There is not in Great Britain any coal-field so characeristic as that of South Wales; nor one which in outward appearance so little agrees with the general notion as to what a coal-field should be like. Instead of the barren and monotonous surface that we usually find in Durham, Staffordshire, Lancashire, or Scotland, we find scenery of a high order,—lofty hills, romantic dales, broken scaurs, and woods feathering down to the banks of the streams that run brawling to the Bristol Channel. It is a wonder indeed that tourists do not oftener explore these gems of South-West landscape, particularly as every valley is now accessible by railway. Nor is it merely in scenic interest that the basin is peculiar; for the very physical arrangement which gives the hill and dale enables much of the coal to be won by level, instead of pit, thus forming a marked feature in the economy of the working. It is with regard to this physical geography that I would say a few words, as viewed in relation to the geology of the basin.

Clays are generally the mud of rivers; sandstones, the detritus of old crystalline rocks; while limestones are organically or chemically formed. If, therefore, there is a great clay, it bespeaks a great river draining lands that were; though small and local clay-bands may be but the ruins of denuded sea-cliffs. The sandstone is the evidence of coast and reef, where and wave disintegrated plutonic rocks, or constructed over again the palæozoic or older sand-rocks. And limestones have been formed either from the denudation of calcareous cliffs in shallow seas.

Probably few geologists pass through Yorkshire en route for the North without paying a visit to the large and most interesting museum illustrative of local, as well as of general, British Geology, formed by Mr. Edward Wood, F.G.S., of Richmond. The joint papers by Prof. L. de Koninck (of Liége) and Mr. Wood on the new and remarkable genus of Crinoids, named by De Koninck Woodocrinus, in honor of their enterprising discoverer, which appeared in the ‘Geologist’ and other scientific journals, have given the genus an important standing among Crinoidea; but since that publication of the material acquired by Mr. Wood he has been so fortunate as to add extensively to his fine collection, chiefly through the kindness of his friend and neighbour Mr. Brown, J.P., who opened quarries on his estate at Holwith for the sole purpose of aiding the researches of Mr. Wood; and the wall-cases in the museum devoted to these fine Crinoids now present a wonderful richness of fossil-wealth. Amongst many other fine specimens I would chiefly notice the exceedingly beautiful specimen of Woodocrinus expansus, which is not only, beyond doubt, the finest ever found, but has a peculiar interest from the fact of its retaining, in a purple-coloured suffusion on the tips of some of the rays, which, with their attendant fringe of pinnules, terminate the arms, some indication of the animal substance which clithed them. This colour is probably due to a phosphate of manganese. As this specimen is thus doubly interrsting, I am much indebted to Mr. Wood for permission to have it figured in illustration of my remarks.