74 Charles Schuchert — Historical Geology, 1818-1918. 



much hesitation, ' ' with the Oriskany and certainly with 

 the five upper members of Hall's Helderberg division, all 

 of the Erie and the Old Red Sandstone. He also adjusts 

 Hall's error by placing in the Devonian the Upper Cliff 

 limestone of Ohio and Indiana, regarded by the former 

 as Silurian. The Oriskany is correlated with the "grau- 

 wackes of the Rhine, and the Onondaga or Corniferous 

 with the lower Eif elian. Cauda-galli, Schoharie, and 

 Onondaga are united in one series ; Marcellus, Hamilton, 

 Tully, and Genesee in another; and Portage and 

 Chemung in a third. Of species common to Europe and 

 America there are thirty-nine. 



The Waverly of Ohio and that near Louisville, Ken- 

 tucky, which Hall had called Chemung, De Verneuil cor- 

 rectly refers to the Carboniferous, but to this Hall does 

 not consent. De Verneuil points out that there are 

 thirty-one species in common between Europe and Amer- 

 ica. "And as to plants, the immense quantity of terres- 

 trial species identical on the two sides of the Atlantic, 

 proves that the coal was formed in the neighborhood of 

 lands already emerged, and placed in similar physical 

 conditions. ' ' 



An analysis of the Paleozoic fossils of Europe and 

 America leads De Verneuil to "the conviction that identi- 

 cal species have lived at the same epoch in America and 

 in Europe, that they have had nearly the same duration, 

 and that they succeeded each other in the same order." 

 This he states is independent of the depth of the seas, 

 and of "the upheavings which have affected the surface 

 of the globe." The species of a period begin and drop 

 out at different levels, and toward the top of a system 

 the whole takes on the character of the next one. "If it 

 happens that in the two countries a certain number of 

 systems, characterized by the same fossils, are superim- 

 posed in the same order, whatever may be, otherwise, 

 their thickness and the number of physical groups of 

 which they are composed, it is philosophical to consider 

 these systems as parallel and synchronous." 



Because of the dominance of the sandstones and shales 

 in eastern New York,.De Verneuil holds that a land lay 

 to the east. The many fucoids and ripple-marks from 

 the Potsdam to the Portage indicated to him shallow 

 water and nearness to a shore. 



