316 On the Geology of the Northwestern Regions of America. 
of the British Museum, and the late Professor Jameson of Edin- 
burgh. A considerable number remain still undescribed in the 
Museum of the Edinburgh University, the British Museum, the 
Museum of Practical Geology in Jermyn Street, and the Museum 
of Haslar Hospital, or aré mentioned for the first time in the 
present paper. 
An examination of these specimens leaves no doubt of the 
existence of a vast development of paleozoic deposits, extending 
with little intermission (so far as is known) from the northern 
frontiers of Canada and the United States to the farthest point 
to which our researches have extended in the Arctic Ocean, and 
from Hudson’s Bay on the east to near the Rocky Mountains on 
the west,—presenting altogether a geological horizon of a grand- 
eur and extent unequalled probably in any other part of the world, 
largely as the researches of Sir Roderick Murchison, Sir Charles 
Lyell, and others have shown such formations to be developed in 
Russia and the United States. 
A slight sketch of the chief physical features of this wide re- 
gion will demonstrate the remarkable symmetry and unbroken 
condition of its sedimentary deposits, and to what an unusual 
degree they have apparently been exempted from those igneous 
disturbances which have complicated} the geological structure of 
aA other countries of far less extent in other parts of the 
world. 
TERRITORIES EAST OF THE ROCKY MOUNTAINS. 
Physical Features ; and Range of the Crysialline Rocks.— 
Separated from Canada by the great granitic range of the Lau- 
rentine or Canadian Mountains, which form the division between 
the hydrographic basins of these northern regions and those of 
the St. Lawrence and its great lakes, the Hudson’s Bay Tertito- 
ries may be considered as forming one vast plain, diversified ouly 
by a single low granitic ridge running northwards from the west 
end and almost the whole north shore of Lake Superior,as far as 
Great Bear Lake, in a direction nearly parallel with the range of 
near the mouth of the St. Lawrence, is deflected northwards in & 
direction again nearly parallel with the Rocky Mountains through 
Labrador and along the shores of Hudson’s Straits and Baffin’ 
Bay until it finally disappears beneath the limestones of Lancas- 
ter Sound and Barrow’s Straits. The striking correspondence 
between the direction of this granitic range, as thus traced, and 
the general contour of Hudson’s Bay will be at once obvious from 
