PLATE VIII. 

 Horns of Bison americanus and B. antiquua. (One third natural size.) 



Figs. 1-5. A series of the horns of the male Bison americanvs, showing variation in size and form with age. 



(Fig. 1, from a specimen about six months old ; Fig. 2, from a specimen about one year old ; Fig. 3, 



from a specimen about three or four years old ; Fig. 4, from a specimen about ten or twelve years old ; 



Fig. 5, from a specimen twenty to twenty-five years old.) 



tnd 7. Horns of very old males of B. americanus, showing diversity in size and form in males of 



corresponding ages. 

 Fig. 8. Horn of a six-year-old female of B. americanus. 

 Fig. 9. Horn of a six-year-old female of B. bonasus. 



10 and 11. Horns of old females of B. americanus. 

 Fig. 12. Horn of /;. antiqwiu (male 1), from St Michaels, Alaska. (Specimen presen ted by W. i;. \V 



Harford, Es<i., Director Cal. Acad. Sciences.) 



