14. Grey and brown clays 18 -- _Ravine Beds._ Total 50 -- In the cliffs west of the end of the lake the upper bed No. 9 continues highly fossiliferous and yields the most perfectly preserved molluscan remains to be found in the Fayûm and probably in Egypt. A few kilometres east of the end of the lake a band of large globular concretions occurs in the thick brown sandstone forming the vertical face of the cliff. In many places the effect of weathering of these rocks is of some interest, numerous “earth-pillars” having been formed; these are largely the result of the action of blown sand, assisted by rain, the concretions being left capping pillars of brown sandstone, the sides of which are sculptured by the wearing action of sand. The curious perforate or cellular appearance which the weathered surfaces of this sandstone assume after long exposure are particularly noticeable in this neighbourhood and in the Zeuglodon Valley further west. In the well-marked hill distant 17 kilometres to the north-east of Gar el Gehannem, the soft fossiliferous sandstones of this series are crowded with _Operculina_, _Nummulites_, and many species of mollusca beautifully preserved. At Gar el Gehannem the series is seen (Fig. 2 and detailed section page 36) forming part of the slope of the hill, underlain by the Ravine beds, and capped by part of the Qasr el Sagha series. It here consists of yellow sandstones divided by a bed of clay; the sandstones are often crowded with nummulites (of two species); also _Operculina_ (_discoidea?_), echinids, _Balanus_ sp., _Ostrea Reili_, _O. Fraasi_, _Carolia placunoides_, and species of _Pecten_, _Pinna_, _Cardita_, _Teredo_, _Turritella_, and _Cerithium_. [Illustration: FIG. 5.—Section of cliffs, western end of the Birket el Qurun. Pleistocene.—(_a_) Lacustrine clays and sands with freshwater shells and fish-remains; _Middle Eocene_, 1. 14 Clays, sandstones and impure limestones; 15 White shaly clays and marly limestones.]