The completion of the 40th volume of the Geological Magazine, and the commencement of its Fifth Decade under the Editorship of one who has been responsibly associated with the undertaking since 1864, and has been Editor-in-chief since July, 1865, furnishes a fit opportunity for a retrospect.

In the opening pages of this Magazine Professor Rupert Jones dealt with “ The Past and Present Aspects of Geology.” He remarked on the tendency to encroach upon the theory of Uniformity, upon the right “to call in the agency of forces which, though not seen in operation in nature, may be evoked in the laboratory.” He further referred to “recent discussions respecting the origin of granite, the mode of formation of river-valleys, the excavation of lake-basins, the doctrine of ‘homotaxis,’ and the origin of species.” At that time, owing to the teachings of Huxley, there was more scepticism than there is now as to the exact truth of “the contemporaneity of strata which contain the same or similar fossils, and which are geographically far apart.”

I have been favoured by P. N. H. Jones, Esq., engineer of the Waterworks, with specimens from a boring at Sangregrande undertaken by the Government of Trinidad with a view to ascertain the extent and position of the Tertiary coal-seams of that district and other facts. The specimens consist of a dark-coloured (blackish) sand-rock, finely (but slightly irregularly) laminated, the lamination being at an angle of about 50° from the horizontal. The samples came from 150, 250, 400, 500, and 600 feet deep below the surface. I examined each one separately, but as the differences between them, whether as regards mineral constitution or organic contents, are only slight, and in fact two portions from the same depth show often as much difference as samples from different depths, I shall describe the whole together. These specimens are from boring No. 3, Plate VII.

This is merely a brief note to record the discovery of fossils of undoubted Silurian age in the “Black Slates with limestone lenticles ” which occur on the shore and in the cliff at Fletching's Cove, near Porthalla, and at Porthluney, near Gorran, in Cornwall.

For many years the most careful search in these beds for fossils has been unsuccessful beyond minute ossicles of crinoids and indeterminable fragments of Orthocerata. I have spent many weeks each year hunting for fossils, often alone, but sometimes in the company of Dr. Barrois, Mr. Teall, Messrs. Vassell, Sherborn, Howard Fox, and others, and beyond finding the well-known Brachiopoda in the quartzites of Gorran and Carne, our search has seemed almost in vain. Some four years ago, however, Mr. Sherborn found in the Black Slates of Fletching's Cove an impression, which he identified as a fragment of Serpulites longissimus, J. de C. Sow., of Ludlow age. This fragment is now in the Museum of Practical Geology. This Spring, in company with Messrs. E. Dixon, of the Geological Survey, and Mr. G. T. Prior, of the British Museum, I paid my usual visit to Cornwall, and was rewarded by finding at Porthluney in these Black Slates a limestone lenticle which contained Orthocerata in quantity. It was only on the 6th June that I showed this to Mr. Sherborn, who at once took it to Mr. G. C. Crick, who recognised two of the fossils therein contained as comparable with Actinoceras baccatum, H. Woodw., and Barrandeoceras holtianum (Blake), together with other fragments also of Upper Silurian age.

In the course of his excavations in the Upper Eocene beds of the Fayûm during the early part of 1902, Mr. H. J. L. Beadnell unearthed a remarkably fine shell of a very large species of Testudo. A brief description of this specimen was afterwards published in Cairo by the present writer, and it was made the type of a new species, Testudo Ammon. At the same time Mr. Beadnell gave a short account of the beds in which it was found, and of the methods employed by him for its preservation and transport to the Museum in Cairo.

Polyzoa, etc.—Among our early contributors stands the well-known name of George Busk, author of a “Catalogue of Polyzoa in the British Museum” (1852–54) and a most valuable monograph on the “Polyzoa of the Crag” (Pal. Soc., 1859). Busk sent a paper (in 1866) to this Magazine on “Polyzoa from the London Clay of Highgate,” describing three genera and species new to science. Professor H. A. Nicholson wrote on Callopora in crassata from the Devonian of Canada; on Heterodictya from the Devonian of Ontario; and on the geological distribution of Solenopora compacta (1885). Professor Dr. Ferdinand Roemer (in 1880) recorded the genus Caunopora in the Devonian of South Devon. Robert Etheridge, jun. (1873), figured and described Carinella, a new genus from Carluke, Lanarkshire, and Bamipora from the Caradoc Beds of Corwen, North Wales. G. R. Vine discoursed on Carboniferous Polyzoa (in 1880); F. D. Longe on Oolitic Polyzoa (in 1881); and Dr. J. W. Gregory on some Jurassic species of Cheilostomata (in 1894).

