wn America and Europe. 278 
adopted by Logan, and by the present writer. The belt of mi- 
caceous, chloritic, taleose and epidotic schists, with greenstones 
and serpentines, the extension of a part of the Azoic of Rogers, 
which, through western New England, is traced into Canada 
(where it has been known as the Green Mountain range), was 
previous to 1862, called by the geological survey of Canada, 
Altered Hudson-River group. It was subsequently referred to 
the Upper Taconic of Emmons, to which Logan, at that date, 
gave the name of the Quebec group, assigning it, as had long 
before been done by Emmons (in i846) to a horizon between 
the Potsdam and the Trenton of the New York system. 
In 1862 and 1863 appeared, independently, two important 
papers bearing on the question before us as to the age of these 
s 
Canada, with portions of the Urschiefer or Primitive schists 
which, in Norway, intervene between the ancient gneisses and 
the oldest Paleozoic (Lower Cambrian) strata. The second 
views of Keilhau on these rocks of N orway in “The Geology 
of Canada” in 1868, with farther Somparieet between the New 
pielend crystalline schists and the 
line schists was being made known in southern New Brunswick, 
Where they were described by G. F. Matthews in 1863, under 
the name of the Coldbrook group, which included a lower and 
an upper division. In a joint report of Matthews and Bailey 
in 1865, these rocks were declared to be overlaid unconforma- 
bly by the slates in which Hartt had made known a Lower 
Cambrian (Menevian) fauna, and were compared with the Hu- 
roman of Canada. The lower division of the Coldbrook was 
then described as including a large amount of pink i, 
quartzite and of bluish and reddish porphyritic slates. In the 
Same report was described, under the name of the Bloomsbury 
8roup, a series lithologically similar to the Coldbrook, but ap- 
rt, resting on the Menevian, and overlaid by fossiliferous 
Pper Devonian beds, into which it was supposed to grad- 
uate. The Bloomsbury group was therefore regarded as altered 
Upper Devonian, and its similarity to the pre-Cambrian Cold- 
