VII 



adorns the "Appendix." The original pen-and-ink drawing; by the 

 eminent artist JACQUES REICH, of New York, which drawing is 

 the property of this office, was placed at their disposal for the 

 purpose of being reproduced. 



The index of the PAL^OCRINOIDEA in Vol. VIII, Part II, Sec- 

 tions 1 and 2, was revised by Mr. CHARLES WACHSMUTH, and 

 those of the SPOXGLE and BRYOZOA in Sections 3-6, by Mr. E. 

 0. ULRICH. In preparing the "General Index," I at first simply 

 consolidated the indices of the eight volumes into one. But 

 finding that such a consolidation would by no means answer 

 the purpose, I undertook to revise every item and make numer- 

 ous additions and re-arrangements, as well as orthographic 

 corrections of pateontological names. This extremely tedious 

 and time consuming work was done last fall when I had reasons 

 to hope that the volume would be published before the end of 

 last year. The index is therefore less elaborate than I would 

 have made it, had I known then that I could spend much more 

 time on it without delaying the printers. As it is, I trust it 

 will still be found of value. 



The Geological Map of Illinois, published in 1875, and distri- 

 buted with Vol. VI. of these reports, has long been out of print, 

 and I have been unable to fill the frequent requisitions from 

 scientists, schools, libraries and private applicants, most of 

 whom have stated that they have the set of reports but not 

 the map. I have therefore added to this volume a reproduc- 

 tion of the old map but on a smaller scale (32 miles =1 inch 

 the scale of the old map being 6 miles =1 inch) and with 

 the geological formations represented by a system of lines of 







shading, instead of by colors. Although the map is copied 

 with as much accuracy as was regarded practicable and desir- 

 able, I have prefixed the word "Approximate" to its title. 

 It is evident that even the original map was never intended to 



B 



