PLATE VII. 



Figures of three skulls of Bison americanus, females, showing the gnat diversity of form that obtains in 

 adult specimens of the same sex. Also figures of a skull of Bison bonasus, female, and of metatarsal 

 bones of Bison americanus and B. latifrons ' (Skulls, one fourth natural size ; metatarsal bones, 

 one third natural size.) 



Fig. 1. Occipital view of a skull of a female B. americanus, about six years old, from Kansas (specimen 



No. 105). 

 Fig. 2. Occipital view of a skull of a female B. americanus, about six years old, from Kansas (spec. 



No. 12). 

 Fig. 3. Occipital view of a skull of a female B. americanus, about six years old, from Big-Bone Lick, 



Kentucky (spec. No. 2059). 

 Fig. 4. View in profile of 8 skull of B. americanus, female, about six years old. from Kansas (spec. 



No. 105). 

 Fig. 5. View in profile of a skull of B. americanus, female, about six years old, from Kansas (spec. 



No. 12). 

 Fig. 6. View in profile of a skull of B. americanus, female, about six years old, from Big-Bone Lick. 



Kentucky (spec No. 2049). 

 Kg. 7. Occipital view of a skull of B. bonasus, female, about six years old (spec. No, \~'M>). 

 Ki_'. B. View in profile of the same. 



Kg. 9. Metatarsal bone of /•'. am male (spec. No. 12). 



Fig. In. Metatarsal bone of B. americanus, male (spec. No. in). 

 Fig. 11. Metatarsal bone of B. latifrons f from Darien, Qa. (The original specimen described by I>r. 



Leidy, now in the Museum of the Boston Society of Natural History.) 



