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formations on the borders of the Lakes Erie and Ontario; and 

 states that in the valley of the St. Lawrence, as far down as Quebec, 

 marine shells of arctic character have been found associated with 

 coarse detritus. As some of this shelly and boulder deposit lies at 

 about 500 feet above the sea, and as Lake Ontario is at a much 

 lower level, it is inferred that the sea in which the drift was formed 

 extended far over the territory bordering that lake. That the same 

 sea extended as far south as 44°, 80' north latitude, is proved by 

 the presence on the shores of Lake Champlain, of marine shells ; 

 which, ill their Arctic forms and close agreement with those of 

 Uddevalla in Sweden, formerly described by himself, are supposed 

 to imply, like those of the St. Lawrence, the former prevalence 

 of a cold climate when the drift originated. In regard to the far 

 transported boulders, they have in one locality (Beauport) been found 

 both above and below the sea-shells. 



The parallel and continuous ridges of sand and gravel, which by 

 Mr. Roy and other authors had been considered to be the shores 

 of an enormous lake, successively let off, are said to rest on clay of 

 the boulder formation, and yet to be occasionally capped by blocks 

 of granite and other hard rocks. Comparing them with the Osars 

 of Sweden, and stating, from the evidence of Mr. Whittlesey, that 

 their base-lines are not so horizontal as had been supposed, Mr. 

 Lyell inclines to the belief, though no shells have been found in 

 them, that they were all formed under water, and probably beneath 

 the sea, as banks or bars of sand, admitting at the same time that 

 some of the less elevated ridges may be of lacustrine origin. 



The last observation seems to open out the whole question of 

 whether vast freshwater lakes, extending far beyond the area of 

 those which now exist, may not, at one period, have covered the 

 interior of America. 



This opinion has been long entertained by our associate, Mr. 

 Featherstonhaugh, who, in his researches eight years ago, amid the 

 western and untravelled tracts, where the sources of the great rivers 

 are separated from each other by very slight elevations, discovered 

 fiuviatile and lacustrine shells, wherever excavations existed or pits 

 had been sunk, and at great distances from the courses of the present 

 streams. I have the more pleasure in making this illusion to the 

 geological labours of Mr. Featherstonhaugh, because he near fifteen 

 years ago pointed out some of the chief phteiiomena connected with 

 the retrocession of the Falls of Niagara. He was among the first 

 persons^ subsequent to his survey of large tracts of the far- west coun- 

 try of Arkansas, to assist in the introduction into the United States 

 of an acquaintance with the most modern school of English geology ; 

 and who, after popularizing the subject by public addresses in 18S8 

 and 1829, urged upon the government of that country that geologists 

 should always accompany geographical surveyors *. 



The view adopted by Mi\ Roy, Mr. Featherstonhaugh and 



* See Monthly American Journal of Geology, 1831, by Mr. featherston- 

 haugh. 



