A little further west, at a point 25 kilometres north of the eastern end of the Birket el Qurûn, thick beds of white coarse sandstone form the upper part of the escarpment. Below comes a bed of yellowish impure limestone and below this an interbedded sheet of basalt 21 metres thick, underlaid by more white sandstone.

The series has almost always a constant dip of two or three degrees to the north. Silicified trees are very commonly found strewn over the surface both near the base and high up in the series.

At a point about 14 kilometres north of Qasr el Sagha definite organic remains other than bone-fragments were for the first time met with in the series. Here a fragment of ochreous-coloured grit containing numerous specimens of a small Melania was picked up and similar rocks were afterwards found in situ. Calcareous grits and impure limestones occurred at the same spot, and one of the harder more compact bands of limestone was found to contain casts of Cerithium.

Also at a point 9 kilometres north of Qasr el Sagha hard grey limestones, generally compact and cherty, and sometimes semi-crystalline, are present, containing casts of Melania, frequently filled with calcite. These overlie variegated sandstones, and occur at about 40 metres below the basalt near the top of the escarpment.

Blanckenhorn has determined my fossils from these localities as follows:—

Melania nov. sp., allied to M. Nysti of the Oligocene.

Potamides scalaroides, Desh., an important guiding form of the Middle Beauchamp Sands of the Paris Basin, and thus Upper Eocene.

Potamides tristriatus, Lam., of the Parisian (Cerithium crispum, Desh.,) is nearly related to the frequent Middle and Upper Eocene C. perditum, Bay, between which, according to Cossmann, transitions exist.

Cerithium tiarella, Desh., of the Middle and Upper Eocene, but more especially in the latter.

Blanckenhorn considers these determinations as certain, and thus marking the complex as Upper Eocene, on the level of the “Beauchamp Sands” of the Paris Basin, and consequently of the Lower Headon Hill beds and Barton Clay of the South of England.

The following section was measured from the base of the series, 2½ kilometres N.N.W. of Qasr el Sagha, to the summit of the escarpments, 2 kilometres N.N.W. of Widan el Faras. The series has its maximum thickness at this point.

Summit of escarpment of Fayûm depression, 2 kilometres N.N.W. of Widan el Faras.
Top.			Metres.
1.	Sandstones with band of coarse dark ferruginous grit; silicified logs occur weathered-out of this bed		18
2.	Coarse sandstone-grit with yellowish calcareous base		1
3.	Greyish clay, possibly a product of decomposed basalt
4.	Basalt sheet, soft friable, grey or bright green, and decomposed at base		5
5.	Hard yellow calcareous-grit with calcite-filled cavities, passing into semi-compacted yellowish sand, hardened at junction with basalt		1
6.	White and red sands		27
7.	Greenish sandstones and yellow concretionary sands with 2·5 cm. layer of calcareous grit, with gastropods including large Cerithium, Melania sp., Turritella pharaonica, Pleurotoma ingens, May.-Eym., occasional lamellibranchs and also Callianassa
8.	White, green and brown sands and sand-rock		17
9.	Hard yellow calcareous grit		10
10.	Red and white clayey sand and sandy clays; some pebbly bands; Lucina sp., Unio sp.,[67] preserved in brown ironstone, common in places on this horizon
11.	Coarse grey and white sand (2 metres)		5
12.	Red clayey sands (1 metre)
13.	White and yellow sand and sand-rock
14.	Red clays		7
15.	Sandy ferruginous band with lamellibranchs and gastropods of genera Unio, Pseudodon, Mutela, Spatha and Lanistes, indicating fluviatile or fresh water conditions of deposition		5
16.	Green clay (1 metre) passing into a red variety		6
17.	White sandy clay (2 metres)
18.	Red clays
19.	White, brown, and red sands, partly consolidated
20.	Bright red clay
21.	Hard coarse sandstone		3
22.	Hard compact light yellow limestone enclosing sand-grains (½ metre)		5
23.	White and yellow sands
24.	Greenish clays (1 metre)
25.	Coarse white sands with Unio and Cardium-like lamellibranchs preserved in brown ironstone
26.	Grey clay		2
27.	Hard yellow impure limestone (forms a small platform)		2
28.	Grey clays
29.	Red and yellow sands with hard base of grey sandstone		15
30.	Grey sandstones. Base of basalt-capped escarpment		7
(Section continued ¾ kilometre south-east).
31.	Hard blue-grey compact cherty limestone (½ metre) with casts of Melania; hollows often filled with calcite		18
32.	Variegated (red, white and yellow) sands, sand-rock and sandy clays		18
33.	Hard compact close-grained limestone
34.	Red and white variegated sands and sand-rock, with some bands of red clay
35.	Hard yellow impure limestone (⅓)		14
36.	Grey clays
37.	Coarse white sand
38.	Brown calcareous sandstones
39.	Greenish and grey sandy clays (3 metres)		8
40.	Alternating white and red sands
41.	Coarse yellow calcareous grit (½ metre)		2
42.	Light green sandstone
43.	Reddish clays
44.	White sand		2
45.	Alternating white and bright red sands		19
46.	Grey sandstone with silicified wood; occasional crocodilian and other bones
47.	Hard red clays		5
48.	Grey and brown clays, sandy clays, and thin beds of sandstone with some silicified wood		19
49.	Grey sandstones and loose false-bedded sandy clays with many silicified trees and remains[68] of Arsinoitherium Zitteli, Bead., Palæomastodon Beadnelli, Andr., Mœritherium sp., Phiomia serridens, Andr. and Beadn., Saghatherium antiquum, Andr. and Beadn., S. minus, Andr. and Beadn., Megalohyrax eocænus, Andr., Ancodus Gorringei, Andr. and Beadn., Pterodon africanus, Andr., Crocodilus sp., Tomistoma africanum, Andr., and large and numerous tortoises (Testudo Ammon, Andr.)[69] and turtles[70], and very rarely fragmentary fish-remains		5
50.	Thin bands of limestone		25
51.	Yellow sand-rock
52.	Grey sandstone with fragments of bone (½ metre)
53.	Brown calcareous-grit (½ metre)
54.	Light green sand-rock and sandstone
	Approximate total thickness in metres		271

