38 THE PEKMO-CARBONIFEROUS. 



the Upper Coal formation beds seen at Gallas Point, and amounting 

 to about 800 feet in vertical thickness, must belong to the upper part 

 of the Pictou series, or may even reach some way above its summit. 

 Accordingly, we find the proportions of the several rocks to be, gray 

 sandstone 2, red and brown sandstone 4, shales 2, or a still greater 

 proportion of red sandstone as compared with Pictou. All this accords 

 with the idea of a gradual increase of red beds in approaching the 

 summit of the formation, so that the Upper Coal formation passes in 

 its upper part into beds having more the aspect of some parts of the 

 Lower Dyas or Permian. No true dolomite is present in these beds ; 

 but Dr Harrington's analyses show that some of the thin beds of 

 concretionary limestone are highly magnesian, and the sandstones 

 contain concretions of sulphate of copper, while the fossil trees which 

 abound in them are often mineralized with sulphides of copper and 

 iron, and sulphate of baryta. 



In the paper referred to, lists are given of the characteristic fossil 

 plants in the upper beds, and it is shown that the species found, though 

 mostly common to these beds and the Middle Coal formation, consti- 

 tute a peculiar group, having strong points of resemblance with the 

 flora of the Lower Permian in Europe. 



In Prince Edward Island the Upper Carboniferous and the Trias 

 are apparently conformable, and may almost be said to pass into each 

 other, though in Nova Scotia the Trias rests unconformably on the 

 Carboniferous. I believe, however, that this apparent conformity in 

 Prince Edward Island, and the resemblance of the two series in mineral 

 characters, arises from the almost horizontal position of the Carboni- 

 ferous beds, and from the circumstance that the Trias has been in 

 part formed from their waste. The Triassic fossils, though few, are 

 of species quite distinct from those of the Carboniferous. Further 

 details as to the relations of these formations in Prince Edward Island 

 will be found in my Repoit on that island. 



To sum up, it may be said that the beds which overlie the Coal- 

 field of Pictou and extend into Prince Edward Island, and which 

 constitute the upper part of the Upper Coal formation, have sucli 

 strong points of resemblance to the lower part of the European Per- 

 mian, both in their mineral character and organic remains, that they 

 may fairly be named Permo-carboniferous, a name already applied to 

 certain marine limestones in the AVest, in which the Carboniferous 

 graduates upward into the Permian. They may also be held to some 

 extent to bridge over the gap which in Eastern America generally 

 separates the Carboniferous from the Trias. 



I may add that in Nova Scotia the Lower Carboniferous beds are 



