In the thirty-eighth volume of the Quarterly Journal of the Geological Society is a paper by me on the Corals of the Inferior Oolite, and in the following volume is one on the Corals of the Great Oolite. The forty-first volume of the same periodical contains a supplement to the latter, but to the former no such addition has yet been made. The present communication makes good that deficiency, and is a supplement to it. It contains, besides the description of some new species, additional remarks on others already known, mention of genera about which doubt has been expressed, and the description of one which I consider new. Another genus, Stephanocænia, though well known elsewhere, has up to the present time remained unrecognized as British, and is now introduced on the evidence of two well-marked species from the Inferior Oolite of Gloucestershire. The addition to our Coral fauna of such genera as the above, and of others equally well known which I have also had the opportunity of making known, is of even greater interest than the discovery of new genera and species. Epismilia, Donacosmilia, Cyathophyllia, Adelastræa, Stylosmilia, Rhizangia, Thecoseris, Zeptophyllia, and Enallohelia, form a valuable contribution towards the Coral fauna of this country.

The “Lake District” of the North Island is too well known to all students of volcanic phenomena, especially of that branch comprising hydrothermal action, to need a detailed description. It will be sufficient to say that it forms a belt, crossing the island from north-east to south-west, and forms a portion of the Middle and Upper Waikato Basins of Hochstetter. The district has been recently brought into prominent notice by the disastrous eruption of Mount Tarawera, very full accounts of which have appeared in New Zealand papers lately received. The eruption commenced in the early morning of Thursday, June 10th, but premonitory symptoms showed themselves a few days before in a tidal wave, three feet high, on Lake Tarawera, great uneasiness of the springs at Ohinemutu, and the reported appearance of smoke issuing from Euapehu, the highest of the great trachytic cones at the extreme south-westerly end of the system. The belt of activity extends from Mount Tongariro at the one end to White Island, in the Bay of Plenty, at the other, a distance of about 150 miles. White Island has undergone considerable change from volcanic action during recent years, and Tongariro was last in eruption in July, 1871; whilst its snowclad sister cone Euapehu has never manifested volcanic action within the historic period until now. This wide zone in the centre of the North Island has, ever since the arrival of the Maoris, been the scene of such extraordinary phenomena, that it has of late been the resort of visitors from all quarters of the globe.

In the paper on the well-section at Brookwood in the August Number of the GEOLOGICAL MAGAZINE, the author pointed out that a comparison of the lithological facts brought to light in that section with those furnished by two other deep-well sections (at Wokingham and Aldershot respectively) lead to an inference in favour of a considerable amount of denudation of the London Clay having taken place during the deposition of the Bagshot Beds; that is to say, irrespectively of the particular horizon in the Bagshot Series to which certain marginal portions of the Bagshot Beds may be ultimately assigned, there seemed to be pretty clear evidence furnished, from the London Clay itself, of the fact, that along their northern and southern flanks the Bagshot Beds rest on beds belonging to lower horizons in the London Clay formation than those on which the Bagshot Beds rest in the more central portions of the area. The present brief paper is an attempt to show that the above conclusion is borne out by a much wider induction from data gathered from the area of the London Basin in general. I have carefully gone through the 448 well-sections appended to Mr. Whitaker's Memoir on the London Basin, and have selected from among them such instances as seemed to throw any light upon this question. A large majority of those sections include the London Clay; but since, in a great number of them, the thickness of that formation in feet is given only, unaccompanied by any lithological notes on the strata, they have been omitted, as affording no help to us in the present investigation. There are, however, as many as 29 sections, in which such notes appear. In every one of these the Beading Beds or the Thanet Sands, and in most cases both these formations, were proved below the London Clay, so that we are quite sure of a correct basal horizon. In many instances also the Basement Bed of the London Clay is noted. In 22 of these 29 sections, the thickness of the London Clay is less than 200 feet, and in all these there is mention of such inclusions in the strata as ‘green sand,’ septaria (‘claystones’), pyrites, flint pebbles, and ‘shells.’ These therefore agree in this respect (without a single exception) with the lower half or rather more of the London Clay of the Brookwood section, as shown in the deep well at the Asylum on Knap Hill, which also (as shown in my last paper) agrees with the London Clay strata pierced at Wokingham on the northern, and at Aldershot on the southern, margin of the Bagshot area. From this I conclude that in all these 22 sections we have (within their several limits) homotaxial equivalents of strata of the lower half or rather more of the London Clay, as that formation is proved in the Brookwood section.

Only a short time since there was discovered in the Lower Coalmeasures at Idle, a magnificent specimen of Megalichthys Hibberti; and now, at Clayton, near Bradford, has been found one of the grandest examples yet seen of a fossil Sigillaria tree. It was in the Fall Top Quarry, at Clayton, worked by Messrs. Murgatroyd and Sons, that this remarkable fossil was discovered, and these gentlemen deserve the highest praise from all geologists for the skill and extreme care with which they have bared the fossil, and also for their kindness in allowing it to be inspected. This quarry is not far from the edge of a bold escarpment overlooking the Thornton Valley, and the well-known Elland Flagstone is worked here for landings, flags, etc. Between the Better-Bed-Coal and the Flagstone there is a great thickness of sandstones, shales, etc., of various characters, and it was in these measures that the fossil tree was discovered about 12 feet below the surface. The sandstones just referred to are of little commercial value, many being irregularly bedded, and others very perishable in their nature; the better kinds are used for rough walling, the remainder being merely rubbish to fill up other excavations. The marketable flagstone is at a considerable depth in this quarry, and blasting operations have to be carried on to remove rapidly the overlying strata. After one of these explosions, Messrs. Murgatroyd observed part of a large fossil tree exposed, and, profiting by their knowledge of geology (which, by the work of the Yorkshire Geological Society and also of the Leeds Geological Association, is rapidly spreading throughout the entire county), they immediately suspended further operations, and, instead, gave orders to their workmen to carefully bare the remainder of the roots.

Erratum.—Geol. Mag. August, 1886, p. 341, legend to woodcut, for “Interior,” read Exterior.