The first of these works, constituting part of the second volume of the "Smithsonian Contributions to Knowledge," may be regarded as a continuation of the author's _Ancient Monuments of the Mississippi Valley_, forming the first volume of those contributions. It gives a succinct account of the aboriginal remains of the state of New-York, which were thoroughly investigated by the author, under the joint auspices of the Smithsonian Institution and the New-York Historical Society, in 1848. It strips the subject of all the absurd hypotheses and conjectures with which it has been involved by speculative and fanciful minds, and gives us a new and full statement of facts, from which there is no difficulty in getting at correct results. The appendix, which forms quite half of the volume, is devoted to the consideration of several of the more interesting questions stated in connection with the subject of our antiquities generally, and has a closer relation to the previously published volume than to the present memoir. The _rationale_ of symbolism is very elaborately deduced from an analysis of the primitive religious structures of the Greeks, and applied, as we think, with entire success, to the elucidation of the origin and purposes of a large part of the monumental remains in the western United States. Indeed this whole work is dependent on, and illustrative of, the other, which must be imperfectly understood without it. The same is true of the second work, on the "Serpent Symbol," etc., which, however, is chiefly devoted to inquiries into the philosophy and religion of the aboriginal American nations, and the relations which they sustained to the primitive systems of the other continent. The principal inquiry is, how far the identities which, in these respects, confessedly existed between the early nations of both worlds, may be regarded as derivative, or the result of like conditions and common mental and moral constitutions. These are radical questions, which must be decided before we can, with safety, attempt any generalizations on the subject of the origin of the American race, which has so long occupied speculative minds. Mr. Squier, in this volume, has brought together a vast number of new and interesting facts, demonstrating the existence of some of the most abstract oriental doctrines in America, illustrated by precisely identical or analogous symbols; but he does not admit that they were derivative, without first subjecting them to a rigid analysis, in order to ascertain if they may not have originated on the spot where they were found, by a natural and almost inevitable process. The work, therefore, is essentially critical, and may be regarded as initiatory to the investigation of these subjects, on a new and more philosophical system. It is the first of a series, under the general title of "American Archaeological Researches," of which, it is announced in the advertisement, "The Archaeology and Ethnology of Central