1408 



CLASS MAMMALIA. 



Finally, it should be mentioned that a portion of a tusk of a 

 Proboscidean, said to have been obtained from the Pleistocene of 

 Australia, has been described as Notelephas. There are, however, 

 no characters in this specimen to indicate its right to generic dis- 

 tinction, and its reputed origin must be looked upon with great 

 suspicion. 



Group Tillodontia. — Here may be noticed a remarkable group 

 of Mammals from the Lower Eocene, of which the position is still 

 unsettled. They are regarded by Professor Marsh as constituting a 

 distinct order ; while Professor Cope subdivides them into Tillo- 

 dontia and Tseniodontia, and includes them in his order Buno- 

 theria. A suggestion has also been made of affinity with the Eden- 

 tates. These Mammals, as will be gathered from the characters 

 mentioned below, present certain characters common to the Ungu- 

 lata, Rodentia, and Carnivora, but to include them in either one of 

 those orders would render it impossible to give anything approach- 

 ing to a definition of the order so enriched. Putting aside the 

 suggestion of Edentate affinities as requiring further evidence, the 

 characters presented by the Tillodonts harmonise with the view 

 that both the Ungulates and Rodents have been derived from a 

 primitive Carnivorous stock. 



Family Anchippodontid^. — The genus Anchippodus (Trogosus), 

 with which Tillotherium (fig. 1289) is closely allied or identical, is 



Fig. 1289. — Left lateral aspect of the skull of Tillotherium fodiens ; from the Lower Eocene 

 of North America. One-fourth natural size. (After Marsh.) 



from the Lower Eocene of North America, and apparently has the 



dental formula I. - , C. -, Pm. ^, M. -. The lower cheek-teeth 

 2i 4 3 



