I.—_The Bounding escarpments._—At the most northerly point of the oasis is a narrow extension some 4½ kilometres wide, enclosing a large black hill, Jebel Horabi. The portion of the scarp, or wall, which bounds this extension is lower and less steep than that further south, as the level of the oasis-floor rises considerably towards the hill just mentioned. The roads from Feshn, Maghagha and the Fayum enter at the north-east point of the extension; the descent is easy, the fall from the plateau into the oasis-area being about 70 metres, with a further drop of some 30 metres just after passing Jebel Horabi. At this latitude the depression opens out considerably, the escarpment on the one side trending to the south-west, while that on the other side turns a little east of south; about 8 kilometres further on there is a sudden widening of the excavation, the scarps retreating respectively east and west, so that before the latitude of the villages is reached the oasis has a width of some 28 kilometres. Between the latitude of the villages and Ain el Haiss a marked difference in the two scarps is noticeable; both curve round so as to enclose a wide oval area, but while that on the east side shows a comparatively smooth outline, broken only by a few small projecting headlands and gullies, the western bounding wall displays a highly irregular shape, long irregular tongues of plateau being separated by wide or narrow “bays.” On the east side, the most considerable irregularity is near Ain Gelid; south-east of this spring the road from Minia enters down a gently-falling open sandy gully, with a long square-ended tongue of plateau to the south of it. Further south two other roads, perhaps branches of the one just mentioned, enter by smaller gullies; the scarp here has become much less formidable than further north, and the top of the plateau is covered with countless small conical hills of white chalk. Near the north end of the large hill-mass E.N.E. of Ain el Haiss, the eastern scarp almost disappears, the oasis-floor having risen considerably; it becomes more marked further on, and continues to the south, though of no great height, with limestone ridges at its foot. Just south of the large hill-mass referred to, the lower limestone ridges unite so as to form a regular escarpment, which continues southward as the limiting-wall of the oasis, the upper scarp now forming the edge of a higher plateau about a kilometre away from the oasis-edge. The two escarpments run almost parallel, one forming a step above the other, to the south end of the oasis; the lower one, forming the oasis-wall proper, is much more considerable than the upper, and the edge of the upper one is frequently broken into hills. Small chalk-hills continue to cover the upper plateau.