PLATE LI.— To face page 152. 



1 



i 



I Upper 

 i Clinton 

 I green 

 ■ shale. 



J 



<. Lower 

 ! Clinton 

 I limestone. 



I 



J 



| Iron ore. 

 1 Green 

 I Clinton 

 f shale. 

 { Grey 

 Medhm. 



.Red 

 Medina. 



Webster & Albee, photo. 



GORGE OP THE GENESEE RIVER, MONROE CO. , BELOW THE LOWER FALLS. 



and Clinton Groups. 



Medina 



