Probably the whole of these fossiliferous beds belong to the Middle Eocene Mokattam Series; the lower beds with _N. gizehensis_, are certainly Lower Mokattam, and probably the upper, although the latter may represent the base of the Upper Mokattam. Whether the upper bed of sandstone capping the eastern scarp belongs to the same series or is equivalent of the silicified grits with silicified wood passed further back is open to some doubt. Beyond the Bahr the desert is formed of a hard limestone much cut up by the action of wind-borne sand as already mentioned. This limestone is very unfossiliferous, occasional obscure nummulites seen on fractured or smooth surfaces being the only indications of its Eocene age. The conical-peaked hills of Gar el Hamra on the left of the road at 151 kilometres were so striking that a detour was made specially to examine them. They were found to be composed of black ferruginous silicified sandstone or quartzite at top, with false-bedded sandstones below. They overlie nummulitic limestones forming the surrounding plain, and are not improbable Post Eocene lacustrine deposits, similar to those within Baharia Oasis (see pp. 60-62). From here onwards up to the oasis-depression the plateau consists of hard brown limestone, more or less silicified, and contains nummulites and oysters. The Eocene strata, thus extend right up to the escarpment of the depression on the north side of the oasis. The geological structure within the depression will be found discussed in Chapter V. [Sidenote: Road from Minia to Baharia.] _Road from Minia to Baharia._—The cultivated land extends for some 9 or 10 kilometres west of Minia town, and at the time of the Survey expedition (early in October, 1897) this area was mostly covered by flood-water. Boats were therefore taken to the edge of the desert, and the march west was commenced from Nasl Nadiub Lengat, a small village on the cultivation-limit in lat. 28° 6′ 24″, long. 30° 39′ 45″ E., bearing from Minia railway station 9° north of west, distance very nearly 10 kilometres. The road westward being ill-defined, and the party knowing that any course followed a little north of west would surely lead to the oasis, no attempt was made to follow the track precisely, the course being rather chosen to take advantage of commanding points so as to map as much topography as possible _en route_. As will be seen further on, however, the road was struck some distance before reaching the oasis, and was thence followed to Zubbo.