29 



CHAPTEE XVIII. 

 Geology of Henderson County, H. A. GREEN 276-287 



CHAPTER XIX. 

 Geology of Warren County, H. A. GREEN 288-300 



CHAPTER XX. 

 Geology of Mercer County, H. A. GREEN 301-312 



CHAPTER XXI. 

 Geology of Knox County, H. A. GREEN... 313-324 



CHAPTER XXII. 

 Geology of Stark County, H. A. GREEN 325-333 



CHAPTER XXIII. 

 Geology of Woodford County, H. A. GREEN 334-342 



PART II PALAEONTOLOGY OF ILLINOIS. 



SECTION I. 



Descriptions of Vertebrates, J. S. NEWBERRY and A. H. 

 WORTHEX 346-374 



SECTION II. 

 Descriptions of Plants, LEO LESQUEREUX 377-508 



30. A. H. WORTHEN. 



Remarks on the Relative Age of the Niagara and the so- 

 called Lower Helderberg Groups. Proc. Am. Assoc. Adv. 

 Sci., 19th Meeting, Troy, N. Y., pp. 172-175, Cambridge, 

 1871. 



31. Geological Survey of Illinois, A. H. WORTHEN, Director, 



Vol. V, Geology and Paleontology, pp. i-iii and 1-619, 

 Plates H, and I-XXX1I, Imp. 8vo., Chicago, 1873. 



CONTENTS. 



PART I. 

 Letter to the Hon. John L. Beveridge iii 



