=Gebel Um Khariga= is the name given to several high hill ranges on either side of the Wadi Um Khariga. Two of these ranges, one on either side of the upper part of the wadi, form like Gebel Ghuel north extensions of the high ridge of Hangalia; the western range can be crossed at a gap by an easy pass, 773 metres above sea-level, which separates the heads of Wadi Gerf from those of Wadi Um Khariga. These two ranges shut in the wadi on either side for some ten kilometres of its northward course, beyond which the country becomes more open and the wadi curves round to the north-east, passing the north end of a third range of high hills which is likewise called Gebel Um Khariga. This third range extends northward for about ten kilometres from Gebel Ghuel, from which it is separated by a pass forming a good road over the head of Wadi Ghadir. Its most conspicuous feature is a twin peak at its north end, 674 metres above sea-level. The main ridge is flanked by high hills, especially on the east side. Only the north and west flanks of this range are drained by Wadi Um Khariga, the eastern side being cut up by feeders of Wadi Sukari. Besides the pass separating it from Gebel Ghuel, there are two other passes, one round its north end into Wadi Sukari, and another at its south end between Wadi Ghadir and Wadi Sukari, so that a complete circuit of this range can be made by camels. Some of the hills composing the mass consist of highly magnetic schists, and compass readings in the region may be disturbed by many degrees. PLATE IX. [Illustration: Descending Gebel Zabara. (Schists).] =Gebel Igli el Iswid= is a rather rugged mountain mass rising among a sea of lower hills, thirty kilometres north of Gebel Nugrus. Its highest point, marked by a triangulation beacon, in latitude 25° 4′ 6″, longitude 34° 36′ 16″, is 975 metres above sea-level. The mountain forms a tripartite watershed between the basins of Wadi Um Khariga (draining the south slopes), Wadi Dabur (draining the north and west slopes), and Wadi Igli (draining the eastern face), each of which three wadis courses separately to the sea. In occupying the triangulation station on the summit, I placed my camp in a gully draining to Wadi Um Khariga, about two kilometres south-south-west of the summit at an altitude of 605 metres above sea. The climb of 370 metres to the top from this camp was not difficult, and occupied only a little over an hour and a half. The mountain consists of very hard grey siliceous rocks, which ring under the hammer, and are probably crushed and devitrified felsites (_see_ p. 281). There are galts in some of the gullies draining from this mountain, hence it is sometimes called _Igli el Rayani_. At the time of my visit (December 1905) there was said to be a little water in a galt on the west side of the mass; but the rock basins in the gully which I ascended were empty.