CLASSIFICATION OF VERTEBRATA 47 



Blbodon. Oligocene, South America. 



Protapirus. Eocene of Europe. 



Tapirus. Miocene of Europe arid India, recent in Central 



and South America, Malacca, Sumatra, and Borneo. 

 Equidae. Lower molars quadritubercular or with two 

 transverse ridges curved into two half-moons, leading to W 

 pattern. Toes ^, or ^. Since the Eocene. 



Hyracotherium. 1^ Lower Eocene, England. 



. , . hloes *. T ^ -CTT 



Eohippos. J Lower Eocene, Wyoming. 



Palaeotherium."! Eocene to Miocene, Europe and U.S.A. 

 Mesohippos. j-Toes ^. Lower Miocene, Dakota. 

 Anchitherium. J Upper Miocene, of Europe = Miohippos, 



U.S.A. 

 Hipparion. Toes . Upper Miocene of Europe, Asia 



and U.S.A. 



Protohippos. Toes -|. Pliocene, U.S.A. 

 Pliohippos. Toes ^. Pliocene, U.S.A. 

 Hippidion. Toes \. Plistocene, South America. 

 Equus. Toes \. Since Miocene in India, since Pliocene 



in Europe. During the Plistocene cosmopolitan, 



excluding Australian region. 



Rhinocerotidae. Lower molars with two transverse half- 

 moons. Toes ^j Since the Eocene. 



Hyrachius. Upper Eocene, Wyoming. 



Hyracodon. Lower Miocene, Nebraska. 



Aceratherium. Oligocene, France ; Miocene, Europe, 



India, North America. 

 Diceratherium. Miocene, Oregon. 

 Khinoceros. Since the Miocene in Asia, Plistocene 



of Asia and Europe. Eecent in the palaeotropical 



regions including Sumatra, Java, Borneo, excluding 



Madagascar. 



Titanotheridae. Eocene and Miocene of Europe and North 

 America. 



Palaeosyops. Eocene, U.S.A. 



Titanotherium (Brontotherium). Lower Miocene, 



U.S.A. 



Leptodon. Upper Miocene, SE. Europe. 

 8. Sub-order ANCYLOPODA, Cope. Plantigrade ; terminal 



