190 THE ILLINOIS GLACIAL LOBE. 



stages, even if less prolonged than some of the earlier stages of deglacia- 

 tion. Should it be proved to represent the interval between the Iowan and 

 Wisconsin deposits, as now seems probable, the evidence above cited, from 

 the peripheral portion, may aid in determining its length, namely, the 

 leaching and erosion of the Peorian stage. As yet the fauna and flora 

 buried beneath the peripheral portion of the Wisconsin drift have received 

 little or no attention. Possibly by the aid of this line of study the ques- 

 tion of correlation may be settled. 



