278 THK ICE AGE IN CANADA. 



31. DenUenlalauta. Rolling River, Manitoba. 

 .'{2. Lkmnpliora (?). Rolling River, Manitoba. 

 '^'^. Cocconeis. Rolling River, Manitoba. 



None of the pbiuts above meiitioiieil are properly 

 arctic in their distribiitiou, and the assemblage may be 

 characterized as a selection from the present Canadian 

 flora of some of the more liardy species having the most 

 northern range, (ireen's creek is in the central part of 

 Canada, near to tlie parallel of 4G , and an accidental 

 selection fiom its present flora, though it might contain 

 the same species found in the nodules, would certainly 

 include with these, or instead of some of them, more 

 southern forms. More especially the l)alsam poplar, 

 though that tree occurs plentifully on tlie Ottawa, would 

 not be so predominant, liut such an assemblage of drift 

 plants might l)e furnished by any American stream flow- 

 ing in the latitude of 50" to 55' north. If a stream flow- 

 ing to the north it might deposit these plants in still 

 more northern latitudes, as the ]\[cKenzie river does 

 now. If flowing to the south, it miglit dejwsit them to 

 the south of 50 , In the case of the Ottawa, the plants 

 could not have been derived from a nif)re southern 

 locality, nor probably from one ^'ery far to the nortli. 

 We may therefore safely assume! tliat the refrigeration 

 indicated by tliese plants would place the region bordering 

 the Ottawa in nearly the same position with that of the 

 south coast of Labrador fronting on the Gulf of St. 

 Lawrence, at present. The al)sence of all the more arctic 

 species occurring in Labrador, should perhaps induce us 

 to infer a somewhat more mild climate than this. 



The climatic indications aff'orded Ijy these plants are 

 not dissimilar from those furnished 1)y a consideration of 

 tlie marine fauna of the period of the Leda clay. 



