From time to time during the last two years brief accounts of a remarkable series of vertebrate remains, from the Middle and Upper Eocene of the Fayûm district of Egypt, have been published in the pages of this Magazine. The species hitherto described include a number of highly interesting animals, but of the most extraordinary of all, viz. Arsinöitherium Zitteli, no figure has yet appeared in this Journal. We are therefore glad to take the opportunity of remedying this omission by availing ourselves of the kind permission of the Editor of The Sphere to reproduce two photographs of the skull of this animal, which appeared in the pages of that journal on September 12th, 1903, as illustrations of a short article by Professor E. Ray Lankester, which is the first account of Arsinöitherium published in this country, and from which some extracts are given below.

The Geological Department at Cambridge is at length provided with adequate accommodation by its transference to the new Sedgwick Memorial Museum. The portion of Cockerell's Building formerly occupied by the Woodwardian Museum has been vacated and put at the disposal of the University Library; and the well-known name is only perpetuated in a special portion of the exhibition galleries in the new building containing the founder's collection.

This is the Progenetta incerta of Depéret, which requires a new name, as it is far from identical with the Mustela incerta, Lartet, from Sansan, with which Depéret identified his specimens from La Grive.

An easy walk from Lourdes through Lésignan, Paréac, Orincles, Leyrisse, and Bénac, to the return station of Ossun, traverses the entire outcrop of the Upper Cretaceous Flysch, lying between the abrupt uprise of the Cenomanien limestone at Lourdes and the Danien that skirts the Tertiary plain towards Tarbes. The age of this Flysch is admitted; every objection regarding it has been successively abandoned; and its appearance, composition, and characteristic fucoids are as typical at Lourdes as at any point within fifty miles on either side. By insensible gradations it passes repeatedly from fresh marly shale with characteristic fucoids into micaceous schists that have been classed as Cambrian. Portions of a sandy character acquire vivid colouring and pass insensibly into a rock indistinguishable from decomposed granulite, while preserving their original bedding. Such changes occur on either side, or on the prolongation, of extensive lenticular intrusions of solid granite, which cross the indicated route between Paréac and Orincles and between Orincles, Visker, and Bénac.

The above paper, read before the Geological Society on the 27th May last, having just reached my hands, with the discussion, I trust you willallow me to make some observations thereon, not having been present on the occasion. As my name does not appear once throughout the paper it might at first sight be considered unnecessary, if not impertinent, for me to take any direct notice of its contents. I must therefore ask permission to state the reasons for this communication as briefly as may be, and they may be summed up in a single sentence—that, being responsible as the officer of the Survey who carried out the geological mapping of the Cotteswold Hills and of the outlying Bredon Hill, I cannot allow reflections on its accuracy to pass unanswered.

In discussing a paper by Mr. J. S. Curtis on the Witwatersrand Gold Deposits, Mr. George Denny has raised the point that the slates or shales of the Witwatersrand, which especially characterise, but are not confined to, the Lower Witwatersrand Beds (Hospital Hill Series), are not of sedimentary, but of igneous origin. He relies chiefly on the fact that he has observed in places that a so-called band of slate cuts across the bedding of the quartzites. I think we are all prepared to agree with him that, where he can point out that this occurs, the rock which traverses the bedded formation must be an igneous intrusion; but such cases are rare. In the vast majority of sections where the slates are exposed, they are found to occur truly bedded, and in conformable relation with the quartzites with which they are associated. It seems to me that, after all, this is in the main a petrological question, which can be easily settled by the examination of the rocks in question under the microscope.

With this end in view I have examined a number of thin sections of these rocks, in all cases prepared from the cores of boreholes, on account of the difficulty of obtaining near the surface specimens sufficiently fresh and unweathered for microscopic examination; and I have selected geological horizons which are well known on the Witwatersrand. They are (1) the band of slates which occurs in the neighbourhood of the Bird Reef Series, and (2) the slates which occur in the footwall of the Main Reef itself, in both cases in the eastern portion of the Witwatersrand, as at Van Ryn and Geduld.

Mr. J. E. S. Moore's interesting work on the “Tanganyika Problem,” reviewed on p. 418 of the September number of the Geological Magazine, raises some interesting points in connection with African geology, though, as your reviewer rightly remarks, we are indebted to Mr. Moore rather for a statement of the problem “than for proposing an adequate solution of it.” At the same time it must be admitted that Mr. Moore's general geological conclusions appear to me, as a worker in Africa, much more in accordance with the facts as I see them in the course of my every-day life, than the hypotheses of certain eminent geologists who have preceded him. There is always a great disposition on the part of visitors to a little-known country to theorise, without having had time or opportunity for making those accurate and detailed observations which are essential if deductions are to be made which will stand the test of time. And the worst of it is, ‘authority’ has so much weight that local workers have the utmost difficulty in removing false impressions which may thus be caused. Two points to which I may refer are the “antiquity of the African continent” and the so-called ‘Rift-valleys.’ Now whatever may be the antiquity of Africa as a land surface, facts are constantly coming to light which throw great doubt on its having the stability attributed to it. Fossils of Jurassic and Cretaceous age are known from numerous places, and though these are chiefly confined to the coastal fringe, fresh discoveries are frequently increasing the area, such as the recent one far inland in the Sahara.

In February of last year Professor Bonney read an instructive paper before the Geological Society, in which he enumerated and briefly described a number of the principal breccias found in the geological series. He also gave a short description of some of the best known recent breccias—the stone rivers of the Falkland Islands and the angular detritus that fringes the foot of the hillsides in Persia, Central Asia, and Northern Hindustan. In conclusion, he expressed his opinion that most of the ancient breccias referred to in his paper indicated “a climate, arid, liable to extremes of temperature, with cold winters. The precipitation probably was connected with this season, and took the form of snow.” He thought, however, that in some cases “hot summers and occasional torrential rainfalls” might produce the same effects.

I have recently had an opportunity of examining an extensive breccia at the foot of the Andes and margin of the Amazonian plain, which is still in process of formation under somewhat different conditions.

In north-eastern Bolivia the Andes consist of numerous parallel ranges trending north-west and south-east. At the point where the river Beni enters the great forest plain the outer or north-eastern chain is that to which I have referred as the Bala-Susi mountains. The highest summits rise to about 5,000 feet above the sea, but some of the saddles do not exceed 2,000 or 2,500 feet in altitude.

The lower slopes are clothed with trees, and from their foot, at an altitude of 650 to 1,500 feet, commences a gentle incline.

The species Vestinautilus crassimarginatus was founded in 1900 by Dr. A. H. Foord upon some (apparently three) spec mens from the Carboniferous Limestone of Little Island, near Cork. It was described as follows:—