522 THE TERTIARY PERIOD 



of North America are still incompletely known, and the list is a 

 short one. Mastodons, Horses, Rhinoceroses, Peccaries, and 

 very large Llamas represent the hoofed animals. Besides the 

 Dogs, Cats, and Mustelines, occur flesh-eaters, which are referred 

 to the Hyaenas. If the reference is correct, this is the only occur- 

 rence of these animals in America. The effects of the connection 

 with South America are seen in the appearance of the gigantic 

 Sloths and Armadillos, and of southern families of Rodents. 



The early Pliocene mammals of southern Europe closely re- 

 semble those of modern Africa, — Wolves, Cats, Civets, Hyaenas, 

 Monkeys, Rhinoceroses, three-toed Horses, Deer (of which Africa 

 has none), a great variety of Antelopes and of Giraffe-like forms, 

 and Swine. Mastodon and Dinotheriun persisted, the latter attain- 

 ing great size. India had a similar fauna, with certain geographi- 

 cal differences. Especially to be noted are the great variety of 

 Oxen, the presence of Bears, true Elephants, and the Hippopota- 

 mus, of the first Old World Camels, and of the extraordinary 

 Sivaiherium and Brahmatherium, great, four-horned creatures 

 allied to the Giraffes. In the Upper Pliocene the Elephants, Oxen, 

 Hippopotamus, and Bears had extended their range to Europe, 

 but not, so far as we know, to North America. 



The climate of the Pliocene was evidently cooler than that of 

 the Miocene, as is shown by the changes in the character of the 

 vegetation and of the marine shells. The inference as to climatic 

 change may be made with unusual confidence in this case, for 

 nearly all the Pliocene species of shells are still living, and can 

 hardly have changed their habits. In the English Pliocene the 

 proportion of Arctic shells rises from 5% in the oldest to over 

 60% in the newest beds. The refrigeration was greater in the 

 sea than on the land, for the vegetation shows that the air had 

 not yet grown cold. That was to come later. 



The South American Tertiary 



South America has comparatively little marine Tertiary. A 

 narrow band of such strata is found on the Pacific coast, and 



