“The remains of the following animals were embedded together at Punta Alta in Bahia Blanca:—The _Megatherium Cuvierii_, _Megalonyx Jeffersonii_, _Mylodon Darwinii_, _Scelidotherium leptocephalum_, _Toxodon Platensis (?)_ a Horse and a small Dasypodoid quadruped, mentioned p. 107; at St. Fé in Entre Rios, a Horse, a Mastodon, _Toxodon Platensis_, and some large animal with a tesselated osseous dermal covering; on the banks of the Tercero the Mastodon, Toxodon, and, according to the Jesuit Falkner, some animal with the same kind of covering; near the Rio Negro in Banda Oriental, the _Toxodon Platensis_, Glossotherium, and some animal with the same kind of covering. To these two latter animals the _Glyptodon clavipes_, described by Mr. Owen in the Geological Transactions, may, from the locality where it was discovered, and from the similarity of the deposit which covers the greater part of Banda Oriental, almost certainly be added, as having been contemporaneous. From nearly the same reasons, it is probable that the Rodents found at Monte Hermoso in Bahia Blanca, co-existed with the several gigantic mammifers from Punta Alta. I have, also, shown in the Introduction, that the _Macrauchenia Patachonica_, must have been coeval, or nearly so, with the last mentioned animals. Although we have no evidence of the geological age of the deposits in some of the localities just specified, yet from the presence of the same fossil mammifers in others, of the age of which we have fair means of judging, (in relation to the usual standard of comparison, of the amount of change in the specific forms of the invertebrate inhabitants of the sea,) we may safely infer that _most_ of the animals described in this volume, and likewise the Glyptodon, were strictly contemporaneous, and that _all_ lived at about the same very recent period in the earth’s history. Moreover, as some of the fossil animals, discovered in such extraordinary numbers by M. Lund in the caves of Brazil, are identical or closely related with some of those, which lately lived together in La Plata and Patagonia, a certain degree of light is thus thrown on the antiquity of the ancient Fauna of Brazil, which otherwise would have been left involved in complete darkness.” LONDON: PRINTED BY STEWART AND MURRAY, OLD BAILEY. [Illustration: Pl. I. _G. Scharf del et lithog._ _Printed by C. Hullmandel._ _Base of the Skull of Taxodon Platensis._ _Nat. Size._ _Published by Smith, Elder & Cº͈ 65, Cornhill, London._ ] [Illustration: Pl. II. _G. Scharf del et lithog._ _Printed by C. Hullmandel._ _Side View of the Skull of Taxodon._ _One-third the Natural Size._ _Published by Smith, Elder & Cº͈ 65, Cornhill, London._ ] [Illustration: Pl. III. _G. Scharf del et lithog._ _Printed by C. Hullmandel._