EXPLANATION OF THE GEOLOGICAL MAP. 



The Map in this Edition, though greatly improved, is still to be re- 

 garded as merely a rude approximation to the truth, and the colouring 

 in many places, more especially in the interior, remote from the coast 

 lines, is little more than conjectural. 



With the permission of Sir W. E. Logan, I have adopted the scale 

 and geographical lines of his large Geological Map of Canada, in 

 which he has spared no pains to obtain the most accurate representation 

 possible of the coast and river lines. To Sir William's Map I am 

 also indebted for the geological lines of the part of the province of 

 Quebec included in my Map, as well as for the geology of portions of 

 the state of Maine and of the province of Newfoundland, in regard to 

 which Sir William has carefully collated and harmonized the observa- 

 tions of Professor Hitchcock and Mr Murray with his own work in 

 Canada. For the geology of New Brunswick I am indebted, in 

 addition to my own observations, principally to the published Maps 

 of Professor Robb, Professor Bailey, and Mr Matthew, and to MS. 

 Maps and Notes on the limit lines, kindly communicated by Professor 

 Hailey. I have also consulted Professor Hind's Preliminary Report, as 

 to the limits of formations, more especially in Northern New Bruns- 

 wick, and have availed myself of the reduction of all these observations 

 by Sir William Logan for his Map. In preparing the General Section, 

 I have been guided, in so far as New Brunswick is concerned, by 

 a MS. section constructed by the late Professor Robb, and communi- 

 cated to me by his brother, Mr C. Robb of Montreal. I have coloured 

 the little-known island of Grand Manan, from notes kindly given to 

 me by Professor A. E. Verrill of New Haven, and which I publish 

 in the Appendix. It is, however, doubtful whether the formations 



