3io 



UXGULATA 



2. The horns of the Bovidce 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 

 conti nuously, 

 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 

 (Aiifiloaqrra), in 

 which the horns 

 also differ from 

 those of all others 

 in being bifurc- 

 ated. Horns are 

 not present at 

 birth, but begin 

 to grow very soon 

 afterwards. The 

 From males of all exist- 

 ing Bovidce possess 

 them, and they are also present (though usually not so fully 

 developed) in the females of all except the genera BoselapJms, 

 Sfrrpsiceros, Tragehphus, Antilope, JEpyceros, Saiga, Cobus, Cervkajpra, 

 Pelea, Nanotragus, Neotragus, Cephcdophus, and Tetraeeros; as well as 

 in some species of Gazella, such as 67. picticaudata and 67. 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 



Fig. 121.— Head of Antelope (Gazella granti), showing horns. 

 Sir V. Brooke, Proc. Zool. Soc. 187S, p. 724. 



