It is so easy these days to overlook recent advances of science that I venture to draw attention to two particularly important papers on Indian tectonics by W. D. West, published in 1939 and 1936, both carrying self-sufficient maps. The 1939 paper deals with Alpine tectonics displayed in the Shali Window of the Himalayas, north of Simla; its partner, with a recumbent fold and slide in the Nagpur district of Peninsular India.

My attention has recently been called to some very interesting comments on the problem of the delimitation of the Silurian and Devonian systems, which were made by Dr. Elles in her Presidential address to Section C of the British Association at Liverpool. I am so heartily in agreement with all the principles of the modern classification of strata, as laid down by Dr. Elles, that it seems of advantage to recall very briefly how closely these principles are adhered to in using the Ludlow Bone-bed as the local base of the Devonian in England.

The controversy which has arisen in recent years in New Zealand regarding the problem of the Pleistocene glaciation of that country resolves itself into the two following main questions:—

1. Was there any glaciation in the North Island?

2. Was there an ice-sheet covering the South Island?

Kames, åsar, and minor topographical features.—Kames and åsar are usually found associated. Indeed, the one class of elevations shades into the other so gradually that it is sometimes impossible to draw the line between them. Though the kames may occur singly, they are often in ranges of several, perhaps extending for miles. Each is usually elliptical in outline, and its longer axis corresponds in direction with the range. The åsar are frequently intercepted by channels of erosion, by which they are divided into ranges of oblong hills, the direction of which is very nearly the same as that of the kames proper. In Dubuque county, Iowa, where these features have been most thoroughly studied, this direction is about S. 75° E. Within 40 miles south-west from there the direction changes to abut S. 45° E., and in the next 50 miles the direction becomes a trifle west of south; and this is the general direction over the greater part of the region examined.

As none of the figures hitherto given of the genus Eophyton show either its internal structure, or articulations of its stems, and as I am in possession of a specimen from the Lower Arenig Rocks, of Ramsey Island, near St. David's, which resembles in some respects the Eophyton Linnœanum Torell, but which shows both articulations of the stem, and an internal vascular structure, a description of the species may probably be useful, and may tend to elucidate the true nature of Eophyton, concerning which so much doubt seems to exist at present.

Perhaps no question in English Pliocene geology has caused so much inquiry as the exact relation of the Red and Norwich Crags. The latter term I prefer as more palæontologically correct than the older one of “Mammaliferous,” and it is now becoming generally used. In the year 1865 I divided the Norwich Crag into two divisions, an Upper and a Lower, and endeavoured to show that the latter was the true Fluvio-marine Crag, the former being distinguished by its purely marine character, and also by its containing a larger per-centage of Northern shells. This Upper Crag was subsequently termed the “Chillesford Crag” by Mr. Searles Wood, and by this name it is usually known. In my paper above mentioned my purpose was to show that this Upper or “Chillesford Crag” connected the latest of the older crags with the lower Drift-beds. The Fluvio-marine beds were formed along the floor of an estuary, but the Upper Crag was deposited along the sea-bottom, when the same area had been depressed. As a consequence, this Crag had a wider and more extensive geographical development. I was unaware at this time that Mr. Searles Wood was working at the same subject; and I subsequently found that he, with his usual indefatigability, had arrived at a similar conclusion respecting the Upper bed of Norwich Crag.

The quarrying operations that have been carried out during the last five years at Handley's Pit, Lincoln, have led to the exposure of some very complete and instructive sections in the Middle Lias.

Handley's Pit is situate on the North Cliff, at a distance of about a furlong from the now disused pit of Glaisiers, and immediately below that of the Lincoln Brick Company (late Swan's). When compared with the sequence exposed in Swan's Pit, it affords some interesting details that assist materially in clearing up some of the doubtful points to which Mr. Dalton referred in the Geological Survey Memoir on Lincoln Geology regarding the limitation of the range of A. margaritatus, and the occurrence of the Marlstone Rock-bed in the Lincoln District.

