Recent investigations appear to have shown that terra firma is a phrase indicating a condition of our solid earth which scientifically has no existence. The crust of the earth is in a state of constant movement. When these movements are sudden and violent, we call them earthquakes; transient shiverings, which require the aid of instruments to make them visible, we call earth tremors; movements of longer period and greater amplitude, causing large areas, like islands and continents, to rise and fall like rafts upon the ocean, are called oscillations. To express the study of the whole of these Earth-movements it would here be convenient to have a special term.

Two years ago if a Palæontologist had been asked to mention a region in Britain most barren of fossils, he might well have ected that great area of Central Wales which is marked by a sombre grey in the maps of H.M. Geological Survey. And even now, after my laborious search in that country, it cannot be said to be anything better than very poor in organic remains.

I Wish to make one or two observations on the Rev. A. Irving's paper on “The Permian and Trias,” which has appeared in the GEOLOGICAL MAGAZINE, and of which he has been so good as to send me a separate copy.

The purpose of this communication is to supplement the author's paper on the “Classification of the European Rocks known as Permian and Trias,” which has appeared in recent numbers of this MAGAZINE. It is based on a short communication made to Section C. of the British Association at the recent meeting at Southampton, and has been expanded into the present paper at the request of the President of the Section, E. Etheridge, Esq., F.R.S.

Brezina points out that in the Catalogue prepared by Tschermak this iron is indicated as of, showing fine-ruled Wiedmanstättian figures. It differs, however, very much from other irons of this group, like that from Lion River, Jewell Hill, Charlotte Co., etc., while it closely resembles the Butler iron. While, however, in the latter case the chief walls of the skeleton inclose very large chambers, here they are very small, so that the skeleton-character is far less marked.

Let us see then what “the Old Masters” had to say on the subject before us. In Mantell's Geology of the South-East of England, 1833, page 28, speaking of the beds of slightly rolled flints which occur on the Downs in Sussex just underneath the turf, he says, “The flints are more or less broken, have suffered but little from attrition, and are so abundant as to form a constant supply for repairing the roads in the south-eastern part of Sussex. This bed has clearly been formed by the destruction of the upper portion of the chalk; and it is equally evident that the cause which produced the disintegration of the superior strata was as transient as it was effective, since, although the chalk in which the flints were imbedded has been entirely destroyed, the latter have sustained but very little injury.”