124 THE ROYAL SOCIETY OF CANADA 



Dawson, and later by Mr. David White of the U. S. Geological Survey, 

 both of whom referred the plants to the Upper Devonian. 



Wherever we find this series of beds in full succession, we find on 

 the top of the red beds or intercalated with them in their upper part, 

 a set of gray beds, with more abundant plant remains, which recall 

 the Pocono forms 'of Pennsylvania or the Sub-Carboniferous fossils 

 in other parts of the continent. Here we meet with the same diffi- 

 culty at a higher horizon as meets us in the upper part of the St. 

 John group, viz., the difficulty of separating parts of series which in 

 Europe are sufficiently distinct, but which, in this district are so 

 closely linked that in the map it would be quite impossible to separate 

 the two. We therefore can only say that the underlying red beds 

 contain a Devonian flora and the upper or gray part of the series is 

 marked by the presence of a Pocono or Lower Carboniferous flora. 



On the margin of the Coal-measures further to the North, this 

 question of age of the overlying gray beds is solved by the occurrence 

 of a band of limestone with well known species of Lower Carboniferous 

 Brachiopods and other forms of marine life which thow that this 

 portion at least is to be referred to the Lower or Sub-Carboniferous 

 Age. 



Carboniferous 



In the earlier reports and maps of the present writers, the following 

 was adopted as the succession of Carboniferous rocks, in ascending 

 order : 



1. The Perry group, embracing conglomerates, sandstones 

 and shales, mostly coarse, of red or brownish red color, but 

 including some gray beds, with numerous plant remains of 

 Devonian type. About St. Andrews the Perry rocks contain 

 numerous dykes and sills of amygdaloidal diabase or dolerite. 



2. Volcanics. Igneous rocks of both acidic and basic types, 

 appearing partly as dykes or pipes and partly as overflows, 

 including basalts, diabase, rhyolite, amygdaloid, etc. In the 

 lower part of the groups the volcanics are mainly rhyolites. 



3. Limestone and Gypsum. With salt springs. Also red 

 sandstones and shale. The limestones hold brachiopods, ortho- 

 cerata, and corals. The beds are usually nearly flat, and the 

 limestones, where penetrated by volcanics, are more or less con- 

 verted into marble. 



4. Millstone Grit. Coarse gray non-calcareous sandstones 

 and conglomerates, of which the lower beds are often almost com- 

 pletely made up of rolled pebbles of white quartz. They are but 

 slightly inclined, and may rest on either of the above series, to 

 which they appear to be unconformable. 



