ILLINOIS STATE GEOLOGICAL SURVEY. 



MONOGRAPH No. 1. PLATE XXX. 



w 



i 



IP 



d 



9 



10 



12 fa 14 



15 



16 



18 



19 



20 



24 



23 



26 27 



28 29 3O 



) 



11 



17 





25 



I 



31 32 33 



34 35 



36 37 



38 39 



54 



43 



44 45 46 47 48 49 5O 



40 41 



42 51 



52 



53 



55 



