ciple more evident than in considering the structure of the carboniferous area of the Mendip Hills, where enormous denudation had taken place long before the New Red Sandstone was deposited. How then could we ignore this operation in other parts of the country? As to faults, he submitted that their existence must be proved rather than assumed. Did they exist, they were not gaping fractures, but closed; and he regarded it as physically impossible for such hollows as those in which the lakes were found to be due to such causes. Even if fractures existed, they could only constitute lines of weakness, along which denuding agents might more readily work. As to the lakes on the summits of ridges, he would not pretend to account for what he had not seen; but he cited similar lakes on the Grimsel, which presented similar phenomena, and which he regarded as undoubtedly due to glacier action. Even on the top of roches moutonnées such basins were found; and though he might not know the exact circumstances under which they were formed, they were undoubtedly due to ice-action. If in Switzerland and other glaciated countries of the present day we find the configuration of the country presenting similar phenomena to those of Scotland, he considered that there was ample ground for attributing both to the same cause, and there was no need of invoking other causes. It was moreover to be borne in mind that though similar contorted gneissose rocks to those of Scotland occurred in several other countries, it was only in those which had been glaciated that such numerous lake-basins were to be seen.
The Duke of Argyll, in reply, agreed with Prof. Ramsay that it was not in all cases that the lake-basins were due to disturbance of the rocks; and indeed in some of the most contorted districts lakes were rarely present. All his contention was that whatever may have been the denuding agent, it was not in all cases ice.
[Plates XVI. & XVII.]
Amongst the additions to appear in the second edition of my 'British Fossil Mammals and Birds' I have anticipated the descriptions of certain species, as in the case of the gigantic Eocene bird, equalling in size the larger New-Zealand Moas[2]. The still more remarkable Ornitholite, also from Sheppey, which I am now about to describe, has stronger claims to be made known, without delay, on account of the transitional character which it manifests to the Pterosaurian order.
The fossil consists of a large portion of the skull, which, when the specimen was received in the British Museum, was more or less imbedded in the London Clay; the clearing out of the matrix by the
