It is needless to recapitulate, for the information of the readers of the GEOLOGICAL MAGAZINE, all the incidents which are known to accompany the formation of new land by rivers, or to repeat the descriptions which have been given of the more remarkable instances of them, such as those of the Nile, the Mississippi, the Ganges, the Rhone, the Po, and the Danube. These have been scientifically discussed long ago, by Lyell in his Principles. The object of this paper is rather to suggest how a careful collation of such facts as may be learned in connexion with the formation of modern deposits at the mouths of great rivers, or in great estuarine areas (such as the Wash), which receive a number of streams from widely-extended inland catchment-basins, may throw light upon the history of older formations of the same kind, and more especially of those of Tertiary times, during which many important changes were wrought in the physiography of the continent of Europe.

In the Geological Magazine for July last the Rev. W. Andrews and Mr. Jukes-Browne gave an account of Lower Cretaceous strata in the Vale of Wardour. I can bear testimony to the correctness of this statement. Many years ago, when geologizing in the vale chiefly among the Purbecks, I found many portions of ironstone and hard ferruginous sandstone, in the fields and by the roadside both at Dinton, Teffont and especially at Chilmark, containing casts of Cyrena, Turritella, and a part of a dermal scute of a Saurian, which I believe belong to the Lower Greensand, but I never saw it in situ, and it seems to have been greatly denuded.

Some specimens of Cherty rock forwarded to England for determination some years since by Mr. H. Y. L. Brown, F.G.S., Government Geologist of South Australia, have lately been submitted to me for examination by my friend Dr. H. Woodward, F.R.S., and their structure, as shown in thin sections, seems to me sufficiently interesting to be recorded. The specimens in question are of a light or yellowish-grey tint, with a waxy lustre, in some portions compact and in others minutely porous, which makes them light to the feel. The rock is hard, scratching glass readily, and there is no reaction with acid.

The extinct genus of Chelydroid Chelonians to which M. Louis Dollo gave the name of Pseudotrionyx, has already been recorded from the London Clay of Sheppey, by Messrs. Lydekker and Boulenger. It is somewhat remarkable, however, that until the recent acquisition by the British Museum of the collection of Mr. J. B. Ogle, no certain evidence had been observed of the occurrence of the genus in the Bracklesham Beds—the English equivalent of the Bruxellian Series which yielded the Belgian Pseudotrionyx Delheidi.

I have already shown that the northern boundary of the Indo-Gangetic alluvium is a structural one, and that the rock area immediately to the north of it has been elevated, while the nature of the boundary on the south, the deep imbayments of the alluvium, the gentle manner in which the older rocks slip under it, and the inliers, alike show that, on the south, the alluvium has gradually encroached on the rock area by the subsidence of the latter.

On the Italian side of the Alps a similar set of lignite beds occurs as on the Swiss side. But these Italian lignites, although occurring beneath, are not underlaid by glacial deposits.

Ten years ago Charles Darwin published his last work, the result of more than forty years' observations on the habits of earthworms and the rate at which they bring up soil to the surface. To ascertain this rate, he made use of two methods. In the first place he measured the rate at which layers of lime or cinders were covered over by the spread-out castings of worms; and, later, he collected and weighed all the castings thrown up over a definite area within a given time. As is well known, the general result of his investigation was greatly to exalt our ideas of the importance of earthworms and of the work they do upon the surface of the land.

The work performed by lobworms on the surface of tidal sands seeming not less worthy of study, I made some observations on the subject during a short stay in Holy Island last August.

Mr. H. M. Ami, F.G.S., of the Geological Survey of Canada, who has devoted special attention to the fauna of the Utica Shale in the neighbourhood of Ottawa, lately sent me for examination several fragments of slabs of this rock containing some peculiar sponge remains, which seem to me to be worthy of notice, although, from their mode of preservation, no decisive determination as to the character of the sponge.to which they belong can be arrived at.

The consideration of the Archæan rocks of Finland, as pointed out in a previous article, naturally divides itself into two parts: I. The treatment of the stratified or foliated members of the series; II. That of the igneous or eruptive rocks. In describing the former, want of space compelled me to handle the subject in what I fear must be regarded as a very fragmentary manner. In addition I confined myself entirely to giving an account of the older members of the formation, omitting all mention of the younger schists, mica-clay slates, phyllites, etc., which go to make up what is in Finland regarded as corresponding to the Huronian subdivision. I did this from two reasons,—firstly, because I was personally better acquainted with the rocks in question ; secondly, because it seemed to me that it is the problem of the origin, sequence and composition of the older members of the series which at the present day possesses most interest for the student of the geology of the Archaean, and in consequence is the one with regard to which the greatest divergence of opinion prevails. In the present article I propose to give a short account of the more important eruptive rocks of Finland; but before proceeding to do so, it would not, I think, be out of place to furnish a short résumé of the conclusions to which the study of the foliated Archæan rocks of the country has led me, and which I believe to be thoroughly supported by the data published in my former article.

