POST-TERTIARY PERIOD. 567 



vers, and Lion of North America ; the Megatheria and other Eden- 

 tates of South America ; the Diprotodon and other Marsupials in 

 Australia. 



2. The characteristic species of each continent were mainly of 

 the same type that now characterizes it. Both in the Post-tertiary 

 period and modern time the Orient is strikingly the continent of 

 Carnivores ; North America, of Herbivores ; South America, of 

 Edentates ; Australia, of Marsupials. 



With the close of the Post-tertiary far the larger part of these 

 species became extinct. The destruction did not extend, as has 

 been before stated, to the Mollusks and other Invertebrates, — for 

 the same species are all or nearly all now living. 



GENERAL OBSERVATIONS ON THE POST-TERTIARY. 



Climate.— The hairy covering of the Elephant and Rhinoceros 

 of Siberia shows that the climate of the Post-tertiary in those 

 regions was not tropical. Still the several species of British and 

 European Mammals, of Rhinoceros, Hippopotamus, Elephant, Lion, 

 Tiger, Hyena, etc., are so closely those of warm climates that it is a 

 safe conclusion — the only safe one — that Britain and a large part of 

 Europe were within the warm-temperate zone. It is evident also that 

 northern Siberia was at least not colder than Lapland, whose annual 

 mean temperature along its northern limit, according to Dove's 

 charts, is now 27J° F., January mean 5° F., and July mean 50° F., 

 while the corresponding quantities for northern Siberia, near the 

 mouths of the Lena, are at the present time 5° F., — 40° F., and 50° F. 

 The great quantities of Elephant remains at numerous points near 

 the Arctic Ocean show that the region was the living-place of the 

 animals, and not one frequented by occasional herds in the very 

 short Siberian summer. This is further proved by the existence, at 

 many places in the Arctic, of the remains of forest-trees, buried in 

 deposits of the Age of the old Elephant. The required climate 

 would have resulted from the Champlain subsidence (p. 554). 



The last or Terrace epoch — in which the continents were raised 

 nearly to their present level — again cooled down the earth, and 

 ended in introducing approximately the existing climates of the 

 globe ; and the extermination of the Cave beasts of Europe and 

 other Post-tertiary species may have been coincident with this 

 great climatal change. 



Remarks on the Geography of the period are included under the 

 General Observations on the Cenozoic. 



