Clays with sandy and ferruginous layers, extending to oasis floor. approximately 22·0 ---- 32·6 The beds are horizontal, and the neighbouring smaller hills which possess a similar limestone covering are precisely of the same height. It would seem impossible to account for these limestone caps in the midst of higher sandstone hills except by assuming that they mark the positions of islands, subsequently denuded, in the post-Eocene lake which deposited the limonite caps on the other hills; at the same time they evidently represent part of a synclinal fold, though the horizontal position and non-crystalline character of the beds show that this syncline must have been wide and shallow. It is scarcely possible to think there can have been a locally calcareous deposit from the lake which generally deposited the sandstone and limonite; the sudden transition from the black sandstone and limonite of the surrounding hills to the snow-white limestones of those under consideration is so strongly marked in the field as to forbid such a supposition. At the same time, no fossils were found in the beds, so they cannot be satisfactorily correlated with the limestones of the oasis-scarps, and they are of somewhat variable character at different points of the hill. It is evident then that in the south part of the depression the Cretaceous beds as a whole form a large flat anticline, which is continuous with that of Farafra to the south.[58] This bears out the statement of Capt. H. G. Lyons,[59] some years ago, that he believed Baharia and Farafra Oases to lie on an anticlinal at right angles to that of Dakhla and Kharga. The anticlinal and synclinal folds of Baharia are parallel and were evidently produced by the same earth-movements. [Sidenote: Age of the folding.] Within the oasis-area too, some other traces of folding are visible; in lat. 28° 11′ N., long. 29° 1′ E. are two small hills of clays and sandstones (the latter locally green in colour), the beds of which dip about 30° E. and W. respectively, showing a local anticline whose axis runs nearly north-and-south. In this neighbourhood, as in the oasis generally, it is not possible to trace the folding in the beds of the low ground, owing to its thick sandy covering.