=Wadi Defeit=, which is probably the most important Egyptian tributary of Wadi Alaqi, has its heads in Gebels Heleikontî and Heianai, about the meridian of 35°. Its general course is that of a flat circular arc convex to the north and having its chord east and west; the total length of its main channel, from its head in Gebel Heleikontî to its junction with Wadi Alaqi in longitude 34° 10′, is over one hundred kilometres, while its numerous tributaries probably reach a total length three times as great. The principal head of Wadi Defeit is called =Wadi Sarid=; its branches extend among the hills close to the heads of Wadi Egat and Wadi Miaus. The name Defeit is applied to the wadi where Wadi Sarid is joined by the feeders from Gebel Heleikontî. Passing between the high ranges of Heianai on the north, and Heleikontî and Shanaiyet on the south, Wadi Defeit receives numerous feeders, of which the principal are the =Wadis Dauriai= and =Hamidâ=, both entering it from the mountain to the south; continuing westwards, it cuts through the north end of the mass of Gebel Um el Tiur el Foqani, and on emergence is joined by the =Wadi Bint el Feqoh=, a great westward-coursing tributary draining the north flanks of the Heianai range and the more northerly mountain of Anweyib. Continuing its westward course, Wadi Defeit passes between Gebels Um el Tiur el Tahtani and Adraq; then it enters on an extensive tract of more open country, receiving three main feeders, =Wadi Meladoyeb=, =Rod Hauanin=, and =Wadi Bagharid=, from the hills to the north, before joining Wadi Alaqi. =Wadi Seiga=, the next great northern tributary of Wadi Alaqi, has only been partially explored. Its head is in the watershed range near the conspicuous twin peaks of Gebel Sheyenit. Pursuing at first a southerly course, it cuts through the east side of the mass of Gebel Seiga; and about thirty kilometres lower down passes through hills with old gold mines on either hand. Below the mines, Wadi Seiga takes a south-westerly course, and receives a large tributary from either side. That from the west, called =Wadi Deheis=, heads in Gebel Deheis and curves round east of Gebel Abu Brush, receiving in its course two great feeders, the =Wadis Um Gholqa= and =Abu Had=, both of which head far to the north in the main watershed. The eastern tributary, called =Wadi Um Derera=, drains the south part of the hill-mass in which the Seiga mines are situated. Wadi Seiga joins Wadi Alaqi in longitude 33° 53′, some forty-five kilometres below the mines; the junction is outside the limits of the maps in this volume. * * * * * [Footnote 84: Dry in 1906.] [Footnote 85: To be distinguished from another mountain of the same name further south, near the Wadi Hodein.] [Footnote 86: To be distinguished from the better known Wadi Egat much further south, a feeder of Wadi Alaqi.] [Footnote 87: “L’Etbaye.” p. 1.]