VERTEBEATA 121 



Incisors growing from persistent pulps ; 



anapophyses ; Daubentonioidea.* 



Incisors with closed roots ; anapophyses ; Quodrumana. 



Incisors with closed roots ; no anapo- 

 physes ; Anthropomorpha. 



The Condylarthra are characteristic of the Postcre- 

 tacic in North America, and the Lower Eocene of both 

 continents. They have not yet been detected in the 

 Southern Hemisphere. Their characters connect insepar- 

 ably the Ungulata and Unguiculata divisions, since the 

 carpus and tarsus are like those of the latter, while the 

 ungues are hoofs or semihoofs. The molars are trituber- 

 cular, quadritubercular or lophodont. The best known 

 genus is Phenacodus (Fig. 56), which is the synthetic type 

 of all ungulates. In the known Condylarthra there are 

 five digits on all the feet. 



The Litopterna are only known, so far, from the Cenozoic 

 of South America, ranging throughout the entire series. 

 The teeth present the variations seen in the Perissodactyla, 

 some being bunodont and some lophodont, but the buno- 

 dont forms are tritubercular, like the lowest Condylarthra. 

 This group displays a remarkable reduction in the digits 

 as in the Perissodactyla, passing to three and one digit, as 



in the horse line. 



The Hyracoidea are only known in the recent state in 

 Africa and Western Asia. Their molar dentition is lopho- 

 dont, while the incisors approximate somewhat the rodent 

 pattern. In like manner Daubentonioidea are only known 

 as recent in Madagascar. They are allied to the lemurs. 



Quadrumana appear in the Lower Eocene in North 

 America and Europe as lemurs (Fig. 57). True monkeys 

 do not appear until the Middle Neocene in the Old World, 

 while they are absent from North America, and occur in 

 the Plistocene of South America. The Anthropomorpha 

 (Fig. 58) appear first in the Middle Neocene of France and 



* The horny coyerings of the terminal phalanges of all but the first digit in the 

 only known genus, are claw-like. 



