There are but few men who, having passed many of the best years of their lives in almost constant retirement, have achieved so vast an amount of solid and lasting work, have attained to so high a position amongst their fellow-workers, and the award of whose numerous and well-merited honours has caused greater satisfaction among his scientific brethren than Thomas Davidson, Esq., of Muirhouse, F.R.S., F.G.S., Vice-President, of the Patæontographical Society; Member of the Geological Societies.of France, Edinburgh, and Glasgow; Member étranger de I'lnstitut des Provinces, France, and Linnean Society of Normandy; Imperial Mineralogical Society of St. Petersburg and of the Imperial Society of Naturalists of Moscow; Royal Academies of Belgium and of Bavaria; Société Royale Hollandaise des Sciences, Haarlem; Royal Society of Liège; Academy of St. Louis; American Philosophical Society, Philadelphia; Zoological Society of Vienna; Palæontological Society of Belgium; Hon. Member of the Geologists' Association, the Dudley and Midland Geological and Scientific Society, etc.

During the past few years Mr. Charles Moore and Mr. J. McMurtrie have called attention to a remarkable inversion of strata, which was indicated by the working of coal under the Mountain Limestone near Vobster, on the north of the Mendip Hills. And this fact renders necessary an important modification in the geological sections of the district.

In many parts of the world large accumulations of blowing sand exist, either on the sea-board or inland. When inland it usually is composed for the most part of silicious particles; but when in the neighbourhood of the sea, it is more or less mixed with shells, corals, etc.; moreover, it may merge into shell-sand, a highly calcareous Drift, formed of the débris of shells, coral, madrepore, and other marine organic remains.

Between the mountains of North Wales and the sea, occur two terraces, an upper composed of Boulder-day sloping towards the sea, and a lower, consisting of peat and alluvium, but little removed above high-water mark, running far inland, wherebroad valleys like the Vale of Clwyd breach the coast, and where rocky headlands jut into the sea, as the Great and LittleOrmes Heads. The two terraces are almost entirely denuded away, but often the lower one has alone suffered, as between Penmaen Bach and Penmaen Mawr, where a bay in the rocks, so to speak, is filled up with Upper Boulder-clay. It is quite evident that before denudation of the coast took place, the peat plain had a far greater extension than at present, which is proved by the foot of the occurrence of peat and a submarine forest at Rhyl, in borings in the Dee, and around the whole coasts of Cheshire, Lancashire, and southern Cumberland. It is also evident that considerable denudation of Glacial beds had taken place before the period of the old forests, and that the sea-ward prolongations of these beds, which themselves rested on an old sea-bottom, had been denuded away, and that a great plain, or series of plains, formed much of what is now the Irish Sea, before the forests came into existence; the lower terrace now fringing the coasts being the landward edge of this plain. It is nowhere better seen than in the Birket plain, forming the northern portion of the Hundred of Wirral, in North Cheshire. It is bounded to the south by an old pre-Glacial cliff, which abruptly terminates the northerly prolongation of all the numerous longitudinal valleys running with the strike of the Triassic rocks, of which this district is composed, each valley having a steep escarpment facing the west, as described by Professor Hull and myself.