OHAFTE^R IV. 



OBSERVATIONS UPON THE SO-CAEEED WAVEREY GROUP 



OF OHIO. 



By Prof. C. E. Herrick, Denison University, Granville, O. 



Introduction. 



It is proper to say that the following pages were prepared, at the 

 request of Professor Orton, as a summary of results arrived at in the 

 course of a number of years of desultory exploration among the sub- 

 carboniferous and infra-carboniferous rocks of Ohio. These studies oc- 

 cupied such intervals of time as could be filched from a laborious pro- 

 fessional life and cannot be said to have had much coherency or system. 

 The results, such as they are, have been published in the Bulletins of 

 Denison University, the American Geologist, and the Bulletins of the 

 American Geological Society. That these studies have contributed 

 something to the solution of a vexed problem of long standing is to be 

 attributed, first, to the method employed, viz.: the strict coordination 

 and mutual supplementing of paleontological and stratigraphical data. 

 In a region where, in the nature of the case, lithological characters are 

 inadequate and unreliable, the necessity of minute and pains-taking study 

 of the organic remains of each horizon is imperative. Such detailed 

 stud}- is chiefly desirable from a biological standpoint and the compara- 

 tively small amount of ..work done in the present case is sufficient to 

 prove that there is a most interesting field for the study of evolutional'}' 

 changes in the Waverly rocks of Ohio. It is only the uninitiated who 

 need to be w r arned that in strata apparently barren of fossils the labor in- 

 volved is enormous. The writer will, perhaps, never hope to again have 

 the patience to examine, literally inch by inch, acres of shales as has 

 been done in the prosecution of this study. The second fortunate ele- 

 ment in our work has been the circumstance that it was begun in a 

 typical portion of the series where the (hitherto over-looked) landmarks 

 separating important subdivisions are conspicuous. The fact that the 

 Waverly has been most often studied as exposed in the northern p?rt of 



