“The first of these migrations we may suppose brought in certain highly specialized ruminants of the Upper Eocene, the anomalures or peculiar flying rodents of Africa; with this invasion may have come the pangolins and ard varks, and possibly certain armadillos, _Dasypodidæ_, if M. Filhol’s identification of _Necrodasypus_ is correct. A second invasion of great distinctness may be that which marks the beginning of the Miocene when the mastodons and dinotheres first appear in Europe, also the earliest of the antelopes. A third invasion may be represented in the base of the Pliocene by the increasing number of antelopes, the great giraffes of the Ægean plateau and in the upper Pliocene by the hippopotami. With these forms came the rhinoceroses with no incisor or cutting teeth, similar to the smaller African rhinoceros, _R. bicornis_. Another recently discovered African immigrant upon the Island of Samos in the Ægean plateau is _Pliohyrax_ or _Leptodon_, a very large member of the Hyracoidea, probably aquatic in its habits, indicating that this order enjoyed an extensive adaptive radiation in Tertiary times. “It thus appears that the Proboscidea, Hyracoidea, certain edentata, the antelopes, the giraffes, the hippopotami, the most specialized ruminants, and among the rodents, the anomalures, dormice and jerboas, among monkeys the baboons, may all have enjoyed their original adaptative radiation in Africa; that they survived after the glacial period, only in the Oriental or Indo-Malayan region, and that this accounts for the marked community of fauna between this region and the Ethiopian as observed by Blanford and Allen. “Against the prevalent theory of Oriental origin of these animals are: first, the fact observed by Blanford and Lydekker in the Bugti Beds (Sind) that the Oligocene or lower Miocene fauna of the Orient is markedly European in type; second, that if these animals had originated in Asia some of them would have found their way to North America; third, the fact that all these animals appear suddenly and without any known ancestors in older geological formations. These are the main facts in favor of the Ethiopian migration hypothesis.” That Professor Osborn’s main contention has already been partly proved by the Fayûm mammal discoveries is apparent, and how far his detailed remarks are confirmed will be seen when the new fauna has been more completely explored and examined. The following is a list of the new species already obtained:— ----------------------------------+---------------------------------- UPPER EOCENE. | MIDDLE EOCENE. ----------------------------------+---------------------------------- _Mammalia_