Cb. 



e. 



f. 



The Ancestors of the Horse and its Relatives compared in size 

 and form with their typical modern representative 



a, Ilyracol her turn of the Lower Eocene ; b, Plagiolophus, or Orohippus, 

 of the Middle Eocene ; c, Mesohippus, of the Oligocene ; d, Merychippus, of 

 the Miocene ; e, Pliohippus, of the Pliocene ; /, the Horse, Eqttus caballus. 



