1. Previous literature relating to the Fayûm 87 2. Fayûm lamellibranchs mentioned in Oppenheim’s “Zur Kenntnis alttertiärer Faunen in Ægypten.” 89 INDEX 91 LIST OF ILLUSTRATIONS. * * * * * PHOTOGRAPHS. PLATES. PAGE. I. — North side of the Birket el Qurûn, looking west _Frontispiece._ II. — Bahr Yusef at Lahûn before entering the Fayûm _to face_ 11 III. — El Wadi, Ravine near Qasr Gebali „ 19 IV. — Western extremity of the Birket el Qurûn „ 29 V. — Alluvial deposits overlying marly limestones (Ravine Beds) in El Wadi, Ravine near Qasr Gebali „ 37 VI. — Escarpment of the Birket el Qurûn series near the western end of the lake „ 41 VII. — Weathered concretionary sandstone (Birket el Qurûn series) on north shore, near Geziret el Qorn „ 45 VIII. — Middle Eocene escarpment (Qasr el Sagha series) 12 kilometres west of Qasr el Sagha „ 49 IX. — Upper beds of Fluvio-marine series with basalt cap, looking west from the eastern extremity of Jebel el Qatrani „ 53 X. — El Qatrani range from the south-east „ 57 XI. — Silicified trees of Fluvio-marine series, 4½ kilometres north of Qasr el Sagha „ 63 XII. — Raised Beach unconformably overlying Middle Eocene limestones (Birket el Qurûn series) in the desert east of Sersena „ 69 XIII. — Borings in false-bedded sandstone, 2 kilometres south of Dimê „ 73 XIV. — Pleistocene lacustrine clays with tamarisk stumps _in situ_ at 50 metres above the present surface of the Birket el Qurûn „ 77 XV. — Isolated sand-dune near Gar el Gehannem „ 81 XVI. — The Birket el Qurûn near the western end „ 85 PLANS. XVII. — General Map of the Fayûm depression, with Wadi Rayan and Wadi Muêla, 1/250000 end XVIII. — Map of the area north-west of Qasr el Sagha, showing principal bone-bearing localities, 1/50000 „