The specimens collected from Bed 15, on about the same horizon as the fossils mentioned from the locality 14 kilometres north of Qasr el Sagha, were examined by Blanckenhorn, who has published the following notice of them:—

“I should first mention the fresh-water shells found by Beadnell in brown sandstone 1 kilometre north of Camp 19 (i.e. at Widan el Faras), which, in the absence of special literature on the Palaeogene fresh-water shells of North Africa and nearer Asia, I have compared with the fauna of to-day, in which I was most kindly helped by Professor v. Martens, Director of the Conchological Collection of the Natural History Museum. The greater number of the forms have a distinctly tropical, and more especially Central African, character.

Unio sp., small, related to the recent U. Nyassænsis of Lake Nyassa.

Unio, related to U. Homsensis[71] Lea, from Syria, and U. Bonneaudi from Cochin China, with many radial folds behind the umbo which run obliquely from the blunt edge backwards towards the hinge-border.

Unio, related to U. teretiusculus, Phil. (Caillaudi, Fer., lithophagus, Ziegli.) of the Nile.

Pseudodon? sp.

Mutela (a genus of tropical Africa) sp., long, with a straight finely-toothed hinge-border which very much recalls that of Barbatia (a sub-genus of Arca).

Spatha sp. related to S. dahomeyensis and S. Droueti of Assinia in West Africa.

Lanistes carinatus,[72] scarcely distinguishable from the Nile form.

The Melania occurring in mass in the uppermost calcareous bed appears to be a new species[73] whose nearest relation must in any case be M. Nysti of the Oligocene, not M. muricata of the Eocene, amongst forms at present known.

Turritella angulata, Sow. A marine form, occurring below the basalt and indubitably this species, as it is well preserved and easily determined[74]; T. angulata ranges from the Middle Eocene to the Lower Oligocene of the East and occurs in the Upper Mokattam of Syria.”

From Widan el Faras the series continues westwards, forming several escarpments, the uppermost that of Jebel el Qatrani, and maintaining the same general characters. The tripartite character of the series, already noticeable between Qasr el Sagha and Widan el Faras (see foregoing section) becomes still more marked. The lowest division is very largely composed of fluviatile sands and sandstones, frequently coarse-grained and usually markedly current-bedded, divided by clays and containing an abundance of silicified trees and quantities of vertebrate remains. These soft beds, some 60 metres in thickness, have as a rule an extensive outcrop, forming an undulating plain averaging two or three kilometres in width. They are overlaid by some 17 metres of harder dark red sandstones, which invariably form a well-marked escarpment capped by a very constant two or three metres band of hard white or pinkish calcareous grit. This grit varies in composition, frequently passing into a marl; and one of the characteristics of this and the underlying red beds is the abundance of nodular masses of calcite and gypsum. In some localities, as for instance 3 kilometres W.N.W. of Qasr el Sagha, numerous spherical nodules of beekitic chalcedony occur in the beds of this division, and some of these when broken are found to be geodes lined with beautiful crystals of quartz and calcite.

