THE CARBONIFEROUS SYSTEM. 85 



geologists was formed by the State of Ohio, and while the geology of this 

 State remained comparatively unknown, the different parties in the dis- 

 cussion could not be brought on to common ground for the adjustment of 

 their differences. The reorganization of the Geological Survey of Ohio 

 was, therefore, regarded with some interest by the geologists of the coun- 

 try as likely to throw new light upon this vexed question, and such as 

 would lead to its final settlement. When, therefore, the directorship of 

 the survey was intrusted to me, the work of tracing the geographical 

 extent and investigating the structures and fossils of this group was one 

 of the first that claimed my attention. 



A careful study was made of the southern prolongation of the Waverly 

 by Prof. Andrews and his assistants ; a study which was continued north 

 of the National Road and carried to the eastern line of the State, and 

 thence far into Pennsylvania and New York, by myself and those imme- 

 diately associated with me. "We found the Waverly far more rich in fos- 

 sils than had been before supposed, . and obtained from it, perhaps, a 

 larger number of species than has been furnished by any other of our 

 formations. Of these some were new to science, while others had been 

 described from collections made in our State by different geologists in 

 years past, or had been obtained in other States from strata now for the 

 first time identified with this by such a community of fossil forms as 

 these common species proved. 



The first result of our study of the Waverly was to show that all its 

 rich fauna is of a decidedly Carboniferous type ; second, that it includes a 

 humber of species characteristic of the Lower Carboniferous rocks of Ken- 

 tucky, Tennessee, Illinois, Iowa, and Michigan ; third, that it furnishes, 

 at nearly all of its fossiliferous localities certain species which are also 

 common in the Coal Measures above ; fourth, that our collections made 

 include no Chemung or Portage species; fifth, that it is continuous with 

 the " Vespertine " and " Umbral " rocks (Lower Carboniferous) of Pennsyl- 

 vania, with the " Sub-Carboniferous sandstones and shales " of Kentucky, 

 and with the " silicious member of the Lower Carboniferous group " of 

 Safford, in Tennessee. Hence we are compelled to regard it as a mem- 

 ber of the Carboniferous system, and as distinct from the rocks of New 

 York, with which it has been so generally supposed to be identical. 



In the prosecution of this investigation, after we had carefully traced 

 the different members of the Waverly group to the line of Pennsylvania, 

 one of my assistants, Mr. A. Sherwood, went to his former home, in Tioga 

 county, Pennsylvania, and took up a line of observation at this point. 

 The geological structure of this region is as follows : The Chemung group 

 forms the bottoms of the valleys. On this rests the Catskill group, 300 



