Page:Quarterly Journal of the Geological Society of London, vol. 28.djvu/537

1872.] of land similarly situated, such as Northern Asia and North America. And these climatal extremes have been deduced, as we have already seen, from the analysis of the Mammalia.

The relation of the Pleistocene to the Pliocene fauna must now be examined; and this inquiry is of very great difficulty, because the latter has not yet been satisfactorily defined, although Prof. Gervais and Dr. Falconer have given the more important species of Auvergne, Montpellier, and the Val d'Arno. The following list is taken from Prof. Gervais's great work 'Zoologie et Paléontologie Françaises,' p. 349, the term Pseudo-pliocene merely implying that the fauna differs from that of the marine deposit of Montpellier, which he takes as his standard.

To these animals Dr. Falconer adds Hippopotamus major, Elephas antiquus, and Rhinoceros megarhinus, and he identifies Rhinoceros elatus with his new species Rhinoceros etruscus. Prof. Gaudry agrees with me in the belief that Hyæna Perrieri is identical with H. striata or the striped species.

Professor Gervais also identifies the Equus robustus of M. Pomel, from the same locality, with the common Horse, Equus fossilis.

The fauna of Montpellier is certainly very different from that of Issoire; but since it is neither Miocene nor Pleistocene, it must belong to one of the intermediate stages of the Pliocene. It includes

The Mastodon brevirostris of this list is considered by Dr. Falconer to be identical with M. arvernensis of MM. Croiset and Jobert. The fauna of the Val d'Arno differs from that of Montpellier and of Auvergne, and yet is considered by Dr. Falconer to be eminently