Having listened with much pleasure to several able lectures on Geology and Palæontology which have already been delivered in this Hall, I believe I am correct in affirming, that the general tendency of these discourses has been altogether in one direction; the object being, to impress forcibly upon your minds the opinion that the various changes which have taken place in the earth's history, inhabitants, and surface configuration, have been mainly effected by what may be termed external agencies, i.e., by forces acting from without, slow but sure in their operations, yet but comparatively so feeble in their energy as to demand a practically unlimited amount of time being placed at their disposal to enable them to accomplish those great revolutions which we see and know to have taken place in the geological history of our globe.

An interesting Article by my colleague, Mr. C. E. De Rance, in the last number of this Magazine, upon “The Surface-Geology of the Lake-District,” induces me to offer a few remarks in connection with the subject.

In the February number of the GeologicalMagazine is a revised list of the Cretaceous Entomostraca, described and figured in my Pal. Soc. Monograph of 1849; and I now propose to offer a revision of the Tertiary Entomostraca published in my Pal. Soc. Monograph of 1856. The general observations on the subject offered in February will hold good in this instance also. A corrected list of the generic and specific names is appended; and to this the numbers in the following notes refer.

At a meeting of the Literary and Philosophical Society of Manchester, December, 1867, a paper was, read by Mr. E. W. Binney, “On the Age of the Haematite Iron Deposits of Furness,” when he exhibited and described some iron-ore fossils brought by me from the Water Blain mines, west of the Duddon.

During a short vacation visit to Derbyshire I have had the opportunity of making some further notes on burrows in limestone rocks, which may be worth recording. These burrows, it will be remembered, have been attributed by Messrs. Darbyshire, Mackintosh, and others, to the action of Pholades, a conclusion which I ventured to oppose, after an examination of several instances in the neighbourhood of Llandudno. Mr. Darbyshire calls attention, in his paper, to the occurrence of these burrows near Buxton, on Grin Edge and Harper Hill, at a height of about 1400 feet above the sea. I was therefore fully prepared to meet with them in the Carboniferous Limestone in other parts of the county.

I Have been led to think that a description of the drift-beds in the neighbourhood of Llandudno might be interesting to the Section, on account of the discussion which took place on Mr. Morton's paper, as to the description of pebbles contained in the “Boulder-clay.”

In my fourth Eeport to the British Association, I described, among other Crustacea, two species belonging to the genus Cyclus, one of which still remains unique. Since that date, I have, by the kindness of Professor T. Rupert Jones, F.G.S., received a number of specimens of this genus, collected by Prof. Harkness, F.R.S.; Mr, Joseph Wright, of Belfast; and Mr. J. H. Burrow, of Settle, Yorkshire; from the Carboniferous Limestone, which I now propose to describe.

A Considerable amount of difficulty has been felt by geologists in accounting for the origin of the Boulder-clay of Caithness. It is an unstratified clay, of a deep grey or slaty colour, resembling much that of the Caithness flags on which it rests.

My friend and colleague, Mr. H. B. Medlicott, published, in the August (1869) number of the GeologicalMagazine, a paper “On Faults in Strata,” in which he endeavoured to show that the evidence usually accepted for faults, in the true geological acceptation of the term, is insufficient; that a large number of the lines of junction between rocks of dissimilar age, usually mapped by the Survey of Great Britain and other Surveys as “faults,” are, in truth, natural junctions, due to deposition against cliffs or other steep surfaces; and that direct evidence of friction is necessary to establish the existence of a fault. The latter is rather left to be inferred than positively asserted; nevertheless it is very clearly intimated that it is the writer's opinion.

In the GeologicalMagazine for March last, Vol. VI., p. 115, I gave a short account of the discovery of Olivine and its pseudomorphs in the igneous rocks of the South Staffordshire Coal-field, and as I have since then made a microscopical examination of similar rocks from the surrounding district, I am induced to offer the following observations.

I Have already described in this Magazine several new species of Brachiopoda from the Lower Greensand of Upware; since then I have obtained many more specimens, and much kind assistance from Mr. Davidson, and I now propose to give the result of the examination of the new forms in this paper; also to more fully describe a Rhynchonella from the Inferior Oolite of Lincolnshire, which have named Rhynchonella Crossii.

I Have much pleasure in furnishing you with the accompanying rough sketch of the rock on which were discovered, some time ago, the remains of a building and its “kitchen-midden,” belonging to a remote period, and in which you took some interest in respect of its bearing upon a geological question of the day, namely, the supposed rise of our coasts within the historical period. The rock in question, situated about three miles east of North Berwick, on the south side of the Frith of Forth, is isolated at spring-tides, but is not at other times separated by the sea from the main-land.

The Article in this Magazine by Prof. Harkness, “On the Middle Pleistocene Deposits of Britain,” will, I trust, call the attention of geologists more prominently to the fact that a break occurred in the Glacial period, wherein the formation of Boulder-clay was arrested for a considerable interval, and an extensive formation of sands and gravels spread out, accompanied, apparently, by some amelioration of the temperature of the sea. Nevertheless, there are several things pressed by Prof. Harkness into his case as to which a word of caution, and even of dissent, seems necessary.

The dispersion of debris from the rocks of the Lake district towards the midland counties, is an old and well established fact. Between 1820 and 1850, we find it occupying the attention of such authors as Sedgwick, Phillips, Murchison, Agassiz. Buckland, Binney, Hopkins, and Mantell; and the present day observer may well be cautious in attempting to improve upon their initiatory labours. Special attention appears to have been directed to eastern and south-eastern lines of transport. The Shap granite was followed to every outpost; and the Cumberland erratics in the South Lancashire and Cheshire plains-and remoter valleys and uplands—received recognition in exhaustive memoirs.

Turning now to the physical evidence, it is well known that the Moel Tryfaen bed is 1390 feet above the sea-level; and a depression which would bring the sea up to that point would, unless we suppose a great change in the relative elevations, place the Chalk many hundreds of feet beneath the sea.

Inasmuch as the subject of the Fossil, or rather Sub-Fossil Mammalia of Ireland, has been brought rather prominently before the notice of the Society during the past two sessions, I have considered that it might not be devoid of interest to our members, if I were to place on record the various genera and species of that class of which remains have been hitherto found in Ireland. Such a communication as this does not make any claim to originality, and I shall endeavour, as far as I can, to give my authority for every statement of a fact which will be embodied in this Catalogue. The chief sources from which the information has been derived are Dr. Scouler's papers, in our “Journal,” and those by Dr. Ball and Sir W. Wilde, in the “Proceedings of the Royal Irish Academy.”

The geologist who rambles through the Mountain-limestone district of Yorkshire is sure to have his attention arrested by the numerous “swallow-holes,” or pits, in the rock, into which rills, streams, or even rivers precipitate themselves; and if he can bring his mind to consider the subject sufficiently, without dismissing it at once by a reference to some vague natural force, he will come to perceive the somewhat complex conditions which a complete explanation must satisfy.