30 THE CANADIAN NATURALIST. [Yoi. ix. 



It seems to me that the well-kDOWii and recognized names 



Laurentian 



Buronian 



Cambrian and Silurian 



— with the introduction, where found desirable, to denote some 

 local break, of the terms upper, middle and lower — meet all pres- 

 ent requirements so far as systems are concerned. 



Unfortunately in Canadian geology, hitherto the stratigraphy 

 has been made subordinate to mineralogy and palaeontology, and 

 as the result we find groups of strata which the labours of the 

 field geologist during the past ten years have now shewn all to 

 occupy a place between Laurentian and Cambrian, assigned to 

 Carboniferous and Upper Silurian in New Brunswick and Nova 

 Scotia, to the peculiar palasontological Levis group and its sub- 

 divisions Lauzon and Sillery in the Eastern Townships ; and to 

 lower and upper Laurentian, Huronian, lower Silurian and Trias- 

 sic on the north side of the St. Lawrence valley and around 

 Lake Superior. The same system of mineralogical stratigraphy 

 is now further complicating and confusing the already quite suf- 

 ficiently intricate problem by the introduction of the new nomen- 

 clature I have referred to, and in some cases these names are 

 applied regardless of and in direct opposition to well ascertained 

 stratigraphical facts. A similar unfortunate instance oi imlceon- 

 tological stratigraphy is found in the history of the Quebec 

 group ; and especially in the late introduction in it of the belt 

 of supposed Potsdam rocks, about which I have already stated 

 my opinion. 



Id the reconstruction of the Geological map of Eastern Canada, 

 — and in this I include the country from Lake Winnipeg to Cape 

 Breton and Labrador — rendered necessary by the present state 

 of our knowledge, I should propose to adopt the following divi- 

 sions of systems to include the groups enumerated : 



I. Laurentian : To be confined to all those clearly lower un- 

 conformable granitoid gneisses in which we 

 never find interstratified bands of calcare- 

 ous, argillaceous, arenaceous and conglome- 

 ratic rocks. 



