94 THE OPEN BOOK OF NATURE 
the Mastodon (Greek, masios=nipple, and odous = 
tooth), which was a big kind of elephant usually 
having two pairs of tusks, one in each jaw; and 
also of the Deinotherium (Greek, deinos = terrible, and 
therion = beast), a big elephant-like animal having 
Fig. 37.—SKULL or DEINOTHERIUM, 
two large tusks in the lower jaw. ‘These tusks were 
curved backwards, enabling their owner to use them 
in tearing up roots. 
IT shall conclude this imperfect sketch of the 
animal life of long ago by a reference to two extinct 
