248 The Taconic Question Restated. [March 
western border in New York, but are found thereon in small un- 
conformably overlying areas, as was admitted by Hall in 1862. 
§ 26. These facts regarding the relation of the Loraine shales 
to the great Graywacke belt were set forth by the writer in 1878. 
It was at the same time shown that within the limits of this belt, 
in the province of Quebec and in Vermont, there were found 
organic forms ranging from a horizon at least as low as the Pots- 
dam (the Olenellus or Lower Potsdam beds of Billings, which 
were the Paradoxides beds of Emmons) to the Phyllograptus 
shales (belofging to the horizon of the Arenig or Skiddaw of 
Great Britain), without counting the fossiliferous beds at Farn- 
ham, Quebec, assigned by Logan to the base of the Quebec 
group, but shown by Billings to be not lower than the Trenton. 
In other words, it was set forth that this First Graywacke, other- 
wise called the Taconic slate group, Upper Taconic and Quebec 
group, had been by Emmons, as long ago as 1842, declared to 
belong to the age of the Silurian of Murchison; that he had 
shown it in 1844 to contain in its various subdivisions trilobites, 
grapolites, and fucotids, and had in 1860 referred the same 
Taconic slate group to the Primordial zone, or so-called Primor- 
dial Silurian of Barrande. Still further, it was shown that it had 
been maintained by Emmons in 1844, and confirmed by Billings, 
that within this belt were accidentally included unconformable 
portions of post-Trenton fossiliferous strata of the Champlain 
division. 
It was further pointed out by the writer in illustration of these 
facts that similar conditions appear in the basin of the Ottawa, 
near the city of that name, where, as the result of an uncon- 
formity between the upper and lower members of the Champlain 
division, a belt twenty miles long of shales and sandstones, 
carrying the fauna of the Utica and Loraine subdivisions, is 
found lying transgressively alike on the Trenton, Chazy, and 
Calciferous subdivisions, as long ago shown by Logan. 
$ 27. The observations of Ford, Dwight, and Dale along the 
great Graywacke belt to the east of the Hudson, in the State of 
New York, which show, besides a Cambrian fauna of Potsdam 
and Calciferous age, the presence of small areas of strata belong- 
ing to the higher divisions of the Champlain divisions, are thus in 
direct confirmation of the original statements of Emmons, the later 
determinations of Billings, and my own teachings. They show 
