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.

Length, 6 to 7 inches, shape fusiform. Cranial roof bones sculptured with undulating ridges passing at times into elongated tubercles. Mandible sculptured externally with slightly undulating longitudinal ridges, which run tolerably parallel with the upper and lower margins of the jaw; dentary margin finely tuberculated. Maxilla of the usual form, its dentary margin likewise finely tuberculated, the rest of the surface covered with undulating ridges. Scales of moderate size; those of the front of the flank are higher than broad; posteriorly they become more oblique and equilateral, while towards the dorsal and ventral margins they become rather lower than they are broad. Their ornament consists of sharp stronglymarked ridges, nearly straight and parallel, and only occasionally bifurcating or intercalated. On the scales of the anterior part of the flank these ridges run rather diagonally over the surface of the scale from above downwards and backwards, but over the greater part of the body they are parallel with the upper and lower margins of the scale, and seldom does any greater obliquity of the ridges in the anterior and lower part of the scale give any indication of the diagonal division of the pattern which is so common in striated scales in the family Palæoniscidfe. Posteriorly, a peculiar and highlyornamental character is given to the squamation by the fact that the lowermost ridge, uniting or not with the one next above it, is of unusual breadth, and stands prominently out.

I am indebted to Thos. Parker, Esq., of Oldham, for the opportunity he has afforded me of examining his large collection of fish-remains from the Carboniferous Limestone of Derbyshire. The specimens have been obtained from quarries near Chapel-en-le-Frith, in the N.W. of the county. They are for the most part in a beautiful state of preservation, though some of the more fragile specimens are only obtained with the most careful manipulation on account of their liability to fracture. The fossils are creamy-white in a light-coloured crystalline limestone matrix.

Among the Selachians of the existing fauna, there are none of greater interest and higher morphological importance than Notidanus, Cestracion, and the recently-discovered Chlamydoselachus from Japanese seas. These are the solitary survivors of once flourishing types, whose immediate congeners are only known to Biological science through the fragmentary remains preserved in the geological record; and the value of the archaic features they present is even further enhanced by the slight information already acquired regarding the geological distribution of their numerous extinct allies.

These rocks may be classed into five or six more or less distinct groups.

I. Syenitic Rocks (Croft Series).

II. Andesite and Andesitic Tuffs (Caldecote Series).

III. Hartshill Quartzite with Breccia at its base.

IV. Diorites.

V. Andesites or Diorites containing Augite.

VI. Basalts or Diorites containing Olivine.

The three last groups appear to graduate into one another, and seem to correspond with similar rocks described by Mr. Allport. Many of the specimens examined are in a more or less advanced stage of decomposition, calcite, serpentine, pyrites, etc., being very commonly present.

The following notes relate to two Brachiopods—a Rhynchonella and a Terebratula—figured by the late Dr. Davidson in his last plates in the Palæontographical. Of the first a change of name is necessary; of the second, I consider that the identification needs revision, and that it deserves a separate name. Both species are from the Inferior Oolite.

I Have not deemed it necessary to examine microscopically the whole of the collection made by Sir J. W. Dawson, but have selected a series of fairly representative specimens, sufficient, I think, to give a general idea of the principal varieties. For purposes of identification I leave the reference numbers borne by the specimens, though their sequence is accidental.

We wish briefly to state an important result, which the study of certain Tertiary and Cretaceous beds in the neighbourhood of Mons has enabled us to arrive at.

For a long time past, the beds, well known in the district just mentioned, by the name of Tuffeau de Ciply, have been considered by all geologists to be the equivalents of the Maestrichtien, that is to say, as belonging to the highest subdivision of the Cretaceous series of Belgium.

Amongst others found by Dr. H. K. Warth, the particular pebble referred to was picked up by its discoverer on the 10th of June, 1886, in about lat. 32° 48' N. and long. 73° 15' E. Its size is 3¼ inches by 2¼ by 2 inches; and its weight is 10¼oz. The material is felsitic rock, the colour reddish-brown, and its density= 2·608 (that of albite being 2·59—2·64).

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.

Since the article on Mesozoic Angiosperms was written, a very important Sketch History of “Pateobotany,” by Lester F. Ward, has appeared in the Fifth Annual Eeport of the U. S. Geol. Survey, a brief outline of which cannot fail to prove of interest in connexion with this subject. The object of the sketch is to collate and reduce the fragmentary and desultory mass of information collected by previous writers into a system that will enable geologists to use the testimony of fossil plants, in the same way that they habitually use that of fossil animals. The author laments that botanists and palaæobotanists have worked and classified almost wholly independently of each other, the former having consequently missed such important data for classification as the order in time in which each type appeared, while the latter have failed to harmonize their work with the more elaborate and best botanical systems, and hence greatly lessened its practical value. “Every candid palæobotanist must admit that he can understand fossil plants only as they resemble living ones, and that the botanist, studying the perfeet specimen with all its organs of reproduction as well as of nutrition, can alone declare with absolute certainty upon its identity or affinity.” This mutual dependence requires recognition at the hands of scientific men.

