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a short distance on to the hind-quarters; otherwise the hind-quarters, tail, 
and hind legs are white, the rump and thighs being a dirtier white than the 
legs. As in the case of the front legs, however, there is a rim of brown 
hairs round the false hoofs, and the tail-tuft, when present, is brownish. 
Belly white. Hairs along middle of neck sometimes reversed. 
The horns attain a length of about 28 inches in a straight line and about 
36 following the spiral. 
Skull and horns as described above. The measurements of a skull are :— 
Basal length 12 inches, greatest breadth 5°30, muzzle to orbit 8:20. 
Female. Like the male, but horns thinner. 
Hab. Desert-regions of North Africa from Dongola to Senegal. 
The Addax belongs to the same group of desert-haunting Antelopes 
as the species of Oryx of which we have just treated, and is essentially 
of the same structure. But it is at once distinguishable by its spiral horns 
and expanded hoofs, and may properly be referred to another genus, which 
Rafinesque in 1815 seems to have been the first to call ‘“ Addaxr,” adopting 
the name from Pliny and other early writers. In 1816 De Blainville gave 
the first scientific description of this Antelope, calling it Antilope naso- 
maculatus, from the conspicuous white blaze across the nose. Combining 
this with the generic term above mentioned, we obtain ‘ Addazx naso- 
maculatus” as the correct scientific name of this Antelope. 
It should be stated that the description given by Pliny of his “ Strepsiceros, 
quem Addacem Africa appellat” is very short and incomplete, and has been 
variously interpreted by subsequent writers. But as it was an African 
animal with twisted horns, and the native Arab name of the present species, 
according to Hemprich and Ehrenberg, is “‘ Adu Akass” (the father of the 
twist), it seems highly probable that we have in it the veritable “ dddax” of 
the ancients. 
The first naturalist of modern days to obtain specimens of the Addax in 
its native wilds was Riippell, who met with it in the deserts of Dongola 
south of Ambukol, where, he tells us, it lives in small families apart from all 
other species of Antelopes, and is hunted by the Arabs on horseback in 
summer time. Riippell forwarded examples of both sexes of the Addax to 
Frankfort, where it was described and figured by Cretzschmar in 1826 from 
VOL. IV. M 
