INTRODUCTION. 3 



land, swimming in the sea, or flying in the air; to understand 

 the meanings of their more obvious structures; and to form some 

 conclusions with regard to their habits, as well as to find out, if 

 possible, their relations, — as far as such questions have been 

 answered by those most qualified to settle these difficult 

 matters. 



All technical details, such as the general reader is unfamiliar 

 with, will be as far as possible suppressed. Let us fancy a long 

 procession of extinct monsters passing in single file before us, 

 and ourselves endeavouring to pick out their "points" as they 

 present themselves to the eye of imagination. It is not, be it 

 remembered, mere imagination that guides the man of science in 

 such matters, for all his conclusions are carefully based on reason ; 

 . and when conclusions are given, we shall endeavour to show how 

 they have been arrived at. 



For millions of years countless multitudes of living animals 

 have played their little parts on the earth and passed away, to be 

 buried up in the oozy beds of the seas of old time, or entombed 

 with the leaves that sank in the waters of primaeval lakes. The 

 majority of these perished beyond all recovery, leaving not a 

 trace behind ; yet a vast number of fossilised remains have been, 

 in various ways, preserved ; sometimes almost as completely 

 as if Dame Nature had thoughtfully embalmed them for our 

 instruction and delight. 



Down in those old seas and lakes she kept her great museum, 

 in order to preserve for us a selection of her treasures. In 

 course of time she slowly raised up sea-beds and lake-bottoms to 

 make them into dry land. This museum is everywhere around 

 us. We have but to enter quarries and railway cuttings, or to 

 search in coal-mines, or under cliffs at the seaside, and we can 

 consult her records. As the ancient Egyptians built tombs, 

 pyramids, and temples, from which we may learn their manner 

 of life and partly read their history, so Nature has entombed, not 

 one race only, but many races of the children of life. Her 



