CHAPTER X. 



THE NEOZOIC AGES. 



BETWEEN the Mesozoic and the next succeeding time, 

 which may he known as the Neozoic or Tertiary,* 

 there is in the arrangements of most geologists a great 

 break in the succession of life ; and undoubtedly the 

 widespread and deep subsidence of the Cretaceous, 

 followed by the elevation of land on a great scale at 

 the beginning of the next period, is a physical cause 

 sufficient to account for vast life changes. Yet we 

 must not forget to consider that even in the Cre- 

 taceous itself there were new features beginning to 

 appear. Let us note in this way, in the first place, 

 the introduction of the familiar generic forms of exo- 

 genous trees. Next we may mention the decided 

 prevalence of the modern types of coral animals and of 

 a great number of modern generic forms of mollusks. 

 Then we have the establishment of the modern tribes 

 of lobsters and crabs, and the appearance of nearly all 

 the orders of insects. Among vertebrates, the ordi- 

 nary fishes are now introduced. Modern orders of 



* The former name is related to Palaeozoic and Mesozoic, the 

 latter to the older terms Primary and Secondary. For the 

 sake of euphony we shall use both. The term Neozoic was 

 proposed by Edward Forbes for the Mesozoic and Cainozoic 

 combined ; but I use it here as a more euphonious and accurate 

 term for the Cainozoic alone. 



