The following is a list of those obtained:—
| Cælosmilia. | Exogyra overwegi. |
| Linthia nov. sp. | Pecten farafrensis. |
| Spirorbis. | Spondylus nov. sp. aff. S. Dutempleanus. |
| Inoceramus. | Nautilus sp. |
| Gryphæa vesicularis | Corax pristodontus. |
As regards the age of this White Chalk the fossil facies has a very young Cretaceous aspect. Zittel[50] has already shown that the White Chalk of the Libyan Desert, studied by him in Farafra, Dakhla and Kharga, is Danian, and the identity of the chalk of Baharia with that of those oases was satisfactorily proved on the traverse from the latter oasis to Farafra.
The White Chalk brings our description of the Cretaceous series of Baharia to a close. As will be shown, it is overlain unconformably by Eocene deposits. Throughout the deposition of the Cretaceous in this area it is clear from the character of the beds that the sea-floor had been continually sinking. After the deposition of the white chalk subsidence probably ceased and the area became one of elevation, the Cretaceous beds rising to form land. During this elevation much folding must have taken place, and subsequently gradual subsidence set in until in Lower Eocene times the area again became marine and the deposition of the rocks now to be described began to take place.
EOCENE.
Upper Libyan—Lower Mokattam.[51]
4. Limestones with Nummulites and Operculina.—In the north part of the oasis, both in the walls and in the isolated hills within the depression, the lower Cenomanian beds, the “Sandstones, clays and marls,” are directly overlain by buff-coloured or yellowish limestone of Eocene age, containing Nummulites, Operculina, Ostrea, etc. The beds of the two series being horizontal, the junction is one of apparent conformability, but in many localities the base of the Eocene is marked by a bed of limestone-grit, indicating the break in continuity of deposition which is known to have occurred from the respective ages of the beds in question and from a study of the same beds further to the south.
In a traverse across the plateau to the west of Bawitti, Operculina-limestones with nummulites were found to form the surface of the desert. Again on the traverse from Maghagha to the oasis, already described, no Cretaceous beds were crossed, so that the plateau N.N.E. and N.W. of the northern end of the oasis is entirely formed of Eocene rocks. On the east side, however, no certain evidence of Eocene age in the beds capping the scarp has been found south of the fault which cuts the scarp as the prolongation of the sharp syncline of Jebel Hefhuf.
Further south, on the west side, a very dissimilar succession was found to that on the north. Here at a distance of 20 kilometres from the oasis wall, at a point 30 kilometres north-west of Ain el Haiss, the uppermost member of the Cretaceous, the White Chalk itself, is overlain by a hard gray crystalline limestone containing an abundance of Nummulites and Operculina, with Lucina, Fusus and Natica. The actual junction of the two series is here difficult to detect, as the White Chalk is itself altered in its upper part into a hard gray crystalline limestone, simulating the Eocene beds themselves, and there is little difference of dip between the two series. The following foraminifera have been determined from this locality by Mr. F. Chapman:—[52]