35 



38. Geological Survey of Illinois; A. H. WORTHEN, Director, Vol. 

 Till, Geology and Palaeontology, pp. i-xi and 1-728 

 Plates I-LXXVIII. Posthumous publication, edited by 

 JOSUA LINDAHL. With an appendix, pp. 1-151, and map. 

 Imp. 8vo. Springfield, 1890. 



CONTEXTS. 



Table of Contents iii-iv 



Letter of Transmittal v-xi 



PART I. GEOLOGY. 



CHAPTER I. 

 Drift Deposits of Illinois, A. H. WORTHEN 1-24 



CHAPTER II. 



Economical Geology (Coal; Natural Gas and Oil; Artesian 

 Water), A. H. WORTHEN 25-67 



PART II. PALEONTOLOGY. 



SECTION I. 

 Description of Fossil Invertebrates, A. H. WORTHEN 69-154 



SECTION II. 



New species of Crinoids and Blastoids from the Kinder- 

 hook group of the Lower Carboniferous Rocks at Le- 

 Grand, Iowa; and A new genus from the Niagara group 

 of Western Tennessee, CHARLES WACHSMUTH and FRANK 

 SPRINGER 155-208 



SECTION III. 

 American Palaeozoic Sponges, E. O. ULRICH 209-241 



SECTION IV. 



Sponges of the Devonian and Carboniferous Systems, E. 

 O. ULRICH... ...243-251 