The Oceanic beds of Naparima, in Trinidad, contain numerous forms of Foraminifera of great interest, and I propose to make some observations on a few of them These rocks and their contents were described by me in the Journal of the Geological Society of London, 1892 (vol. Xlvii, p. 519). Messrs. Jukes-Browne and Harrison treated of the same subject in the same journal in 1899 (vol. lv, p. 177), and I have given further particulars in the Proceedings of the Zoological Society, 1894 (p. 647), in the Proceedings of the Trinidad Field-Naturalists Club, 1893, and in the GEOLOGICAL MAGAZINE, 1900, p. 322. A few further observations are published in the Proceedings of the Victoria Institue.

That broad trench through the Palestine Highlands, an ancient highway and battlefield of nations—the plain of Esdraelon or the valley of Megiddo, together with the plain of Acre—has for long presented to me a difficult problem in Physical Geology, for it seemed inexplicable by subaerial denudation under existing conditions. Its floor varies roughly from five to eight miles in breadth; running approximately from south-east to north-west, it is bounded on the more western side by the limestone mountains of Samaria and on the more eastern by those of Galilee. The former descend from the ridge of Carmel (1,742 feet at highest) with a fairly steep escarpment, which becomes a little less regular as we follow it to the bastion-mass of Mount Gilboa; the latter correspond in their general outlines with those of the eastern portion of Samaria, but the advance of a lower spur towards the south-west divides the plain of Esdraelon from that of Acre, by a kind of strait in which, so far as I could see, there is but little level ground on either side of the Kishon. This spur, however, of the northern hills, hardly does more than interrupt the floor of the Kishon valley, for above it the great trench is continued between two hill masses, much of these ranging from thirteen to sixteen hundred feet above sea-level. Beyond the strait the upper basin (plain of Esdraelon) quickly broadens out, extending towards the south-east for about fifteen or sixteen miles, where it is divided into two arms by Jebel Duhy (Little Hermon) (1,690 feet), which is thus isolated from Tabor (1,846 feet) on the north, and from Gilboa (1,698 feet) on the south; a broad, rather shallow, grassy valley descending from the last-named mass to lose itself in the plain.

There is one complete individual of a species of Phacops from the Orthis-argentea zone of Prendergast Lane, Haverfordwest, showing certain interesting characters which make it worthy of notice. The head is somewhat crushed and imperfect, but the glabella is seen to be large and broad and to expand regularly towards the front; the frontal lobe is transversely rhomboidal and nearly half the total length of the glabella; there are three pairs of lateral lobes, of which the anterior pair is the largest; the second pair is narrower, and the third pair is subequal to the second in size. The first pair of lateral furrows is oblique; the second pair is horizontal and slightly arched forwards; the third pair is slightly oblique and the most strongly marked of all; the occipital furrow is strong and curved forwards in the middle. There is only a narrow median strip of the glabella not crossed by the lateral furrows, for they are rather long and all reach inwards to about the same extent.

The thorax has a prominent axis about three-fourths the width of the pleuræ, which are bent downwards and backwards beyond the fulcrum, which is situated at about half their length. Their extremities are slightly bent forwards and apparently rounded or bluntly pointed; a deep diagonal furrow traverses the whole length of each pleura.

The pygidium is nearly semicircular, with a regular rounded margin, except behind the axis, where there is developed a long, pointed, straight posterior spine, about two-thirds the length of the pygidium.

Geology is a science which owes, not only its inception, but its continued existence largely to its non-professional disciples and lovers. In fact, of the two classes existing at the present time, the ‘amateur’ and the ‘professional,’ it would by no means be difficult to show that the former gave birth to. the latter, and that some of the best living professional geologists have been recruited from the ranks of the amateur class. To a small band of early amateurs we are indebted for the foundation alike of the Geological Society and the Geological Survey in this country.

