Fairly hard yellow-white glauconitic marl } 10 Marly limestone with _Nummulites gizehensis_ forming top of Rayan beds. [Illustration: FIG. 2.—Section at Gar el Gehannem, showing the relation of the Wadi Rayan Series to the Ravine Beds.] The clays, marls, and limestones of the Ravine beds are generally found to contain fairly numerous shell-impressions, including _Nucularia_ sp., _Leda_ sp., _Cardita_ sp., _Corbula_ aff. _pixidicula_, _Lucina_ sp., _Oudardia ovalis_, Desh., _Tellina tenuistriata_,[42] numerous small fish-scales, and occasional large teeth of sharks; while the skeletons of the toothed-whale _Zeuglodon Isis_ are fairly common, although usually in poor preservation. In the ravine of El Bats, about one kilometre west of Sêla, these beds (5-6 metres thick) are seen unconformably overlaid by 12 metres of false-bedded gypseous sands and clays passing up into the superficial cultivated loam. The junction of these alluvial deposits and the underlying Eocene is distinctly unconformable and an intervening pebble-bed is occasionally present (Fig 3). In the large ravine known as El Wadi, which traverses the west side of the cultivation of the Fayûm, these beds are frequently well exposed; their lithological characters remain very constant. Here, as in El Bats, they are unconformably overlain by a varying thickness of Pleistocene and Recent clays. Their surface, a plain of subaerial denudation, represents the original floor of the depression before the entry of the sediment-carrying water from the Nile Valley through the Lahûn gap; its irregularity is seen in Plate V. The plain bordering the cultivation to the east of Sêla and Rubiat likewise consists of these same white marls with fish-scales, etc.; they pass regularly under the cultivated land. Shaly marls, gypseous clays, and chalky limestones of the same age are seen in, and to the south of, the railway crossing the desert between Sêla and Medum. Eastwards they stretch into the Nile Valley, being found exposed along the desert-edge bordering the cultivation at Medum, Nawamis and Masaret-Abusia. { 1. Marsh and poorly cultivated land. { RECENT { 1a Cultivated loam. AND { PLEISTOCENE { 2. Sands and clays, with gravelly bands; { often concretionary and gypseous beds. { { 3. Pebble-bed marking unconformable junction. MIDDLE } RAVINE { 4. Gypseous saliferous marly clays, white EOCENE } BEDS { marls and limestone with fishscales and } { _Tellina Corbula_, etc. FIG. 3.—Sketch-Section across _El Bats_, 1 kilometre West of Sêla.]