Granite of Firbogh. Galway Bay.—I propose, as time and opportunity permit, to give the results of observations on the microscopic structure of Irish Granites, commencing with one from Galway.

The paper of Dr. A. Kunth, “Ueber Pteraspis,” Zeitschr. der Deutscheri Geol. Gesellsch., 1872, Hft. 1, came into my hands at a time when I had just been examining the specimen of which a restored figure is given in the Plate accompanying this paper. I took an early opportunity of replying to Dr. Kunth's adventurous assertions in the Academy, and the remarks then made have been reproduced in, this Journal (April, 1873). I need, therefore, here, in reference to that matter, only make one or two additional observations Dr. Kunth based his statements on a single specimen in a bad state of preservation. His figure shows how inadequate the specimen is to support his views. Out of the many hundreds—I may even say thousands—of specimens of Heterostraci which have passed through my hands, I could easily pick several exhibiting all varieties of juxtaposition of Pteraspis with Scaphaspis, and of specimens of a single species of either genus with other specimens of the same species. The packing of several shields one within another not unfrequently occurs, as happens very generally in the embedding of concave shells. The mere association of these shields, as in Gallicia and in Herefordshire, is not a phenomenon on which any one familiar with them—through examination of numbers of specimens from various localities—would venture to base any argument as to structural connexion.

In a paper recently read before the Geological Society, Mr. Dawkins has re-stated his views concerning the climate of the Pleistocene period, and has replied to certain objections to his theory brought forward by myself in former numbers of this Magazine. After carefully reading the paper referred to, I find no reason io alter or modify what I have written upon this question. Mr. Dawkins has unfortunately missed the point of my objections; and my argument, as it seems to me, remains unanswered. But as that gentleman has introduced some new matter into his own argument, I shall endeavour as briefly as may be to review his position.

Time with slow and measured tread moving over the buried records of the past—Time, upon whose ample store the geologist is wont to draw with an unsparing hand, seems to have accelerated his pace in this nineteenth century, and hurries onward as if his few remaining sands were well-nigh run.

The genus Halonia was established in the Fossil Flora (vol. ii., p. 13) by Lindley and Hutton for those fossils in which, to the surface of Lepidodendron, is added the mode of branching of certain Coniferœ, and which were therefore inferred to be of a nature analogous to the latter. It was assumed that Lepidodendron, being an extinct form of Lycopodiaceœ, must be limited to the fossils in which the branching was dichotomous, since no other kind of branching is met with in recent Lycopodiaceœ. But when we look at such plants as Lycopodium cernuum and L. densum, we find branching precisely similar to that in Halonia gracilis, L. and H.; and whether these were produced or not by the division of a terminal bud, it is certain that in their developed condition they are arranged in an alternate manner round a common elongated axis— a plan of branching characteristic, as the authors of the Fossil Flora supposed, of Coniferœ.

Mr. Mansel-Pleydell's Memoir on the Geology of Dorset, contained in the last two Numbers of this Journal (pp. 402 and 438), refers to a theory of the formation of the Fleet proposed by Messrs. Bristow and Whitaker in 1869 (Geol. Mag. Vol. VI. p. 433).

Interruptions in the continuity of a Coal-seam, whether in the form of intercalated layers of sand or shoals of clay, are not rare; but I have been able to find little on record concerning the occurrence of pebbles of any considerable size, except where there was reason to suppose that the miners had struck upon an old river channel. The Boulder, which forms the subject of this paper, was found in the 13th Coal of the sinkings belonging to the Cannock and Rugeley Colliery Company; and I am indebted to the kindness of its manager, E. C. Peake, Esq., for the opportunity of exhibiting the specimen and for much of the following information. The seam occurs at a depth of about 540 feet from the surface of the ground; the Boulder was completely enveloped in the coal, but its precise distance from the top of the seam was not ascertained. This 13th coal is considered to be identical with the 12th coal in the Brereton Colliery. In the latter colliery this seam is about 135 feet above the lowest or 15th coal; and by boring to a depth of 68 feet, red rocks were reached, which very probably, like those detected in the sinkings at Halesowen, belong to the passage-beds between the Silurian and Old Red Sandstone.

The eastern margin of the Vale of Eden, in the neighbourhood of Blencairn, Ousby, and Melmerby, is abruptly terminated by a steep and lofty escarpment, which rises to an eminence of 2892 feet at Cross Fell, 2331 feet at Melberby Fell, and 2082 feet at Fiends Fell, the elevations between these points being nearly as great. Eastwards, from the top of the escarpment, a large expanse of elevated moorlands slope gradually towards the North Sea.

The GeologicalMagazine is fortunate in having received within its pages many contributions relative to the discovery of Fossil Insect-remains, both in this country and abroad.

