PHYSICAL FEATURES. xv 
traversed, from Khartum to Ambukol, by a depression known as the Wadi Mokattam, 
along which probably once flowed an arm of the Nile, and to the west of it is a short 
ridge of hills consisting of pink sandstone, from which numerous lines of drainage run 
into the Wadi Mokattam, each generally with a certain amount of vegetation of the 
usual desert character. On the other side of this ridge, which is known as Jebel 
Simrieh, there is another long and important valley, the Wadi Malik, along which part 
of the drainage of northern Dar-Fur percolates to the Nile. This wadi, which is of 
considerable breadth in some parts of its course, and narrow at others, is dominated 
in places by castellated rocks, and along its course it is marked by a variety of thorny 
shrubs and by a fair amount of grass. Between Abu Gus, where the wadi debouches 
into the Nile, and Sotahl some distance up the valley, the Wells of Mahtul are 
situated in a miniature plain surrounded on all sides by sand-hills. Similar wells are 
found to the east of the Nile on the route to Suakin. At some distance beyond the 
Wells of Mahtul the valley narrows and becomes choked with sand, but afterwards it 
widens and shows signs of the presence of water in quantities, and is thickly wooded 
with acacias. The route to Khartum traverses the Wadi Sotahl, which has even 
a more dense vegetation than the Wadi Malik. Leaving this wadi, the route lies 
through ravines and over rocky plateaus, past other wells, and crosses over a tract 
having coarse grass but no trees, to enter the Wadi Mdesis, in which are many 
varieties of acacia. A considerable quantity of water passes down this valley in the rainy 
season. The route then passes into the Wadi Mokattam, and in the neighbourhood 
of the Wells of Gabra there is an area thickly wooded with acacias and euphorbias. 
It is evident from the foregoing slight sketch of the general features of the Bayuda 
Peninsula that it does not altogether merit the term desert generally applied to it, 
seeing that it gives support in places to extensive herds of goats, sheep, and camels. 
From the presence of so much vegetation it is doubtless tenanted by many species of 
lizards and snakes, and from its physical configuration it may possibly be the meeting- 
ground of species from Central, Western, North-western, and South-eastern Africa. 
Von Barnim and Dr. R. Hartmann 1 , on their journey from Debba to Khartum, met 
with the following reptiles, viz. : — Stenoclactylus elegans, Tarentola annularis, Varanus 
griseus, V. ocellatus, Cerastes cornutus, Echis carinatus, and Bitis arietans, and two 
species of the genus Agama. All of the foregoing identified reptiles, with the exception 
of Varanus ocellatus and Bitis arietans, are present in Egypt proper to the south of 
the Delta. The peninsula is absolutely devoid of permanently-running streams, is 
only very slightly affected by the sometimes long intermittent periodical rains, is 
intensely hot, the heat attaining at times to 41° Cent, in the shade, with a diurnal 
range occasionally of as much as 35° Cent., and has an extremely dry atmosphere. 
On the other side of the Nile Valley from the Bayuda Peninsula lies the tract of 
country intervening between the river and Suakin. This region is traversed by 
1 Eeise Xord-Ost-Afr. 1859-60. 
