Bulletin 



OF THE 



Illinois State Laboratory 



OF 



Natural History 



Urbana, Illinois, U. S. A. 



STEPHEN A. FORBES, Ph.D., LL.D., 

 Director 



Vol. XII. June, 1917 Article IV. 



THE ZYGOPTERA, OR DAMSEL-FLIES, OF ILLINOIS 



BY 



Phiup Garman, Ph.D. 



