true conditions of the period; and how difficult it is to separate the river alluvia of this age from the deposits in the seas and estuaries, and these again from the older Glacial beds. Further, in not a few instances the animals of a cold climate must have lived in close proximity to those which belonged to ameliorated conditions, and the fossils of the older Post-pliocene must often, in the process of sorting by water, have been mixed with those of the newer. [AL] Mr. Tylor has well designated this period as the Pluvial age. _Journal of the Geological Society_, 1870. Many years ago the brilliant and penetrating intellect of Edward Forbes was directed to the question of the maximum extent of the later Post-pliocene or Post-glacial land; and his investigations into the distribution of the European flora, in connection with the phenomena of submerged terrestrial surfaces, led to the belief that the land had risen until it was both higher and more extensive then at present. At the time of greatest elevation, England was joined to the continent of Europe by a level plain, and a similar plain connected Ireland with its sister islands. Over these plains the plants constituting the "Germanic" flora spread themselves into the area of the British Islands, and herds of mammoth, rhinoceros, and Irish elk wandered and extended their range from east to west. The deductions of Forbes have been confirmed and extended by others; and it can scarcely be doubted that in the Post-glacial era, the land regained fully the extent which it had possessed in the time of the Pliocene. In these circumstances the loftier hills might still reach the limits of perpetual snow, but their glaciers would no longer descend to the sea. What are now the beds of shallow seas would be vast wooded plains, drained by magnificent rivers, whose main courses are now submerged, and only their branches remain as separate and distinct streams, The cold but equable climate of the Post-pliocene would now be exchanged for warm summers, alternating with sharp winters, whose severity would be mitigated by the dense forest covering, which would also contribute to the due supply of moisture, preventing the surface from being burnt into arid plains.