﻿PAET 
  II. 
  

  

  PALEONTOLOGY 
  OF 
  ILLINOIS, 
  

  

  SECTION 
  I. 
  

  

  DESCRIPTIONS 
  OF 
  FOSSIL 
  VERTEBRATES. 
  

  

  By 
  ORESTES 
  ST. 
  JOHN 
  and 
  A. 
  H. 
  WOBTHEN. 
  

  

  