While engaged this autumn in reinvestigating the relations of the “Dingle Beds” and “Glengarriff Grit Series” to the Silurian rocks below, and the Old Red Sandstone above, in the South-West of Ireland, my mind naturally reverted from time to time to the Devonian district, and the succession of its beds, upon which there has recently been so much discussion, and to which the late Professor Jukes devoted so much time and labour. With him I agree in believing that the key to the solution of the Devonian problem is to be found in the structure of the South of Ireland, though with reference to the actual explanation which he proposed, I can only see my way to a partial concurrence.

In England and Wales there is scarcely any area whose geological structure is so little known as the neighbourhood of Aberystwyth. Every year a stream of geologists passes through the northern parts of the Principality, through the varied old-volcanic districts of Snowdon and Cader Idris, and the rich collecting grounds of the Berwyns: and another such stream takes its course to the southern borders along the far west Pembrokeshire coasts, being guided by the careful work of Dr. Hicks. The border counties too are in many places attractive enough, for there it was that Murchison first saw the order of the Silurian rocks, and there also the best-preserved fossils are found. Llandeilo, Builth, Woolhope, May Hill, Malvern, and Wenlock have long yielded rich harvests to palæontologists.

Having paid but little attention to geological literature during the last two years, it was not until September, 1878, that I became aware of Mr. A. J. Jukes Browne's article in the GeologicalMagazine of August, 1877. In this article, amongst other matters, the author criticises very fairly the classification of the Upper Greensand and “Chloritic Marl,” so-called, as set forth in my paper on the Cretaceous Rocks of Beer Head. In justice to certain questions involved, I find myself compelled to reply to this criticism, and to say a few words besides respecting the Chloritic Marl and Upper Greensand.

I am grateful to Mr. Hill for noticing my former paper “On Possible Changes of Latitude on the Earth's Surface” in his letter, October, 1878, p. 479. I wish, however, that he had gone into the subject more in detail; in which case I, and perhaps others, would have felt more satisfied with his reply. He epitomizes my appeal to physicists by making me ask, “Assuming that a thin crust surrounds a fluid substratum, could then a deformation shift the crust over the nucleus?” And he replies that, Mr. G. Darwin having proved that the earth is “enormously stiff,” the discussion would be fruitless. But in this statement of my question and reply to it, he has omitted what seems to me the important proviso, based on Hopkins’ reasoning about the mode of cooling, that this fluid substratum is shallow, and encloses a rigid nucleus; and given no reply to my inquiry whether such a supposition might not afford the required rigidity.

A valuable paper by T. Davidson, Esq., F.R.S., appeared in the Proceedings of the Dorset Natural History and Antiquarian Field Club for 1877, “On the species of Brachiopoda that occur in the Inferior Oolite at Bradford Abbas and its vicinity.” Since then, during a recent visit to this locality, I have added a few species to this list, including two which have not been discovered in England before. I propose to give a short account of these species, and also a table showing the relative distribution of the Brachiopoda in the Inferior Oolite and Fuller's Earth deposits at Cheltenham and France, compared with this district.

The genus Meyeria was established by Prof. M'Coy, in 1849, for the reception of certain Crustaceans from the Gault and Greensand, found at Speeton, Yorkshire, and at Atherfield, in the Isle of Wight. A new form has been most obligingly sent to me for examination by Henry Willett, Esq., F.G.S.; and this being in a more perfect state of preservation than any heretofore obtained, enables me to refer to the same species about eight other remains from the Chalk preserved in the British Museum and including the carapace figured on pl. xxxviii. fig. 8 of Dixon's Geology of Sussex.

During the summer of 1877 I made a geological excursion, in company with one of my students, to the western part of our State, to examine the junction of the Upper Silurian (“Clinton” of the Ohio Survey) and the Cincinnati group of the Lower Silurian. Whilst thus engaged near Eaton, in Preble Co., my companion, Mr. Leven Siler, of that town, picked up and handed to me a slab bearing what appeared to be a mould of the well-known bark of the Lepidodendron, somewhat weathered. More careful examination confirmed the first impression, and convinced me that I had indisputable proof of the existence of arborescent vegetation of an earlier date than had hitherto been announced upon equally conclusive evidence.