Reptilia et Aves.—Our two greatest Anatomists of the past century, Owen and Huxley, both contributed to this section of our palaelig;ozoological record. Owen (in 1865) described some remains of a small air-breathing vertebrate, Anthrakerpeton crassosteum, from the Coal-shales of Glamorganshire, corresponding with those described by Dawson from the Coal-measures of Nova Scotia; and in 1870 he noticed some remains of Plesiosaurus Hoodii (Owen) from New Zealand, possibly of Triaasic age.

The genus Desorella was founded by Cotteau in 1855 to include four species from the Corallian named D. icaunensis, D. Orbignyana, D. elata, and D. Drogiaca, and one from the Neocomian—D. incisa. The first and the last of these five species were subsequently shown to belong to the genus Pyrina, the second was placed by Etallon in a new genus, Pseudodesorella, whilst the fourth has been referred to Hyboclypeus. So that of the five species originally regarded as belonging to Desorella, one only, D. elata, is left in that genus. Another species, described in 1862 as Desorella Guerangeri, was afterwards shown to be a Pyrina. Cotteau accepted these modifications, and, in 1873, gave an emended diagnosis of the genus, naming as the type Desorella elata, and describing another species, D. Grasi. M. Jules Lambert is of the opinion that Pachyclypeus semiglobus (Goldftiss) should be placed in the genus Desorella.

In any retrospect of scientific progress there are always special points, ‘golden milestones,’ along the road by which we travel, which mark unusual stages in our journey. Zittel, in his “History of Geology and Palæontology,” fixes the ‘heroic period’ from 1790 to 1820, when the great masters of our science, Werner, Pallas, Saussure, Huttoti, Playfair, William Smith, Leopold von Buch, Alexander von Humboldt, Alex. Brongniart, and Cuvier arose and laid the foundations of Geology.

The Arenig Series, as originally defined by Sedgwick, has undergone much subsequent modification by its founder and other authors. There have been separated off from it the Tremadoc Series at the base, and the Llandeilo Series above, and a certain amount of ambiguity has arisen as to what constitutes the Arenig thus restricted; possibly, therefore, the recognition of three well-defined graptolite sub-faunas within the series in certain districts may help in some degree towards the solution of the problem.

Mr. A. L. Du Toit, of the Cape Geological Commission, who has been for some months engaged in studying the Stormberg beds in the eastern part of the Colony, has been fortunate in making a number of discoveries of very great interest to the palæontologist. Among Vertebrates his most important finds have been the remains of two small crocodiles.

The first specimen, which was discovered by Mr. A. Isted in the Cave Sandstone at Funnystone, Barkly East, consists of the impressions of the under sides of most of the upper bones of the skull and of most of the dorsal armour. There are also preserved the remains of a scapula, a humerus, a radius and ulna, a femur, and a number of ribs. A restoration of the skull is shown in Fig. 1. When complete it probably measured 130 mm. in length, and the length of the whole crocodile was probably about 600 mm. Though the skull is too imperfectly preserved to show what are the relations to the already known families, enough is preserved to show that the crocodile belongs to the suborder Amphicœlia of Owen (= Mesosuchia, Huxley). The skull is characterised by the very large size of the squamosal bones, by the moderate size of the supra-temporal openings, by the nasals taking little part in the formation of the snout, and by each maxillary having only a few large teeth—’ probably 6 or 8.

In the district of Tullstorp in Scania (Southern Sweden) the white ‘Writing Chalk’ is dug rather extensively, and in exploring the ground numerous borings have lately been made which have shown that this Chalk is not actually in place as supposed by Angelin, B. Lundgren, J. Jönsson, J. C. Moberg, W. Dames, and others, but occurs only in extraordinarily large transported masses or boulders (Schollen), up to 850 metres long, 300 metres broad, and 15 metres thick, which are embedded in the glacial deposits.