The next division consists of some 60 metres of alternating sandstones and clays with occasional thin calcareous bands in the upper part, and capped by a well-marked hard cherty limestone, frequently passing into a dense tabular chert or flint. This exceptionally hard band generally forms a dip-slope plain of some width, before the softer basal members of the third and highest division overlie it. The siliceous bed caps many of the most notable hills in the district; among others may be mentioned the big isolated hill 9 kilometres north-west of Garat el Esh, and the hills five kilometres N.N.E. of the same point. This is the only horizon throughout the Eocene succession of the Fayûm on which an abundance of flint is met with; that it was well known and exploited in early times is evident from the old pits met with on the summits of the hills overlooking the main bone-pits, a few kilometres north of Garat el Esh. As no worked flints were noticed round the workings it is probable that the material was excavated and carried away to the borders of the lake, there to be fashioned into the harpoons, saws and other implements which are so commonly found scattered at the present day near the margin of the old lake site.

The uppermost division of the Fluvio-marine series consists of over 100 metres of variegated sediments and forms the escarpment of Jebel el Qatrani itself, capped by the conspicuous band of hard black basalt, which is itself overlain by a further 20 metres of similar sediments. The basalt has a thickness of over 20 metres in places, though its average is considerably less; at the base it is frequently decomposed, soft, and of a brown colour.

At a point due north of the western end of the Birket el Qurûn the interbedded basalt sheet terminates, and no further flows were seen as far as the point up to which the series was mapped, nearly due north of Gar el Gehannem. As far as could be seen on a traverse through the Zeuglodon Valley to the south-western limits of the depression no further basalt flows occur.

Section from the base of the Fluvio-marine series, 2 kilometres north of Garat el Esh, to the summit of Jebel el Qatrani 5½ kilometres north of the bone-pits. (See Plates XVIII and XXIV).

Summit of plateau.			Approximate thickness in metres
1.	Coarse sandstones and grits		13
2.	Basalt		25
3.	Yellow sands and sandstones, capped by 3 m. of hard concretionary grey sandstone with occasional mammalian bones (underlying basalt in scarp and capping outlying hill)		15
4.	Hard sandstones with clayey bands		8
5.	Sandy and clayey beds		5
6.	Hard yellow calcareous grit		5
7.	Clays and clayey marls		7
8.	Sandy beds		15
9.	Hard sandstone (forms connecting ridge between hill and escarpment)		½
10.	Clays with thin sandstone bands		40
11.	Variable sandy and marly red clays with a hard yellowish sandstone band ten metres from base
Base of isolated hill.
12.	Soft sands with chelonian and crocodilian remains		4
13.	Sandy clays with chelonian and mammalian (Arsinoitherium) bones, capped by coarse grit, in part ferruginous silicified grit and quartzite		1
14.	White calcareous grit and marly limestone. Band of flint in places
Summit of hill overlooking bone-pits.
14.	Sandstone, becoming calcareous and passing up into 3 m. of hard white calcareous grit, and yellowish white bedded marly limestone with calcite druses. Capped by ¼ m. hard tabular chert and flint		10
15.	Finely laminated grey shaly clays, sandy and marly clays, capped by 2 m. of mottled yellow and red sandstone and sandstone-grit		10
16.	Hard red, green, and brown sandstone
17.	Variegated grey, green and red clays, marly clays and sandy beds, with thin bands of sandstone. More arenaceous towards top		21
18.	Hard grey sandstone; greenish sandy clays; hard dark red marls and marly clays at top		6
19.	Thin band of hard yellow limestone, capping salty red clays and sandy clays		6
20.	Soft greenish clayey sandstone capped by ½ m. of hard false-bedded concretionary sandstone with numerous enclosed coprolites		3
Base of hill overlooking bone-pits.
21.	Pink calcareous grit (forming summit of lowest escarpment), with small flint and quartz pebbles in some layers. An abundance of calcite and gypsum		3
22.	Mottled red and green clayey sandstone, clays and clayey marls. Passing up into a hard sandy (or clayey) dark red marl with greenish mottlings		7
23.	Light yellow finely-laminated sandrock passing up into dark red sandrock. Some clayey bands		10
24.	Coarse unconsolidated false-bedded sands, with occasional bands of clay and consolidated sandstone bands. Numerous silicified trees and abundant mammalian and reptilian remains. (See list in Bed 49 of Widan el Faras section). Bone-pits are in this bed		40
25.	Thin band (½ m.) of hard sandstone with sometimes impure calcareous grit		10
26.	Hard light yellow sandstone, often very coarse, and with red bands
27.	Soft brick red and light yellow sands and sandstones, (seen on plain and overlying uppermost limestone of the Middle Eocene)		20
Base of Fluvio-marine Series.

