42 Field Museum of Natural History — Zoology, Vol. XI, 



GROUP 2. Order UNGULATA. Hoofed Mammals. 



SECTION 1. Horns branched and solid (not hollow) and annually 

 shed. 



Family CERVIDiE. 

 , Deer, Moose, Caribou, etc., p. 58. 



SECTION 2. Horns simple (not branched), permanent (not annually 

 shed), and more or less hollow. 



Family BOVIDiE. 

 American Bison or Buffalo, etc., p. 86. 



GROUP 3. Order GLIRES. Gnawing Mammals. Squirrels, Rab- 

 bits, Rats, Beavers, etc. 



Front teeth (incisors) large and chisel- 

 shaped and separated from the molars on 

 side of jaw by a wide gap; canine teeth ab- 

 sent; toes with nails or claws. 



Skull of a Rodent. 