As I have recently seen certain cases of the curious hollowing out of rocks in Corsica, described by Mr. F. F. Tuckett (with a note from myself) in the January number of this Magazine, for which Mr. Lake suggested an explanation in the following number, I will add something to that note and intimate why I did not refer to desert regions for an explanation. The case which Mr. Lake mentions (“Das Gesetz der Wüstenbildung,” fig. 7) undoubtedly much resembles Mr. Tuckett's photographs, and so, to some extent, do figs. 16 and 17, more especially the latter. With these I was not then acquainted, perhaps having overlooked the book, because I wrote a notice of “Die Denudation in der Wüste,” when it appeared in 1891, and had formed the opinion that the author was disposed to work his hypothesis for rather more than it would stand. As, however, I knew there would shortly be a chance of my getting a glimpse of the Egyptian desert, I postponed stating why I had not suggested that kind of atmospheric erosion. In this region, however, I saw no more than I already knew, but on our return, owing to an unexpected change of plans, we spent an afternoon and part of the next day in harbour at Ajaccio, when, by a lucky chance, I hit upon some curious instances of erosion, which I think may be worth a brief description.

In the Annals and Magazine of Natural History, ser. VII, vol. i (1898), pp. 333–334, pi. xxvii, a numerous series of fossil Ostracoda, with bivalved carapaces, having more or less resemblance to those of Cypridina, were described and figured. The specimens selected had been collected by various observers in different regions; and comprised two from the Tertiary of France, two from the Cretaceous of Belgium, one from the Permian of Durham, seven from the Carboniferous of Britain, three from the Devonian of Devon, three from the Upper Silurian and two from the Lower Silurian (Ordovician) of distant regions. References were made to several allied Palæozoic forms; and one other species from the Carboniferous of North America (Ulrich) and two from the Upper Silurian of Scania (Moberg) ought to have been mentioned.

At the heart of Africa lies a vast area, so remote, so inaccessible, and hence so little known, that for the explorer it possesses a fascination all its own. The interests of the geologist have perhaps received less recognition than those of his fellow-scientists from the pen of the traveller; and there must be much that he would wish to know lying hidden in these distant regions awaiting discovery and publication. There is thus an encouragement to make known any facts which may throw light upon the geological structure of those parts, however small the contribution may be.

While serving recently with the Anglo-French Boundary Commission (Niger-Chad) we found an outcrop of a fossil-bearing stratum in the region of the Sokoto, having, as shown in the accompanying map, giving its latitude and longitude, a position near the verge of the Great Sahara Desert. On my return, the specimens secured were submitted to the palæontologists of the British Museum, one of whom, Dr. F. A. Bather, has kindly drawn up the description which follows in a separate paper. For me it only remains to give a few particulars of the general and localized formation to supplement his account.

Generally, the country consists of sandy plains, roughly estimated as lying some 500 or 600 feet above sea-level. These plains are traversed by watercourses, which contain running water only for some five or six weeks in the year, the rainfall of 535 mm. lasting during three months. A permanent water-supply is obtained by deep wells, which in some places reach a depth of 400 feet before tapping a constant source.

The recent gift to the Museum of a fine series of Lower Palæozoic fossils from the Haverfordwest area by Mr. V. M. Turnbull, M.A., who has personally collected them with much care, has at length provided us with the means of determining many of the interesting species which were mentioned without specific names (on account of their imperfect preservation) by Messrs. Marr and Roberts in their paper on this district. The collections from which their lists were drawn up are in the Sedgwick Museum.

In a notice published on page 160 of the present volume it was suggested that Arsinoitherium, of which a brief description was there given, must be placed in the order Amblypoda, constituting a new family, the Arsinoitheriidæ. Having further considered the evidence available, and having, moreover, had the advantage of some discussion on the subject with Professors H. F. Osborn and W. B. Scott, I have now come to the conclusion that Arsinoitherium differs from the Amblypoda in so many points that it seems necessary to refer that remarkable mammal to a new subdivision of the Ungulata of equal value with the Amblypoda and Probosoidea, to both of which a certain degree of relationship may exist. For this new order the name Barypoda is proposed, in allusion to the massive character of the limbs in the species at present known. The existence of two orders so marked as the Proboscidea and the Hyracoidea in the Eocene beds of Egypt, and their absence at that period from the rest of the world (with the possible exception of South America), at least make it seem likely that in an area so isolated there were other equally distinct groups which died out before circumstances became favoui'able to allowing them to pass over to other regions. That Arsinoitherium may be the representative of such an order is probable, for its great size and highly specialised character point to its being the closing member of a long line, of which the earlier forms are at present quite unknown, and must be sought in earlier horizons in the Ethiopian region.