In some localities pebbly bands occur in the sandstone-grits, especially in some of the beds above the basalt: the pebbles are mostly quartz or flint, subangular or rounded, the layer averaging perhaps two cm. in diameter, although occasional specimens three or four times that size are met with. Silicified trees of two distinct types[75] occur, and they are met with chiefly on two horizons; usually large numbers of trees occur together, completely covering the surface in places; they lie as a rule scattered about in every direction, although occasionally a large proportion may show considerable parallelism of deposition, as if arranged by the direction of the current which floated them to the spot. They always occur in a horizontal position or parallel to the dip of the bed, and it seems quite certain that none of them ever grew near where they are now found. The trees never bear attached branches, the latter having always been broken off at or near the point of junction with the trunk, where the scars are often plainly seen; this points to the trees having been drifted a considerable distance. Many trees over 25 metres[76] in length have been met with, but this by no means represents the original height, as the trunks have lost considerably in length during transport to their present localities. Although, as a rule, found completely weathered-out and exposed on the surface, in numerous localities these silicified trees are to be observed firmly embedded in the sandstones in which they were deposited, many being met with in our excavations for bones.

As the Fluvio-marine series is followed westwards from the central part of the area, the different divisions become more and more attenuated and the outcrops more and more obscured by superficial gravel. North-west of the Zeuglodon Valley an escarpment capped by a conspicuous bed of white calcareous grit occurs and perhaps represents the lower beds of the series. The higher are lost on the gravelly undulating plateau above.

F.—Age of the “Fluvio-Marine Series”.

The beds in question being as a whole remarkably unfossiliferous, a determination of their exact age on palaeontological grounds is an undertaking of some difficulty. The series, however, in certain beds is very rich in vertebrate remains; a considerable number of new and important forms have already been obtained and further additions are probable. Until the survey of the area in 1898 it appears that the only fossils obtained from these rocks were a few casts and badly-preserved specimens of mollusca from the highest beds above the basalt, collected by one or two observers from localities between the summit of the Fayûm escarpments and the Pyramids of Giza.

The Rohlfs Expedition did not visit this part of Egypt, and Zittel[77] tabulated the beds, which he called the “Schichten von Birket el Qurûn” as doubtfully Oligocene; probably the beds referred to are those of the island Geziret el Qorn, which, as already mentioned, belong to the lower division of the Birket el Qurûn series, and are therefore of Middle Eocene age. Mayer-Eymar[78] states that he was able to subdivide the series under discussion into Upper and Lower Ligurian and Lower Tongrian. Schweinfurth[79] considered the series as Miocene, comparing them with the lithologically similar Scutella beds of Der el Beda to the east of Cairo. Blanckenhorn, on the evidence of the writer’s fossil collections, states, as already mentioned, that the upper part is certainly to be regarded as Lower Oligocene and the lower part as Upper Eocene.

First as to the stratigraphical position of the series. There is no doubt that the lowest beds of the group were deposited (at any rate in the central part of the area) in practical continuity with the Qasr el Sagha series, which, as shown, is certainly of Middle Eocene age. A great change in the lithology of the beds, however, makes the junction a perfectly natural one. We pass from a truly marine series into an estuarine or fluvio-marine set of beds, and such a change near the summit of the Eocene is not an uncommon one in some parts of Europe. The stratigraphical position in the field, therefore, favours an Upper Eocene age for the lower beds. The dip being northwards, newer and newer beds are met with from south to north on the great undulating, but more or less level, desert north of the escarpment summit. The occurrence of Lower Miocene beds at Mogara, some 100 kilometres north or north-west, also points to a somewhat younger, or Oligocene, age for the underlying beds, (i.e., those between the Fayûm escarpment and Mogara). The actual relations, however, of the beds in the two localities have not yet been determined, but it is probable younger beds are continually met with from south to north.

Until the entire collection of fossils has been examined and determined, it is somewhat premature to attempt to fix the age of the series on palaeontological grounds. Up to the present the foregoing lists show the species which have been provisionally or finally determined. Some of these appear to be identical with species which have been recorded from Upper Eocene deposits of Europe, such as Potamides scalaroides, P. tiarella, while others, such as Melania cf. Nysti, Natica crassatina (found below the basalt in the so-called Sandberger Hills north-east of the Fayûm escarpment), are typically Lower Oligocene. Other forms, such as Turritella angulata, are common to both Eocene and Oligocene elsewhere.

