If truth is elicited by the conflict of opinion, we ought to arrive at a right conclusion as to the physical history of the English Trias. Unfortunately, however, some of the hypotheses propounded result, as it seems to me, from dwelling too much on certain minor difficulties, or limiting the view to one group of facts, while others not less important are excluded. From these objections Mr. Mellard Reade's interesting communication, printed in the GEOL. MAG. for last December, does not appear to me exempt.

The origin of the Lower Trias is evidently a question of interest to the readers of the Geological Magazine. Professor Bonney, in an article, to the tone of which no exception can be taken, criticizes the view which I have ventured to put forth, and very properly supports his own. It would be impossible and a waste of paper and type for me to traverse all his statements, as in many cases my reply would amount to little more than a reproduction, in a different form perhaps, of the arguments already made use of. There are, however, one or two points on which I should like to express myself, and there are some misconceptions that require clearing up.

For many years my thoughts have been occupied with the phenomena of eruption at or near the surface, and although a detailed study of the Vesuvian volcano and its products gave me the key to the mechanism of eruption and injection of igneous matter near the surface, I was always at a loss to understand, on the older theories, how lava could ever start upwards in fissures

The question proposed in the heading to this paper seems a startling one. That the drainage of such a wide continental area as Northern Asia should have been entirely reversed at such a recent geological period as the Mammoth age, so that its present great drains, the Ob, the Yenissei and the Lena, did not exist at all, but their places were taken by other rivers pouring their waters, not into the Arctic basin, but into some great Mediterranean Sea in Central Asia, seems a paradox. It is nevertheless a conclusion which has been forcing itself upon me for a considerable time, and which I should like to be allowed to argue.

It is I think, practically admitted that the present condition of the Weald is the result, firstly of marine, and secondly of subaerial denudation. A plain of marine denudation was first formed, and the valleys were carved out by subaerial action.

Astay in Finland of some months' duration (in the summer of 1885) enabled me to make an acquaintance of considerable intimacy with the Archæan rocks of that very interesting district.

The Fossil Fishes of the English Portlandian Formation are as yet almost unknown, and every small contribution to the subject is thus of interest. Ischyodus Townsendi, Microdon pagoda, the partially described Caturus angustus, an undetermined species of Thrissops, and an undescribed species of Mesodon, appear to be the only forms hitherto recorded; and to these may be added a large bony fish allied to Ditaxiodus, represented by jaws in the British Museum.

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.”

During a residence of six weeks at Bude, in the autumn of 1889, I enjoyed the opportunity of studying the Culm-measures exposed in the bold cliffs of that part of the coast of Cornwall. I know of no easily accessible place where the flexures and contortions into which strata have been thrown by earth-movements can be studied with greater advantage. Between Bude-haven and Menachurch Point, a distance of one mile as the crow flies, there are at least eleven synclinal and as many anticlinal folds, presenting a variety of flexures of considerable interest to the geological student.

This interesting species has hitherto been known only by the single type-specimen, a mandibular tooth, contained in the York Museum, originally described by Mr. T. P. Barkas, and recently very correctly redescribed as well as figured by Mr. A. Smith Woodward. It so happens that some years ago a considerable number of these teeth, both mandibular and palatal, occurred in the Borough Lee ironstone: my own collection contains no less than forty specimens, and there are many others in the Museum of Science and Art, so that I may now add considerably to the knowledge of the species

Naturalists who refer to their “Baedeker” for information respecting the Continental Natural History Museums are too often disappointed by finding that if the author does happen to have mentioned them, either that he has confined his attention to the exterior of the building or has summarily dismissed the collection as “unimportant.” Hence geologists are dependent upon such, papers as those in which M. Cotteau has recapitulated the principal contents of several French and Swiss Museums, or that in which Mr. Smith Woodward has enumerated the most interesting specimens of many German and Austrian collections. The last paper, as is indicated by its title, “Vertebrate Paleontology in Continental Museums,” is restricted solely to the Vertebrata. But as the value of a Museum, as far as the Invertebrates are concerned, is dependent more on the possession of collections than of single famous specimens, the student of this group is more in need of such information than is the Vertebrate palæontologist; every one knows where he must go to see an Archæopteryx, a mounted Iguanodon, or a Neanderthal skull, but the last resting-place of a local collector's hoard is, as a rule, less known to fame. Hence the following notes may be of some service as a supplement to Mr. S. Woodward's paper.

