66 
P. Ac. Philad. 1896, p. 519; Pousargues, Ann. Sci. Nat. (7) iv. p. 131 (1896) ; 
Elliot, Publ. Chicago Mus. Zool. 1. p. 130 (1897) ; Neumann, Elephant-Hunting, 
p. 863 (1898) (Lake Rudolf) ; Trouessart, Cat. Mamm. fase. iv. p. 954 (1898). | 
Oryx biessa, Gray, Ann. Mag. N. H. (1) xviii. p. 232 (1846). 
Vernacutar Names :—Beisa of Arabs at Massowa (Riippell) ; Beida (Heuglin) ; Baet 
of Somalis (Swayne) ; Ari of Danakils (Heuglin). 
Height at withers about 46 inches. Colour of neck and body a tolerably 
uniform tawny. Head and throat with the same ornamentation of black 
stripes and patches as in the preceding species, but the nose-patch does not 
spread so far laterally, and does not fuse with the lower extremity of the 
stripe that runs from the eye; this stripe also stops short at a point about on 
a level with the corner of the mouth, and is not produced inferiorly on to 
the lower side of the jaw; thus the whitish muzzle is not surrounded by 
a complete black ring as is the case in O. gazella, and there is less black on 
the inter-ramal area and on the upper end of the throat. Hair of throat not 
produced to form a mane or beard. Ears black at tip and on rim as in O. gazella. 
Black spinal stripe more sharply defined than in that species and extending 
from a point near the middle of the rump; hind-quarters of the same colour 
as the body and neck, there being no black patch on the rump and none on 
the lower half of the thighs. ‘The black stripe that passes backwards from 
the chest along the side of the body above the white belly is narrower than 
in O. gazella, and is not continued on to the thighs. Hind legs whitish, not 
black above the hocks, and without a black spot on front of the cannon-bene, 
but stained with black above the false hoofs and below the hocks. Fore legs 
whitish, banded as in O. gazella, but the stripe above the knee narrower and 
only extending about halfway up to the shoulder on the outer side, and to 
the chest on the inner. ‘Tail-tuft black. Hairs along the neck and spine 
lying forwards, the parting situated on the rump. 
Horns nearly straight, ribbed in their basal half; about 36 or 37 inches in 
length, often only about 50. 
A skull gives the following measurements :—Basal length 14 inches, orbit 
to nose 12°75, greatest width 5°75. 
Female. Similar to the male, but horns rather longer and thinner. 
Hab. Western shores of the Red Sea from Suakin southwards to Danakil- 
land; Somaliland and British East Africa north of the Tana. 
