POST-TERTIARY PERIOD. 



561 



tusks are gathered for exportation. At the mouth of the Lena one 

 of these animals was found, at the beginning of this century, frozen 

 and encased in ice. It measured 16 feet 4 inches in length to the 

 extremity of the tail, and 9 feet 4 inches in height. It retained the 

 wool on its hide, and was so perfectly preserved that the flesh was 

 eaten by the dogs. 



The Elephant has in all twenty-four teeth (grinders), but usually 

 only eight at a time, two in each side of each jaw. The new teeth 

 come up behind and push the others forward and out ; and thus 

 there is a succession until the last has grown. * 



The Ehinoceros of Post-tertiary Europe is the R. tichorinus. It 

 spread from England to Siberia. A frozen specimen in Siberia was 

 found near Wilui in 1772. It had a length of 11J feet, and appears 

 to have been a hairy species. 



The Irish Elk (Megaceros Hibernicus) is another of the gigantic 

 animals of the Post-tertiary. Specimens have been found in marl 

 beneath the peat of swamps in Ireland and England, and fragments 

 in the bone-caverns. The height to the summit of the antlers was 

 10 to 11 feet, and the span of the antlers was 8 feet, or twice that of 

 the American Moose. 



America. — America in the Post-tertiary period was inferior to 

 Europe in the number of its Carnivores, but presents the gigantic 

 feature of the life of the time in its species. 



In North America the remains have been found in the ancient and 

 surface alluvium, but not yet in the unstratified drift. The species 



Fig. .837. 



Fig. 838. 



Elephas Americantis. 



Mastodon gigaiiteus. 



included an Elephant (E. Americanus, fig. 837) as large as the Euro- 

 pean ; a Mastodon (M. giganteus, fig. 839) of still greater magni- 



37 



