DUIKERS AND SMALL ANTELOPES 547 
The skull exhibits a large anteorbital fossa which usually 
equals or exceeds the orbit in diameter, being smaller than 
the orbit only in the steinbok, Raphicerus . The bones of 
the snout are normal in development and arrangement, the 
premaxillary bones being in contact with the nasals and a 
lachrymal-nasal sinus being present. The genera included are 
Nesotragus, Ourebia, Nototragus, Raphicerus , and Neotragus, 
the last named confined to the forested area of the Congo 
and the West Coast of Africa. 
Key to the Genera 
Anteorbital fossa large, the diameter about equalling that of the orbit; 
horns heavily ringed at least at the base 
Size diminutive, about equalling a hare; general coloration red¬ 
dish; horns small, projecting straight backward in line 
with the snout; lateral hoofs absent; no knee-brushes 
Nesotragus 
Size larger, in height equalling a goat; general coloration yellow¬ 
ish; horns small, projecting upward at an obtuse 
angle with the snout; lateral hoofs present; knee- 
brushes well developed; a bare spot on the side of the 
head below the ear Ourebia 
Anteorbital fossa small, the diameter only one-third that of the orbit; 
horns smooth, not ringed Raphicerus 
The subfamily Neotragincz of Sclater and Thomas is a 
heterogeneous association of genera of small antelopes. It 
has been used almost universally by systematic naturalists 
as a left-over repository for the smaller species of antelopes 
which are not obviously allied to the better-marked divisions 
into which the larger may be arranged. It has thus come 
to be an association based almost solely upon small size. 
As constituted by its authors in 1892 it included the genera 
Neotragus, Nesotragus, Ourebia , Raphicerus, Oreotragus , and 
Madoqua. Gray, some years earlier, in 1872, proposed the 
family Nesotragidce for Nesotragus, Nanotragus {Neotragus), 
