422 Messrs. Sclater and Mackworth-Praed on [Ibis, 



Geographical. 



(See PI. IX.) 



The Angio-Egyptian Sudan extends from Wadi Haifa, 

 22° N. lat., to Nimule, 3^° N. lat,, a distance of about 

 1200 miles; while its greatest breadtb, from the Darfur- 

 Wadai frontier to the Abyssinian border, is about 950. 

 The whole of it except the coast-belt of the Red Sea 

 Province is in the basin of the Nile and its tributaries, 

 and is remarkable for its low elevation throughout. 

 Between Khartoum (1260 ft.) and Lado (1525 ft.) the 

 level of the Nile only rises 265 ft., and while there are 

 isolated groups of hills here and there, there is nothing 

 which can be called a mountain anywhere in the country, 

 except the range parallel to the coast of the Red Sea behind 

 Port Sudan. Here some of the peaks rise to over 7000 ft. 

 elevation. Elsewhere there appears to be no hills reaching 

 the 5000 foot contoui-. 



The northern part of the Sudan from Wadi Haifa to 

 Shendi is practically rainless, and the country away from 

 the Nile is a desert in the stiictest sense of the word. 



From Khartoum southwards to Lake No the rainfall is 

 progressively greater, and the country gradually becomes 

 less arid. At Khartoum the rains fall almost entirely in 

 August and do not amount to more than a few inches, 

 while at Taufikia they are a little earlier, in June and July, 

 and perhaps amount to 10 inches. In the Bahr el Ghazai 

 there is a good deal more rainfall, mostly between June and 

 October, perhaps amounting to 20-25 inches. Kordofan is 

 very dry and is without perennial streams. P'inally, in 

 Mongalla Province the rains are more evenly distributed 

 over the year and there is a tendency for two lainy seasons, 

 one in June-July, the other in September-October. 



It is important to bear in mind the occurrence of tiie 

 rainy season in ti'opical and sul)tropical countries ; for 

 the breeding-time of birds depends much more on the 

 rainy season than it does on the seasonal changes of 



