PLATE Vill. 
Horns of Bison americanus and B, antiquus. (One third natural size.) 
Figs. 1-5. A series of the horns of the male Bison americanus, 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.) 
Figs. 6 and 7. Horns of very old males of B. wmericanus, 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. 
Figs. 10 and 11. Horns of old females of B. americanus. 
Fig. 12. Horn of B. antiquus (male ?), from St Michaels, Alaska. (Specimen presented by W. G. W. 
Harford, Esq., Director Cal. Acad. Sciences.) 
