118 The American Geologist. Fcbinaiy, is97 
)>art, perhaps even in totality Triassic. or the upj)er ])ortion 
may belong to the Jura. The Gw^medd shales represent the 
whole Trias of Europe. To correlate it with only the small 
Rhetic group is an error, due to a too narrow interpretation 
of fossil plants and their true stratigraphical positions in the 
beds of the Gwynedd shales, where they are scattered all over 
the 3,500 feet. As to the 6,100 feet of Norristown shales, they 
represent the Chatham series of North Carolina, and can be 
safely correlated with the Dyas (Permian) of Europe. 
West of the Mississippi river the New Red sandstone was 
not discovered until 1853, when ond*of-the parties of the Pa- 
eitic Railroad exploration in following the 35th degree of lat- 
itude brought out the fact of the existence in the Indian ter- 
ritory, Texas, New Mexico and Arizona of a series of 6,000 
feet, divided into 5,000 feet of Trias and 1,000 feet of Dyas 
(Permian). In 18ft3 an exploration of Nebraska proved there 
the existence of the Dyas, south of the Platte river, more spe- 
cially at Nebraska city. Those two discoveries, made by the 
present writer, evoked one of those too numerous passion- 
ate critiques from the two recognized leaders of American 
geology, Messrs. James Hall and James D. Dana, who, with 
the help of Messrs. Newberry, Meek, Blake and others, made 
the most stupendous and unreasonable opposition. As a re- 
sult arrived at by their observations and researches in the field 
and in the laboratories, they caiue to the conclusion that the 
series of beds, instead of representing the Dyas and Trias, 
belonged to the Lower Cretaceous (Dakota formation, the 
American equivalent of the Turonian of France) and to the 
Carboniferous. Such a correlation would have been only 
comical if it had not stopped for a quarter of a century, and 
more, the progress of American geology, and had not brought 
before the International Congress of Geologists at Berlin, in 
1885, the emphatic and most positive declaration from Messrs. 
James Hall and Newberry that the Permian (Dyas) did not 
exist anywhere in North America. A single quotation of one 
tj^pical locality will suffice as an example. The section at 
Nebraska city, with descriptions of fossils and plates, was 
published in 1864-'66 and '67 at Paris and Dresden (Saxony), 
and all European geologists, more specially the German and 
Russian — where are the typical localities of the Dyas — recog- 
