NO. 2021. EXTINCT BISONS OF ^'ORT^ AMERICA— HAY. 199 



Plate 12. 

 Skulls of Bison occidentalis. 



Fig. 1. — Dorsal view of skull from Alaska, No. 6832, Field Museum of Natural History, 



Chicago. 

 2. — Rear view of same skull. 

 3. — Dorsal view of skull in American Museum of Natural History, New York. 



Exact locality unknown. 

 4. — Rear view of same skull. 



Plate 13. 

 Skulls of Bison occidentalis. 



Fig. 1.— Dorsal view of skull in Dawson, Yukon Territory, shows the preservation of 



the horns. 

 2.— Dorsal view of skull found at Kotzebue Sound. From a cast in the United 



States National Museum. Original in British Museum of Natural History. 

 3. — Rear view of same skull. From a cast. 



Plate 14. 



Skulls of Biso7i crassicornis. 



Fig. 1.— Dorsal view of skull found in Alaska, No. 5726, United States National 



Museum. After Gilmore. 

 2. — Rear view of same skull. 

 3.— Dorsal view of skull found in Alaska, No. 6834, Field Museum of Natural 



History. 

 4. — Rear view of same skull. 

 5.— Rear view of skull found in Yukon Territory, now in Memorial Museum, San 



Francisco. 



Plate 15. 



Skulls of Bison priscus ? and B . alleni. 



Fig. 1.— Dorsal view of skull of supposed B. priscus, found in Siberia and retaining the 

 horns . After Tscherski . 

 2. — Rear view of same skull. 



3.— Rear view of skull of B. alleni, found in Alaska, No. 2383, United States 

 National Museum. After Gilmore. 



Plate 16. 



Skull of Bison alleni. 



Fig. 1.— Dorsal view of skull with horns, found in Alaska, No. 7706, United States 

 National Museum. 

 2. — Rear view of same skull. 



Plate 17, 



Skull and cervical vertehrse of Bison alleni. 



Fig. 1.— Lateral view of same skull as that of plate 16. 

 2. — Ventral view of atlas found with same skull. 