Of the upper dental series, Probst attempts to give a tolerably complete account, but it is only illustrated by very imperfect woodcuts. Two of the foremost awl-shaped teeth are figured by Lawley (l.c. figs. 2, 3), and the same author ascribes to the upper jaw of this species three other of the Pliocene specimens. Fig. 19 represents an anterior upper tooth from the Middle Eocene of Hampshire, and the original of Fig. 20 is another from the Miocene of Baltringen, Wurtemberg. The former (B. M., p. 4707) exhibits a short thick base with an oblique principal cone, in front of which are a number of minute denticulations; posteriorly there is only one secondary cone, pointing sharply backwards, and about half the size of the principal cone; and this is followed by another small denticle. The second specimen (B. M. 35533) has also a short thick root, and shows a somewhat similar crown; the large principal cone is followed by one small secondary and a terminal denticle, and in front there are a few coarse serrations at its base.

One of the most important discoveries in Seismology is that which proved the close connexion in position between earthquakecentres and lines of fault, leading up to the view that the earthquake is an effect and not a cause of fault-formation. It may be the momentary result either (1) of the sudden fracturing of the earth's crust, or (2) of the impulsive friction that must accompany the relative displacement of the rock-masses adjoining the fissure. Now, earthquakes are frequent at places where faults are already advanced in the process of formation.

While recently turning over the plates of this Monograph, my attention was arrested by the lobe-line figured on plate 63, and on looking at the explanation of the plate given on the opposite page, I was much surprised to see that it was stated to be the “Lobe-line of Harpoceras ovatum, magnified.” On the same plate, just below (fig. 4) is a side view of the Harp, ovatum with its lobeline in situ, and I suppose it to be this lobe-line that is magnified. But there must surely be some mistake here. Compare the lobeline, fig. 7, with that on fig. 4, and notice the much greater width of the siphonal saddle in fig. 4 (than in fig. 7), where, on account of the curvature of the fossil, it would be really smaller. To say nothing of the obliquity of the inner portion of that on fig. 4, where is the first auxiliary lobe (nearly as large as the inferior lateral in fig. 7) to be found in fig. 4? I think it will be apparent that for some reason or other the two lobe-lines are different. But is the lobe-line, fig. 7, the correct lobe-line for such a species as the Harp, ovatum here figured? I must say No! Turning for a moment to Wright's description of the lobe-line of Harp, ovatum, page 446, we find it stated, “The suture-line is of the radians type.”

Since the publication of William Smith's Map of Norfolk in 1819, the sections around West Dereham and Shouldham have been accepted as proving the occurrence of true Gault in this part of West Norfolk. Messrs. Rose,2 Fitton,3 and later writers, all accept this determination. Mr. Teall,1 writing in 1873, points out the close relation of the fossils from the “Coprolite Bed” of West Dereham to those of the “Ammonites mammillaris zone” of Folkestone, and correlates the overlying blue marly clay with the Gault, from the occurrence in it of Ammonites interruptus.

In my last essay I had occasion to refer to the former existence of icebergs in localities which now lie in latitudes lower than those in which glacial action is known to have reached, even during the last Glacial period. But, surprising as it may be to find evidence of glacial action within a few degrees of, and, as in the case of the Eowen Eiver Coal-field, a few degrees within, the tropics, this sinks into insignificance in the face of the evidences of repeated Glacial periods that may be found in India, and especially in the Himalayas.

The writer has for some time hesitated to seek in the pages of the Geological Magazine a publication of his-experiences upon the above subject. He fell last year into a grievous mistake with regard to it, and suffered that mistake to be published in the “Transactions of the Devonshire Association for the Promotion of Science, Literature, and Art.” It will be his duty, when the opportunity comes round (as shortly it will), to call attention to that mistake in the pages of the same periodical. In the meantime he thinks that the subject, and even the mistake associated with it, may be of something more than local interest. At least the recantation of a published error cannot be too widely circulated.

The Lower Lias in Leicestershire commences with clays and limestones (Strenshain Series), succeeded by clays and shales. In its palasontological characters, as well as in its petrological features, it agrees in the main with the Lias of contiguous districts. The following life-zones are apparently represented, viz. zones of Ammonites planorbis, angulatus, Bucklandi, semicostatus, oxynotus, armatus, Jamesoni and capricornus.

These works were at first only supplementary to the Lewes Road Works, on the east; but now are the chief source of supply. They were begun in 1865, and are placed in a hollow in the Chalk, in open ground. at the north-western edge of Brighton. This hollow, the bottom of which, I am told, is 30 feet below the lowest part of its rim, is perhaps in itself an evidence of the existence of underground water, being due, most likely, as is usually the case in limestone-districts, to the dissolving away of the rock by underground water and to the consequent sinking-in of the surface. It is an analogous occurrence to the Meres of Norfolk, except that these are generally more or less filled with water, whilst Goldstone Bottom is quite dry at the surface. I may mention that at the time of my visit there was so thick a fog that it was impossible to see the hollow.