THEIR FLORA AND FAUNA. 205 



sediments contemporaneously with the deltic deposits of the 

 Po, Danube, and Volga, and these again contemporaneously 

 with the silts of the Venetian and Hungarian lakes ; so in 

 tertiary times the same sort of operations went simultane- 

 ously forward, and thus we find throughout the system a 

 variety not only of sediments, but of fossils, though all 

 belonging to one great and continuous period of world- 

 history. 



There were also throughout the deposition of the tertiary 

 strata abundant manifestations of volcanic activity, and in 

 few tertiary districts are there wanting the cones, crateri- 

 form hills, lava overflows, ash-beds, and trachytic tufas that 

 mark the comparative recentness of their production. In 

 Central France, the Lower Ehine, Italy, Hungary, Greece, 

 Western and Central Asia, Australia, and 'New Zealand, 

 such evidences are everywhere abundant, and even in our 

 own islands the basalts of Antrim and the trap-tuffs of Mull 

 present their concurrent testimony. Less crystalline than 

 the greenstones, felstones, and porphyries of the secondary 

 and primary periods, and more compact than the lavas and 

 cinder-beds of the present day, the tertiary traps are readily 

 distinguished ; and even where most consolidated, their age 

 is easily determined by the associated strata. In Auvergne, 

 the Lower Ehine, and Greece, they are found with beds of 

 eocene and miocene age ; in Australia, basaltic overflows 

 cover auriferous gravels of pliocene date ; and in New Zea- 

 land they spread over lignites of perhaps still later origin. 



As a Life-period the tertiary system stands in remarkable 

 contrast with all that we know of the preceding formations. 

 In these the scheme of life, as now known to us, was incom- 

 plete either some great order being largely predominant, 

 or one or more orders altogether wanting. Taking the 

 fauna alone, the Laurentian, Cumbrian, and Silurian were 



