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 }