If Blanckenhorn’s determinations of these forms are confirmed, we may regard the upper beds, i.e., those immediately above the basalt, as undoubtedly of Lower Oligocene age. The beds below the basalt mark the transition from the Eocene to Oligocene, while the base of the series, so far unfossiliferous as far as molluscan remains are concerned, must be regarded as of Upper Eocene (Bartonian) age.

We may hope that when the important vertebrate fauna occurring chiefly in the basal part of the series has been thoroughly exploited, and the remains systematically determined, confirmatory evidence will be obtained. At present the only forms described and determined, beyond pointing to a pre-Miocene age, do not indicate any definite horizon. Probably most of the animals will prove to be new, and although on that account more interesting from one point of view, will probably not assist us greatly in the exact determination of the age of the beds in question.

G.—The Position of the Land-mass from which the Mammal Remains were Derived.

The existence of remains of land animals throughout the larger part of the Qasr el Sagha series and in still greater quantity in the basal beds of the overlying Fluvio-marine series, and occasionally in the highest beds also, points to the presence of continental land within no great distance of the area in which these deposits were laid down. That the animal-remains were carried out from the land by river currents is almost certain, and although in some cases such currents are known to persist to great distances from their points of emergence, it seems probable from the quantity and mode of distribution that the Fayûm bones were deposited within a moderate distance of land. Moreover, the silicified trees, by which the bones are so often accompanied, occur together in very great quantities, and we should imagine that the individual trees would have been far more scattered if they had been floated to considerable distances from land. On the other hand the fact that among the hundreds of trees examined, in no single case were branches found attached to the trunk, points to the conclusion that these trees had travelled great distances; probably the branches were lost during their river journey, from constant jamming together of a great number in a more or less constricted space, and not after they had left the river mouth.

The exact position of this land-mass is a highly interesting and important question. There is no reason to suppose that land of any extent occurred to the north, except possibly an occasional island, such as that of the Cretaceous massif of Abu Roash,[80] west of Cairo, which probably formed an island in the sea at that time; without doubt the great Eocene sea which covered the area stretched northwards, and was continuous with that in which the southern European deposits of this period were laid down. To the west also there was certainly no land-mass within approximate distances. Eastwards, possibly part of the Red Sea Hills igneous range may have formed a restricted land-area, but even this is not probable; in fact, it seems certain that we must look to the south for the nearest land of any extent. In supposing the land lay in this direction we are confronted at the outset with the fact that the Lower Eocene limestones stretch southwards for several hundred kilometres. In Egypt the Lower Eocene consists of a great mass of nummulitic limestones, some 400-500 metres thick, with no intercalated clays or sandstones except at the base, and was evidently formed in water of considerable depth. The thickness of, and superficial area covered by, these limestones show that they were formed in a truly open sea, in contra-distinction to a littoral area; the nummulitic sea in fact covered an enormous part of Europe, North Africa and Asia. To the south of this sea lay the African continent, a land-mass dating possibly from Palæozoic times. Since, and possibly partly during, the deposition of the Lower and Middle Eocene formations, a gradual elevation of the land or lowering of the sea, resulting in a retreat of the latter, took place; this continually brought the shore-line further northwards until, during the deposition of the beds of the Qasr el Sagha series of the Middle Eocene, we may surmise that it was not very far to the south, though the exact distance is extremely doubtful; while in Upper Eocene times it was still further north. We may assume therefore that the Upper Eocene bone-bearing strata of the Fayûm represent sediments transported by rivers and currents from a fairly adjacent continental land-mass to the south and laid down as littoral and delta deposits beyond the margin of the land. That at least one large river emerged from the land in the neighbourhood of the Fayûm is certain; drainage was then, as now, from south to north, although not probably confined to a single channel like the present Nile.

Apart from broader considerations a minute examination of the more typically fluviatile beds favours the conclusion that the currents were from the south or south-west. The general dip of the strata, probably the natural inclination of the sediments at the time of deposit, is from south to north; the most frequent lamination in the current-bedded arenaceous deposits is also from south to north. In our excavations for fossil bones it was noted that of seven tortoise shells exposed at the same time in different parts of the pit, six lay with their long axes similarly orientated and were distinctly tilted to the north-east, or exactly away from the point of the compass from which, as will presently be shown, the main river probably came. As a rule, however, the scattered fossil bones and trees in these beds give no definite clue as to the direction from which they were floated. The existence of separate accumulations of fluviatile sand at different horizons, but lying one above the other in the series and along a north and south line, is of importance as indicating the continued appearance of a river current from the same quarter.

