THE MIOCENE OF EUROPE, ASIA, AND NORTH AMERICA 251 



and far to the southwest in Portugal near Lisbon. In this Lower Bur- 

 digahan stage the flora of Auvergne {Myrica, Cinnamomum, Liquidamhar) 

 indicates a warm and dry chmate.' In the strata of the basin of Mayence 

 the OHgocene flora, Sabal, Sequoia, Laurus, Cinnamomum, also persists.^ 

 The marine cetacean of the period is Squalodon bariensis. 



The Lower Miocene mammals are very widely distributed from India 

 (Sind) on the east to Portugal on the west, and singularly uniform in species. 

 Of the surviving Oligocene forms the robust anthracothere Brachyodus is 

 especiall}" widespread and characteristic of the Lower Miocene; it is 

 the last survivor of this great Oligocene stock. Among perissodactyls, it 

 is interesting to note the survival of the pair-horned rhinoceroses (Dicera- 

 therium), a line also about to disappear. Arising from Oligocene ancestors 

 and highly characteristic of the entire Miocene period are the descendants 

 of three other lines of perissodactyls, namely: the tapirs (Paratapirus) , 

 the aceratheres {Aceratherium) and the aberrant chalicotheres {Macro- 

 therium) . 



The views of Stehlin are somewhat different from those of Mayet. 

 He regards (1907) ^ the fauna of the sables de VOrleanais as preceding that 

 of Montabuzard and as composed of two elements of very different origin. 

 One is indigenous to Europe and has survived from the Oligocene, the 

 other is foreign, recently immigrated from an unknown center, probably 

 from central Asia. Although we now know that the mastodons originated 

 in Africa, the forms that accompanied them when they first appeared in 

 Europe may lead one to suppose that they reached Europe by way of 

 southern Asia. The forms that have developed directly out of the Eu- 

 ropean Oligocene fauna include: Amphicyon, Steneofiber, Palceochoenis, 

 Hyotherium, Brachyodus. Among the immigrants are: Mastodon, Dinothe- 

 rium, Anchitherium, Rhinoceros [T eleocer as] oi the T . aurelianensis brachypus 

 type, Listriodon, Choerotherium, Hymmoschus? , Palosomeryx cf. Kaupi. The 

 different deposits of the sables de VOrleanais are not, as was formerly 

 supposed, identical in age. To the differences in age as well as to the 

 differences in location may be ascribed the fact that the various faunas are 

 not exactly equivalent. The faunas of the successive stages of the sables 

 are increasingly similar to that of Montabuzard, although none of them 

 seem to be quite as modern ; in other words, the calcaire de Montabuzard is 

 held to be more recent than the sables. 



The Lower Miocene horse Anchitherium aurelianense, described by 

 Cuvier himself from the sables de VOrleanais, is a small, relatively primitive, 

 three-toed horse with l)rachyodont molars, in which the cones and conules 

 are very distinct, teeth quite similar, in fact, to those of certain of the 



1 Boulay, 1899, and Giraud, C. R., Vol. CXXXI, p. 91G. 

 ' De Lapparcnt, A., Traite de GooIokio, 1906, p. 1604. 



' Stehlin, H. G., Notices Paleomainmalogiques sur quelques Depots Miocenes des Ba.ssins 

 de la Loire ct de I'Allier. Bull. Soc. Geol. France, Ser. 4, Vol. VII, 1907, pp. 525-550, 5.36, 543. 



