1887] l The Taconic Question Restated. 243 
his Primordial group is only Lower Silurian. I conceive that 
we have exactly his Primordial group in the band of slates con- 
taining the Paradoxides.” (Olenellus.) 
§ 20. The study of these Upper Taconic rocks in the province 
of Quebec by the geological survey of Canada was carried on in 
the vicinity of the city of Quebec in 18 52-1855, the present writer 
being at intervals an assistant to Logan in his field-work in that 
district. The official reports of Mather and Emmons on the geol- 
ogy of New York were then repeatedly consulted, and the Ta- 
conic system of the latter being then generally discredited, the 
passages in accordance with the views of Mather, which, as we 
have already noticed, are to be found on certain pages of that 
volume, were alone accepted, and the Graywacke series of Quebec 
and its vicinity was referred to the horizon of the Second Gray- 
wacke of Eaton. This great thickness of contorted shales and 
sandstones, with intercalated limestone and dolomite beds, al- 
ready described, in 1827, by Bigsby as “a slaty series of shales 
and graywacke,” was then called Hudson River group, and as- 
signed to a position above the horizontal and well-characterized 
Utica and Trenton divisions found a very few miles away on the 
west side of the St. Lawrence, while the green sandstones which 
apparently overlie these inclined strata were designated Oneida 
sandstone. They were thus described and mapped in the “ Es- 
quisse Géologique du Canada,” bearing the names of W. E. 
Logan and the present writer, but prepared by the latter, and 
published in Paris in 1855. 
§ 21. The great belt of disturbed strata described, in 1827, by 
Bigsby as “a slaty series of shales and graywacke,” which by 
the united labors of Eaton, Emmons, and Logan had now been 
traced with little interruption from the banks of the St. Lawrence 
below the city of Quebec, along the west side of Lake Cham- 
plain, and thence nearly to the Highlands of the Hudson, con- 
stituting the Upper Taconic of Emmons and the larger part of 
the Hudson River group of Vanuxem. That this, contrary to 
the teachings of Eaton, but in accordance with the views of . 
Mather, was regarded as above, and not below, the horizon of 
the Trenton limestone appears, from James Hall's Report to the 
geological survey of Canada, published in 1857, on the grapto- 
* Letter of Emmons to Marcou, November 20, 1860, in Marcou’s “ Taconic 
VOL. XXI.—NO. 3. 17 
