It is with pleasure I embrace this occasion of returning you my thanks for the favor of your very valuable works, _sur les poissons et les cetacées_, which you were so kind as to send me through Mr. Livingston and General Turreau, and which I find entirely worthy of your high reputation in the literary world. That I have not sooner made this acknowledgment has not proceeded from any want of respect and attachment to yourself, or a just value of your estimable present, but from the strong and incessant calls of duty to other objects. The candor of your character gives me confidence of your indulgence on this head, and I assure you with truth that no circumstances are more welcome to me than those which give me the occasion of recalling myself to your recollection, and of renewing to you the assurances of sincere personal attachment, and of great respect and consideration. _Contents of the large square Box._ A Fibia. A Radius. Two ribs belonging to the upper part of the thorax. Two ribs from a lower part of the thorax. One entire vertebra. Two spinous processes of the vertebra broken from the bodies. Dentes molares, which appear to have belonged to the full-grown animal. A portion of the under-jaw of a young animal with two molar teeth in it. These teeth appear to have belonged to a first set, as they are small, and the posterior has but three grinding ridges, instead of five, the common number in adult teeth of the lower jaw. Another portion of the under-jaw, including the symphisis, or chin. In this portion the teeth of one side are every way complete; to wit, the posterior has five transverse ridges, and the anterior three. A fragment of the upper-jaw with one molar tooth much worn. Molar teeth which we suppose to be like those of the mammoth or elephant of Siberia. They are essentially different from those of the mammoth or elephant of this country, and although similar in some respects to the teeth of the Asiatic elephant, they agree more completely with the description of the teeth found in Siberia in the arrangement and size of the transverse lamina of enamel. This idea, however, is not derived from actual comparison of the different teeth with each other, for we have no specimens of Siberian teeth in this country; but from inferences deduced from the various accounts and drawings of these teeth to be found in books. A few of these teeth have been found in several places where the bones of the American animal have existed. An Astragalus. An Oscalcis. Os naviculare. In the large box in which the preceding bones are, is a small one containing a promiscuous mass of small bones, chiefly of the feet.