NIAGARA FALLS. 
403 
It will be seen that the elevation of the point where these shells occur at the whirlpool cor¬ 
responds with Goat Island and the fourth terrace on the east bank of the river. This can 
leave no doubt that these points are portions of a once continuous deposit, and it is not im¬ 
probable that it may be traced still farther to the north. It will be recollected that the tooth 
of a mastodon, and shells of Cyclas and Valvata, were dug from the fourth terrace, eleven feet 
below the surface, or about four feet lower than those seen at the whirlpool, though these may 
have extended as low. In the terrace at the falls, these shells have not been found at an 
elevation so great by about six feet as at the whirlpool. 
51 
