20 THE ROYAL SOCIETY OF CANADA 



Dana and other writers since him, have assumed that a part at least 

 of this region was then emerged and in that way accounted for the pro- 

 duction of the coal seams of Carboniferous time in the deltas of the 

 rivers of Pennsylvania in that distant time. Such an area in the 

 Maritime Provinces of Canada, would, with its highlands in what is 

 now the coastal border of the sea and its maritime border toward the 

 present interior plain, have afforded a gathering ground for the waters 

 of rivers flowing northward and westward to the ocean sound that 

 then stretched from the depression of the Gulf of St. Lawrence into 

 the central part of New England affording an area where the fresh- 

 waters from the hills could reach the ocean. In this area, now sub- 

 merged, there would have been ample space on Cambrian and Pre- 

 Cambriam rocks, for the sources and channels of rivers that have 

 drained the southeastern highlands that existed here in Silurian times. 



These conditions form the basis of the hypothesis which the author 

 now puts forward as the most feasible in explanation of the unique 

 conditions associated with the accumulation of the Cordaite slates 

 (or shales) and sandstones. 



1. There was an outburst of effusive rocks at the beginning of 

 the period, leading to the production of masses of dolerites and ash 

 rocks, that are found at the bavse of the plant — bearing beds in many 

 places in this district. 



2. The main basin containing the plant beds was separated 

 from the sea to the northwest by a land barrier that lusted throughout 

 the time the plant remains were accumulating. And the basin itself 

 settled slowly and gradually allowing the regular and continuous 

 accumulation of alternating sand and mud-beds in this area. 



3. There is a connection and resemblance between the species 

 of the basin of plants throughout the deposits from the base upwards. 

 Some species of plants are found in all parts of the deposit. 



4. Beside the plant remains there are several kinds of fresh- 

 water animals, as Phyllopods, Ostracods and Fishes. 



5. Also land animals, as Batrachians, Insects, Myriapods, 

 Molluscs. 



6. The land plants show a number of the Palaeozoic types, as 

 Pteridoserms, Pteridophyta, &c. 



7. The depression of the Bay of Fundy area, or other cause, 

 eventually cut off the supply of freshwater, bearing plant remains ; and 

 the covering slates are those of the Mispec group, in which slaty 

 cleavage is even more marked than in the earlier Cordaite slates. 



