In the Transactions of the Edinburgh Geological Society (vol. x, 1912, p. 49, pl. v, f. 8) I gave a figure of an Ichthyocrinid which occurred in No. 1 Bed, Invertiel, along with other members of the family, all of which were referred to ? Forbesiocrinus. In the spring of 1913 I had the pleasure of sending my specimens of flexible crinoids to the eminent crinoid authority, Dr. Frank Springer, of the United States Museum, Washington, who was then engaged on a comprehensive study of the group. For some reason or other I did not forward this particular specimen, probably because I did not think it well enough preserved (No. 939, Fig. 3 of present paper). The other Ichthyocrinids from Invertiel were referred by Springer to his new species Amphicrinus scoticus. It so happens that No. 939 was the only specimen of its kind which I had at that time cleaned and mounted in my collection, although as the sequel will show it is evident that I had found several others in the field, but had erroneously laid them aside as Amphicrinus scoticus. This is a mistake which could easily be made, since I was not then fully aware of the special characters which distinguished A. scoticus.

During the course of a reconnaissance mineral survey of Western Togoland in 1918–19 many streams were panned, and the concentrates were afterwards examined to ascertain to what extent the heavy minerals in them could be used as a guide in geological mapping.

A recent investigation of the igneous rocks of Sark revealed the presence of an interesting series of basic intrusions particularly well exposed near the northern extremity of the island. Some of the phenomena there seen seem to be identical with those described by Harker from the Isle of Muck in rocks of widely different age, and they throw some light upon the mechanics of intrusion.

In this paper no new theory is offered as to the formation of those rocks, found in so many places in the Tropics, known as laterites and lateritoids. Rather is it offered as confirmatory evidence of the hypothesis, which has been put forward by several writers (5), that in general they are formed by the evaporation of iron-bearing waters as they are brought to the surface by one or more causes, such as capillarity and hydrostatic pressure. The part that animal life may play in the deposition of the iron, as well as in the solution of it, does not appear, however, to have been noted (5).

The fossils described below were collected by Messrs. B. K. N. Wyllie, Keir A. Campbell, and G. M. Lees, working on behalf of the Turkish Petroleum Company, who have kindly made arrangements for me to investigate their collection, which proves to be of some interest.

Recently I had an opportunity of paying a brief visit to the localities described by Miss Elles as affording a clue to the horizon of the Hirnant Beds. As I have for many years believed that the fauna of the Hirnant Beds is Ordovician, I was anxious to see upon what evidence the assignment of those beds to the Silurian was based. The Bwlch-y-groes locality was visited with Professor W. J. Pugh, University College of Wales, Aberystwyth, who will shortly deal with the structure of that area. It is sufficient for the present to state that this section has been misinterpreted by Miss Elles, and so far from proving that the Hirnant Beds lie within the Valentian, shows, if anything, that they cannot possibly form part of that series, which is fully represented there and has much the same characters as throughout Central Wales. To anyone thoroughly familiar with the Ordovician-Silurian succession of Central Wales, the structure and rock-succession of the Bwlch-y-groes Pass presents no difficulty and it certainly gives no support to the idea that the Hirnant Beds are of Lower Valentian age.

The Memoirs of the Geological Survey (355–6) contain a note of the 1866 exposure of the submerged forest at Thurlestone Sands in Bigbury Bay. This is usually covered by sand and (except between half tide and low tide) by a considerable depth of water. The writer has reported to the Authorities of the Geological Survey a further exposure in March, 1923, which they consider “The best exposure that has ever been visible” and which they desire him to put on record.