“In advocating this opinion regarding the extermination of the mastodon, I have reference to the remains as they have come under my own observation: and I do not mean to be understood as opposing _in toto_, the views so generally entertained, that the mastodon has existed during the present epoch; or that the opinion held by some of our scientists, that the animal may have existed both before and since the glacial period, is untenable. I refer only to the phenomena usually accompanying these remains, and the conditions attending those which have been exhumed within the State of New York and adjacent parts of New Jersey, and to some extent in other parts of the country. The locality of Big Bone Lick in Kentucky, which has furnished the fragmentary parts of so many skeletons (and some other Western localities), I have not visited; but the evidence already given in relation to the bones from this place, indicates very clearly that they had suffered from glacial action; and the animals were, as we infer, of the glacial period.” On the great Osage River, the mastodons were sunk in the mud in a vertical position. Perhaps the most interesting find in New-York State was what is known as the Cohoes mastodon. In the fall of 1866 a number of workmen were employed in excavating the foundation for the Harmony Mills Company, in Cohoes; and after much labor, during which several thousand loads of muck or peaty soil, and old trunks of trees, had been removed, one of the men discovered the jaw-bone of some gigantic animal. The bone was found almost at the water-level, and at a depth of twenty-five feet below the surface; the entire locality being clay and earth, which formerly had been filled in to cover a swampy depression.