122 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



doubts of the Devonian character of the Old Red sandstone of New 

 York when he had previously announced his conviction of the equiva- 

 lency of the Marshall and Chemung groups, and of their common Car- 

 boniferous character. Since that time the confirmation of his doubts 

 led Winchell to include within the Marshall (Chemung) group the Old 

 Red sandstone of New York. 



In his researches among the rocks of this age, the writer found an 

 almost universal generic identification, establishing fully the equiva-' 

 lency of the Chemung, Marshall, Ohio, Rockford, Burlington, and 

 Chouteau strata. He gives as evidence that these localities are all of 

 Carboniferous age : " First, the fact that of the 135 species now known 

 from the yellow sandstones of Burlington no less than 40 ascend into 

 the base of the Burlington limestone, while 2 rise to the upper portion 

 of it, and 1 recurs in the Coal Measures ; second, the fact that of the 

 known species of this horizon, at least 9 occur in the Coal Measures, or 

 upper part of the Carboniferous limestone ; while third, multitudes of 

 species are clearly the local representatives of European and American 

 Carboniferous types." Mr. HalFs declaration in the Canadian Naturalist 

 "that large areas of the rocks of New York hitherto regarded as Che- 

 mung, do really fall within the limits of the Hamilton group," is said 

 to account for the Devonian aspect of some portions of the Chemuug 

 fauna, as heretofore understood, and, Winchell adds, " tends to con- 

 firm a broad generalization, and complete the adjustment of American 

 to European Paleozoic formations." l 



Mr. James Hall 2 in 1870 announced that he had previously regarded 

 the so called "Montrose sandstone" (of Pennsylvania) and "Oneonta 

 sandstone" of Vanuxem as lying above the Chemung rocks. The same 

 views were held by Mr. Mather, who made the Montrose and Oneonta 

 series equivalent to the upper part of the Catskill rocks. Further ex- 

 amination proved this conception of their relations to be erroneous and 

 brought out the following parallelism of the groups in the eastern and 

 western parts of the State : 



Old Red sandstone of Tioga, etc. : 

 Chemung group. 

 Portage group. 

 Hamilton group. 



Catskill Mountain sandstone: 

 Chemung group. 

 Oneonta group. 

 Hamilton group. 



The Oneonta sandstone does not occur in the central part of the State, 

 and its western extension has not been traced beyond Chenango County. 



In 1875 Mr. Hall 3 again referred to the age of the Catskill formation. 



In 1870 it was the prevalent opinion that, contrary to the author's 

 statements, the Old Red sandstone did not exist in New York State. 



1 Regarding the development of Winchell's views on the correlations here announced, see the chapter 

 on the Waverly Problem. 



2 flail, James : On the relations of the Oneonta Sandstone and Montrose Sandstone of Vanuxem 

 with the Hamilton and Chemung groups. Am. Nat, vol. 4, 1870, pp. 563-565. 



3 On the geology of the southern counties of New York and adjacent parts of Pennsylvania ; espe- 

 cially with reference to the age and structuro of the Catskill Mountain Range. Am. Assoc, Proc, vol. 

 24, pt. 2, pp. 80-84; Am. Jour. Sci., 3d ser., vol. 12, 1876, pp. 300-304. 



