_Tomistoma africanum_—35, 51, 59, 70. Tongrian beds—13, 64, 88. Toothed whales—39. Topography and structural geology—11-28. Tortoises, Large—10, 53-54, 59, 66, 87. _Trachelochetus bituberculatus_—51. Tropical shells in Fayûm—60. Tuba, El—40. _Tudicla_ aff. _umbilicaris_—51. Tufaceous gypsum—77. _Turbo Parkinsoni_—43. _Turritella_—38-39, 44-53. _Turritella angulata_—43, 45, 60, 64. _Turritella carinifera_—35, 38, 43, 51-52. _Turritella imbricataria_—51-52. _Turritella Lessepsi_—51. _Turritella parisiana_—51. _Turritella pharaonica_—34-35, 45, 51-52, 58. _Turritella transitoria_—43. _Turritella turris_—43. Turtles—53-55, 59, 60. Twelfth Dynasty—26, 82. Twigs preserved in clays—53. U Um el Atl—84. Unconformable junctions—39-40, 73, 76. Underground outlets of Birket el Qurûn—14. Ungulate, Horned—10. _Unio_—34, 53, 58-60. _Unio abyssinicus_—81. _Unio Bonneaudi_—60. _Unio Caillaudi_—60. _Unio Homsensis_—60. _Unio lithophagus_—60. _Unio Nyassænsis_—60. _Unio Schweinfurthi_—81. _Unio teretiusculus_—60. Upper Eocene—10, 32-34, 53-70, 76. Upper Mokattam beds—33. Upper Nile basin—87. Ur-Nil—66. V _Valvata nilotica_—80, 84. Vegetation in water-courses—25. _Velates Schmiedeli_—37. _Venus_—46. _Venus plicatella_—35. _Vermetus_—46. Vertebrae of _Mœritherium_—52. Vertebrae of _Zeuglodon_—45, 47, 50. Vertebrate fauna, Discovery of—9. Vertebrates, Extinct—10, 34-35, 43, 49, 51-52, 55, 61, 63, 65, 67, 70, 87. _Voluta_—46. _Voluta arabica_—35. _Vulsella chamiformis_—37, 89. _Vulsella crispata_—89. _Vulsella lignaria_—89. _Vulsella moëlehensis_—89. W Wadi, Ravine of El—29-30, 37, 39. Wadi Rayan, Muêla, etc. (see under Rayan, Muêla). Wadi Rayan series—35-37. Warshat el Melh—20. Water analyses—22. Water-courses—25. Water-rounded pebbles—56, 72. Water-supply of Fayûm—11, 88. Weathering—57. Wells—21. Western, Colonel—16-18, 22, 87. Whales, Frequency of river and shore-frequenting—53. Whales, Toothed—39. Whitehouse, Cope—88. White Nile fauna, Absence of—81. Widan el Faras—28, 55, 58, 60, 62, 75-76. Willcocks, Sir William—13-14, 17-19, 80-88. Wind-shadow—84. X Xiphodonts—29. Z _Zeuglodon_—9, 39, 44, 49, 52, 87-88. _Zeuglodon brachyspondylus_—44. _Zeuglodon Isis_—35, 44-45, 47, 70. _Zeuglodon macrospondylus_—44. _Zeuglodon Osiris_—35, 44, 47, 49-51, 70. _Zeuglodon Zitteli_—44, 70. Zeuglodon Valley—41, 46-49, 61, 63, 85. Zittel, Prof. K.—43, 49, 62, 89. * * * * * [Illustration: PL. XVII. GEOLOGICAL MAP OF THE FAYUM DEPRESSION _Survey Dept. Cairo._] [Illustration: PL. XVIII.