In the following note I propose to give a brief account of the chief results obtained during an expedition to the Fayûm in the early part of the present year (1903). The localities in which collections were made lie to the north of the lake Birket-el-Kerun, and are almost the same as those examined on previous occasions. Practically nothing was found in the Middle Eocene beds, but from those of Upper Eocene age a fairly large collection of vertebrate remains, including several new forms, was obtained. A few interesting tilings were also found in the Quaternary lake-beds in the neighbourhood of Schweinfurth's Temple (Qasr-es-Sagha); these will be referred to more fully below.

For some years it has appeared to me that in the Order Theriodontia as generally accepted there were included a number of forms not at all nearly related to the typical genus, Galesaurus, and in a number of papers I have referred to these as ‘Primitive Theriodonts.’ The best known genera are Ælurosaurus and Ictidosuchus, but as in neither of these have the details of palatal structure been very clearly made out, it has been impossible to say how far they differed from the typical Theriodonts.

In the collection of Mr. Alfred Brown, of Ariwal North, which I had recently the pleasure of looking over, I came across the right lower jaw of a small mammal which Mr. Brown had discovered in sandstone near Ariwal. Though unfortunately the teeth are lost, there is evidence of there having been a large canine. The most remarkable character of the jaw is its extreme shortness, and in its general proportions it agrees much more with the jaws of some of the small carnivorous Eutherians than with those of the small carnivorous or insectivorous genera already known from the Secondary rocks. The angle is well developed and but very slightly inflected. The condyle is practically in a line with the alveolar margin.

Plutonic rocks of acid composition are very extensively developed in Africa south of the Equator. These rocks present many features of interest, and, especially under the microscope, many minerals may be recognized besides the usual quartz, felspar, and ferromagnesian constituents. Thus the granite of Cape Town itself is remarkably rich in accessories. Tourmaline, in particular, is very abundant in places. In thin sections it is of a yellowish brown colour frequently bordered and zoned with pale blue, while some crystals show alternate bands of yellow and brown. Cordierite also appears to be sometimes present in the normal granite. It may be quite fresh and almost indistinguishable from quartz, while in other cases it is entirely replaced by the yellowish micaceous ‘pinite’ pseudomorphs. The intermediate stages of the alteration are well shown, while it is interesting to note that it seems to have crystallized sometimes before and sometimes after the felspar.

The present notes are based on field observations made in 1900. The section described is now obscured.

Corundum is abundant in the gem-bearing gravels of Ceylon, but with the exception of the case here described no localities are known where it occurs in sitû; the present occurrence is therefore of considerable interest, although not very satisfactory in itself.

Crystals of corundum were found in the surface soil on a piece of land known as Tenna Hena, and situated east of Kandy, and three-quarters of a mile north-east of Talatnoya bridge. The exact spot is shown in a map accompanying a paper on the crystalline limestones of Ceylon (Quart. Journ. Geol. Soc, 1903, vol. lviii, pl. xiii). A small excavation had been made, and a few pounds of corundum extracted and sold for use as emery, before my visit to the spot. All the rock exposed was decomposed, and crumbled in the fingers, being in a condition resembling sand. I therefore carried on an excavation for two months, hoping to reach hard rock suitable for microscopic examination, but although a depth of about 30 feet was reached, no sufficiently hard rock was found.

At the corundum pit the ‘beds’ of granulite dip northwards at a high angle. A conspicuous soft yellow micaceous band 7–3½ inches wide marks the position of the sapphire-bearing zone. The sapphires occur in fair abundance in a less decomposed felspathic rock occupying a few inches on either side of this yellow micaceous band in the upper part of the shaft, but on the south side only in the lower part. The associated types of granulite are chiefly acid leptynite.

In the Geological Magazine for October, 1902, Dr. Callaway mentions the explanation of these curves that I gave in a paper printed twenty-one years ago. His quotation should be read with the immediate context—”These [the tributary streams] keep open a channel into which the larger stream falls.” This is the essence of my argument.

Professor Phillips and Sir A. Geikie have remarked that an alluvial plain in the course of a river may be regarded as an old lake-bottom, now drained; the lake-like appearance being renewed in times of flood. Let us suppose ABCB (Fig. 1) to represent such an area with a river flowing through it in a straight line, and, on one side, a tributary stream, or, to use a shorter and more expressive term, an affluent, coming in at an angle. Such a condition, if it existed, would not continue even in consolidated alluvial soil; it is still less likely to have existed in the soft mud when the area was first drained. A succession of floods would certainly wash away the bank where the affluent, coming through it, had caused a break in its continuity. By this the river-bed opposite the affluent would be expanded beyond its requirements when at low water. At every flood the whole of the bed of the river and the adjoining area of land will be covered with water, the ordinary river channel being effaced. From this water suspended matter falls and forms a deposit, visible after the flood has subsided, but in greater quantity on the banks by the sides of the low-water channel than on the adjoining land.