The publications of the 600th Number of the Geological Magazine completes fifty years of its existence, and the Editor gladly avails himself of the occasion to express to his numerous friends and colleagues his most cordial thanks for their unfailing and generous support since 1864. Without their aid he would have been on many occasions at a loss to sustain the difficult task of providing for the monthly issue of the Magazine through so many years.

It is very gratifying to the Editor that the Rev. Osmond Fisher, M.A., F.G.S., Sir Archibald Geikie, K.C.B., P.P.R.S., F.G.S., Professor W. Boyd Dawkins, M.A., D.Sc., F.R.S., and Professor Edward Hull, M.A., LL.D., F.R.S., F.G.S. (who represent the contributors to the 1864 volume) have sent him letters of congratulation on his Jubilee; for, alas! by far the larger number of the early friends and supporters of the Geological Magazine have “joined the majority”. The ranks of the geologists have, nevertheless, maintained their strength, as will be seen by a reference to the retrospect of the work in the forty years from 1864 to 1903, in which a splendid record is furnished of geological and palæontological contributions, summarized by the late Horace B. Woodward and the Editor. The subsequent decade (1904–14) has been no less prolific in good work. Indeed, one may venture to maintain that the quality of the contributions in these later years has been distinctly in advance of those preceding them; whilst the illustrations have increased very greatly both in numbers and excellence.

The inclusions to be described in this paper occur in the Whin Sill at Snook Point on the coast of Northumberland. This is the most northerly exposure of the whin in the coast-section which stretches from Cullernose Point, through Dunstanburgh, to Beadnell Sands; and it is here that the outcrop leaves the coast and sweeps out to sea, to reappear further north in the Fame Islands and, on the mainland, at Bamburgh.

Verminculum globosum, Montagu, 1803: Test. Brit., p. 523.

Entosolenia globosa, Reuss, 1862: Sitzungsb. d. k. Ak. Wiss. Wien, vol. xlvi, p. 318, pl. i, figs. 1–3.

Lagena globosa, Burrows, Sherborn, & Bailey, 1890: Journ. Roy. Mier. Soc., p. 555, pl. ix, figs. 1, 2, 4.

Remarks.—This species has been recorded in rocks as old as the Wenlock Limestone and shale (Brady), and is stll living in almost every depth of water and in all latitudes.

Horizon.—Present in C1, C2, C10. One specimen from each bed.

In my account of the Lower Carboniferous rocks of the North-West of England, published in 1912, I figured an organism, probably the thallus of a calcareous alga, which plays an important part as a rock-builder at the base of the Seminula gregaria sub-zone in Westmorland and Lancashire. More recently, at the meeting of the British Association in Birmingham, I pointed out the need of some distinctive name for this important form, and suggested for it the generic name of ‘Ortonella’, from the village of Orton, near Tebay, in the neighbourhood of which this fossil is specially abundant. Two other structures were mentioned at the same time which occur constantly in microscopic sections of the Lower Carboniferous rocks of the North-West of England and elsewhere. The first of these was alluded to under the general descriptive term ‘festoon structure’, and the other was referred to Gurich's somewhat obscure genus Spongiottroma. In view of the zonal value of these organisms in the North-Western Province and the probability that they will be found to be widely distributed in the Lower Carboniferous rocks elsewhere, I propose here to give a somewhat fuller description of these forms than could be attempted in the limits of a presidential address.

In certain geological horizons where there is evidence of continuous deposition of salts from the waters of inland basins, gypsum and anhydrite are found closely associated, while in other similar horizons gypsum may occur with apparently no trace of anhydrite. Some Upper Silurian occurrences in North America, the Lower Carboniferous of Eastern Canada, and the Zechstein of Northern Germany are illustrative of the association of both minerals, while in more recent gypsum horizons anhydrite seems to appear less frequently. Even in the one horizon anhydrite is found to be of only local occurrence. In New York and in Michigan the Salina formation contains both gypsum and salt deposits, but practically no anhydrite. In Manitoba, on the other hand, in an Upper Silurian formation which cannot be definitely correlated with the Salina of New York, but which is at any rate of approximately the same age, gypsum and anhydrite occur in the most intimate relationship.