IV 



SECTION V. 



Descriptions of Lower Silurian Sponges, E. O. ULRICH and 

 OLIVER EVERETT 253-282 



SECTION VI. 



Palaeozoic Bryozoa, E. O. ULRICH 283-678 



Index to Part I 689-691 



Index to Part II, Sections I, II 693-699 



Index to Part II, Sections III, IV and V... 701-706 



Index to Part II, Section VI 707-727 



Table of Contents to Part II, Section VI 728 



Plates I-LXXVIII and explanations. 



APPENDIX. 



The Private Life and Scientific Works of PROF. AMOS HENRY 

 WORTHEN, by N. W. Bliss and C. A. White, with a portrait 

 of Prof. Worthen, by Jacques Reich 3-37 



General Index to Geological Survey of Illinois, A. H. WOR- 

 THEN, Director, Vols. I-VIII, by Josua Lindahl 39-151 



Approximate Geological Map of Illinois. 



