Introduction.—In previous papers upon the Geology of the English Lake District, which I have had the honour of laying before the Geological Society, special considerations of theoretic significance have been dwelt upon, and in the official memoir upon the Geology of the northern part of the English Lake District, detailed facts have been brought forward and a sketch given (in chap. xii.) of the original relation of the formations to each other, and their physical history. I yet venture to think, however, that there is need of a general summary of the facts relating to Physical Hiatory which may reach a wider circle of readers than do the offical memoirs, and which may stimulate further inquiries into this deeply-interesting subject. The following pages may therefore be regarded as a sequel to my former papers on the district, and in some measure as a last chapter to the story told thus far.

In the GeologicalMagazine for December, 1876, appeared a short paper on certain clay beds near the south-eastern shores of Lough Neagh. The paper is intended to supplement a more extended communication entitled, “On the Age and Mode of Formation of Lough Neagh,” read by the same author—Edward T. Hardman, Esq., F.C.S., H. M. Geol. Survey of Ireland— before the British Association in 1874, and also read before the Royal Geological Society of Irealand in January, 1875. The beds in question are described“as a very extensive and important deposit spreading (under water and on shore) over an area that cannot be less than 180 square miles in extent, and probably in some places 500 feet thick. They repose on the basalt, and are covered by drift. All the evidence we have points to their being of Pliocence age.” The author, after giving a sketch of the Geology and physical Geography of the district, proceeds with a description of the clay beds and associated lignites, and gives abstracts of numerous borings ranging in depth from a few feet to 192 feet, which have been made over this area. These borings disclosed a series of light-grey and variously-coloured plastic clays, containing hard nodules of clay-ironstone inclosing leaf and other plant-remains, also large quantities of black lignite, occurring frequently in masses throughout the beds, but sometimes bedded.

A quarter of a century ago it was a disputed question whether it the Old Red Sandstone was a separate formation or not. About that time, or a few years later, the subject. engaged the attention of the Geological Section of the British Association.

The best description of St. Michael's Mount, as it now exists, that I can find, is by Mr. Wm. Pengelly, F.R.S.,1 as follows: “The Mount is an isolated mass of granite measuring about five furlongs in perimeter at its base. At high-water it plunges abruptly into the sea, except on the northern or landward side, where the granite comes in contact with the slate, into which it sends veins and dykes, as may be well seen on each side of the harbour.Here there is a small plain occupied by a village, adjacent to which is the harbour, built in 1726−7, and as Mr. Johns, the harbour-master, has been good enough to write me, capable of receiving ships of 500 tons burthen” Its sityation is described as follows: “ The distance between the neatest point of Marazion Cliff and spring-tide high-water mark on the Mount is 1680 feet. A tidalb isthmus (Hogus) of highly inclined Devonian slate and associated rocks, in most cases covered with a thin layer of gravel or sand, is at spring-tide, in still weather, 12 feet below; and at low-water 6 feet above the sea-level. This ridge is dry in fine westher from four to five hours every tide, but occasionally during stoms and neap tides it is not passable for two or three days.”

In Mr. Dakyns' letter in the Geol. Mag. January, 1879, p. 46, line 11 from bottom, the words river base should have been river Ouse.