=Adar Aqdeib=, a granite hill 736 metres high on the north side of the Wadi Didaut, about half-way between Qara Saba and O Shakafa, is a landmark for two small water sources and a pass. The first of these water sources, Megwel Adar Aqdeib, is on the east side of the hill, in a little tributary of Wadi Didaut. The second, Megwel Didaut, is at the head of Wadi Didaut itself, in a separate rugged hill tract south of Adar Aqdeib. The west faces of Adar Aqdeib are drained by the Sarob Kwan, half of which courses south-east to Wadi Didaut, and half north-west to Wadi Meisah, and the divide forms a well known easy pass. =Gebel Um Ein= is a huge hill-mass of dark rocks, rising to 901 metres above sea-level, nine kilometres south-south-west of Qara Saba. The beacon which marks the summit is in latitude 22° 11′ 52″, longitude 35° 39′ 4″. Gebel Um Ein is mainly drained by the Wadi Baueiwai, which curves round the south half of its circumference. A small water source, Megwel Um Ein, is said to exist on the north-east side of the hill, in a small wadi which forms a tributary of Wadi Baueiwai. A great tract of high hills lies between the Wadis Baueiwai and Di-ib. The northern part of the tract, which is cut off from the rest by the Wadi Warabeit, and is called =Gebel Geror=, has several peaks rising to over 500 metres; on the north it is flanked by huge accumulations of blown sand, while its southern faces are drained by fairly well-wooded wadis, tributaries of Wadi Warabeit. The part of the hill tract south of the Wadi Baueiwai is much cut up by wadis into masses which bear separate names. =Gebel Hamida=, which with =Gebel Nubitra= forms the westernmost hill-mass of the group, is a series of high steep schist ridges rising in places over 700 metres above sea-level. The highest point, 754 metres above sea, is best reached by following up the Wadi Hamida till one comes due west of the hill, and then striking up eastwards on foot; it can also be reached from the east side _via_ the tiny trickling salt spring of Megwel Hamida, but I found this a long and wearisome climb. To the north-east of Gebel Hamida is the pass called Bani Sana, which is important both as a pass and as being the boundary between the territories of the Kurbeilab and Hamedorab Arabs. =Gebel Warabeit=, the part of the tract which forms the head of the Wadi Warabeit, lies south-east of Gebel Hamida, being connected with Gebel Hamida on the one side and Gebel Mashushenai on the other; its highest point is 794 metres above sea-level. =Gebel Mashushenai= (634 metres) lies a little to the east of Gebel Warabeit; its north parts are drained by the Wadi Hashimaiyib, while the south portions are drained by Wadi Mashushenai, in the head of which is a well, Bir Mashushenai. All the drainage from hereabouts ultimately reaches Wadi Di-ib by way of Wadi el Qurat. =Adar Aweib=, a conspicuous and extensive granite hill-mass lying east of the foregoing, from which