From the examination of this list, the peculiar mixture of Pliocene and Pleistocene species is evident. The Ursus arvernensis, Cervus Polignacus, Hippopotamus major, Rhinoceros etruscus, and R. megarhinus, the Horse, Elephas meridionalis, and E. antiquus were living in the Pliocene age in France and Italy, and probably in Norfolk. The Cave-bear, the Wolf, Fox, Mole, Beaver, Irish Elk, Roe, Stag, Urus and Wild Boar, and the Mammoth have not as yet been discovered in the Continental Pliocenes, as judged by the standards offered by the Val d'Arno and Southern France, and are more or less abundant in the late Pleistocene age. This singular association seems to me to imply that the Forest-bed fauna is intermediate between the two and, from the fact that only three out of the whole series, viz. Ursus arvernensis, Rhinoceros etruscus, and Cervus Polignacus, are peculiar to the Continental Pliocene, that it is more closely allied to the Pleistocene than to the Pliocene.
It is also very probable that this early Pleistocene age was of considerable duration; for in it we find at least two forms (and the number will probably be very largely increased) which are unknown in Continental Europe, although Pliocene and Pleistocene strata have been diligently examined in France and Germany. The very presence of the Cervus Sedgwickii and C. verticornis implies that the lapse of time was sufficiently great to allow of the evolution of forms of animal life hitherto unknown, and which disappeared before the middle and late Pleistocene stages. The Trogontherium also, as well as the Cervus carnutorum, both of which occur in the forest-bed and in the gravel-beds of St.-Prest, near Chartres, and ewhich re peculiar to this horizon, point to the same conclusion.
The Cervidæ of the forest-bed, in this list, do not represent approximately the number of species: there are at least five, and perhaps six, represented by a series of antlers, which I do not venture to quote, because I have not been able to compare them with those of the Pliocenes of the Val d'Arno, of Marseilles, or of Auvergne.
Dr. Falconer pointed out that one of the peculiar characters of the fauna of the forest-bed is the presence of the Mammoth; and the evidence on which he considered the animal to be of Preglacial age in Europe has been fully verified by the molars from Bacton, which are now in the Manchester Museum. They were associated with Elephas meridionalis and E. antiquus, and are incrusted with precisely the same matrix as the teeth and bones of those species.
7. M. Lartet's Classification.
Before we proceed to the examination of the Pleistocene Mammalia of the Continent it will be necessary to ascertain the value of the received classification.
The late M. Lartet proposed in 1861 (Ann. des Sciences Nat. Zool. 1861, p. 217) the following chronological divisions of the Quaternary or Palæolithic age, or that which corresponds with the late Pleistocene. Acting on the à priori consideration that all the animals found in the caves and river-deposits of France did not invade Europe at one time,
