Mr. Marr's valuable communication on the Coniston Limestone Series, which appeared in the March Number of this Magazine, is sure to be welcomed as an excellent summary of the geology of this interesting group of rocks. It contains a digest of most of the published work relating to the Coniston Limestone Series, and also many new facts and arguments drawn from Mr. Marr's own observations in the field.

During my visits to West Bay, Bridport, in the years 1887 and 1888, I was able to examine the following inland sections of the Lias Junction Bed, and I communicated a paper to the British Association at Leeds in 1890; an abstract of this paper appeared in the Report. I had hoped to obtain more evidence of the nature of this deposit, but, unfortunately, last year, 1891, I found that the working of the Allington brickfield was being abandoned, and that it was difficult to further work the roadside cuttings without doing considerable damage. I therefore think it better to lay before the readers of the Geological Magazine my notes on this deposit, which I shall be able to show is variable in different sections, due to the amount of denudation which has taken place.

I Venture to offer some remarks on the above-mentioned paper of Prof. Bonney, which appeared in the Quarterly Journal of the Geological Society for May, 1890 (vol. xlvi. pp. 187–240). As the result of ten years' geological researches in the St. Gothard district, I have become familiar with most of the statements and arguments brought forward by Prof. Bonney; many of them, I am glad to see, agree with my own observations and views, already made known in official and other publications; others, however, I feel bound to dispute.

In the Devonian sandstones and grits of Torbay abundant quartz veins are occasionally developed, indicating a moderate amount of heat. Neither the quartz-grains nor occasional fragments of felspar are to any extent affected.

At Dartmouth, on the raised-beach platform, quartz is largely developed together with a little felspar and chlorite, indicating sufficient heat to form or re-form these minerals. At Slapton Sands the grits are about the same as in Torbay: felspar granules remain angular and intact.

Between Beesands village and Tinsey Head the quartz-grains occasionally show signs of incipient solution, as also do the tourmalines. In one slide (No. 5) the approach of schistosity seems to be heralded by minute roughly parallel cracks cemented by iron ores and a pale-green mica. Minute crystals of pyrites, some rectangular, are formed in the rock. At the Start, in rare cases, grains or remnants of grains of original granitic quartz can be detected in the schist. Tourmaline is partially dissolved with recrystallization.

In working out, at the request of Sir Archibald Geikie, the petrography of the Lower Carboniferous Volcanic rocks in Haddingtonshire (the results of which I propose shortly to publish), I have been led to examine the igneous material that builds up the isolated hills (necks), situated on the margin of the volcanic area of the Garlton Hills. Among these, the rock of Traprain Law especially attracted my attention. It is a close-grained, dark brown to grey rock. Some varieties have a glistening or greasy surface, and are speckled over with dark spots, while others show glancing cleavage surfaces of a clear glassy felspar (sanidine).

In the course of investigations amongst the Microzoa from the Gault of Copt Point, Folkestone, some Forarainifera came under my notice, which are hyaline representatives of the usually arenaceous type Webbina. These forms are remarkably similar in external appearance to those of the arenaceous group, but microscopical examination of the test under a high power reveals the finely tubulated structure characteristic of the hyaline type.

The Government of Western Australia, through their Geologist, Harry Page Woodward, Esq., F.G.S., has recently presented to the British Museum an important series of Palæozoic invertebrate fossils which have been collected from various localities during the progress of the geological survey of that colony.

Compared with that of the year before, the British seismic record for 1891 is somewhat meagre. It includes a slight earthquake felt in North Cornwall on March 26, several at Invergarry, Ardochy, and Loch-hourn Head in Inverness-shire; and one other, believed to be that of an earthquake, at Bournemouth on October 25. The remarkable series of earthquakes felt between November 15 and December 14, 1890, in the district round Inverness seems to have ended at the latter date; for Mr. J. Birnie, a very careful observer residing at Balnafettack, informs me that he has felt none during the past year; and his evidence is especially valuable, since the epicentra of nearly all the shocks must have been close to that village.

When writing my paper “On the Igneous Rocks of the South of the Isle of Man,” I was led to compare a Manx melaphyre, from Scarlet Point, with a rock described by Prof. E. Hull as a melaphyre, occurring at Ballytrasna, near Limerick, and belonging to the “Upper Trap-band,” a little below the basal shales of the Coal-measures. Through the kindness of Prof. Hull, a chip of the rock was sent to me by the Irish Geological Survey. The specimen was black and basaltic-looking. I did not obtain satisfactory sections of it in time for my paper, but have since had excellent ones made. On examining them I was immediately struck by the resemblance of the rock to the augitite of Paschkapole, between Velmin and Boreslau, in Bohemia, with a section of which I compared it. Professor Hull describes the rock of Ballytrasna as containing “numerous large crystals and groups of banded felspar”; but I failed to find a single felspar in four sections, nor did I observe any in Allport's section, No. 1902, from the same locality, which agrees with my sections.

In recent papers which I have printed in the GEOLOGICAL MAGAZINE I have tried to show that some of the greatest mountain chains in the world are of very recent origin; and that this accounts for their showing no traces, or very slight ones, of the action of ice on a wide-spread scale.

