[Footnote 89: Doubt has recently been thrown by American writers on the possibility of large or thick deposits of gypsum being formed by precipitation. See R. S. SHERWIN. _Notes on the theories of origin of gypsum deposits_, Kansas Acad. Sci. Trans. Vol. 18. 1903, pp. 85-88.] [Footnote 90: Egyptian Irrigation (1899), p. 32.] [Footnote 91: The southern limits of the site (broken line) are taken from the maps of Brown and Willcocks.] [Footnote 92: The mammalian remains collected from these lacustrine clays have not yet been systematically examined. Dr. Andrews has however determined some of the genera present: see, “_Notes on an Expedition to the Fayum, Egypt_”, Geol. Mag. No. 470 Aug. 1903, pp. 337-343.] [Footnote 93: MARTENS _Subfossile Süsswasser-Conchylien aus dem Fajum_, Sitz. Ber. Gesell. naturforsch. Freunde, Berlin July, 1879, S. 100 u. Oct. 1886, S. 126.] [Footnote 94: _Geologie Ægyptens_, pp. 444-446.] [Footnote 95: For figures and details of these flints see a paper by the writer, _Neolithic Flint Implements from the Northern Desert of the Fayûm, Egypt_, Geol. Mag., Dec. IV., Vol. X., pp. 53-59, Febr. 1903.] [Footnote 96: _Mémoires sur les principaux travaux d’utilité publique exécutés en Egypte depuis la plus haute antiquité jusqu’à nos jours_. 1872-1873, Chap. II.] [Footnote 97: Op. cit. pp. 28-40.] [Footnote 98: “_The disposition of the Lake Mœris_,” in the Archæological Report of the Egypt Explor. Fund 1898-1899, Pt. I. D., pp. 13-15.] [Footnote 99: BLANCKENHORN, op. cit. p. 463.] APPENDIX I. =PREVIOUS LITERATURE RELATING TO THE FAYUM.= * * * * * ANDREWS C. W.—_Extinct Vertebrates from Egypt_. Parts I, II, Geol. Mag. N.S. Dec. IV. Vol. VIII, Sept. and Oct, 1901. _Notes on an Expedition to the Fayûm, Egypt, with description of some new Mammals_, Geol. Mag. N.S. Dec. IV. Vol. X. Aug. 1903. _Further Notes on the Mammals of the Eocene of Egypt_, (Pts I, II, III), Geol. Mag. N.S. Dec. V. Vol. I. March, April, May, 1904. _A note on the occurrence of a Ratite Bird in the Upper Eocene beds of the Fayûm, Egypt_. Proc. Zool. Soc. London, 1904, Vol. I. ANDREWS, C. W. AND BEADNELL, H. J. L.—_A preliminary note on Some New Mammals from the Upper Eocene of Egypt_, Survey Dept., P.W.M., Cairo, 1902. _A preliminary Notice of a Land Tortoise from the Upper Eocene of the Fayûm, Egypt_. Survey Dept., P.W.M., Cairo, 1903. BEADNELL, H. J. L.—_Découvertes Géologiques Récentes dans la Vallée du Nil et le Désert Libyen_, VIII. Congr. Géol. Intern. 1900. Paris, 1901. _The Fayûm Depression; a Preliminary Notice of the Geology of a district in Egypt containing a new Palaeogene Vertebrate Fauna_. Geol. Mag. Dec. IV. Vol. VIII No. 450, Dec. 1901. _A preliminary note on Arsinoitherium Zitteli, Beadn._, Survey Dept., P.W.M., Cairo, 1902.