Blanckenhorn has published[81] diagrams showing what he supposes to have been the relative areas occupied by land and sea in Upper Mokattam, Lower Oligocene, Middle Pliocene and Pleistocene times. Various lines of drainage are shown, the main river, which he calls the Ur-Nil, being placed some 70 kilometres to the west of the modern Nile, although closely following the trend of the latter. We have been unable to ascertain on what evidence Blanckenhorn relies for assuming rivers in Upper Mokattam and Lower Oligocene times to have occupied the positions shown on his diagrams; the number and positions of such rivers must remain more or less problematical. In this connection however it is interesting to recall[82] the lacustrine ferruginous grits which were brought to notice by the writer in 1900 as having been deposited in a lake, occupying in post-Middle Eocene times a shallow depression in that part of the Libyan desert now occupied by the oasis-depression of Baharia. Similar deposits were found forming the hills of Gar el Hamra a few kilometres east of the extreme north end of the depression. Finally, during a traverse through the unexplored country south-west of Gar el Gehannem in the winter of 1902-1903, hills capped with dark hard ferruginous silicified grits and puddingstone were met with in the extreme south-west of the Fayûm depression at a point nearly midway, and in the direct line, between the hills of Gar el Hamra and the chief bone-bearing localities in the north of the Fayûm. The deposits in question—at Baharia, at Gar el Hamra and in the hills to the south-west of the Fayûm—are evidently of lacustrine and fluviatile origin; and we may infer, with some degree of probability, that they were laid down along the course of a river which flowed in a north-easterly direction and formed extensive delta deposits in what is now the northern part of the Fayûm. That this river had its origin in the interior of a well-wooded continent hundreds of miles to the south of Baharia is not to be questioned; its size, length and exact position must remain matters of doubt, but of its existence we can be as certain as if in times of flood we had stood on its banks and watched the passage northwards of its turbid swollen waters, laden with matted rafts of forest trees and bearing seawards the carcases of those curious Eocene animals, the remains of which are so abundant in the Fayûm of to-day.

In the Middle and Upper Eocene beds we first obtain an idea of the animals which inhabited Africa in Tertiary times, and the collecting and working out of this fauna will throw much light, not only on our actual knowledge of the African vertebrata of the Eocene period, which was practically nil until the discovery of the remains here described, but also on other wider biological questions, such as the origin of certain groups of animals, some of which were evolved in this part of the world.

As recently pointed out by a writer in the Field (No. 2605, Nov. 29, 1902) many years ago the late Prof. Huxley, to account for the present distribution of the mammalian fauna of Africa and Magadascar, advanced the theory that in the early part of the Tertiary period Madagascar was connected with Africa, and Africa with Europe or Asia, a connection which allowed of the immigration into Africa and Madagascar of numerous small types of European and Asian mammals. Madagascar later becoming separated from the mainland, its fauna, undisturbed by the larger carnivora, was able to develop to its present remarkable extent. Subsequently to the isolation of Madagascar the ancestors of the modern fauna were presumed to have invaded the African continent from the north.

The extinct fauna of the Fayûm, however, shows that in early Tertiary times Africa already had its own mammalian fauna, which, besides containing some remarkable large types of somewhat doubtful position, such as Arsinoitherium, Barytherium, etc., certainly in Mœritherium and Palæomastodon included the earliest known elephants, the forbears of the Mastodon and the modern elephants. There is little doubt therefore that in Upper Eocene and Oligocene times these early members of the elephant group ranged northward and eastwards into Asia and India, and since in the Upper Tertiary deposits of India and eastern Asia the extinct transitional types between the mastodons and modern elephants appear to have been found, it is not unlikely that during the later phases of the evolution of this group of animals the radiation was back towards Africa, so that the African elephant may be, as it has usually been regarded, an immigrant from the Oriental region. Further research among the later deposits of the Fayûm and the deserts to the north may, however, throw an entirely new light on the subject and it is somewhat premature to theorise at present.