Mr. W. M. Hutchings' “Notes on the Fireclays of the Coalmeasures,” published in the April Number of the Geol. Mag., contains many interesting facts and suggestions on which I should like to offer a few remarks.

Time of occurrence, 13 h. 58 m.; Intensity, about IV. Epicentrum, probably not far from Ben Nevis.

I am indebted to Mr. E. T. Omond, Director of the Ben Nevis Observatory, for the only information I have been able to obtain with reference to this earthquake. “It was,” he says, “sufficiently strong to make part of the wooden roof creak, but was, as far as I know, not noticed in any other part of the country.” The few inquiries that I have been able to make confirm this remark, and I think we may therefore conclude that the epicentrum cannot have been very distant from Ben Nevis. The great fault, which crosses Scotland from Inverness in a south-westerly direction, passes at the surface within a short distance from Ben Nevis; and being, in other parts of its course, closely associated with recent earthquakes, may possibly, by a slip, have given rise to the Ben Nevis shock.

Until recently no outcrop of the Vectian or Lower Greensand was known to occur between Lulworth on the coast of Dorset and the neighbourhood of Devizes in Wiltshire. It was supposed that, with the exception of a small area of Wealden in the Vale of Wardour, the whole of the Lower Cretaceous Series in Dorset and South Wilts was concealed and buried beneath the overlapping Upper Cretaceous strata. A recent examination of this district however has revealed two areas where the Vectian sands emerge from beneath the Gault. One of these has already been indicated in the pages of the Geological Magazine; the other is the subject of the present communication.

In 1887 a quadri-radiate Echinoconus (Galerites) subrotundus from the Lower Chalk of Shudy Camps, Cambridgeshire, was presented to the Woodwardian Museum by J. Carter, Esq., F.G.S. The specimen is in a good state of preservation, but it has been subjected to a slight amount of crushing, and this has caused (1) the apex of the test to be pushed backwards to a very small extent, and (2) an abrasion of the antero-lateral border. It has the subconoidal form of the normal examples of this species, but is subquadrate in section, and this is due to the fact that only four ambulacral and four interambulacral areas are present, the fifth area of both kinds being completely wanting.

In 1853, in his “Description of the Fossil Eemains of Mollusca found in the Chalk of England” (Mon. Pal. Soc.), Sharpe described and figured a specimen under the name of Nautilus Neocomiensis, d'Orbigny. He states (loc. cit. p. 15), “We have only seen one small specimen from the Grey Chalk, which we can refer to this species; it is from Urchfont near Devizes, in the Collection of Mr. Cunnington, and is 2 inches in its greatest diameter and 1¼ inch in breadth; although a good deal broken, it shows all the peculiar characters of the species. The species is more common in the Lower Greensand of Dorking, Atherfield, Sandgate, etc., where it sometimes reaches above 7 inches in diameter. M. d'Orbigny quotes it as common in the lower beds of the Middle Division of the Neocomian Formation in France.”

In the originally epistolary form of my previous communication on this subject brevity was aimed at as far as possible. It was written at the time the letters therein referred to appeared, and my object in throwing out such suggestions as I have ventured to make, was to call the attention of writers on petrological subjects to the desirability of avoiding a certain looseness of thought, which seemed to attach itself not infrequently to the terms ‘chemical change’ and ‘chemical action.’

The Geological Survey of India Records, vol. xxiv. part 1, 1890, only came to hand to-day, enabling me to see Mr. Middlemiss's late paper on the Salt Range.

In the year 1865 portions of the upper and lower jaws of a large extinct fish that had been found imbedded in the Globigerina Limestone of Malta were submitted by Dr. Leith Adams to Professor Owen for identification. Adams had considered them as being the remains of a crocodilian; but in a paper that appeared in the GEOLOGICAL MAGAZINE for April, 1865, Owen pronounced them to be the remains of a large extinct fish that belonged to “the cycloid order, and having sauroid dentition,” and he proposed that “this fine addition to Miocene Tertiary fishes” should be known by the name of Stereodon Melitensis.

A portion of the bony skeleton of a fish of the same species was also discovered in the same locality; but as it was not sent with the other specimens, it has been neither figured nor described.

Considerable doubt having been expressed with regard to the occurrence of the zone of Ammonites jurensis in the neighbourhood of Northampton, much interest attaches to the discovery, by Mr. T. Jesson of Great Houghton, of the typical Ammonite in some abundance in this area. It is perhaps remarkable that there should have been any doubt about the matter, seeing that in Samuel Sharp's earlier paper Am. jurensis was recorded among the fossils from Duston, and this should have stimulated further search when the doubt arose which seems to have caused this species to be omitted from the later paper by the same author, in which some palæontological errors of the earlier paper were said to be corrected.

The following is the fundamental principle of the theory of terrestrial evolution which has been sometimes called the “expansion theory”:—

Masses of sediment laid down in an area of subsidence are gradually lowered to regions of the earth's crust that are at a higher temperature than that in which they were deposited. The sediment, being heated, expands, is crumpled and folded internally, and, bulging up at the surface, is reduced by denudation to the form of a mountain-chain.