A small tributary which joins Wadi Abu Hamamid from the north-east, in longitude 34° 41′, called =Wadi Marasani=, is important as leading to a pass over the main watershed into Wadi Marasan, a tributary of Wadi Huluz. The altitude of the pass is 685 metres above sea; it is quite practicable for baggage camels. =Wadi el Sheikh=, the only great tributary of Wadi Abu Hamamid, originates in longitude 34° 40′, in the hilly tract west of Gebel Abu Hamamid. In the upper part of its course, it is a narrow winding wadi, mostly shut in by high hills, pursuing mainly a direction a little west of south, fed by numerous lateral wadis entering from among the hills to the east, of which the principal are the =Wadis Um Somra=, =Krioni=, =Um Nasir=, =Um Hereini=, =Um Sereiha=, =Um Deheisi=, =Um Retba=, and =Um Hargal=. Near the point where Wadi Um Deheisi joins it, the Wadi el Sheikh emerges from the hill country and meanders over a plain. At its entry on to the plain is the tomb and well of =Sheikh Shadli=, views of which are given on Plate V. The tomb, from which the wadi derives its name, is a white domed structure, tended by a Moorish guardian. The Ababda Arabs hold the memory of Sheikh Shadli in high veneration, and make yearly pilgrimages to his tomb. The well, =Bir Shadli=, close to the tomb, is a shallow excavation in the stony alluvium of the wadi floor. Here there is a perennial supply of water, which, however, varies much in quality and quantity; after rain, there forms a large pool of good water, the surface being maintained almost level with the ground by underground influx; while when there has been no rain for a year or more the water is only found by digging to several metres depth, and then only infiltrates slowly at the bottom of the hole, the quality simultaneously falls off and the water acquires a saline and purgative character. After passing Bir Shadli and entering on the plain, Wadi el Sheikh splits up into numerous channels, one of which joins the Wadi Abu Hamamid, while the others continue in a south-westerly direction, fed by the Wadis Um Retba and Um Hargal, draining from the north flanks of Gebel Kahfa. Uniting together as they leave the plain to re-form a single Wadi el Sheikh, these drainages turn westward among the hills to join the Wadi Abu Hamamid.