In this connection it is interesting to notice the observation of so eminent a palæontologist as Prof. H. F. Osborn. In two recent addresses[83] to the New York Academy of Sciences he pertinently points out his belief that the African continent has been a great centre of radiation of certain groups of the mammalia, and especially mentions the Proboscidea as likely to have been evolved in the Ethiopian region. Our discoveries in the Fayûm and Andrews’s determinations, made subsequently to these addresses, so completely confirm this view, at any rate with regard to the elephants, that it may not be out of place to give here a somewhat lengthy extract of his “Theory of Successive Invasions of an African Fauna into Europe” (op. cit. pp. 56-58). “In Europe there are in the Upper Eocene two classes of animals, first those which have their ancestors in the older rocks; second, the class including certain highly specialized animals which have no ancestors in the older rocks, among these, perhaps, are the peculiar flying rodents or Anomaluridæ, now confined to Africa, and secondly the highly specialized even-toed ruminant types the anoplotheres, xiphodonts and others, the discovery of which in the gypse near Paris Cuvier has made famous. It is tempting to imagine that these animals did not evolve in Europe but that they represent what may be called the first invasion of Europe by African types from the Ethiopian region.

“It is a curious fact that the African continent as a great theater of adaptive radiation of Mammalia has not been sufficiently considered. It is true that it is the dark continent of palæontology for it has no fossil mammal history; but it by no means follows that the Mammalia did not enjoy there an extensive evolution.[84]

“Although it is quite probable that this idea has been advanced before, most writers speak mainly or exclusively of the invasion of Africa by European types. Blanford and Allen, it is true, have especially dwelt upon the likeness of the Oriental and Ethiopian fauna, but not in connection with its antecedent cause. This cause I believe to have been mainly an invasion from south to north, correlated with the northern extension of Ethiopian climate and flora during the Middle Tertiary. It is in a less measure due to a migration from north to south. Let us therefore clearly set forth the hypothesis of the Ethiopian region or South Africa as a great center of independent evolution and as the source of successive northward migrations of animals, some of which ultimately reached even the extremity of South America, I refer to the Mastodons. This hypothesis is clearly implied if not stated by Blanford in 1876 in his paper upon the African element in the fauna of India.

“The first of these migrations we may suppose brought in certain highly specialized ruminants of the Upper Eocene, the anomalures or peculiar flying rodents of Africa; with this invasion may have come the pangolins and ard varks, and possibly certain armadillos, Dasypodidæ, if M. Filhol’s identification of Necrodasypus is correct. A second invasion of great distinctness may be that which marks the beginning of the Miocene when the mastodons and dinotheres first appear in Europe, also the earliest of the antelopes. A third invasion may be represented in the base of the Pliocene by the increasing number of antelopes, the great giraffes of the Ægean plateau and in the upper Pliocene by the hippopotami. With these forms came the rhinoceroses with no incisor or cutting teeth, similar to the smaller African rhinoceros, R. bicornis. Another recently discovered African immigrant upon the Island of Samos in the Ægean plateau is Pliohyrax or Leptodon, a very large member of the Hyracoidea, probably aquatic in its habits, indicating that this order enjoyed an extensive adaptive radiation in Tertiary times.

“It thus appears that the Proboscidea, Hyracoidea, certain edentata, the antelopes, the giraffes, the hippopotami, the most specialized ruminants, and among the rodents, the anomalures, dormice and jerboas, among monkeys the baboons, may all have enjoyed their original adaptative radiation in Africa; that they survived after the glacial period, only in the Oriental or Indo-Malayan region, and that this accounts for the marked community of fauna between this region and the Ethiopian as observed by Blanford and Allen.

“Against the prevalent theory of Oriental origin of these animals are: first, the fact observed by Blanford and Lydekker in the Bugti Beds (Sind) that the Oligocene or lower Miocene fauna of the Orient is markedly European in type; second, that if these animals had originated in Asia some of them would have found their way to North America; third, the fact that all these animals appear suddenly and without any known ancestors in older geological formations. These are the main facts in favor of the Ethiopian migration hypothesis.”

That Professor Osborn’s main contention has already been partly proved by the Fayûm mammal discoveries is apparent, and how far his detailed remarks are confirmed will be seen when the new fauna has been more completely explored and examined.

