Concerning North American flint implements of the European drift type in general, Mr. Stevens expresses himself thus: "The legitimate conclusion at which we may at present arrive, is that implements, in form resembling some of the European palaeolithic types, were made by the aborigines of America at a comparatively late period, and that the people usually termed the 'mound-builders,' were, probably, the makers of these implements." (p. 443.) There is no sufficient ground, I think, for attributing these implements exclusively to the mound-builders, considering that they occur on the surface, and in deposits below it, in regions where the people designated as the mound-builders are not supposed to have left their traces. In the States of New York and New Jersey, for instance, such articles repeatedly have been met. I will only refer to the leaf-shaped implements in possession of Mr. Cowing, which were found in New York, and are the finest specimens of that kind ever brought to my notice. That the people who erected the mounds made and used tools resembling the palaeolithic types of Europe, is proved by the occurrence of those tools in the mounds; but it follows by no means that they are to be considered as the sole makers of that class of implements. Supposing that the mound-builders really were a people superior in their attainments to the aborigines found in possession of the country by the whites, it is certainly very difficult to draw a line of demarcation between the manufactures of the ancient and those of the more recent indigenous inhabitants of North America. The mound-builders--to preserve the adopted term--certainly did not stow away all their articles of use and ornament in the mounds, but necessarily left a great many of them scattered over the surface, which became mingled with those of the succeeding occupants of the soil. Both the mound-builders and the later Indians lived in an age of stone, and as their wants were the same, they resorted to the same means to satisfy them. Their manufactures, therefore, must exhibit a considerable degree of similarity, and hence the great difficulty of separating them.