557 IL6b 

 no. 90 



TATE OF ILLINOIS 1964 



feSES*®/ DEPARTMENT OF REGISTRATION AND EDUCATION 



Spores in Strata of 



Late Pennsylvanian Cyclothems 



In the Illinois Basin 



R. A. Peppers 



BULLETIN 90 

 ILLINOIS STATE GEOLOGICAL SURVEY 



URBANA, ILLINOIS 



