.OG-Y. 



L. O. HOWARD, Entomologist and Chief of Bureau. 



THE STRUCTURE OF CERTAIN DIPTEROUS 



LWIE WITH PARTICULAR REFERENCE 



TO THOSE IN HUMAN FOODS. 



BY 

 NATHAN BANKS, 



Assistant. 



Ismi'Ei) .Ianuaky 10, 1912. 



. WASHINGTON: 

 GOVERNMENT PRTNTTNG OPPICK. 

 19r2. 



