TERTIAET PERIOD BY MEAXS OP THE MAIDIAXIA. 385 



The presence of a living Marsupial genus in a fauna in which 

 Placental living genera are absent might be expected, since the 

 Marsupials lived throughout the Secondary period, while the 

 Placental mammals only appear in the Tertiary. The former there- 

 fore in the Lower-Eocene age were in a more advanced stage of evo- 

 lution than the latter. 



The Tapir-like CorypTiodon is widely distributed, and marks the 

 horizon of the Lower Eocene, not merely in Prance and Britain, 

 but in Switzerland and Xorth America. It was pentadactyle, and 

 i^ossessed a brain shown by Prof. Marsh to be remarkably small. 



The genus LopModon appears to be characteristic of the Mid- 

 Eocene Mammalia of Europe. 



In the Upper Eocenes the Carnivora present the same association 

 of Marsupial with Placental characters which has been observed in 

 the Lower Eocenes, and have not yet lost the traces of their descent 

 from a long line of Marsupial ancestors. . Among the European 

 Ungulates the Palseothere and Anoplothere are the two most charac- 

 teristic forms. 



The Upper-Eocene forests of Erance were also haunted by repre- 

 sentatives of the highest order of Mammalia, or the Primates, which 

 includes the families of Man, the Ape, and the Lemur. The Adapis^ 

 of the Paris basin, classified by Cuvier with the Anoplotheres, has 

 recently been proved to be related to the last of these, as well as to 

 the hoofed quadrupeds and Insec1?ivores. To the sa«ne family also 

 belong the ^"ecrolemurf. discovered in the south of Erance, and the 



^& 



CcenopitJiecus t. of liiitimeyer, found in Switzerland. The family is 

 also proved § by Marsh and Cope to have inhabited the forests of 

 I^^orth America during the whole of the Eocene age in New Mexico, 

 Wyoming, Dakotah, and i^ebraska. j^one of these are identical 

 with any living genus of Lemurs ; but all possess characters bringing 

 them into relation with one or other of the families of hoofed qua- 

 drupeds living in the Eocene period. 



6. The Miocene Mammalia. 



The Miocene Mammalia, represented in Britain by the Hyopo- 

 tamiis, are well defined by discoveries made in various parts of the 



* Gervais, ' Zool. et Paleontologie Grenerale/ p. 28 ei seq. ; ' Journ. de ZooL' 

 i. p. 476 ; ' Phosphorites de Quercy, Tarn-et-Garonne et Lot.' 



t Filhol, 'Journ. de Zool. ii. p. 476 ; Gaudry, op. cit. iy. p. 21 ; Delfortrie, 

 op. cit. ii. p. 476; Gaudry, ' Les Encbainements,' ch. x. 



j Eiitimeyer, ' XJeber die Herkimft unserer Thierwelt' (4to, 1867), p. 52. The 

 I'auna of the Bohnerz, in which the Ccenopithecus was found, is considered by 

 Heer to be of Mid-Eocene age. It seems to me more probable that it represents 

 also the Upper and Lower divisions. The local deposit of Bohnerz (iron-ore) 

 in Switzerland had begun in the Cretaceous age, and may have been continued 

 throughout the Eocene period. The fauna contains characteristic forms of 

 Upper- as well as Middle-Eocene species. 



§ Marsh, "Introduction and Succession of Vertebrate Life in America," 

 American Association for the Advancement of Science, 1877; Cope, ^' Hyop- 

 sodus" Eeport of U.S. Geological Survey of the Territories, Fossil Vertebrates, 

 i. p. 75. 



Q.T.G. S. K'o.MS. ./ 2d 