I Have much pleasure in calling attention to an unusually large Gasteropod, which I had the good fortune to find last February near Copt Point, Folkestone, when in company with Mr. Griffiths, the well-known collector.

It is proposed in the following pages to give a concise account of the progress of investigation of the lower Palæozoic rocks during the last forty years. The subject may naturally be divided into three parts: 1. The history of Silurian and Upper Cambrian in Great Britain from 1831 to 1854; 2. That of the still more ancient Palæozoic rocks in Scandinavia, Bohemia, and Great Britain up to the present time, including the recognition by Barrande of the so-called primordial Palæozoic; fauna; 3. The history of the lower Palæozoic rocks of North America.

Amongst a small collection of fossils lately forwarded to the writer for identification, by Dr. Rankin, of Carluke, from the Carboniferous beds of that neighbourhood, are some remains of Polyzoa, peculiar from the combination of characters presented by them, such as have hitherto been considered characteristic of separate genera. In Fenestella, Miller, as restricted by King, each interstice or stem of the frond is provided on one side only with two or more rows of cell-apertures, separated by a median keel. In Polypora, McCoy, on the contrary, the interstices or dissepiments are not carinated, and the former are always provided with numerous rows of cell-apertures, generally arranged more or less in quincunx, the dissepiments as in Fenestella, being non-celluliferous. In the specimens under consideration a combination of some of the above characters takes place, forming a connecting link between the two genera Fenestella and Polypora. An examination of the accompanying drawings will at once show that the fossils there represented cannot be referred to either of the above, but they, certainly appear to be the type of a new genus, which it is proposed to call Carinella. Only one species is at present known, which might with advantage be termed C. cellulifera.

The nine specimens of Phyllopodous Crustacea about to be noticed are, with one exception (that from Lanarkshire), all from the undoubted Carboniferous Limestone series, East Kilbride, a locality already well known to local geologists as having yielded a very rich series of Carboniferous forms.

The deep placers of California are often covered by a thick capping of lava; in other places, the eruptive matter overlying the auriferous gravels occurs in the form of columnar basalt, beneath which is found the auriferous strata of sand, clay, and gravel. These deposits often contain immense numbers of large tree-trunks, which, with those portions of their branches which remain, are either silicified, or are converted into a lignite, often containing a considerable amount of iron pyrites.

In the course of last summer I visited the banks of the Dniester, in Podolia and Galizia, where I was fortunate in collecting, near Zalesczyki, a number of shields belonging to Pteraspis (Scaphaspis) Kneri, Lank.

In a recent paper (American Journal of Science and Arts, vol. iii., March, 1872), I founded a new genus, under the name of Conchicolites, for the reception of some singular Tubicolar Annelides found growing upon the shells of Orthocerata in the Lower Silurian of the North of England.

I was led to make this analysis with the view of determining if possible whether the extreme hardness of the Irish Chalk were due to either a chemical, a mechanical, or a calorific alteration, from the influence of the overlying basalt. If it were owing to chemical change, we should expect to find a large per-centage of silicates and a diminution in the amount of lime; if to the influence of heat, carbonic acid would be driven off, silica would be in excess, and the presence of the insoluble bases, such as the peroxide of iron, oxide of manganese, and alumina, would become more apparent; while if a mechanical cause or pressure were the reason, no change would take place in the relative amount of the constituents. I believe the result seems to show that the induration of the Chalk must be set down chiefly to the last agency,—if to anything apart from the original formation of the rock,—and that the power of alteration exerted over it by the heat of the molten basalt has been small indeed. At the same time a certain addition has been made to it by means of water holding chemical bodies in solution.

Genus Palæontina, Butler (fossil). Frontwing ovate triangular; costal nervure much swollen at base; subcostal four-branched, the first two branches emitted about half-way between discoidal cell and apex; the third emitted abnormally just beyond the cell, and therefore springing from beneath the nervure; the fourth emitted in a still more unusual manner from the third; so that the third and fourth branches might be described as springing together from a footstalk emitted from beneath the subcostal; discocellular and discoidal nervures precisely as in Caligo; median branches nearer together than in Caligo; submedian nervure following the same direction as the median nervures, but even more distinctly inarched, so that the internal area is considerably widened: hindwing and body wanting. Type Palæontina oolitica.

Many curious cases of rock fissuring have attracted my attention while working out the geology of part of the English Lakedistrict. A notice of some few of them may perhaps draw forth remarks from those who have had longer and wider experience in the field of nature.

Having seen an account, in Notes of the Geology of the District round Llandudno, by the Rev. W. S. Symonds, that shells had been found by Mr. R. D. Darbishire, F.G.S., in some clay near the New Baths at the Great Orme, it occurred to me that the clay was Boulder-clay, and would probably not be limited to so small a patch, but that it most likely extended far over the hills. And I now propose to give, very briefly, the result of some observations on the subject made during a short stay at Llandudno.