The specimen here figured is a typical example of Actinostroma clathratum. In all its general characters, and particularly in the regular development of the radial pillars and the presence of small astrorhizas, it resembles the specimens from the Middle Devonian of Germany, which may be regarded as the normal form of the species. Very similar examples, however, occur in the Devonian Limestones of Devonshire. The surface of the specimen is not shown, being concealed beneath a crust of Stromatoporella Eifeliensis.

In an Appendix to the Explanatory Memoir on Sheet 17 of the Map of the Geological Survey of Ireland (Dublin, 1889), I have furnished a description of the petrographical characters of the Epi-diorites of the district. Some of the facts elicited by the examination of the rocks are sufficiently interesting to deserve a wider circulation.

If, in the growth of the American continent, the moulding of the land features had not largely depended upon its projection above the sea, favouring or retarding the action of rains and rivers, in sculpturing its surface, there would be little interest as to what was its relative height, before the commencement of the Pleistocene period. But we find valleys vastly greater than meteoric agents could have produced under existing circumstances. Thus, there are not only deep cañons, but also vast depressions, descending to levels far below the sea, which are now filled with the earlier drift accumulations, or form channels submerged beneath ocean waves, or constitute basins occupied by lakes.

No better example could perhaps be quoted of fossil plants which have given rise to a number of species and even genera founded on imperfect and fragmentary specimens than the Sigillariæ and Lepidodendra.

The question of the physical conditions under which the Lower Triassic sandstones and pebble-beds were formed is certainly one which should interest all readers of the Geological Magazine, if only that it is strange that it should still be an open question whether so important a formation is of marine or fluviatile origin.

My paper on the Culm-measures at Bude has elicited two communications, from Messrs W. Maynard Hutchings and Alfred Harker, on which I desire to offer a few comments.

I take this opportunity of saying that I am extremely glad to find that the conclusion at which I arrived regarding the impotence of pressure alone to produce metamorphism is in accord with the published views of my friend Mr. J. J. Harris Teall. “Pressure” alone, he states, in a footnote at p. 410 of his valuable work, British Petrography, “produces no effects on rocks—work must be done upon rocks before change takes place.” This footnote escaped my memory at the time of writing my paper, or I should have called attention to it.