614 
AFRICAN GAME ANIMALS 
The Impalla 
Alpyceros 
JEpyceros Sundevall, 1847, K. Vet. Akad. Handl., 1845, p. 271; type 
A . melampus. 
The impalla is one of the aberrant members of the sub¬ 
family Antilopince , of which the gazelles are typical. It 
resembles the gazelles more closely in skull structure than 
any other group, and in conformity with them the snout 
shows a large narial chamber and broad, short nasal bones, 
but differs by having a large oval sinus on the sides of the 
snout between the premaxillary and maxillary bones. In 
the absence of anteorbital fossae it differs decidedly from 
African gazelles, but in this respect resembles such Asiatic 
members as the chiru, Pantholops , of Tibet and the Mon¬ 
golian gazelles of the genus Procapra. The absence of 
false hoofs distinguishes the impalla from all other large 
antelopes. Other characters which serve to separate it 
from the African gazelles are the absence of the anteorbital 
gland and pore on the face, the absence of horns in the 
female, the lack of stripes on the face or body, the bushy 
tail and the presence of four mammae in the female. The 
only gazelle marking in the coat is the black pygal stripe 
on the hind quarters. A color character, confined to this 
antelope alone, concerns the feet. The hind legs are marked 
on the cannon-bones by two oval black patches in which the 
hair is much longer and coarser and overlies a glandular 
area of the skin similar to the metatarsal glands of the 
white tail deer. The position of the fetlocks is marked by 
two smaller black patches. The sexes are alike in color, 
but the female is somewhat smaller than the buck in size. 
The newly born young differ in no way conspicuously from 
the coloration of their parents. 
The genus contains a single species which is confined to 
the Ethiopian region, where it ranges from the Orange 
River, in South Africa, northward on the East Coast as far 
as British East Africa and southern Uganda. In the south¬ 
ern part of its range it spreads westward to Angola, but is 
not found north of that district in the Congo forest area or 
the Nigerian region. 
