Cheilostomatous Polyzoa are anything but common in the Chalk exposed on the Norfolk coast between Cromer and Weybourne, and which I will call the Weybourne Chalk as it is best exposed in the Weybourne half of the area. It was only quite recently that I realized that the gradual accumulation of material had produced a sufficient volume to give some idea of the general nature of the fauna. The precise position of this chalk in the zone of B. mucronata cannot be fixed on physical data, but the Survey view that it is only a little way below the Trimingham Chalk is highly probable. It is therefore rather remarkable to find that the Membraniporæ include several new species, in addition to M. flacilla (ante, p. 338), which are unknown so far at Trimingham. It will be interesting to see if these, which I proceed to describe, prove to be characteristic of any definite range of chalk in the Norfolk Senonian. They must all be described as scarce at Weybourne.

The new material on which this paper is based has lately been received through Mr. D. Ferguson, who recently investigated the geology of the island, and collected the rocks described in an earlier paper. It consists of twenty-seven rock specimens from the south-eastern end of the island, between Cape Disappointment and Cooper Island, and nine specimens from Gold Harbour on the north-east coast between Cooper Island and Royal Bay. All these were collected by the staff of the South Georgia Co., Ltd., under the instructions of Mr. Th. E. Salvesen, managing director, of Leith.

About one mile to the north of the railway station at Ayer Kuning, in the south of Negri Sembilan, one of the Federated Malay States bordering on Johore and Malacca, is a low but conspicuous range of hills covered with long grass. The highest of the hills, on which is a beacon used by the Trigonometrical Survey, stands about 300 feet above the level of the surrounding country. The general trend of the hill range is in a direction of S. 60° W. to N. 60° E., and there are several hills which branch from the main axis, usually more or less at right angles to it. The eastern half of the range over a distance of about half a mile only need be considered, as there are no rock exposures on the western half.

The groups of ophiolithic, that is, crystalline ferro-magnesian rocks in the comprehensive sense, to be dealt with in this and the subsequent paper are those west and east of Genoa. Of these the principal western or Voltri group was already referred to in the preceding paper as being, on its western margin, contiguous to the crystalline massif of Savona, and as constituting with the latter the geological contact-zone of the Alps and the Apennines. The anomaly of its position and petrological character is enhanced by the abrupt, clean-cut division of its eastern margin from the adjacent, more recent, and smaller ophiolithic group of Sestri and Isoverde, which is coeval with the groups of Eastern Liguria.

[In the Geological Magazine for June last, p. 255, Mr. W. R. Jones refers to a Preliminary Report of Mining in the Main Granite Range, Federated Malay States, 1913. This report bore a slightly different title, and was not published. It is the property of the Federated Malay States Government, but I have the permission of the Chief Secretary to forward to you a typescript marked “Office Copy” and initialled by Mr. Jones, and to ask you to publish that portion of the report which refers to Gunong Bakau.—J. B. Scrivenor, Geologist to the F.M.S. Government. Geologist's Office, Batu Gajah, July 14, 1916.]

The economic resources of the Trias as a whole are not great, if we exclude the two main industries (bricks and gypsum), but they are of interest from a practical standpoint, so that a short summary will be given here.

Cordierite was first found in Travancore at Teruwulla (lat. 9° 22′ N. and long. 76° 37′ E.) in a kind of diorite. In the hand-specimen the mineral appears as violet patches and spots. Monazite, magnetite or ilmenite, garnet and biotite with probably a little hornblende, occur in association with it. In the sections the mineral is found to contain numerous globular inclusions which are surrounded by pleochroic halos. The larger of these may be identified as monazite under the microscope. The mineral is itself pleochroic, light vibrating in the direction of the axis of mean velocity (Y) showing a pronounced violet tint. When light vibrates in other directions the plates do not show any distinct colour, but a faint yellow tint may be observed in some plates. When light vibrates in the direction of the Y axis the pleochroic halos round the inclusions disappear and assume the violet tint of the crystal plate. Cordierite is supposed to occur usually in metamorphosed sediments, and the pleochroic halos are regarded as due to the presence of organic impurities. But a sedimentary origin is out of the question in the present case. It is held by some that pleochroic halos are due to the presence of radio-active substances. I kept an Ilford Empress photographic plate exposed in a dark box to a crushed sample of the mineral for more than twelve hours, but on development the plate did not show any indication of having been affected by the mineral.

Dr. C. A. Cotton desires to correct an error in his paper, “On the Geological Structure of New Zealand” (see Geol. Mag., June, 1916). On p. 247, line 36, for ‘left’ read ‘continously’ above water.—Ed. Geol. Mag.