PLATE V. 



Skulls of Bison americanus, males, showing the great diversity of form that obtains in adult individuals 

 of the same sex. (One fourth natural size.) 



Fig. 1. Occipital view of the skull of an old male from the plains of Kansas (specimen No. 1215). 

 Fig. 2. Occipital view of the skull of a male five or six years old frmn Kansas (spec. No. 94). 

 Fig. ::. Occipital view of the skull of an old male from Big-Bone Lick, Kentucky (spec. No. 2047). 

 Fig. 4. Occipital view of the skull of a middle-aged male from Big-Bone Lick, Kentucky (spa 



No. 2060). 

 Fig. •"). < Iccipital view of the skull of a male about six years old from Kansas (spec. No. 102). 

 Fig. 6. Occipital view of the skull of an old male from Kansas (spec. No, 10). 

 Fig. 7 < kxipital view of the skull of a male about six years old from Kansas (sped No. U). 



Occipital view of the skull of a male four or five years old from Kansas (spec. No. 100)- 



