PREFACE. vii 



Selwyn, Esq., Director of the Geological Survey of 

 Canada, who placed at the Author's disposal a number 

 of engravings of Silurian and Devonian fossils, from the 

 publications of the Survey. The Author has likewise 

 to acknowledge a similar obligation to Principal Daw- 

 son, of M'Gill University, Montreal, who kindly per- 

 mitted the use of several of the illustrations of his 

 ' Acadian Geology.' A considerable proportion of the 

 engravings, however, are taken from D'Orbigny's beau- 

 tifully illustrated ' Cours Elementaire de Paleontologie,' 

 by an arrangement with the publishers of that work. 



UNIVERSITY COLLEGE, TORONTO, 

 October 16, 1872. 



