250 EXTINCT MONSTERS. 
well-established fact, that throughout most of the Tertiary era 
the climate of northern latitudes was very much warmer than 
now—in fact, sub-tropical. What cause, or causes, brought about 
so great a change, we cannot stay to consider here. 
In conclusion, it only remains to express a hope that the 
reader may have heen interested in our humble endeavours to 
describe some of the largest, most strange, and wonderful forms 
of life that in remote ages have found a home on this planet. 
And perhaps a few of our readers may be induced to add a new 
and never-failing interest to their lives by searching in the stony 
record for traces of the world’s “lost creations.” If so, our 
labour will not have been in vain. 
