198 ROYAL SOCIETY OF CANADA 
Cambrian. As has been already pointed out by Dr. Selwyn, Dr. G. M. 
Dawson, and more recently by Dr. A. E. Barlow, these two formations 
which appear to overlie the Archæan unconformably, form the base 
of the palæozoic column. In the vicinity of Sudbury certain shales and 
felspathic sandstones, at times concretionary, have been ascribed to 
the Cambrian by Dr. Bell, and are so coloured in his geological map of 
that region. The rocks which constitute the Nipigon and Keweenawan 
formations consist for the most part of conglomerates, sandstones, ash- 
rock, slates, argillites, quartzites, cherts, amygdaloidal and porphyritic 
traps and diorites, and are extensively developed in the Thunder bay 
district of Lake Superior. 
The Cordilleran Region—In the Kamloops district of British 
Columbia, and in the West Kootenay, Dr. Dawson recognizes a Cambrian 
horizon in the dark argillites of the Nisconlith series (15,000 ft. in thick- 
ness), which are superimposed by 25,000 feet of volcanic rocks, described 
as the Adams Lake series. In the Rocky mountains proper, Mr. 
McConnell and Dr. Dawson have described lower, middle and upper 
Cambrian sedimentaries. In the Castle Mountain group in the Bow 
river series, along the valley of the Kicking Horse river, and near 
Donald, limestones and slates and sandstones have afforded fossil re- 
mains, which enable the geologist to recognize (1) a lower Cambrian or 
Olenellus zone; (2) a middle Cambrian or Ptychoparia zone; and (3) an 
upper Cambrian or Ogygopsis zone: In the Yale district of British 
Columbia, and in the Selkirk range, schists, sandstones, argillites, and 
limestones, constitute the Cambrian of the southern interior of the 
province. The Cambrian strata of Mt. Stephen, near Field, along the 
line of the Canadian Pacific Railway, are highly fossiliferous, and that 
locality proves to be one of the best in the world for collecting Neo- 
Cambrian trilobites which occur at about 11,000 ft. altitude. The de- 
signation Stephen formation is suggested for the trilobitic beds of shale 
and limestone with Ogygopsis Klotzi, Zachanthoides spinosus, Ptycho- 
paria Cordillerae and associated fauna. 
It is not unlikely that the quartzites and slates so prevalent in the 
gold-bearing district of the Yukon district are also of Cambrian age. 
This precise position of Paleozoic sediments in the column has not been 
definitely ascertained, but Mr. McConnell has recently defined the 
various series under the following designations in descending order :— 
Moose Hide group (in part) ; Klondike series; Hunker Creek ile 
Indian River series. 
Messrs. S. F. Emmons and J. E. Spurr have described the “Ram 
part” series, “ Birch Creek” and Forty-mile series from the Klondike 
and adjacent Alaskan districts of North Western America. 

