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MANUAL OF ZOOLOGY. 



ORDER IX. TOXODONTIA. This order includes certain large 

 extinct Mammals from the later Tertiary deposits of South 



Fig. 414. Tillodontia. Side-view of the skull of Tillotherhtmfodiens, with the lo\ 

 jaw displaced downwards, one-fourth of the natural size. (After Marsh.) 



America, the true systematic position of which is still very 

 doubtful; since they present affinities to the Ungulata, the 

 Rodents, and the Edentates. The skull is massive and the 

 dentition is very peculiar. The molars and praemolars are 



Fig. 415 A, Right upper jaw of Toxodon Bnrmeisteri, and(B) left lower jaw of the 

 same ; c Lower canine. (After Byrmeister.) Greatly reduced in size. 



bent so as to be strongly convex outwards and concave inwards, 

 with flat grinding-surfaces (fig. 415), and presenting the pecu- 

 liarity that they are rootless and grow from persistent pulps. 

 Canines are present in the lower jaw; but are of very small 



