III.] 



RELATIONS OF THE FAUNA. 



117 



or less unlike any from other regions. In addition to true mar- 

 supials, the only carnivorous types were the problematical 

 Borhycenidce. 



Now, as stated in the earlier part of the chapter (p. 68), 

 this fauna cannot be older than the lowest Miocene or highest 

 Oligocene ; and among its deficiencies may be noted lemuroids, true 

 carnivores, creodonts, artiodactyle and perissodactyle ungulates, 

 and opossums, all of which were in existence during the Oligo- 

 cene or Miocene in North America and Europe. Moreover, at those 

 epochs the former country lacked the whole of the Neogaeic types. 



Clearly, then, there must have been a barrier between North 

 and South America during the Oligocene and a 



Early Separ- 



portion or the whole of the Miocene; but before ationofN.and 

 entering into the consideration of other evidence S ' Amenca - 

 showing the nature of that barrier, it may be well to give a table of 

 the mammaliferous Tertiary strata of North and South America, 

 with their approximate European equivalents 1 . In descending 

 order this runs as follows : 



Plistocene 

 Up. Pliocene 

 Low. Pliocene 



Miocene 



Up. Oligocene 



Mid. Oligocene 



Low. Oligocene 

 Up. Eocene 

 Mid. Eocene 



Low. Eocene 

 Lowest Eocene 



South America. 

 Pampean 



Santa Cruz 

 Patagonian 



North America. 

 Equus beds. 

 Blanco 



Monte Hermoso f Palo Duro. 



(?) Parana Loup-Fork -j Nebraska 



tDeep River 



(Hiatus) 

 John Day 



/ Protoceras 

 Beds 



White River j reodon 

 Beds 



Titanother- 



ium Beds 

 Uinta 



rWashakii 

 Bridger -I Bridger. 



IWind River. 

 Wahsatch 

 Puerco 



Europe. 



Cave-deposits etc. 

 ? Crag. 

 | Pikermi 



Sansan 



St Gerand-Le-Puy 



Ronzon. 



Montmartre 

 Parisian 



Suessonian 

 Cernaysian 



1 In compiling this table the writer is indebted to Prof. W. B. Scott. 

 Many American geologists (among them Dr Scott) include the whole of the 



