340 Canadian Record of Science. 



himself from an examination of the plant remains from 

 the two areas, and also by Mr. Kidston. 



Mr. Fletcher, working independently in the eastern por- 

 tion of Nova Scotia, had in the meantime encountered pre- 

 cisely similar rocks and reached a similar conclusion as to 

 their age. While therefore the inference was plain that 

 these formations in the two provinces were similar in age, 

 Sir William Dawson, from an examination of a few plants 

 found in the beds near Eiversdale, some years previously, 

 had found what he supposed to be a Millstone-grit horizon 

 at that place. The collection on which this determination 

 was based was, however, but small and lacked the com- 

 pleteness of material found in the St. John beds. More- 

 over, these strata, near Arichat, at the Strait of Canso, 

 East Eiver of St. Mary's, Middle Eiver of Pictou, the 

 mouth of Shubenacadie River, Brookfield and the Cobe- 

 quid hills, were assigned to the Devonian and lower 

 horizons by Sir William Dawson. 



In his report on the Fossil Plants of the Devonian and 

 Silurian, 1871, page 70, Sir William calls attention to the 

 great similarity existing between the floras of the Devon- 

 ian and Carboniferous systems in many particulars. The 

 presence of some forms, therefore, poorly preserved and 

 presenting a Millstone-grit facies, should not be taken as 

 conclusively overturning the conclusions which he had 

 arrived at from the systematic study of the great collec- 

 tions from the similar sediinents in New Brunswick which 

 he had previously assigned to the Devonian. Certain it 

 is that the plants which he found at liiversdale did not in 

 any way affect his own opinion as to the age of the latter. 



The question of lithological resemblance between rocks 

 of similar formations over wide areas is also entitled to 

 some consideration in discussing such a problem. Thus 

 the strata of the Carboniferous proper are distinctly much 

 less altered both in New Brunswick and in Nova Scotia 

 than those which we have regarded as of Devonian age. 



