TERTIARY MAMMAL HORIZONS. 43 



sence of Elcphas antiqims in geological deposits which are 

 chiefly diluvial valley gravels and sand cla\'s. These facts alone 

 indicate a prolonged colder period, a nortJicrn or boreal 

 climate. The fauna presents a great variety adapted to different 

 degrees of temperature but decidedly of northern type. Other 

 facts indicate that this colder period was initiated by a distinct 

 second advance of the ice followed by a gradual recession, 

 namely the occurrence of arctic and subarctic types succeeded 

 by north temperate types, in a number of localities, typically 

 near Schaffhausen (Schweizerbild, Steinmann, '93, p. ii/) 

 (Franken, Schlosser, '95, p. 2ii). 



These successive northern faunas in single localities are typi- 

 cally as follows : 



I. TuNDRE Fauna. 2. SxEPrE Fauna. 



(Frozen subsoil, arctic and subarctic.) 



Myodes torquatus, Alactaga, 



" obensis, Spermophilus, 



Lepus glacialis, Lagomys pusillus, 



Rangifer tarandus, Arvicola, 



Ovibos moschatus, Cricetus pbaeus, 



Lagopus mutus, Equus, 



" albus, Antilope saiga. 



The prevailing types of this stage are the typical ElepJias pri- 

 migenius which succeeded EUplias trogontlicrii. Rhinoceros ticJio- 

 rhiniis and Rangifer tarandns. The reindeer, first the barren 

 ground then the woodland variety, increased rapidly in number 

 during this period and constitute its most distinctive form ; hence 

 this is known as the Reindeer period. 



It includes the most remarkable diversity of life of Asiatic 

 both Siberian and Oriental, and of African origin. The persist- 

 ence of the following southern forms : Felis {Ico) spelcea : Felis 

 pardns, Hycuna {crocntd) spelcea, Eqnns caballns, Eqnns (^asintis) 

 hemiones, Rhinoceros tichorhinns (with affinities to R. sin/ns), 

 Eleplias primigenins. All these types, excepting possibh' the 

 Mammoth, now inhabit warm, dr)", semi-arid regions. There is 

 therefore an Ethiopian and Oriental fauna, in certain localities 

 succeeding a steppe and tundre fauna. At no period either be- 

 fore or since was Europe so thoroughly cosmopolitan, a fact 



