GEOLOGICAL SURVEY OF ILLIIOIS. 



A. H. WOETHEN, Director. 



VOLUME VI. 



GEOLOGY AND PALEONTOLOGY, 



GEOLOGY, 



By A. H. WORTHEN, and Ass'ts G. C. BROAMEAD and E. T. COX. 



PALEONTOLOGY, 



By ORESTES St. JOHN, A. H. WORTHEN and F. B. MEEK. 



ILLUSTRATED 



BY JULIUS MAYER & CO., BOSTON, MASS. 



PUBLISH ED 



BY AUTHORITY OF THE LEGISLATURE OF ILLINOIS. 



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