426 THE CANADIAN NATURALIST. [Vol. vi. 



superior to the St. Lawrence limestones." In 1845, Captain, now 

 Admiral Bayfield, maintained the same view, fortifying himself 

 by the early observations of Bigsby, and expressing the opinion 

 that the flat limestones of Montmorenci and Beauport passed 

 beneath the graywacke series. These limestones, from their fos- 

 sils, were declared to be low down in the Silurian, and identical 

 with those which had been observed at intervals along the north 

 shore of the St. Lawrence to Montreal, [Geol. Journal, i. 455] 

 the fossiliferous limestones of which were then well known to 

 belong to the Trenton group of the New York system. The 

 graywacke series of Quebec, which was still supposed by Bay- 

 field to hold in its conglomerates fossils from these limestones, was 

 therefore naturally regarded as belonging to the still higher 

 members of that system ; and, as we have seen, the green sand- 

 stone near Quebec, a member of that series, had already in 1842, 

 been regarded by Emmons as the representative of the Oneida 

 or Shawangunk conglomerate, at the summit of the Hudson-River 

 group of New York. 



It is to be noticed that immediately to the north-east of Que- 

 bec, rocks undoubtedly of the age of the Utica and Hudson- 

 Biver divisions overlie conformably the Trenton limestone, on 

 the left bank of the St. Lawrence; while a few miles to the 

 south-west, strata of the same age, and occupying a similar strati- 

 graphical position, appear on both sides of the St. Lawrence, and 

 are traced continuously from this vicinity to the valley of Lake 

 Champlain. These moreover ofi"er such lithological resemblances 

 to the so-called graywacke series of Quebec and Point Levis, 

 (which extends thence some hundreds of miles north-eastward 

 along the right bank of the St. Lawrence,) that the two series 

 were readily confounded, and the whole of the belt of rocks along 

 the south-east side of the St. Lawrence, from the valley of Lake 

 Champlain to Gaspe, was naturally regarded as younger than the 

 limestones of the Trenton group. It was in 1847 that Sir Wil- 

 liam Logan commenced his examination of the rocks of this 

 region, and in his report the next year [1848, page 58] we find 

 him speaking of the continuous outcrop "of recognized rocks of 

 the Hudson-River group from Lake Champlain along the south 

 bank of the St. Lawrence to Cape Rosier." In his Report for 

 1850, these rocks were farther noticed as extending from Point 

 L^vis south-west to the Richelieu, and north-east to Gaspe, 

 [pages 19, 32]. They were described as consisting, in ascendin 





