APPENDIX 297 



attenuated by the enormous denudation which the 

 whole region has undergone. It may also be found 

 that the beds of limestone are fewer and their 

 repetitions more numerous than had been supposed, 

 and that the Grenville series may be closely associ- 

 ated locally, at least, with beds hitherto of uncertain 

 age, or associated with the Lower Huronian. The 

 Huronian proper, on the other hand, may be con- 

 siderably extended, and the Kewenian and Animike 

 series overlying it have already been ascertained 

 by the Canadian Geological Survey to overlap the 

 Huronian and Lauren tian over vast areas between 

 the great lakes and the Arctic sea, evidencing much 

 submergence at the close of the Huronian age, and 

 opening of the Palaeozoic. I have noticed in the 

 text the apparently wide development of deposits of 

 this age over the area of the Rocky Mountains of 

 Canada, and the corresponding territories in the 

 United States. There would seem to be in these 

 regions a great thickness of unaltered sediments 

 between the Lower Cambrian and the crystalline 

 rocks below, representing the Huronian and Lau- 

 rentian. In these very few fossils have yet been 

 found, but they afford perhaps the most promising 

 field, next to their representatives in Newfoundland 



