In the year 1861 I communicated to the Geological Section of the British Association, which that year met at Manchester, a description of certain fossils discovered by J. H. Cockburn Hood, Esq., in the Canterbury Settlement of the Middle Island of New Zealand; which fossils, kindly submitted to me for description by that gentleman, were afterwards presented by him to the British Museum.

In the GeologicalMagazine for September, 1868, I described a section of Drift deposits which, had been exposed in the cutting of the ‘Kilmarnock and Crofhead Extension Railway.’ If the reader refers to that paper he will fine it stated that the Lower Boulder-clay of the locality in question contains certain intercalated beds of clay, sand, and gravel which, have yielded Bos primigenius. Quite recently the remains of the horse and the great Irish deer have been met with in the same deposits. In the present paper I do not mean to say more about the character of the stony clay which overlies the beds with mammalian remains. There can be no doubt whatever that it is truly Boulder-clay. But as I understand that several members of the Glasgow Geological Society have since visited the section, and, while agreeing with me as to the glacial origin of the overlying Till, have yet expressed an opinion that this bed is not in its natural position, but has slipped down upon the stratified deposits from the adjacent hill-slope, it may be well to point out how all the facts are against such a supposition.

In replying to Mr. Forbes” strictures upon my paper at Cambridge upon “The elevation of Mountains, etc,” I may be permitted to say, what would otherwise be of no consequence. The paper was read in April 1868. I received it back from the referees, accompanied by some valuable suggestions, in September. I was at that time much occupied, and did not work out those suggestions until January 1869. After having done so I wrote to Mr. Forbes, received his reply on the 29th, and a week later sent the paper back to the referees.

The number of Scientific Opinion for October 27 (page 457), contains a note by the Rev, Osmond Fisher, calling attention to a suggestion, with regard to the liquefaction of deeply buried rocks, made by him in a paper read before the Cambridge Philosophical Society in April, 1868, and since published in the Transactions of that Society. In a notice of this paper by him, in the Geological magazine for November, 1868, Mr. Fisher insists that deeply buried and intensely heated portions of rock, which, in accordance with the conclusions of Mr. Hopkins, are kept in a solid state by great pressure, may, by a diminution of pressure consequent upon movements of the earth's crust, assume a liquid condition, and thus give rise to lavas. This suggestion is however claimed by Mr. Scrope, in a communication to the same Magazine for December, 1868, as his own, and as having been put forward by him in both editions of his now classic work on Volcanos. This statement of Mr. Scrope was questioned by Mr. Fisher in the Geological magazine for January, 1869, and Mr. Scrope does not appear to have replied. In a paper in the same magazine for June, 1869, I have referred to this view as belonging to Mr. Scrope, and as also advocated by Mr. Fisher, who has availed himself of the republication of my paper in Scientific Opinion for October 20, to re-assert his claim to be the originator of this view, and to demand either of Mr. Scrope or myself some justification of our assertions.

Turning now to the physical evidence, it is well known that the Moel Tryfaen bed is 1390 feet above the sea-level; and a depression which would bring the sea up to that point would, unless we suppose a great change in the relative elevations, place the Chalk many hundreds of feet beneath the sea.

The Millstone Grit of the North Wales Border follows the eastern slope of the Carboniferous Limestone, from Crickheath and Sweeney, South of Oswestry, to the shores of the Irish Sea; it is also thrown up into the range of hills which the traveller by the Great Western Railway may see to the west of the line between Oswestry and Chester. This range serves as a natural boundary between this part of England and Wales, and forms a second line of natural fortification, strengthened on the English side by numerous outposts of low hills of clay, gravel, and sand, which give place, upon the Welsh side, to precipitous escarpments of Mountain Limestone, beyond which the change in the language, dress, and manners of the people is marked and sudden.

I have lately been urged to revise the Cretaceous species of Entomostraca, enumerated in my Monograph, published by the Palæontographical Society in 1849. This I ought to have done ten years ago, after the publication of memoirs on the Cretaceous Entomostraca of Germany, the Netherlands, etc., by Reuss, Bosquet, and others, wherein some of my determinations of species are corrected from actual comparison of specimens. An improved classification was attempted in my Monogr. Tert. Entom., 1856; but a total revision is still more necessary now, because the late researches by Sars and G. S. Brady, in the structure and character of the recent Entomostraca, have multiplied and elucidated species and genera of these little bivalved Crustacea to an amazing extent. So clearly has Mr. Brady's “Monograph of the recent British Ostracoda” (Linnean Soc. Trans., 1868), in particular, defined the several groups, that we may in very many cases form a safe opinion of alliances from the shape, hinge, and other characters of the carapace-valve, at least far more satisfactorily than when in 1849 (Monogr. Cret. Entom.), and in 1856 (Monogr. Tert. Entom.), I laboured to institute some definite distinctions for fossil Entomostraca, founded on these characters.

Of the existence of Annelides during the Silurian period we are almost as uncertain as of the existence of plants. Indeed, we might reasonably doubt whether any Silurian fossils can with certainty be referred to this class.