=Gebel Zergat Naam=, sometimes called =Hagar el Fil=, is a mountain mass on the main watershed thirty kilometres west of Gebel Um Bisilla. It forms a curved range round the head of the Wadi el Kreim, a tributary of Garara. Its northern part is drained partly by the Wadi Abu Had, a feeder of the Rod el Kharuf, and partly by the heads of the Wadi el Fil, which is itself the head of Wadi Naam. The highest peak of the range is a conical one near its south end, 845 metres above sea-level, but the northern peaks are more conspicuous from some points of view, and it is on the highest of these, 823 metres above sea, in latitude 23° 45′ 28″, longitude 34° 40′ 34″, that the triangulation beacon has been erected. My camp at the base was in one of the heads of Wadi el Fil, 527 metres above the sea, and about 700 metres north-east of the beacon. The ascent from here on foot to the beacon was fairly easy. Zergat Naam is a mass of syenite rising through schists, but the northern summits are formed by east and west bands of a very hard quartz felsite. From the summit, looking northwards one sees long lines of north-and-south felsite dykes forming ridges on either side of the head of Rod el Kharuf, while close south of one is the enclosed sloping plain across which run the feeders of Wadi el Kreim. To the south-south-east, a range of lower hills runs north-westward from the end of the main range, and between the two there appears to be a remarkably sudden drop into the head of Wadi Abu Seyal. The Arabs state that there is a very large galt at this point, reached by ascending the Wadi Abu Seyal; the galt is said to hold water for five months after rain. But during my occupation of the station recent rains had filled other smaller rock basins in the gullies to the north, and it was unnecessary to send far from the camp to get supplies. It is interesting to observe from the summit of Zergat Naam the disposition of the rocks forming the lower hills to the south and west; these are of sandstones with marked dips, the area being one of much disturbance by faulting along the Wadi el Kreim. On the great sandy plain to the north and north-east of Zergat Naam are two extensive groups of low hills, which stand out remarkably owing to their dark colour. One of these groups, twenty kilometres north of Zergat Naam, is called =Gebel Geneina Gharbi=; it is a mass of hills composed chiefly of dioritic and gabbroid rocks (through there are some schists and granites intermingled) and is drained northward by the Rod el Geneina, a feeder of Wadi Kharit. The other group, called =Gebel Geneina Sharqi=, is smaller and situated fifteen kilometres further east; I did not visit it, but from its dark colour it is probable that it consists of similar rocks to those above-mentioned. The hills of both groups rise to about 550 metres above the sea, or about eighty to one hundred metres above the plain.