ANCIENT GLACIERS. 65 



places in Maine, only some four or five hundred feet above the present ocean ; and 

 they occur in clay or gravel that has been thoroughly rounded. These remains 

 (along our coast) belong altogether, I believe, to existing species, and the molluscs 

 even yet retain the epidermis. They must, therefore, have been deposited at a 

 period vastly posterior to the drift. The Delphinus Vermontanus, described by 

 Professor Thompson, from the clays near Lake Champlain, was found only one 

 hundred and fifty feet above the present sea level, and hence we should not think 

 it strange that he found it difficult to distinguish it from an existing species. 



Still more recent are the remains of extinct land animals, which have often in a 

 general way been referred to the drift. I mean the mastodon, elephant, horse, &c, 

 for they occur most usually in peat and marl swamps, and these may have been 

 quite recent. Such is the case at Newburg and Geneseo, New York, and at the 

 summit-level of the Burlington and Rutland railroad in Mt. Holly, Vermont. 



In Wales, marine shells were found nearly 1400 feet above the sea, in what, 

 though called drift, was most probably modified drift, which I saw at even a 

 greater elevation in that country. 



36. So far as this continent is concerned, I think we may as yet safely say, that 

 there is no evidence of the existence of life in the seas that covered it during the 

 period of unmodified drift; and, indeed, we might say the same of a considerable 

 part of modified drift and alluvium. I mean that the lowest drift and most of the 

 terraces have not furnished any example of fossil animal or plant. And when we 

 find such proof of glacial agency, especially in the oceans, during those periods, we 

 do not wonder that life was mostly absent. Sir Charles Lyell has also assigned 

 some other reasons for this paucity of organic remains, in the pleistocene deposits, 

 which are probable. {Manual of El. Geol., p. 136.) 



37. With such views of the climate in regions now temperate, we should expect, 

 that as mountains emerged from the ocean, glaciers would be formed upon their 

 crests and slopes. Those descending towards the ocean, would produce strise upon 

 the rocks, radiating from the highest points, or directed outwardly from the axes 

 of ridges, and more or less obliterating the traces of the drift agency, where, as 

 in our country, the strise that have resulted from it, run nearly in a north and 

 south direction over the whole continent. As far down the mountains as the 

 glaciers extended, they would obliterate, also, the beaches and terraces that may 

 have been formed by the retiring waters. 



In Wales, as I have already stated, the marks of ancient glaciers seem to me 

 most manifest, and they have erased most of the marks of the former presence of 

 the ocean, though they do not prove that the country was not all once beneath 

 the ocean, but only that the glaciers have since occupied its higher parts and 

 so changed the surface that the proofs of oceanic agency are less obvious. And, 

 moreover, the ragged aspect of the highest peaks, makes it probable that they 

 never were rounded, as nearly all the mountains in our country are, by drift 

 agency. 



In Switzerland, I think we can easily find proofs of the action of water from 

 2000 to 3000 feet high: but all the regions more elevated, show marks of ancient 

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