leave the question open, to be solved by future dis- coveries, with the remark that in this case there is no inherent improbability of its being answered in the affirmative, as in the alleged cases of man's presence in more ancient deposits, since numerous mammalia now living in Europe were then in possession of the land.
The Mid-Pleistocene Mammalia.
A group of animals, differing in many important particulars from the above, has been met with at Ilford and Grays Thurrock in Essex, at Erith and Crayford in Kent, and at Clacton on the Essex coast. They differ from the early Pleistocene group chiefly in the absence of most of the Pleiocene survivals, as well as by the incoming of species hitherto unknown, among which man is to be reckoned.
The extraordinary mixture of forms will be seen from the examination of the following table, in which the survivals have been separated from the newcomers, constituting fifteen out of a total of twenty-six species. The extraordinary deer of the Forest-bed are no longer to be seen, and the Etruskan rhinoceros has been replaced by the leptorhine or small-nosed rhinoceros of Owen. The woolly rhinoceros, the companion of the mammoth in its wanderings from the steppes of northern Siberia as far south as the Alps and Pyrenees, appears for the first time. It must also be remarked that the valley of the lower Thames is the only place known where the woolly and leptorhine rhinoceros are found side by side with the big-nosed species. The southern elephant, which survived from the Pleiocene into the early Pleistocene stage, is no longer present, and had either become extinct
