l8 BULLETIN OF THE LABORATORIES 



Let it be observed that, in our opinion, the diversity of opinion 

 as to the affinities of the Waverly Group is very largely due to the 

 vain attempt to regard it as homogeneous and the failure to distin- 

 guish the Berea Grit from the sandy upper layers — Logan. 



Finally Prof. Hall, in Vol. V, of the Palaeontology of New York, 

 seems to withdraw quite fully from his early view of the identity of 

 the Waverly of Ohio with the Chemung of New York, (always com- 

 paring our Middle and Upper members — the lower being considered 

 unfossiliferous.) He says : 



" A careful examination of those species supposed to have a ver- 

 tical range from the Chemung group to the Waverly group, has shown 

 that they are allied forms but specifically distinct." He nevertheless 

 admits that the genera are identical with those of the Chemung, only 

 four genera of lamellibranchs being found in the Waverly not also 

 found in the Hamilton or Chemung. The series accessible to Prof. 

 Hall was also very incomplete. 



If it should prove that many Chemung forms persisted in Ohio 

 long after the shallowing waters of New York were unfitted for them 

 and that forms of carboniferous habit were gradually introduced it 

 would only furnish another to the long list of similar instances stand- 

 ing to the credit of evolution. 



For an extended and very valuable discussion of the age of these 

 rocks, see Winchell's papers in Proc. Philos. Soc. \'ols. XI and XII, 



1870. 



That the series of freestones and shales with occasional inter- 

 spersed bands of conglomerate which occupies a belt of 250-^^00 feet 

 below the coal measures is really homogeneous may have been doubt- 

 ed, but it is left for the present occasion to point out the nature of the 

 variations in the fauna. The stratigraphy of the Waverly as seen in 

 central Ohio may now be confidently regarded as correctly determined 

 in at least its general contours. The interest attaching to the Waverly 

 grou]j as affording a transition from Devonian to carboniferous faunae 

 under peculiar conditions will naturally be greatly enhanced if within 

 its own limits transitional forms or facies can be discovered. To 

 gather facts instructive upon this j)oint it is necessary, first of all, to 

 identify continuous and unmistakable horizons. To this end we first 

 directed attention, and found such reference lines in two narrow bands 

 of conglomerate separated by an interval of from 38 to 50 feet, which 

 includes the quarry rock or freestone employed in this county. 



