=Gebel Is=, the next great mountain to the south, forms the main watershed just north of the Sudan frontier, the triangulation cairn on its summit having the position latitude 22° 2′ 36″, longitude 35° 28′ 4″, altitude 1,736 metres above sea. As seen from the north, Gebel Is is a somewhat flat-topped mountain of dark aspect; but judging by analogy the apparent flat top is probably only a narrow ridge seen broadside on. From the main mass a long spur of flanking mountains runs westward, and a high ridge, more or less detached, rises to 1,474 metres six kilometres south-east of the main summit. The northern and western faces of Gebel Is are drained by feeders of Wadi Alaqi, while its eastern and southern parts are drained by various heads of Wadi Is. Between Hadal Aweib Meisah and Gebel Is there stretches a mass of mountains with many peaks over 1,200 metres high; these appear to bear no special names. My guides stated that there are two passes over the main watershed in this region. The first, called =Adar Ameit=, is a high pass practicable for camels; it lies about four kilometres to the north of the beacon on Gebel Is, and connects the two Wadis Adar Ameit el Sharqi and Adar Ameit el Gharbi which lie on opposite sides of the watershed. The second pass, said to be a difficult one, crosses the watershed some five kilometres further north, forming a connexion between the heads of Miti Kwan and Wadi Soaorib. =Gebel Miatit= (1,257 metres) and =Gebel Suruk= (1,377 metres), are mountain masses a little east of, and semi-detached from, the main Is group. Gebel Miatit sends out a long spur north-eastward, ending in a rather conspicuous hill at the foot of which there is said to be a water source called Megwel Aqwem. =Gebel Shiab= is a collection of peaks rising from a rugged country of lower hills about twenty-eight kilometres east of Gebel Is. Its highest point is 987 metres above sea-level. Gebel Shiab appears to form the main head of Wadi el Qurat, an important feeder of Wadi Di-ib. =Eqrun= (the horns) is a conspicuous group of schist hills lying between the Wadis Meisah and Ibib. It has two principal peaks; the higher one, surmounted by a triangulation beacon, has the position latitude 22° 30′ 10″, longitude 35° 37′ 9″, and is 473 metres above sea-level; the other is about 400 metres south-east of the beacon, and is only five metres lower. Eqrun itself is an isolated hill group, but close to the north-east of it there is another hill-mass of greater extent and of but little inferior height. The country south of Eqrun forms an extensive tract of low hills with much blown sand. Two conspicuous hills in this tract rise above the rest and bear special names; these are =Tahaqayet= (432 metres) and =Titailibab= (593 metres).