162 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



Feet. 

 ( Genesee division (" Black slate " and 



f Hamilton period.. < grayish shales 100 



| ( Hamilton bed s '. 120 



Devonian system.. <( Upper Helderberg period. Corn iferous and Onondaga beds 25 



| i Oriskany, upper bed 40 



I Oriskany period.. < Oriskany, lower beds or Clear Creek 



( group 200 



Silurian system Lower Helderberg period. 



In this table the use of the term " Subcarboniferous" as meaning 

 below the coal-bearing strata is clear. The recognition of the absence * 

 of upper Devonian is to be noticed. In the Oriskany the upper cherty 

 part only of what was originally included in the "Clear Creek group" 

 is placed in the Devonian. The lower part as it arrives at Bailey's • 

 landing, Perry County, was correlated by its fossils with the " Shaly 

 limestone of the lower Helderberg group." 1 



* The authors, after the proposal of the name " Kinderhook group," 

 examined the rocks in Ohio and concluded that the u Waverly sand- 

 stone " or more properly u Waverly group," is of the same age, and sug- 

 gested that it may be necessary to adopt the earlier name. Still they 

 thiuk it wise to retain the local State names until exact parallelism be I 

 established. 



The th ird volume was published in 1868. The authors of the Geology, I 

 besides A. H. Worthen, were H. Eugelraann, H. C. Freeman, and H. M. 

 Barris. The paleontology was by Meek and Worthen. In this report 

 " Lower Carboniferous " is substituted for " Subcarbon iferous " of the 

 earlier reports. In the volume are described a number of invertebrates 

 from the Devonian, Kinderhook, and other deposits of Illinois, and 

 there are descriptions of sections for several of the counties in the west- J 

 ern part of the State. 



The fourth volume was published in 1870. Bradley and Green took 

 the place of Engelmann and Freeman. The paleontology of vertebrates 

 was by Newberry and Worthen ; of plants, by Lesquereux. " Lower/ 

 Carboniferous" and "Carboniferous system" are used to cover the 

 upper and lower divisions of the Carboniferous. 



The fifth volume was published in 1873. A. H. Worthen and James 

 Hall were the geologists, and Messrs. Meek and Worthen the paleon- 

 tologists. In this report the nomenclature is " Carboniferous system * 

 and " Lower Carboniferous system." 



The sixth volume was published in 1875. The geologists were Messrs. 

 Worthen, Broadhead, and Cox ; the paleontologists, Messrs. Orestes St. 

 John, Worthen, and Meek. 



The seventh volume was published in 1883. Mr. Worthen, the geolo- 

 gist; paleontologists, Messrs. Worthen, St. John, and S. A. Miller. 

 Addenda appear in this volume, written by Messrs. Wachsmuth and 

 Barris. 



I have noticed no particular change in the geological nomenclature 



1 Am. Jour. Sci., vol. 33, pp. xi-xu, 