In the former notes “On the growth of soil,” I omitted to speak of the labours of the ants—these workers, although such pigmys in this country, and, therefore, compared with the earth-worms, less capable, individually, of work, are so numerous and energetic, that in the special places to which they resort, their yearly work is much more conspicuous than the annual worm-work; but the animals operate in different places, for while the earth-worm luxuriates in rich highly-cultivated land, the hill-building-ant loves a dry, sandy or peaty soil. In the spring the ants may be observed beginning their work, and from that time they carry on their operations all through the summer, to the late autumn, or early winter. On a moor they raise hillocks scattered promiscuously about over the ground, getting closer and closer together as the colonies increase. But where the ants are most useful is in places where crags and large stones are mixed up with patches of sandy peat. In such a locality they will always build on a rock, the foundation of their habitation being at its junction with the soil. These ants seldom raise their structures as high as the moorland ants, but they make up in extent for absence in height, and by this means the rocks are gradually covered with soil and vegetation; for, on account of the season of the year at which they build, the growth of the plants keeps pace with the formation of the ant-soil, and protects it in a great measure from “Meteoric abrasion.” During the winter, however, the shape of the ant-hills is somewhat modified, but the matted roots of the plants preserve the major part of the soil which will thus remain, forming an envelope for the rock.

In a previous paper we showed that the extinction of the Mammoth was sudden, and was accompanied by a sudden change of climate throughout Northern Siberia, which enabled its soft parts to be preserved intact. We did not mean that the change of climate was the cause of the Mammoth's extinction. This it clearly was not, for this change on a large and marked scale was apparently confined to Siberia, while the Mammoth disappeared from a much wider area, where this climatic revolution could not have been so fatal. A sudden change of climate could not account for a catena of Mammoth carcases found buried several feet underground from the Obi to Behrings Straits. If they had been killed by the cold merely, their bodies would have lain on the surface where they fell and become long ago the prey of the predatory animals. Nor again can we, with such a postulate merely, account for the remains occurring in many cases in hecatombs, and in many cases also with a mixture of various species of animals. The cold would hardly have destroyed the bears and hyænas which are found linked in a common fate with the Mammoths and Rhinoceroses. Nor, as we shall see, would a mere change of climate, however severe, account for other factors in the problem. The change of climate accounts perfectly for the preservation of the carcases, which preservation again necessitates the conclusion that that change was a sudden or very rapid one; but we have clearly still to seek the real cause of the disappearance of the animals of which the change of climate was a concurrent effect.

I Should not have presumed to publish an opinion as to the geological position of the roacks of Casterton Low Fell without having examined the typical region of Coniston and Windermere, had not Mr. Woodward thought it desirable to notice the occurrence there of a species of Ceratiocaris and asked me to furnish him with a note on the bed from which I obtained it. Having therefore collected all the evidence I could in that Limited and complicated area, I now, with the permission of the Director of the Survery, send him some extracts from my notes, which may be of interest, as showing the character and relations of the rocks there seen.

It must inevitably happen sometimes that an author does not quite convey to his readers the whole of his own conception of a subject. It may be perhaps that certain objects in his mental picture are to him so obvious as to be unworthy of emphasis, and he is apt to forget that to his readers no part of the picture is, in the first instance, obvious. From the recent paper by Messrs. A. K. Wells and S. W. Wooldridge (“The Mechanism of Sedimentation Cycles”, Geol. Mag., Vol. LX, December, 1923, pp. 545–50), it is evident that I have failed to convey, to them at least, the whole of my conception of the Anglo-Franco-Belgian Basin. I apologize, therefore, to readers of my Introduction to Stratigraphy for any lack of clarity, and I should like to thank Mr. Wells and Mr. Wooldridge for bringing the matter into the light of day and allowing me an opportunity of stating very simply my ideas, all of them already published, on the geography of the Anglo-Franco-Belgian Basin in Eocene times. Perhaps had my critics, before rushing into print, read pages 278–9 of my book as well as page 267, the occasion would never have occurred.

The interesting note by Mr. Strahan in the Geol. Mag. for September, 1887, on explosive slickensides, reminded me of some similar phenomena which were not of unfrequent occurrence near Dent Head and Ribble Head in Yorkshire.

In the limestone quarry from which the black marble of Dent is procured the workmen found that, when they were quarrying the lower beds and struck the rock with a pick or bar, fragments flew up into the air with greater force than, could be due to their blow and in an unexpected direction.