C.—_Birket el Qurun Series._—Homotaxial with quarried limestones of Cairo. Foraminiferal beds. Extension of series. Section at Ezba Qalamsha. Section north of Lahûn pyramid. East of Sersena and north-east of Rubiyat. Section 17 kilometres 28° N. of E. of Tamia. Series characterized by large globular concretions. Development and fauna in Geziret el Qorn. Zeuglodon remains. Profile at Geziret el Qorn. Rich molluscan fauna. Section on mainland opposite Geziret el Qorn. Section at west end of Birket el Qurûn. Formation of earth-pillars. Extension west of the lake. Development of the series in the Zeuglodon Valley. Abundance of skeletons of whales. Molluscan fauna. Pseudomorphs in celestine. Hill mass south of the Zeuglodon Valley. Junction of Birket el Qurûn series with overlying stage 41 D.—_Qasr el Sagha Series._—Equivalent of the Upper Mokattam of Cairo. Greater development in Fayûm. Vertebrate fauna of series. Schweinfurth’s original discovery of cetacean remains. Recent discovery of land and marine mammals. Extension of series generally. N.N.E. of Tamia. At Garat el Faras. In the cliffs north of the Birket el Qurûn. Detailed section near ruin of Qasr el Sagha. At Gar el Gehannem and westwards. Land animals floated out from land by river currents. The series a littoral deposit. Lignitic beds and thin seams of coal 49 SECTION XI.—UPPER EOCENE — LOWER OLIGOCENE— E.—_Fluvio-marine Series._—Nature of sediments, Interbedded basalts in upper part. Character of its invertebrate fauna. Conditions of deposition of series. Continuance of similar conditions to Miocene and even Pliocene times. Bone-beds at base of series. Association of skeletons of animals and forest trees. Preservation of remains. Analysis of fossil bones. Relation of Fluvio-marine series to underlying stage. Characteristics of the group. Its development in the field. Its slight development at Elwat Hialla. Section near Elwat Hialla. Constant northerly dip. Organic (molluscan) remains 9 and 14 kilometres north of Qasr el Sagha. Detailed section from near Qasr el Sagha to Widan el Faras. Determinations of mollusca from the series. Tripartite character of the series west of Widan el Faras and Qasr el Sagha. Occurrence of calcite, gypsum and chalcedony. Tabular chert and flint. Ancient workings. Extent of basalt. Silicified trees 53