1880.] 1"»^ [White. 



By a singular fatality, it also happened that the supplemental Report of 

 Prof. Orton on the Hanging Rock district of Southern Ohio came into my 

 liancls at about the same time. 



It is well known that in the Report in question Prof. Orton takes the 

 ground (in which he was also sustained by the Chief Geologist, Prof. New- 

 berry), that the Jackson shaft coal of that State is of Sxibcarboniferous age, 

 since, as he maintained, its place comes below the horizon of the Maxville 

 (Cheater) Limestone of Andrews, and as the Maxville was placed in the 

 section about 100' above the Jackson shaft coal, I supposed there could be 

 no doubt about it. 



I also knew that wherever the Jackson shaft seam was placed, the Sharon 

 must go with it, since the general stratigraphy, the flora connected with each, 

 and everything else found in connection with Ihem go to prove that they 

 are identical. 



Then the fact that Prof. Orton placed the Maxcille Limestone ihe same dis- 

 tance below tlie Zoar Limestone (= our Lower Mercer) that I had found 

 the neto limestone below our Lower Mercer, strengthened the supposition 

 that it might be synchronous at least with the Maxville. 



And in order to bring out these new facts, I prepared a special chapter 

 for my Report on Mercer countj^, QQQ, entitled "The Place of the Sharon 

 Coal in the Rock Series," in which the fiicts were given tliat seemed to 

 favor the view that the Sharon Coal was of Sibhcarhouiferous age, and 

 the Conglomerate below it. Vespertine. 



Before the volume was published, however, I had studied the matter 

 still farther in the Crawford and Erie district, as well as elsewhere, and as 

 before stated, saw reasons for the giving up the probability of its Subcar- 

 boniferous age. I accordingly requested Prof. Lesley to suppress the 

 chapter in question, as its publication at that time would have done more 

 harm than good. Hence QQQ was allowed to leave the press with Chap. 

 VII stricken out. In the meantime Prof Orton has written me that he will 

 have to give up the position tliat he took in Vol. Ill, of the Ohio survey 

 Avith regard to the Subcarboniferous age of tlie Jackson shaft coal, and 

 with that abandoned there remains so little evidence that the Sharon coal 

 is Subearbonifr roits, that for the present it is not worth serious considera- 

 tion. 



The foregoing explanation is relevant in this connection because of the 

 currency given in Prof. Lesley's preface to QQ, to the views expressed in 

 the afterwards discarded Chapter VII, of QQQ. 



But while it thus appears that the SJiaron Conglomerate is the true base 

 of the Carboniferous epoch propei', it must also be remembered that like 

 the Sharon coal resting on its top, it seems to have been a deposit peculiar to 

 the northern rim of the Coal measures, everywhere skirting them around the 

 north, but seldom passing far south under them, so that although toward the 

 north the succession is definite enough, and it is plainly seen that the Subcar- 

 boniferous rocks end with the base of this stratum, yet toward the south in 

 the absence of this rock the Subcarboniferous beds, with tlieir fossils, extend 



