26 OSBORN. 



The climate was extremely mild, subtropical but becoming more 

 temperate, with a persistence of Sequoias and Palms (Sabal), 

 ev^en far north, a gradual increase in the number of deciduous 

 trees which include a large proportion of North American types, 

 and a marked increase in the grasses, stimulating the evolution 

 of deer in the north and antelope in the south, especially towards 

 the close of the period. 



1. Langhien or Burdigalien, Lower Miocene 



The Sables dc rOr/canais (Paris Basin, max. 20 metres) at 

 Neuv'ille-aux-Bois, Chevilly, Avaray, Chitenay (Loire-et-Cher), 

 with a rich typical fauna, consitute the base of the Langhien> 

 overlying the Aquitanien (Calcaire de Beauce) and underlying 

 the Marncs dc i Orlcanais, and the Calcairc-dc-Montalnizard, 

 beds which are parallel with the Sahlcs-dc-Salognc (40 meters). 



The Calcairc-dc-Montabjizard has a mammal fauna ^\•hich 

 Douville compared with that of Simorre, while the Sables de 

 rOrleanais fauna was formerly compared with that of Sansan. 

 But French palaeontologists (Gaudry, Deperet, '92, p. 155) 

 now consider the Sables de rOrleanais fauna somewhat older 

 than that of Sansan, especially because it contains succes- 

 sors of certain Upper Oligocene types such as Bracliyodus 

 ouoideiis, the last of the anthracotheres in Europe, Palaoehirnis 

 typus also a survival, and Pioceri'iilns or Dicroccras (Deperet, 

 '92, p. 155). On the other hand the Sables de T Orleauais 

 mark a faunal change from the Oligocene of the sharpest kind 

 in the presence of the Proboscidia, Dinotheriiivi bavarieuin and 

 Mastodon angustidois, both typically and exclusively Miocene 

 species, which possibly had recently migrated into Europe from 

 Africa by means of a favorable land connection. The Sables de 

 rOrleanais therefore constitute the typical loiucr Miocene of 

 Etu'ope. Freshw^ater equivalents (Deperet, '95, p. 397) of 

 these beds are the Granen Susswasser Molasse (Lausanne) con- 

 taining a rhinoceros ; Engelhaldc (Bern) ; Rappenfluh (Aarburg). 

 The Brackischc Schichten (Ulm) are transitional ; partly calca- 

 reous deposits near Ubn (Eckingen, Eselsberg, Hockheim), con- 

 tain Ancliitheriiini and a fauna which is partly Oligocene, partly 



