XIII 



PHYLUM CHORDATA 



573 



The fibula does not articulate with either the astragalus or the 



calcaneum. 



Another extinct primitive sub-order of the Ungulata is the 

 AmUi/poda, the members of which have been found, like the 

 Condylarthra, in the Eocene of North America and of Europe. 

 'These resemble the Condylarthra and Hyracoidea in the relation 

 of the scaphoid to the trapezoid ; both magnum and unciform 

 articulate with the lunar. The fibula articulates with the 

 Calcaneum: the cuboid articulates with both the astragalus and 



FIG. llGG.-DinOtherium giganteum. Side view of skull, ^th natural size. 

 (From Yittel's Palaeontology, after Kaup.) 



tbhe calcaneum. The feet are short, pentadactyle, and plantigrade. 

 -Canines are present in both upper and lower jaw ; the pre-molars 

 .and molars are short and lophodont in type. 



Found hitherto only in the Patagonian lower Tertiary (Upper 

 Cretaceous?) formations are two imperfectly known groups of 

 primitive Ungulates, the Pyrotheria and Astrapotheria. 



The true Carnivora of the Tertiary period are, as compared with 

 those of the present time, remarkable for the absence of the well 

 marked distinction into groups such as are now to be recognised ; 

 .numerous intermediate forms connect together the Dogs, < 



