The actual position of Lake Moeris has been the subject of much discussion, the late Linant de Bellefonds[96] having asserted that it was a high-level lake, quite distinct from the Birket el Qurûn, occupying the gap in the hills by which the Bahr Yusef enters the Fayûm, its encircling bank commencing at Edwa and passing through Biahmu, Medinet, etc. Sir Hanbury Brown has,[97] however, completely demolished Linant’s theory, which is shown to be absolutely untenable; and has proved conclusively that the ancient Mœris occupied the greater part of what is now the cultivated land, as well as the area covered by the present lake and a considerable part of the surrounding desert, the reclaimed land being in fact part of the very district Linant supposed the lake to have occupied. Since the publication of Brown’s work complete corroborative evidence has been forthcoming from two distinct sources, one archæological, the other geological. The latter has already been mentioned. [Illustration: FIG. 10.—Sketch Map showing approximately the site of Lake Moeris.] It was clear from the map of Claudius Ptolemy that the route through the Fayûm to the Oasis Parva left Bacchias near the north end of the lake, and passing between Arsinœ and Lake Mœris, reached Dionysias near the other end. The archæological researches of Messrs. Grenfell and Hunt[98] have shown that Bacchias occupied the site of the modern Um el Atl close to one end of the Birket el Qurûn, while Dionysias was probably in the neighbourhood of Qasr el Banat or Qasr el Qurûn. Thus the Ptolemaic Lake Mœris was almost identical with the modern Birket el Qurûn. Neither did the sites excavated yield a trace of anything older than the third century B.C. Theadelphia and Philoteris were founded in the reign of the second Ptolemy, when a great reclamation of the land from the lake took place, and probably Euhemeria, Dionysias, Karanis and Bacchias date from the same reign. The archæological evidence is thus briefly summed up by Grenfell and Hunt: “Originally the lake filled the whole basin of the Fayûm, the first reclamation being carried out by Amenemhat I, who built the great dam at El Lahûn, where the Bahr Yusef enters the province, and recovered the high ground near the entrance as far as Biahmu, and a point between Abshawai and Agamiin. This remained the Pharaonic province until the time of Herodotus, when the water still came up to the colossi at Biahmu. Subsequently all the land now cultivated below the level of the Pharaonic province was reclaimed, chiefly in the reign of Ptolemy Philadelphus, when Lake Mœris was reduced nearly to the size of its modern representative, the Birket el Qurûn”. [Sidenote: Present day Fauna of the Birket el Qurûn.] As mentioned above, the Pleistocene fauna of the Fayûm differs in one or two particulars from the fauna of the present day. The commonest living molluscan forms include the following:— _Corbicula fluminalis_. _Neritina nilotica_.