Dr. Buckland, the learned professor of geology at Oxford, has since made the megatherium the subject of a chapter in his "Bridgewater Treatise," wherein he has fully described the remarkable peculiarities of its structure, in which, as he observes, it exceeds its nearest living congeners in a greater degree than any other known fossil animal. With the head and shoulders of a sloth, it combined, in its legs and feet, an admixture of the characters of the ant-eater, the armadillo, and the chlamyphorus: the latter it probably still further resembled in being cased with a bony coat of armour. Measuring the bones only, its haunches were more than five feet wide;[48] its thigh bone was twice the thickness of that of the largest elephant; the fore foot was a yard in length, and terminated by a gigantic claw; the tail, the width of the upper part of which was at least two feet, and which was probably clad in armour, must have been infinitely larger than that of any other known beast, amongst extinct or living mammalia. The whole body, according to the learned professor's calculations, was about eight feet in height, and twelve in length.[49] The annexed plate, carefully drawn from the original bones, under Mr. Clift's superintendence, will serve not only to give a general idea of the strange structure of this extraordinary monster, but to show the parts which are still wanting to make up the specimen. I will only add that, if any of those parts should fall into the hands of a casual collector, he will render a service to science by transmitting them to the curator of the College of Surgeons in London. [Illustration: MEGATHERIUM. _Note: The Parts uncoloured are wanting._ _Scale of 3 feet 3/8 of an Inch to a foot._] FOOTNOTES: [46] With respect _to the past_, it is, I fear, useless to look for any very positive data as to the state of the river previously to the last century:--the only allusion to it which I can find is in the 'Argentina,' an historical poem by Barco Centenera, who went out in 1572 with the Adelantado Zarate, and who, speaking of its depth between Buenos Ayres and San Gabriel, off Colonia, on the opposite shore, says:-- "De ancho nueve leguas ó mas tiene El rio por aqui, _y muy hondable_. La nave hasta aqui segura viene Que como el ancho mar es navigable." The river's here nine leagues or more, _And very deep_, twixt shore and shore; _So far the navigation's free, As tho' twere on the open sea_. ARGENTINA, CANTO II.