310 UNGULATA 
2. The horns of the Bovide consist of permanent, conical, 
usually curved bony processes, into which air-cells continued from 
the frontal sinuses 
often extend, 
called “horn- 
cores,” ensheathed 
in a case of true 
horn, an epider- 
mic development 
of fibrous  struc- 
ture, which grows 
continuously, 
though slowly, 
from the base, and 
wears away at the 
apex, but is very 
rarely shed entire. 
The only existing 
species in which 
the latter process 
occurs regularly 
and periodically 
is the American 
Prong-Buck 
(dntilocapra), in 
which the horns 
also differ from 
those of all others 
in being  bifure- 
ated. Horns are 
not present at 
birth, but begin 
to grow very soon 
afterwards. The 
Fic, 121.—Head of Antelope (Gazella granti), showing horns. From 7 
Sir V. Brooke, Proc. Zool. Soc. 1878, p. 724, males of all pages 
ing Bovide possess 
them, and they are also present (though usually not so fully 
developed) in the females of all except the genera Boselaphus, 
Strepsiceros, Tragelaphus, Antilope, AEpyceros, Saiga, Cobus, Cervicapra, 
Pelea, Nanotragus, Neotragus, Cephalophus, and Tetraceros y as well as 
in some species of Gazella, such as G. picticaudata and G. walleri. 
Another character by which different members of the Pecora can be 
distinguished among themselves is derived from the nature of the molar 
teeth. Although there is nothing in the general mode and arrange- 
ment of the enamel-folds, or in the accessory columns, absolutely 
distinctive between the two principal families, existing species may 
