176 THE CANADIAN NATURALIST. [Vol. 



IX. 



be an upper member of the Quebec group, and were mapped as 

 Sillery. They were thus placed in the same position with the 

 serpentine and chloritic formation of Newfoundland, as described 

 by Murray, with the Cobequid series as I have described it in 

 Nova Scotia, ^^ and with the Borrowdale igneous rocks resting on 

 the English e(juivalcnts of the Levis beds as defined by Ward iu 

 Cumberland. 



Mr. Selwyn, on tlie other hand, thinks that the main mass oT 

 these peculiar rocks either comes out unconformably from beneath 

 the Levis series or is separated from it by a fault, and is in all 

 probability older, though the obscure traces of fossils found in 

 some of the beds would indicate that they are not older iu any 

 case than Lower Silurian or Upper Cambrian. 



It is obvious that with reference to a formation so greatly dis- 

 turbed, either of these theoretical views may be correct, or that 

 there may be two crystalline series, one below and another above 

 the Levis beds. Where I have had opportunity to observe the 

 formation, at Melbourne, and in a few other places, I have seen 

 no reason to dissent from Sir W. E. Logan's view ; but at that 

 time Mr, Selwyn's explanation was not before my mind, nor have 

 I examined the sections on which he chiefly relies. 



Had Sir W. E. Logan lived, it was his intention to have, at 

 liis own cost, bored through the crystalline rocks at some selected 

 site, in order to obtain positive proof of the subterposition of the 

 Levis beds. This expense is not now likely to be incurred, but 

 the whole question will in course of time be settled by the careful 

 re-examination and mapping, which now that these new viewg 

 have been suggested by the head of the Geological Survey, tlie 

 district is likely to receive. 



Mr. Selwyn's third division, supposed to be still older, possibly 

 Lower Cambrian, in some respects resembles the second, but is 

 predominently slaty and quartzose, though still with dolomites 

 and other magnesian rocks. These would naturally fall into the 

 place assigned to them, if the age attributed to the second series 

 be admitted, otherwise they come into the period of the Sillery, 

 or some newer formation, in an altered condition. I do not know 

 that fossils have been found in these rocks, within the limits of 

 Canada at least, but if they are really of Cambrian age, the 

 richness of this fauna elsewhere in N, E. America would warrant 



* Acadian Geoloarv. t)iir<l edition. 



