686 



MAMMALIA 



[CH. 



roamed over Northern Europe and Asia and was hunted by primitive 

 man. In older deposits we come on the remains of Elephants known 

 as Stegodon and Mastodon in which the ridges crossing the molars 

 of Elephants reveal their character by breaking up into pointed 

 cusps like those on the teeth of Insectivores. In the earlier species 

 of Mastodon a rudimentary pair of lower incisors is present in 

 addition to the tusks. In Miocene deposits remains of a creature 

 termed Tetrabelodon are found in which there was only a short trunk, 

 but which possessed a pair of long lower incisors in addition to the 



... ii 



FIG. 343. Skull of a young Indian Elephant, Elephas indicus, seen from the 

 right side, the roots of the teeth have been exposed x . 



1. Exoccipital. 2. Parietal. 3. Frontal. 4. Squamosal. 5. Jugal. 

 6. Premaxilla. 7. Maxilla. 9. Supra-occipital. 13. Basi-occipital. 

 14. Postorbital process of the frontal. 15. Lachrymal. 16. Pterygoid 

 process of the alisphenoid. i 1. Incisor. mm 3, mm 4. Third and 

 fourth milk molars. m 1. First molar. 



upper tusks. In the contemporaneous Dinotherium these lower 

 incisors formed downwardly curved tusks and the upper incisors 

 were absent. The animal could not have used these inwardly 

 curved incisors for offence but must have used them for grubbing 

 up roots. Finally in the Eocene period a beast is found with com- 

 paratively short upper and lower incisors and the trunk was not 

 better developed than it is in Insectivora. It adds to the interest 

 of these discoveries to know that the remains of all this ancestral 



