IXi.L'LATA. 



573 



ml being most worn ; the mandibular symphysis was elongated but not 

 so long as in the last genus, and the basis cranii and facial region of the 

 maxilla longer. 



Moeritherium Andrews, Middle and Upper Eocene of Fay urn ; den- 

 tition tfcpj-m$; i 2 in the upper jaw is tusk-like though not 

 so large as in the other genera, il and iS are small as is the canine ; in the 

 lower jaw i'2 

 is larger than 

 il, i3 being 

 absent ; the 

 premolars are 

 cuspidate and 

 the molars 

 bilophodont 

 (quadri tuber- 

 cular). This is 

 the ordinary 

 dentition, save 

 for the absence 

 of pi in the 

 upper jaw and 

 of i3, c and pi 

 in the lower. 

 The mandibu- 

 lar symphysis 

 is but slightly 

 elongated. 



Barytherium 

 Andrews, M. 

 Eocene. 



Pyrotherium 

 Am., from the 

 Cretaceous 

 (Eocene) of 

 Patagonia has 



been claimed FIG. 295. Skull of Dinotherium giganteum, from the Lower Pliocene 

 (after Kaup, from Flower and Lvdekker). 7)3, 4 premolars ; 

 as a member lf 2, 3 molars. 



of this order. 



Order 8. UNGULATA. 



Usually hoofed, digitigrade animals in which the digits of the 

 pes never exceed four and the carpal and tar sal bones interlock. 

 There is no os centrale in the carpus and no entepicondylar 

 foramen in the humerus, and clavicles are always absent. The 

 scapula is usually devoid of an acromion. The placenta is 

 diffuse or cotyledonary , the mammae inguinal or abdominal, and 

 the testes always descend into a scrotum. 



The Ungulata as thus defined includes the Perissodactyla, and 

 Artiodactyla and excludes absolutely the Proboscidea and 



