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10 



CANADIAN FOSSILS. 



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Resting upon these, and dipping at high angles toward Gasp^ Bay, are the 

 Devonian sandstones, which are exposed in rugged cliffs slightly oblique 

 to their line of strike, along a coast-line of ten miles in length, to the head 

 of the Bay. On the opposite side of the Bay they reappear ; and, thrown 

 into slight undulations by three anticlinal curves, occupy a line of coast 

 fifteen miles in length. The perfect manner in which the plant-bearing 

 beds are exposed in these fine natural sections may serve to account for 

 the completeness with which the forms and habits of growth of the more 

 abundant species can be described in the following pages. 



It will be necessary, before closing these introductory remarks, to state 

 the reasons which have induced me to suggest in the following pages the 

 use of the term " Erian, " as equivalent to " Devonian, " for the great 

 system of formations intervening between the Upper Silurian and the Lower 

 Carboniferous in America. I have been induced to adopt this course by the 

 following considerations : 1. The great area of undisturbed and unaltered 

 rocks of this age, including a thickness in some places of 18,000 feet, and 

 extending from east to west through the northern states of the Union and 

 Western Canada for nearly 700 miles, while it spreads from north to south 

 from the northern part of Michigan far into the middle states, is undoubt- 

 edly the most important Devonian area now known to geologists. 2, This 

 area has been taken by all American geologists as their typical Devonian 

 region. It is rich in fossils, and these have been thoroughly studied and 

 admirably illustrated by the New York and Canadian Surveys. 3. The 

 rocks of this area surround the basin of Lake Erie and were named in the 

 original reports of the New York Survey the " JJn'e Division." 4. Great 

 difficulties have been experienced in the classification of the European 

 Devonian, and the uncertainties thus arising have tended to throw doubt 

 on the results obtained in America in circumstances in which such diffi- 

 culties do not occur. 



These reasons are, I think, sufficient to warrant me in holding the great 

 JErie Division of the New York geologists as the typical representative of 

 the rocks deposited between the close of the Upper Silurian and the beginning 

 of the Carboniferous period, and to use the term Erian as the designation 

 of this great series of deposits as developed in America, in so far at 

 least as their flora is concerned. In doing so, I do not wish to commit 

 to the use of this term the officers of the Survey of Canada, or to introduce 

 a new name merely for the sake of novelty ; but I hope to keep before 

 the minds of geologists the caution that they should not measure the 

 Erian formations of America, or the fossils which they contain, by the 

 comparatively depauperated representatives of this portion of the geolo- 

 gical scale in the Devonian of Western Europe. ^^ 



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