276 Canadian Record of Science. 



an absolute correlation with the Pottsville, to whose flora 

 nearly all of the species from the beds in question are 

 common. On the other hand the plants from the Rivers- 

 dale beds are practically totally different from, as well as 

 assuredly younger than, the Horton flora. 



From the palteobotanical standpoint there appears to be 

 little room for the belief that the Riversdale- Harrington 

 River plant beds may in any case be lower than the St. 

 Louis, while on the other hand the plants seem strongly 

 to indicate a level at or above the top of the Lower Car- 

 boniferous. At the present stage of our knowledge of the 

 fossil floras these beds can not, without disregarding pale- 

 obotany, be correlated with beds below the Carboniferous 

 Limestone (Windsor) unless it be understood that the 

 Limestone is no older than the upper portion of the Lower 

 Carboniferous. The Mississippian equivalents of the 

 Carboniferous limestone (Windsor) and the time interval 

 which it covers are not yet definitely ascertained ; but, if 

 it represents one or more stages in the lower portion of 

 the Lower Carboniferous, my observations of the plants of 

 the Devonian, Pocono, Mauch Chunk and Pottsville 

 formations in the Allegheny region, and my faith in the 

 validity of their evidence, lead me to urge that the Rivers- 

 dale and Harrington River plant beds are probably above 

 the Carboniferous Limestone, though; if the latter extends 

 without unconformity up to the Millstone Grit, they may 

 lie within it. They can not be Middle Devonian. If the 

 extrusions of eruptive rock cut the Riversdale plant 

 formation, as is stated by the JSTova Scotia geologists, the 

 metamorphic action is certainly Carboniferous, and it 

 appears probable that it can not very long antedate the 

 close of the Lower Carboniferous. 



Possibly Dr. Ells and Mr. Pletcher were influenced in 

 referring the Riversdale beds to the Middle Devonian 

 through first correlating them with the " fern ledges" at St. 

 John, N.B. It would be a singular incident in paheontol- 