I have, in fact, ventured to lay down the conclusion that the presence or absence of such traces of ice-action is a test of whether these mountains existed at the so-called Glacial period or not.

It is not impossible that readers of a paper lately published by our venerated senior geologist may have been startled, some for one reason others for another and opposite. On reading the suggestions he has put forward as to the results from rapid elevations over southern England, some will recoil as at a revival of catastrophic machinery; some on the other hand may hail the invention of anovel and most potent agency. I doubt whether either view is altogether correct or defensible.

Palæontologists and others concerned with fossils often X have need of some method of taking impressions of fossils, which shall at the same time be simple and efficacious, and shall also be of such a nature as not to cause injury of any kind to the original. Many different processes have been tried, with varied success. The following method has stood the test of application to a wide range of subjects, and has answered its purpose well in the hands of a considerable number of workers:—

I Quite agree with Mr. Goodchild's statement in the July Number of the Geol. Mag. that the stratigraphy of some of the areas in which the Coniston Limestone Series is developed “presents very considerable difficulties,” so much so that in the areas of Cross Fell and Settle portions of the “country might be described as consisting of a gigantic fault-breccia,” and that it is necessary “to go over a large part of this faulted area again and again” in order to interpret its structure. I do not know whether Mr. Goodchild would class me amongst the “less fortunate” ones who have not been over the ground again and again; possibly I have not devoted the amount of time which he has been able to give to the study of the rocks of the Cross Fell Inlier, but it must be remembered that Prof. Nicholson, with whom I had the pleasure of working at this inlier, has returned to the ground again and again during a long course of years, whilst more recently, he and I have devoted several vacations to its study, and we have carefully compared the beds and their fossils with those of adjoining and more distant areas.

It is a pretty well recognized fact that Obsidian is a hydrous silicate of indefinite composition and your fusion experiments confirm that fact. Now molten obsidian may give off its H2O in consequence of two processes—by simple vesiculation, or by the individualization from the glass of a definite anhydrous silicate. More commonly these two processes have gone on together, but modified by the vicissitudes of temperature that the molten aquiferous glass is exposed to during its eruption.

During the summer of 1890, Professor Cole and I, whilst geologising in North Wales, were led to examine the Hirnant Limestone. Since then the further examination in the laboratory of the specimens collected by myself have revealed some remarkable characteristics which, as they are as yet undescribed, I think are worthy of notice.

The specimens on which the following observations have been made were obtained from a small cutting opposite to the farm named Cwm-yr-aethnen, in the valley of the Hirnant, which descends towards Bala Lake. The limestone occurs here between two beds of fossiliferous slate. The exposure is very small, and being considerably overgrown, it was only by careful search that we succeeded in finding it. The Survey Memoir mentions that an. outcrop occurs at Trum-y-gwrageda, and also that loose blocks were found by Sedgwick at the Bwlch-y-groes; but after a careful search we failed to find it at either of these localities.

In his recently published excellent Memoir on the “Fauna of the Lower Cambrian or Olenellus Zone,” Mr. Walcott has referred briefly to the presence of the fauna in Wales. The following additional facts bearing on the question may therefore be of some interest, and they will, I think, show that there is strong evidence in favour of the conclusion arrived at, that the Olenellus fauna occurs in the Caerfai Group of St. Davids, and in beds at the same horizon in North Wales.

In the Geological Magazine of last year I described a system of Miniature Faulting observed by me in a fine bed of banded silty clay at Nevin, Carnarvonshire. This year I have had the good fortune to observe Faulting in Drift on a much larger scale in the neighbourhood of St. Bees, Cumberland, which is highly instructive and explanatory of several features of Normal Faulting which the other illustration did not touch.

In the October Number of this Magazine, a paper by the Rev. A. Irving, D.Sc, calls for some comment. The subject, “The Malvern Crystallines,” is one which has engaged my close attention during the last seven years, and two expositions of my views have appeared in the Quarterly Journal of the Geological Society. I am glad to find that Dr. Irving accepts my main conclusion —that the Malvern gneisses and schists are of igneous origin; but there are some important details in which he has formed a different opinion. It will not be necessary for me to discuss these differences with any fulness, since my third and final paper, which is nearly ready, treats of some of his more material objections to my views.

The sound-phenomena accompanying earthquakes have not often been made the subject of special investigation; and, consequently, their value and significance may have been somewhat underrated. I believe that much remains to be done, that many observations must yet be made, before the problem of their origin can be regarded as completely solved; but the facts already known, seem to me sufficient to show that the inquiry is one full of interest and worthy of development beyond that here attempted.

In some papers which you have done me the favour to print in the GEOLOGICAL MAGAZINE, I have endeavoured to apply a new touchstone to test the age of high mountain chains and of land of high elevation, namely, the presence or absence of distinct and prominent traces of former glaciation, and I have argued that where such traces are not forthcoming in a very unmistakable manner, we are justified in concluding that these highlands have been elevated since the so-called Glacial Period. I have endeavoured to apply the touchstone in question to the Ural and Altai Mountains, to the Thian Shan and Himalaya ranges in Asia, and to the great Cordillera which binds together the two continents forming the New World. I wish to make my survey more complete by an examination of an interesting area comprising Eastern Europe and South Western Asia.