x AUTHOR'S PREFACE 



has, from age to age, been enacted on the terrestrial stage, of 

 which we behold the latest, but probably not the closing scenes. 



When our poet wrote "All the world's a stage," he thought 

 only of " men and women," whom he called " merely players," 

 but the geologist sees a wider application of these words, as he 

 reviews the drama of past life on the globe, and finds that 

 animals, too, have had " their exits and their entrances ; " nay, 

 more, " the strange eventful history " of a human life, sketched 

 by the master-hand, might well be chosen to illustrate the birth 

 and growth of the tree of life, the development of which we 

 shall trace briefly from time to time, as we proceed on our 

 survey of the larger and more wonderful animals that flourished 

 in bygone times. 



We might even make out a " seven ages " of the world, in 

 each of which some peculiar form of life stood out prominently, 

 but such a scheme would be artificial. 



There is a wealth of material for reconstructing the past 

 that is simply bewildering ; and yet little has been done to 

 bring before the public the strange creatures that have perished. 1 



To the writer it is a matter of astonishment that the 

 discoveries of Marsh, Cope, Leidy, and others in America, not 

 to mention some important European discoveries, should have 

 attracted so little notice in this country. In the far and wild 

 West a host of strange reptiles and quadrupeds have been un- 

 earthed from their rocky sepulchres, often of incredibly huge 



1 Figuier's World before the Deluge is hardly a trustworthy book, and is 

 often not up to date. The restorations also are misleading. Nicholson's 

 Life-History of the Earth is a student's book. Messrs. Cassells' Our Earth 

 and its Story deals with the whole of geology, and so is too diffusive ; its ideal 

 landscapes and restorations leave much to be desired. H. R. Knipe's Nebula to 

 Man contains a large number of beautiful restorations and landscapes. See also 

 Sir E. Bay Lankester's Extinct Animals. 



