160 



THE MAMMALIA. 



Frontal protuberances very elongated, 

 beams with single branches are 

 there, but no burr (Fig. 23). 

 The genus has been described 

 under various names, as Dicro- 

 cerus, Prox, Procervulus. The 

 tynes are often found broken off, 

 and it cannot be said with cer- 

 tainty where accident ends, and 

 the regular periodical casting off 

 has begun. It would seem as if 

 the casting had become estab- 

 lished from the irregular occur- 

 rence partly the drying up of 

 the skin and the brittleness con- 

 nected with this. 



Riitimeyer observes that it 

 is difficult to distinguish the 

 primary stags from the primary 

 antelopes, and that perhaps the 

 North American prong-horned 

 antelope which, curiously enough, 

 casts its horns annually, must be 

 traced back to those indefinite 

 primary forms. Cope had made 

 the same observation in 1877 when he wrote : ' The 



FIG. 23. Prox fur- 

 catus. Left antler. 

 One-half nat. size. 



