TO THE 



HON. JOHN L. BEVERIDG-E, 



governor op illinois. 



Sir: 



The sixth volume of my report on the Geological Survey of Illinois, 

 the publication of which was provided for by the 28th General Assem- 

 bly, is herewith submitted. Its appearance has been delayed by causes 

 beyond my coutrol, and mainly by the length of time required to engrave 

 the plates and map accompanying this volume, the work in this instance 

 being assigned exclusively to one engraving establishment instead of 

 being divided between two or more, as was done with the preceding 

 volume. 



Although the Palaeontology of the State is by no means completed, 

 and some departments, especially those of the corals and bryozoaus, 

 remain almost untouched, while many of our most common fossils have 

 never been fully illustrated, and the descriptions even have not been 

 published in any work now accessible to the general student, yet, in 

 consequence of the manifest desire on the part of the law-making power 

 to cut off all appropriations not deemed by them as absolutely neces- 

 sary, I have not thought it advisable to make any provision for contin- 

 uing the work beyond the publication of this volume, which includes 

 the geology of all the counties in the State not heretofore reported on. 



Moreover, important facts are constantly being developed in regard 

 to our coal resources, by experiments with the drill, and by shafts sunk 

 in various portions of the Illinois coal field, which should be collated 

 and made available for the information of the public ; for it is quite 

 impossible that a State survey covering so large an area as that pos- 

 sessed by the State of Illinois, could be carried on with the detailed 

 accuracy with which such work is prosecuted in the older countries of 



