THE MINOR ANTELOPES AND GAZELLES 343 



Two of the desert-forms the ariel and addra are 

 comparatively large animals, corresponding in size with 

 Grant's gazelle in East Africa ; the rest are smaller, 

 comparable with Thomson's gazelle. 



The following table roughly summarises their respective 

 sizes, distinctive marks, and distribution 1 : 



Desert- Gazelles. 



The ariel, a big upstanding animal, and the little 

 Isabelline gazelle characterise the Eastern Sudan 

 that is, the area between the Nile and Red Sea littoral ; 

 but since our experiences with both these are narrated 

 later, no more need here be said. The range of 

 Heuglin's gazelle lies along the extreme east of Sudan, 

 bordering on Eritrea, hardly extending beyond the 

 Atbara on the west. 2 On the north Heuglin's gazelle 



1 While following the accepted classification, I am yet doubtful whether 

 the two gazelles, Dorcas and Isabelline, should rank as separate species, 

 the differences between them being confined solely to the "set" of their 

 horns. I notice that a distinguished zoologist, Mr R. I. Pocock, holds 

 that " Far too many species have been admitted to the genus Gazella? 

 2 General C. T. Blane informs me that in 1920 he met with black-banded 

 gazelles, which were presumably Heuglin's (also koodoo), on the Dinder 

 river, a little above Abu-Hashim. 



