424 CHARLES S. PROSSER 



in the southeastern corner of the peninsula, 1 and entering Ohio 

 at about the locality where the Hamilton or upper part of the Cor- 

 niferous has been represented on the state maps. Since then Pro- 

 fessor Sherzer has given a more detailed account of the "Traverse 

 (Hamilton) group" of Monroe County, Mich., in his geological 

 report of that county. 2 



In 1902 Professor Weller published a paper on "The Composition, 

 Origin, and Relationships of the Corniferous Fauna in the Appa- 

 lachian Province of North America," in which he stated that "in 

 Ohio the fauna occurs in the Columbus limestone." 3 The Delaware 

 limestone was not mentioned, and apparently he did not consider 

 its fauna as that of the Corniferous. Professor Claypole, in his 

 account of "The Devonian Era in the Ohio Basin," stated near the 

 close of the section devoted to "The Corniferous Limestone," that 

 what has already been said must not be referred to the whole mass of strata which 

 have usually been classed under the name Corniferous in Ohio geology, but only 

 to that part lying below the bone-bed and to the bone-bed itself. 4 

 The division succeeding the bone-bed Professor Claypole called 

 "the Corniferous-Hamilton period," and stated that "the period 

 was, in Ohio, evidently one of transition." 5 His correlation of the 

 several members of the two periods is shown in the following table: 



Shale at Prout's Station - Hamilton 



Blue limestone, thin-bedded - Corniferous-Hamilton 



Dublin blue [brown] shale - - - Marcellus 



Bone-bed ------ Corniferous 



Gray and buff limestones - Corniferous 6 



The same year Professor Schuchert, in his paper on "The Faunal 

 Provinces of the American Middle Devonic," apparently accepted 

 Whitfield's correlation of the Devonian limestones of central Ohio. 7 



Finally, in New York state, which is the standard one for the 

 correlation of the American Devonian, the geographic name of 

 "Onondaga limestone" has been adopted in place of "Corniferous 



1 Water-Supply and Irrigation Papers, U. S. Geological Survey, No. 30 (1899), 

 -Plate VI. 



2 Geological Survey of Michigan, Vol. VII, Part I (1900), pp. 31-35. 



3 Journat of Geology, Vol. X, p. 424. 



4 American Geologist, Vol. XXXII (1903), p. 31. 



5 Ibid., p. 35. 6 Ibid., p. 35. 7 Ibid., p. 148. 



