CHAP, xviir. AGE OF THE MASTODON. 353 



I cannot help suspecting that many tusks and teeth of the 

 mammoth, said to have been found in peat, may be as spu 

 rious as are the horns of the rhinoceros cited more than once 

 in the s Memoirs of the Wernerian Society,' as having been ob 

 tained from shell-marl in Forfarshire and other Scotch coun 

 ties ; yet, between the period when the mammoth was most 

 abundant, and that when it died out, there must have elapsed 

 a long interval of ages when it was growing more and more 

 scarce ; and we may expect to find occasional stragglers buried 

 in deposits long subsequent in date to others, until at last we 

 may succeed in tracing a passage from the post-pliocene to 

 the recent fauna, by geological monuments, which will fill 

 up the gap before alluded to (p. 144) as separating the era 

 of the flint tools of Amiens and Abbeville from that of the peat 

 of the Valley of the Somme. 



How far the lacustrine strata of North America, above 

 mentioned, may help to lessen this hiatus, and whether some 

 individuals of the Mastodon giganteus may have come down 

 to the confines of the historical period, is a question not so 

 easily answered as might at first sight be supposed. A geolo 

 gist might naturally imagine that the fluviatile formation of 

 Groat Island, seen at the falls of Niagara, and at several 

 points below the falls,* was very modern, seeing that the 

 fossil shells contained in it are all of species now inhabiting 

 the waters of the Niagara, and seeing also that the deposit is 

 more modern than the glacial drift of the same locality. In 

 fact, the old river bed, in which bones of the mastodon occur, 

 holds the same position relatively to the boulder formation as 

 tbe strata of shell-marl and boggy-earth, with bones of mas 

 todon, so frequent in the State of New York, bear to the glacial 

 drift, and all may be of contemporaneous date. But in the 

 case of the valley of the Niagara, we happen to have a measure 



* Travels in North America, by the Author, vol. i. ch. ii. ; and vol. ii. ch. xix. 



AA 