The several bore-holes which have been put down through the A- Red Kocks in the south-east part of the county Durham to win the bed of Eock Salt there have directed attention to the age and classification of these rocks.

In the Geological Magazine for last month (January) I proposed to establish the genus Phlyctænius for the peculiar Coccostean from the Lower Devonian beds of Campbelltown in Canada, named by Whiteaves Coccostens Acadicus. In this paper I propose describing that form more in detail, along with an allied, though at the same time very strongly marked species from the Lower Old Eed Sandstone of Herefordshire, to which on that occasion I also referred.

The Bunter and Keuper formations of the Trias are very fully developed in the country around Liverpool, and leaving out of consideration the Red Marl, both of these formations seem to be thicker there than anywhere else in Great Britain. The object of this paper is to give a few notes recording the thickness of the Trias, the structure of the various sandstones of which it is composed, and the character of the included pebbles, many of which are of local derivation.

The application by Dr. Johnston-Lavis of the theory of the secular straining of the Earth, with which my name and Mr. Davison's is connected, to an explanation of the deeper phenomena of volcanic action, is ingenious and suggestive. It will, therefore, I trust, be of some use if I am allowed to discuss and criticize the principles and propositions that appear to me to be necessarily involved in the views put forth by Dr. Johnston-Lavis. Before doing this, I feel it incumbent upon me to point out that Mr. O. Fisher's position with regard to the question seems to have been misunderstood. So far from occupying an antagonistic position, he has done much to mathematically develop the theory; and it is only when we come to its practical application to the explanation of geological phenomena, that he, myself and Mr. Davison differ.

If, in the growth of the American continent, the moulding of the land features had not largely depended upon its projection above the sea, favouring or retarding the action of rains and rivers, in sculpturing its surface, there would be little interest as to what was its relative height, before the commencement of the Pleistocene period. But we find valleys vastly greater than meteoric agents could have produced under existing circumstances. Thus, there are not only deep cañons, but also vast depressions, descending to levels far below the sea, which are now filled with the earlier drift accumulations, or form channels submerged beneath ocean waves, or constitute basins occupied by lakes.

In Professor Henry Drummond's “Tropical Africa,” 8vo. London, 1888, pp. 183–199 are occupied with an interesting “Geological Sketch” of the country between the Zambesi River (about 18° S. Lat.) and the Tanganyika plateau (about 3° S. Lat.), his own observations having been made along a route from Kilimane on the coast, to the Shiré, and up that river, by Lake Shirwa and Lake Nyassa, to Karonga (or Karonga's village) on the north west shore near the end of the lake; and thence through the Uchungu district, for about 70 miles, in a part of the Tanganyika plateau.

“With regard to the probability of coal under cretaceous W rocks in the South of England it seems hardly possible to conceive that the commercial enterprise of Englishmen could have failed to discover it long ago if it had been in existence.”

Since the excellent and interesting series of papers on the history and description of these celebrated volcanoes by Professor Judd, which appeared in the Geological Magazine for 1875, there is, as far as I know, no connected record of their condition. The islands, though affording such excellent opportunities for the study of volcanic action, are but rarely visited by geologists; but having had the opportunity of examining them myself in the autumn of last year as a member of the party arranged by Dr. Johnston-Lavis under the auspices of the Geologists' Association, I thought it would be well, whilst recording my own observations, to prefix a brief account of the volcanoes since the above-mentioned date. The information, on which the following brief sketch is based, has been derived partly from a series of papers by Prof. Mercalli, on notes derived by correspondence with Sig. Pincone, the former manager of the lately existing Chemical Works at Vulcano, who now resides at Lipari, and partly from papers in various periodicals to which I will refer as occasion requires.

In my last communication, “On the Schists of the Lizard District,” published in this Magazine for April, which was meant as preparatory for the present paper, my object was to show that the rocks known as the “talco-micaceous,” “hornblendic,” and “granulitic” groups were of true igneous origin, also plutonic? and had been formed out of a common, but complex magma, and that all of these groups were made up of rocks differing widely from the types of each of them, which in some instances were seemingly due to differences in the rate of cooling, and to chemical affinity; and yet again in other instances to subsequent mechanical movements and pressure during or after consolidation.