The following is a list of the new species already obtained:—

Upper Eocene.	Middle Eocene.
Mammalia
Arsinoitherium Zitteli, Beadnell.	Barytherium grave, Andr.
„  Andrewsii, Lankester.	Mœritherium Lyonsi., Andr.
Palæomastodon Beadnelli, Andrews.	„  gracile, „
„  minor, „	„  sp., „
Mœritherium Lyonsi, „	Eosiren libyca, „
„  trigodon, „	Zeuglodon Osiris, Dames.
Megalohyrax eocænus, „	„  Zitteli, v. Stromer.
„  minor, „	„  Isis, Beadn. (M.S.).
Saghatherium antiquum, Andr. and Beadn.
„  minus, „   „
„  magnum, Andr.
Ancodus Gorringei, Andr. and Beadn.
Geniohyus mirus, Andr.
„  fayumensis, Andr.
„  major, „
Phiomia serridens, Andr. and Beadn.
Pterodon africanus, Andr.
„  macrognathus, Andr. and another much smaller and imperfectly known creodont.
Birds.
Eremopezus libycus, Andr.
Reptiles.
Testudo Ammon, Andr.	Gigantophis Garstini, Andr.
Pelomedusa progaleata, v. Reinach.	Pterosphenus (Mœriophis) Schweinfurthi, Andr.
Podocnemis fayumensis, Andr.	Psephophorus eocænus, Andr.
„  Blanckenhorni, v. Reinach.	Thalassochelys libyca, Andr.
„   „  var. ovata, v. Reinach.	Podocnemis antiqua, „
Stereogenys libyca. Andr.	„  Stromeri, v. Reinach.
Tomistoma sp.	„   „  var. major, v. Reinach.
Crocodilus sp.	Stereogenys Cromeri, Andr.
	„  podocnemioides, v. Reinach.
	Tomistoma africanum, Andr.
Fish.
Occasional fragments of siluroids and rays.	Propristis Schweinfurthi, Dames.

H.—The absence of Miocene deposits in the Fayûm.

No traces of deposits of this age having been met so far south as the Fayûm we may presume that in Miocene times the area had become land, the sea margin having receded northwards. The slight depression of Mogara, some 100 kilometres further north-west, is however cut out in Lower Miocene beds, lithologically somewhat similar to the Upper Eocene and Oligocene deposits of the Fayûm. Probably similar conditions obtained throughout, and the existence of vertebrate remains indicates the persistence of river-currents from the south. The fauna of the Mogara beds has only as yet been very incompletely examined, the locality being rather inaccessible.[85]

Section XII.—PLIOCENE.

We have presumed that in Miocene times the Fayûm remained land, no traces of deposits of that age having been recorded; possibly the area underwent considerable denudation during the Miocene and early Pliocene periods, but of this it is difficult to adduce definite evidence. The records of Pliocene times in the Fayûm may be classed as follows:—

(J). Marine deposits of Middle Pliocene age.
(K). Borings on rock surfaces, exact age doubtful.
(L). Gravel Terraces, probably late Pliocene.	⎱ ⎰	(or early Pleistocene).
(M). Gypseous Deposits, probably latest Pliocene.

J.—Marine Deposits: Middle Pliocene.

In Middle Pliocene times the area, which had probably undergone considerable denudation, was again invaded by the sea, and we find at Sidmant el Jebel, on the south-east side, definite evidence of deposits of this age in the shape of sands containing such well known forms as Ostrea cucullata and Pecten benedictus.

The beds in question reach an altitude of from 60 to 70 metres and were first brought to notice by Schweinfurth. Although they are in reality on the Nile Valley side of the separating ridge or saddle, there is little doubt that the same beds will, when looked for, be found within the Fayûm depression in places where they have been preserved. As has already been mentioned this south-eastern side of the Fayûm yet remains to be examined and mapped in detail, and the determination of the relation of these marine sands to the gravel terraces shortly to be described is a matter of primary importance for the proper interpretation of their relative ages.

K.—Borings on Rock surfaces; of doubtful age.

There are within the Fayûm depression numerous rock-surfaces pierced by borings, apparently the work of marine boring mollusca but naturally offering no exact evidence as to their age and origin. These borings are found at two distinct levels, approximately from zero to 20 metres above sea-level, and at 112 metres above sea-level.

(α) Low level borings.

Between Tamia and Dimê, near the eastern end of the Birket el Qurûn, the lowest ground, consisting of poor sandy land with tamarisk scrub, bordering the lake and cultivation, is bounded by a low escarpment of beds of the Birket el Qurûn series. Along certain horizons one or more beds of calcareous sandstone weather into large globular masses, which as already pointed out are in reality huge concretions, but which may have been further rounded by water-action. The chief point is, however, the fact that these blocks are honey-combed in the most remarkable way by beautiful examples of borings; their presence was first noticed by Schweinfurth. The globular masses of sandstone, often several feet in diameter, are worn on the surface into a number of parallel ledges, each of which is perforated with countless numbers of vertical holes, averaging 10 millimetres in diameter (maximum 15 millimetres), placed at right angles to the ledges; these holes are not, as a rule, connected from one ledge to another. They occur in every stage of perfection, from hollows as small as the finger tips and only a few millimetres deep, to long completed chambers which generally show considerable tapering, and are often placed so close together that the dividing wall is pierced.

Fig. 7 and Plate XIII show the appearance of these bored rocks.