Three large pipes of brecciated Torridonian sediments set in matrices of calcite and calcareous mudstone occur on the island of Raasay. Previous work has shown that these structures may be due to explosive fumarole activity during the Tertiary volcanic episode. A recent study of the Torridonian stratigraphic succession has made it possible to demonstrate that there was considerable variation in the amount of vertical collapse of the local country rock caused by the explosions. In one vent local fracturing and brecciation took place with no downward movement; in another it is possible to show that Torridonian boulders tumbled at least 350 metres down into the throat of the fumarole. The amount of vertical collapse increases from vent to vent southwards towards the Cuillins volcanic centre.

These vents are of particular interest for two reasons. Though clearly of volcanic origin they contain no volcanic material. Secondly, the carbonate matrix of analogous structures is generally believed to be due to the hydrothermal solution of underlying limestone beds. The latter are absent in these examples and the carbonate material seems to be solely of volcanic origin.

Although it is now nearly twelve years since I left India, my interest has not abated in the scenes and subjects of former labours in that country, and I am still careful to note anything which is published in reference to them. This practice enabled me to add some facts to the history of the two above-named volcanoes in my Second Notice, besides quoting from the account by Mr. F. R. Mallet, the principal results of his survey made in conjunction with Captain Hobday, eleven years after my visit to them, which took place in the year 1873.

The hill of the Great Doward rises above the right bank of the river Wye to the N.W. of the well-known limestone escarpment of Symonds Yat. The section of the Great Doward, geologically considered, is best seen by ascending the hill from theMonmouth road, a quarter of a mile from the village of Whitchurch. The basement beds consist of Upper Old Red Sandstone, which thins out considerably in its Southern strike from the Brecon Vans; and we pass upwards over the Old Red Conglomerate, and the Passage beds of the Upper Yellow Sandstones, while the hill itself is capped by the Lower Limestone shale and the Carboniferous Limestone.

I have from my boyhood been intimately acquainted with Snowdon and its neighbourhood, and for some years past I have been investigating the geology of the district in a systematic manner. In doing this I have paid particular attention to the lake basins, and shall in the following pages give an account of some of my investigations as far as they have gone. I say as far as they have gone, because I hope in the future to make by means of a level more accurate measurements than can be made with a pocket aneroid; and I also hope that next Summer the lakes and tarns will be sounded either by myself or by someone else; for at present we know nothing about the depth of Llyn dur Arddu, next to nothing above that of Glaslyn, and very little about Llydaw, though that little is of great importance.

In a paper on the Lias of Ilminster, by my friend Mr. Charles Moore, F.G.S., communicated to the Somerset Natural History Society, and published in their Proceedings (1865–6, vol. xiii. p. 72), I gave a list of the Crustacea submitted to me for examination by Mr. Moore, among which was a species belonging to the genus Penæus, referred by me to P. latipes, Oppel, from the Upper and Middle Lias of Ilminster.

The Nahan sandstone of the Nainital district is a soft, fine-grained sandstone of subgreywacke type. Like massive igneous rocks it is very well exfoliated and consists of many concentric layers. Petrographic study of different layers of this sandstone, modal analysis, grain size analysis, and size distribution of the various samples, have revealed that physical processes are mainly responsible for exfoliation of the sandstone. The study of various sedimentary parameters indicated that the provenance is from the schistose and granitic rocks of the surrounding Himalayan mountains and the material was deposited in a shallow slowly sinking basin.

In this paper no new theory is offered as to the formation of those rocks, found in so many places in the Tropics, known as laterites and lateritoids. Rather is it offered as confirmatory evidence of the hypothesis, which has been put forward by several writers (5), that in general they are formed by the evaporation of iron-bearing waters as they are brought to the surface by one or more causes, such as capillarity and hydrostatic pressure. The part that animal life may play in the deposition of the iron, as well as in the solution of it, does not appear, however, to have been noted (5).

To ascertain the most recent movement to which a country has been subjected, and by careful comparison with the past to discover what insensible changes are now progressing, is of the utmost importance in approaching its Quaternary History.

The physical conditions under which the Old Red Sandstone of Scotland was formed is a subject that has long occupied the attention of many of our leading geologists, from the time of Hugh Miller and Sir Roderick Murchison down to those of the present day. It has been variously regarded as of fresh-water and marine origin, as having been thrown down in lakes and in the open sea, or in inlets of the latter. But as yet the whole matter seems to remain an open question, which the unique physical and palæontological elements of the formation make difficult of solution.

The petrology of the Mid-Jurassic sands in the south-west of England has been described both by Professor P. G. H. Boswell and Dr. J. G. A. Skerl. Professor Boswell has dealt with the Toarcian-Aalenian sands from various localities between Cheltenham and the Dorset coast; Dr. Skerl with certain Bajocian and Bathonian beds in the North Cotteswolds. The present paper gives some account of the lithology and terrigenous minerals of the oolitic limestones of Dundry, an area approximately midway between the Cheltenham region and the south coast. Dundry Hill is an isolated patch of Oolite some 8 miles west of the Bath Hills, and Dundry village, which stands on its crest, is 5 miles south of Bristol. The geology and palaeontology of the area have received the attention of many geologists from the time of Conybeare and Phillips, but here only the work of S. S. Buckman and E. Wilson need be referred to, since these authors fully review the previous literature. Buckman and Wilson described the rocks in great detail, and their classification of the strata has been utilized here.

The two Cephalopods—an Ammonoid and a Belemnoid—referred to in the present note were obtained in the summer of 1907 by Dr. A. P. Young from the Tarntaler Köpfe, an isolated mountain-mass in Tyrol, to the north of the Tuxer Alps, and about 20 kilometres south-east of Innsbruck. The Ammonoid was found “at a height of nearly 2500 metres above sea-level, on the surface of a scree-cone which has accumulated under the high hanging valley known as the Lower Tarntal”, and the Belemnoid was found “somewhat lower on the slope of the same cone”. They are the fossils referred to by Dr. A. P. Young on p. 342 of his paper on the Structure and Physiography of the Tarntal Mass, published in the August number of this Magazine (pp. 339–346), where a photograph of the scree-cone is given (Pl XVII, Fig. 5), and now form part of the National Collection.

Owing to the defective character of Sowerby's description and figure of Nautilus elegans, the latter has been variously interpreted, specimens belonging to other species having been frequently referred to it. In the present paper we shall show what is the true N. elegans, tracing the history of the type-specimen, which we have been fortunate enough to identify in the collection of the British Museum. This done, we shall proceed to describe three other species, viz. N. elegantoides, d'Orbigny, N. Atlas, Whiteaves, and N. pseudoelegans, d'Orbigny, all evidently allied to N. elegans, and forming with it a group of species which may be appropriately called the “Group of Nautilus elegans.”

Those who maintain that Till or Boulder-clay has not only originated but accumulated underneath glacier-ice may sometimes have felt puzzled to account for the preservation of beds of more or less incoherent materials below a deposit which they have so many cogent reasons for believing to be a true moraine profonde.

The following article originally appeared in the Times Trade Supplement of August 28 last. It is here reprinted with some small additions by the courtesy of the proprietors of that Journal.

Shoetly after the great volcanic eruption at Krakatoa,inAugust, 1883, the Royal Society appointed a Committee to collect and sift the records of that remarkable outbreak and to study, the effects which appear to have resulted from it. The investigation of the volcanic phenomena and of the materials ejected from the volcano having been committed to me, I have been led to some conclusions of considerable geological interest, the full discussion of which could scarcely find a place in the report which has been published by the Committee. It is these general results which I propose to discuss in the following communication.