As a basis for the following observations on the classification of Tertiary and Post-tertiary strata, we submit a comparative view of the nomenclature adopted by various authors.

During the course of a systematic investigation of the drifts of Flamborough Head, I have somewhat unexpectedly come across a fragment of marine Arctic beds enclosed in Boulder-clay, similar to those which form the well-known fossiliferous deposits of Bridlington and Dimlington; and as this occurs under very different conditions from those already described, it adds materially to our knowledge of the beds, and illustrates more clearly their origin.

The District included under the term “South Bedfordshire” is that which lies between the escarpment of the Lower Greensand and the extreme southern limit of the county. Within this area the portion that has been most closely examined is that through which the Midland Railway passes, every excavation of which has been visited, in many cases frequently, both during the construction of the line, and also subsequently.

Echinarachnius Woodi was founded by Forbes in his “Monograph of the Echinodermata of the British Tertiaries” on two fragments from the Red Crag of Suffolk; of all the species described in that work, this has been regarded as the most interesting and problematical. As this species certainly belonged to a genus now foreign to the British or European seas, it was felt, that if its correct generic position could be determined, it and Temnechinus would indicate the true affinities of the Crag Echinoderm fauna, better than the cosmopolitan genera with which they were associated.

The late Prof. Louis Agassiz, whilst on a visit to Halifax with Prof. John Phillips, during the years in which he was preparing his “Recherches sur les Poissons fossiles,” identified the caudal extremity of a large species of Cœlacanth fish to which he appended the name of Cœlacanthus Phillipsii in honour of his friend. The specimen is from a large “baum-pot,” as the calcareous nodules are locally termed, obtained from the Lower Coal-measures. This specimen was found at the Swan Bank Pit at Halifax, and, so far as I know, is the only one which has been discovered. The surface exposed by splitting the nodule is 0.295m. diameter, and the part of the fish preserved extends across it; it consists of the caudal portion of a large individual, which, had it been perfectly preserved, would have been between four and five feet in length.

In a paper dealing with some phases of volcanic action in North Wales, it was urged that contemporaneous eruptive rocks occurred on Cader Idris at lower horizons than the acknowledged base of the Arenig, although the actual vents from which they had arisen were lost and concealed under later accumulations. It was pointed out that the mass of Rhobell Fawr was of composite character, but was probably distinct from the series on Cader Idris. The fragmental character of much of its material having been recognized by the author of the Survey-Memoir, several theories are discussed in that work to account for its stratigraphical position. In spite of the lack of detail, when compared with other areas, with which Rhobell Fawr has been represented on Sheet 75 S.E. of the Map of the Geological Survey, the ashes, “breccias,” and other materials piled here upon the edges of the Lingula Flags are fully dealt with in the text of the Memoir, and we are left finally to select the most probable explanation of those put forward.

From one cause and another efficient education in modern languages has been exceptional in this country until quite recent years; and so it is no reproach to the geologist for him to have to confess that he “can't read German.” He must therefore get some friend to translate for him, or wait until translations of many important papers and books are published; and in many cases this never happens. So it is thought that towards the present controversy, which has been raised about the schists, etc., of the Val Bedretto and the adjoining districts, the mental attitude of many geological students may be pretty much that of the Bavarian veteran. It is with the hope of throwing a little light on the subject that the present writer has put pen to paper. For it is not too much to say that the subject is one of critical importance.

No better example could perhaps be quoted of fossil plants which have given rise to a number of species and even genera founded on imperfect and fragmentary specimens than the Sigillariæ and Lepidodendra.

Free discussion is a valuable aid to research when entered upon in a proper spirit. I am glad to see the contribution of Mr. Jukes-Browne to this subject, together with the letter from Prof. Bonney, in the May Number of the Geological Magazine.

Notwithstanding the large number of Mammalian remains which have been found in the Brick-Earth of the Thames Valley, they have for the most part been portions of the larger forms, and very few examples of the smaller Mammals have hitherto been discovered. Professor W. Boyd Dawkins and Mr. W. A. Sanford (Brit. Pleist. Mam. Pal. Soc. vol. for 1864, p. xxxvi, 1866) have noticed the occurrence of Arvicola amphibia in the Pleistocene of Ilford, Crayford, and Erith; while from the last-named locality Mr. R. W. Cheadle (Proc. W. London Sci. Assoc. vol. i. p. 71, 1876) recorded the remains of Spermophilus, which Mr. Lydekker has more recently (Cat. Foss. Mam. Brit. Mus. part i. 1885, p. 212) referred to Falconer's species S. erythrogenoides.

