8 INTRODUCTORY. 



those which are properly Sikirian, due mainly to the labours of 

 ]\Iatthew and Hartt, but first brought prominently forward in the 

 second edition of this work, has been greatly extended in its geo- 

 graphical range ; and American text-books no longer terminate Palaeo- 

 zoic life on the horizon of the Potsdam. The still greater fact of the 

 extension of animal life backward into the Eozoic age, though still 

 denied by some, is steadily advancing in acceptance. 



My own work in the geology of the Acadian Provinces, since 1868, 

 has necessarily been limited by distance and by other occupations. 

 It includes — (1.) A geological reconnaissance of Prince Edward 

 Island,* in which I Avas assisted by Dr B. J. Harrington, and by 

 which the subdivisions of the Trias in that island and the existence 

 and distribution in it of rocks of the Upper Coal formation were 

 first ascertained ; (2.) A detailed Report on the Flora of the Upper 

 Silurian and Devonian Rocks, published by the Geological Survey of 

 Canada in 1871, in which the fossil plants of the New Brunswick 

 Devonian Avere first adequately figured and described, and their 

 geological relations discussed ; (3.) A similar Report on the Fossil 

 Plants of the Lower Carboniferous and Millstone-grit, in which these 

 plants and the beds containing them were correlated with those in 

 other parts of America and in Europe ; (4.) A Revision of the Post- 

 pliocene Geology, in my "Notes on the Post-pliocene of Canada ;"-|- 

 (5.) Memoirs on the Relation of the Upper Coal Measures of Nova 

 Scotia to the Permian ; | On the Impressions and Footprints of 

 Animals in the Carboniferous Rocks ; § On Sigillaria^ Calamites, and 

 Lepidodendron ; || On New Carboniferous Batrachians ;^ and on the 

 Geological Relations of the Iron Ore Deposits.** I have besides 

 given assistance in the determination of fossils and in other ways to 

 most of the other workers who have been in the field, so that my 

 connection with Acadian geology has been continuously maintained. 

 I may add that, in connection with the preparation of this supple- 

 ment, I have twice visited Nova Scotia, and re-examined districts of 

 special interest, and that I have in many instances been delighted to 

 find how much, previously inaccessible or obscure, had been dis- 

 closed by new lines of railway, mining operatiuns, and other changes. 

 The extension of the Geological Survey of the Dominion to the 

 Acadian Provinces has brought into the field a host of workers, 

 armed with those advantages of am})le time and public funds which 



* Keport on Geology of P. E. I., 1871. f Montreal, 1872. 



X Journal, Geological Society, Aug. 1874. § Am. Jl. Science, Januai-y 1873. 



ii Journal, Geol. Socy., May 1873. ^ Am. Jl. Science, Dec. 1876. 

 ** Proceedings Am. Association, 1874. 



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