12 THE GEOLOGICAL MAP. 



1868 to be properly Cambrian, though in deference to the classifica- 

 tion of Murchison — then almost universally adopted — it was mapped 

 as Silurian. Such fossils as have since been found in it by Selwyn, 

 Hind, and myself, and those of its extensions in Newfoundland and 

 New England, would seem to confirm this conclusion. Mr Selwyn 

 has, however, found that in the west the granite and gneissose areas 

 should be much extended, and Prof. Hind proposes to separate por- 

 tions of the gneissose rocks as Laurentian and Huronian. These 

 points also will be discussed in the sequel. 



The above corrections in the Upper and Lower Silurian districts of 

 the map may be summarised as follows: — If the reader will consider 

 the blue tint indicating Upper Silurian to cover Lower Silurian as 

 well, and the purple tint representing Lower Silurian to indicate Cam- 

 brian, the map will be approximately correct, with the exceptions 

 already referred to in New Brunswick, and some areas in Northern 

 Cape Breton and the western part of Nova Scotia, to be subsequently 

 referred to. 



The Huronian rocks of New Brunswick, as marked on the map, 

 are still recognised as such ; but it has been proposed to join to them 

 several other groups, on the ground of mineral character principally. 

 As this conclusion is still under discussion, I defer its consideration 

 till farther on. 



Messrs Bailey and Matthew have introduced several new areas of 

 Laurentian rocks in their recent maps of Southern New Brunswick ; 

 and large areas in Southern and Eastern Nova Scotia and Cape 

 Breton have been referred to this age by local geologists and officers 

 of the Survey, whose views on this subject, however, I do not regard 

 as established by my own observations. They will be referred to 

 on subsequent pages. 



The little island of Grand Manan, at the mouth of the Bay of 

 Fundy, has fared very badly in my map. I have not myself visited it, 

 and it seems that the information accessible to me in 1868, and given 

 in the appendix to my book, had led to very incorrect inferences on 

 my part. From recent reports by Prof. Bailey and Mr Matthew, and 

 by Prof. Chapman, it seems that the western half of the island con- 

 sists of Triassic trap resting on tufa and red sandstone, the eastern 

 half of old crystalline rocks, possibly Laurentian. 



The Magdalen Islands, though politically connected with the 

 Province of Quebec, fall within the map of Acadia. They are 

 represented as Carboniferous; and I can now confirm this from the 

 inspection of an interesting series of specimens collected by the Hon. 

 Judge M'Cord. These show that the rocks of these islands belong 



