318 THE AGE OF MAMMALS 



first time the majestic southern elephants (E. meridionalis) which herded 

 with the last of the European mastodons and roamed all over Europe from 

 Italy to Great Britain. The tridactyl hipparion disappears, being replaced 

 by the true monodactyl horse {Equus stenonis). The larger Etruscan rhi- 

 noceros {Dicerorhinus etruscus) succeeds the D. leptorhinus of the Lower 

 Pliocene. The macaques {Macacus florentinus) reappear, closely related to 

 the living apes of Gibraltar. The hippopotami are now widely spread 

 over southern Europe. 



Equally striking is the first appearance in Europe of the true bovines^ 

 ancestors of the existing wild and domestic cattle. The deer also multiply 

 and increase in size, and are especially distinguished by their large and 

 splendidly developed branching horns. Mingled with these new forms 

 are some of the practically unchanged survivors of the ancient Pliocene 

 fauna, such as the saber-tooth tiger (Machcerodus cidtridens), the bears 

 {Ursus arvernensis) , the tapirs (T. arvernensis) , the short-jawed mastodons 

 (M. arvernensis, M. borsoni). 



This period is, however, sharply defined by the disappearance of several 

 members of the earlier fauna, namely, of the Asiatic langur (Semnopithecus) , 

 the civet (Viverra), the panda (Ailurus), and the flying squirrels (Sciu- 

 ropterus). 



Physiography. — Great Britain is still broadly connected with the con- 

 tinent,^ so that in the fluvio-marine deposits of the Norwich Crag of Nor- 

 folk (p. 321) we find many of the mammals characteristic of northern Italy 

 and central France. The remains of mammals are chiefly preserved in 

 river and lake deposits. There is evidence that the climate is gradually 

 becoming cooler. Among the typical marine formations of Sicily, which 

 give the name to this stage, there is a sudden appearance of shells of northern 

 type, an invasion due to the opening of the Straits of Gibraltar and inflow 

 of Atlantic waters. In the Norwich Crag of England there are also a great 

 many shells of boreal type which increase in number during the latter part 

 of the Sicilian stage. With the cooling of the sea and introduction of 

 northern currents naturally came a lowering of temperature and a retreat 

 of palms and other tropical plants to the south. The dwarf fan palm 

 {Chamcerops) occurs for the last time on the Lipari Islands, north of Sicily.^ 

 The advent of the northern types of shells in the sea is prophetic of the 

 -Glacial Period. 



In the accompanying map (p. 310) is displayed the wide distribution 

 of formations in which the remains of this splendid fauna are preserved 

 (Nos. 10-29). We owe to Forsyth Major (1884, 1890) and to Deperet 

 (1885, 1890, 1893) ^ especially the study of the mammals of the Val d'Arno 

 near Florence, of Olivola in northern Tuscany, and of Perrier (Puy-deDome). 



The mammals of Perrier have been found in gravels at the base of the 



1 De Lapparent, A., Traite de Geologie, 1906, pp. 1648-1652. 

 ^ For principal titles see Bibliography. 



