172 THE CANADIAN NATURALIST. [Yol. ix. 



into innumerable undulations, a vast majority of which present 

 anticlinal forms overturned on the north-western side. The 

 general sinuous north-east and south-west axis of these undula- 

 tions is parallel with the great dislocation of the St. Lawrence, 

 and the undulations themselves are a part of those belonging to 

 the Appalachian chain of mountains. It is in the western basin 

 that we must look for the more regular succession of the Silurian 

 rocks, from the time of the Chazy, and in the eastern, including 

 Newfoundland, for that of those anterior to it." 



In studvino- these rocks, as Sir William well knew that the 

 great line of disturbance and igneous action lay to the east, as 

 he further knew that in this belt of country rocks all the way up 

 even to the Carboniferous had been profoundly altered, he was 

 not surprised to find that in tracing the Quebec rocks to the 

 south and east, the clay slates, still holdinsr the same fossils, 

 became micaceous or nacreous slates, the bituminous shales 

 graphitic slates, the limestones crystalline marble ; and that 

 even serpentine, chloritic slate and hard felspathic rocks appeared 

 to take the place of ordinary aqueous sediments. Consequently 

 he arrived at the large generalizations on the subject embodied 

 in his map of Canada, and to which I believe he adhered to the 

 last. 



Was he right in these generalizations ? In part, at least, it is 

 certain that he was. I have myself, following in his track, seen 

 distinct Lower Silurian fossils in the nacreous slates and graph- 

 itic slates of the Townships, and T have seen these slates alternat- 

 ing with hard quartzites, and felspathic and brecciated rocks, 

 and so far as could be made out by stratigraphy, with chloritic 

 rocks, crystalline dolomite, soapstones and serpentine, these rocks 

 seemingly representing the shales of Point Levis if not still newer 

 members of the series. Dana has recently shown that rocks 

 in Connecticut, usually referred to the Quebec group, or even 

 to the Lower Taconic series of Emmons, and often in a highly 

 crystalline state, actually contain fossils newer than those of 

 the Quebec group, or of Hudson River age. ^-^ Murray in 

 Newfoundland has found the most unequivocal superposition of 

 serpentine and chloritic slate on fossiliferous rocks of the Quebec 

 group, and intervening in age between them and the Hudson 



♦ Ameiican Joiuiial of .Science, May, 1879, One of the fossils recog- 

 nized by Dana seems to be the Stromatopora covijmcta of Billings 

 really a Stenopora, known in Canada both below and above the Levis, 



