The majority of geological formations have certainly been deposited in what was at their respective periods the sea; but Sir Charles Lyell, Prof. Geikie and others have shown that the action of the waves and currents upon sea-cliffs, and their power to remove matter from above to below the sea-level, is very insignificant compared with that effected by atmospheric agents, by rain and rivers, in the interior, in consequence of the immensely more extended area upon which these act; so that, even supposing the height of ancient cliffs to have been very much greater than those of the present time which have been considered to average not more than twenty-five feet, it appears difficult or rather impossible to attribute the origin of the materials of which they consist, sometimes amounting to several miles in thickness, to the erosion of coast-lines, with the exception of a comparatively thin stratum situated at their base. Those who have ascribed their origin to marine denudation have given no satisfactory explanation of the manner in which the débris from the disintegration of the cliffs has been redistributed to form these strata.

Notwithstanding the very inconsiderable amount of sulphur it contains, this Greenland iron has a remarkable tendency to fall to pieces by the action of the air. The weathering depends on an oxidation, probably produced by a quantity of chlorine contained in the iron, and its great porosity; nevertheless, some of the phenomena connected with the weathering still appear to me inexplicable. I shall therefore somewhat more fully detail the observations and experiments made towards explaining this very disagreeable circumstance.

On the previous occasions upon which I have had the honour of lecturing in this hall, my observations were confined to the consideration of the structure of the earth beneath our feet. Now, however, I would crave your indulgence still further, when I attempt to carry your thoughts with me to infinitely higher regions by directing your attention to the study of what may be termed the mineralogy of the heavens above us.

During the summer of last year I had the opportunity of visiting various localities in the State of New York which are of great geological interest; and I was particularly struck by the numbers of valleys which are exclusively the work of the rivers by which they are occupied, as compared with those which are in every way caused by mechanical disturbance of the beds through which they run.

This pit has already formed the subject of communications to the Society. In one read February 16th, 1863, and in a subsequent paper published in the GeologicalMagazine, Vol. II., p. 529, Mr. Seeley maintained, as I believe Professor Sedgwick had always held, that the singular juxtaposition of Kimmeridge Clay, Cretaceous rocks, and Boulder-clay, was due to faulting. In 1868 the Rev. O. Fisher communicated a paper, in which he accounted for the phenomena, by considering the Cretaceous beds as a huge boulderlike fragment, dropped into a valley which it had excavated in the Kimmeridge Clay, with the intervening space filled up with Boulderclay. Shortly after this had been read, Mr. Seeley published a paper in the GeologicalMagazine (Vol. V., p. 347), in which he attacked Mr. Fisher's view. The explanation of the phenomena may therefore be fairly regarded as still sub judice. During the last three years I have from time to time visited the pit, and purpose to lay before the Society the conclusions at which I have arrived, from repeated comparison of the rival theories with the sections exhibited during the progress of the works.

The Fossil Flora, by Lindley and Hutton, has been long known as the only general work containing figures and descriptions of the vegetable remains found in a fossil state in this country, and which must always be consulted by every scientific investigator of this subject. Since the completion of the third volume, more than thirty years ago, many important papers have been published on the Palæontological Botany of the British Islands, by Dr. Hooker, Bunbury, Prof. Haughton, Prof. Heer, Carruthers, and others, but no general work or continuation of the Fossil Flora has appeared, a desideratum very much needed, and which it is now proposed shall be supplied.

In a former paper I referred very briefly to the succession of glacial deposits in Switzerland. It was stated that no interglacial beds like those of Scotland and America occur in the Swiss grundmoräne. But, as every geologist is aware, Professor Heer and others have shown that the lignite-beds of the Cantons of Zurich and St. Gall are really of interglacial age, since they not only rest upon but are covered by glacial deposits. There can be but one opinion as to the position in the series occupied by these lignite-beds; they are clearly intermediate in date between the accumulation of the old grundmoräne and the deposition of that “moraine rubbish” which marked the new advance of the glaciers. ‘This being the case, they cannot represent the beds that occur in the “till” of Scotland, but must belong to a later stage. If this correlation be correct, it seems to me that the Swiss beds will serve partly to fill up a great blank in our record, and help us to realize the condition of our country in the long ages that elapsed between the disappearance of the great confluent glaciers and the subsequent period of submergence, which gave rise to the “kames” and “esker-drift.” This will appear probable, as I hope to show, after we have taken a glance at the glacial deposits in the north of Italy.

In his fourth paper Mr. Geikie sweeps the entire Glacial series of the Eastern side of England into correlation, not only with the Scotch Till, but with the Boulder-clay, both Upper and Lower, of the North-west of England. This he does, so far as I follow him, without any other grounds than that there are beds of “gravel, sand, mud and clay” in the Scotch Till. It is impossible, within the compass of these remarks, adequately to contest Mr. Geikie's views; but if the evidence of organie remains is to be regarded as worth anything, such a correlation cannot, I contend, be maintained.

The Foraminifera of the Chalk were treated of in Nos. 89 and 90 of the Geol. Mag., November and December, 1871, with the view of aiding collectors and authors in their arrangement of these numerous and puzzling microzoa in their catalogues and cabinets. We shall be rendering further service to students, if we refer them to the Rev. Henry Eley's clear and useful, though somewhat hard, drawings of the Foraminifera usually found in the English Chalk and Flint. These were published ia his “Geology in the Garden; or, the Fossils in. the Flint Pebbles.” 8vo. London, 1859.

Before proceeding to give an account of these changes in the fauna of Greenland, I wish to draw attention to the possibility which exists in these parts of obtaining a comparison between the units of geological and historical chronology, that is—if by collecting observations and reports from many different localities, it be possible to determine certain limits for the velocity with which the border of the inland ice moves. One may arrive at the lower limit from the following considerations. The breadth of the slip of border-land at Auleitsiviksfjord is about 60 miles, or 350,000 ft. The annual retreat can, of course, never exceed the thickness of the covering that yearly melts, divided by the sine of the inclination of the icy surface, which in the places passed by us was nowhere less than 30°.