Biological Notes No. 81 
ANNOTATED CHECKLIST OF THE 
BUTTERFLIES 
OF ILLINOIS 
Roderick R. Irwin © John C. Downey... .... 
ILLINOIS NATURAL HISTORY SURVEY 
URBANA, ILLINOIS MAY, 1973 
STATE OF ILLINOIS 
DEPARTMENT OF REGISTRATION AND EDUCATION 
NATURAL HISTORY SURVEY DIVISION 
juL 2 6 1973 Oe OGY LIBRARY 
