JUL 25 19ir 



Bulletin 



OF THE 



Illinois State Laboratory 



OK 



Natural History 



Urbana, Illinois, U. S. A. 



STEPHEN A. FORBES, Ph.D., LrL,.D., 

 Director 



Vol. XII. f June, 1917 Article IV. 



THE 7.YGOPTERA, OR DAMSEE-FI^IES, OF IL,L,INOIS 



BY 



Philip Gakman, Ph.D. 