The general question of the rise of older rocks beneath the Cretaceous beds of south-eastern England is now so familiar to geologists that there is no need to discuss it here: it is enough to note that the Secondary beds (beneath the Gault) thin northward, for many miles, from the axis of the Weald. The practical application of our knowledge of the subject is however in its infancy, and our knowledge stops short at the Wealden axis; for we do not know what happens south of it.

The researches of the officers of the Geological Survey of X Canada have brought to light, in the Devonian rocks of Scaumenac Bay and of Campbelltown, a series of fossil fishes which are of especial interest to the geologist as well as to the zoologist, on account of the analogies which they bear to the fishes of the Old Eed Sandstone of Great Britain. Principally collected by Mr. G. H. Foord, these fishes have been described by Mr. J. F. Whiteaves, and are indeed remarkable for their beautiful state of preservation, which enables them to throw fresh light on many points in the structure of these ancient forms.

North-west Carnarvonshire.—There are here two or three separate areas which, at all events historically, must be considered more or less independently, viz. the district between Bangor and Carnarvon, the Llyn Padarn and Moel Tryfaen range, and the Lleyn Peninsula. Except in reference to the last of these, it is certain that the belief in Precambrian rocks in Carnarvonshire began with Prof. Hughes. This author, indeed, quotes Prof. Sedgwick as recognizing such rocks here, but the passages he quotes have a very different meaning in the original. The slates near Bangor and Carnarvon, which Sedgwick says are amongst the oldest of North Wales, are those which occur “along the shores of the Menai Straits from Bangor to Carnarvon,” which he describes as “dark earthy-coloured slates which, were we to judge only by mineral structure, might easily be confounded with Upper Silurian rocks,” and these are “cut through by a great intrusive rib of syenitic porphyry of a different epoch, which ranges nearly with the beds.”

The question of the physical conditions under which the Lower Triassic sandstones and pebble-beds were formed is certainly one which should interest all readers of the Geological Magazine, if only that it is strange that it should still be an open question whether so important a formation is of marine or fluviatile origin.

Under the name of “Loess” there has been confounded two kinds of deposit which are due to entirely distinct and different causes. One is the fine-grained sediment left by the muddy water of flooded rivers and streams of all sorts; the other is the powdery dust and sand carried by wind, which in dry regions often produces large accumulations of this nature.

In a characteristic article by Prof. Blake, “On the Base of the Sedimentary Series in England and Wales,” in the July Number of the Geological Magazine, amongst other erroneous statements, there is one which I must beg leave to correct. At page 310, in referring to the rocks of St. Davids, he makes the following statement: “While accepting the later petrological descriptions of Dr. Hicks, he (Dr. Geikie) minimized the separation between this [the Pebidian] and the Cambrian conglomerate, and challenged Dr. Hicks to prove his statement that the latter is chiefly composed of fragments of the rock on which it lies. This Dr. Hicks has never been able to do, seeing that the most marked feature of the conglomerate is that it is not composed of such fragments; instead of doing so, he now attempts to show that the matrix might have been derived from granitoid rocks.”

This paper is intended as preliminary to one shortly to follow on the nature and origin of the banded structure in these rocks. I have deemed it necessary to treat of the present subject as introductory to the other, giving my own views as to what I believe to be the true origin and relations of these rocks to each other, as these seemed to me to have a very direct and important bearing on the question of their banded structures.

In this paper I purpose giving a few examples to show the powerful influences which have been exerted by Earth-movements in producing changes in the rocks, and in obliterating the evidences of succession in some of the disturbed areas in Wales and Shropshire. For a long time past it has been well known that certain changes such as cleavage, etc., have been induced in the rocks in Wales and elsewhere by pressure, but only of late years has the magnitude of the results due to Earth-movements been fully understood.

I Have derived much help towards understanding Mr. Harker's instructive letter upon the above subject from making the following simple geometrical construction.