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PRE-CARBONIFEROtIS PLANTS. 



11 



II. Revision of the Pre-Carbontferous Flora, with Descriptions 



OF New Species. 



1. Devonian or Erian Plants. 



Under this head I shall catalogue in order the several species of fossil 

 plants which have been recognised in these beds in Canada, referring in the 

 case of species previously described to the memoirs in which their 

 characters have been published, and adding descriptions of new species, 

 corrections of errors, new facts and structures recently obtained, and 

 discussions of the nature and afl5nities of the several species, so as to 

 bring the whole subject, as far as possible, up to the present state of 

 knowledge ; and also introducing such allied species from New York, 

 Ohio and Maine as may serve to illustrate the Canadian species. 



In order that distinct notions may be conveyed as to the geological 

 horizons of the species, I may state that the typical Devonian or Erian 

 series of Canada and New York may be divided in descending order into — 

 ■1. The Chemung group, including the Chemung and Portage sandstones 

 and shales. 2. The Hamilton group, including the Gencsse, Hamilton and 

 Marcellus shales. 3. The Corniferous limestone and its associated beds. 

 4. The Oriskany sandstone. As the Corniferous limestone, which is the 

 equivalent of the Lower Carboniferous limestone in the Carboniferous period, 

 is marine, and affords scarcely any plants, we may, as is usually done for 

 like purposes in the Carboniferous, group it with the Oriskany under the 

 name Lower Erian. The Hamilton rocks will then be Middle Erian, and 

 the Chemung group Upper Erian, In the present state of our knowledge, 

 the series may be co-ordinated with the rocks of Gasp^, New Brunswick 

 and Maine as in the following table : — 



