STATE OF ILLINOIS 

 DEPARTMENT OF REGISTRATION AND EDUCATION 



DIVISION OF THE 

 NATURAL HISTORY SURVEY 



STEPHEN A. FORBES, Chief 



Vol. XV. 



BULLETIN 



Article VIIL 



An Entomological Survey of the Salt Fork of 



the Vermilion River in 1921, with a 



Bibliography of Aquatic Insects 



BY 



CHARLES P. ALEXANDER 



PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS 



URBANA. ILLINOIS 

 October. 1925 



