CENOZOIC TIME — TERTIARY. 919 



2. Upper Miocene. 



Loup Fork Group. — (1) Deep liiver beds. (Ticholeptus beds.) — Ungulates: 

 Miohippus, Desmatippus*, Anchitherium, Protohippus, Aphelops, Mastodon. 



(2) Nebraska beds or Loup Fork proper. — Rodents : Steneofiber, Sitomys (Hes- 

 peromys), Hystricops, Palceolagus, Panolax. Edentates: Caryoderma. Ungulates: 

 Chalicotherium, Pliohippus, Protohippus, Hipparion, ? Tapiravus, Aphelops, Teleoceras ; 

 Artiodactyl Ungulates, Merychyus, Merycochoerus, Protolabis, Procavielus, Platygonus, 

 Pliauchenia, Blastomeryx, Cosoryx. Proboscideans : Mastodon. Carnivores : ? Canis ! 

 uElurodon, Pseud^lurus, Mach^rodus, Stenogale, Brachypsalis. 



PLIOCENE. 



1. Palo Diiro beds. — Rodents: ? Arctomys, f Qeomys. Ungulates: Protohippus, 

 Equus !, Hippidium, Aphelops; Artiodactyl Ungulates, large Camel, probably Pliauche- 

 nia. Proboscidean : Mastodon. 



2. Blanco beds. — Edentates: Megalonyx. Ungulates: Equus ! ; Artiodactyl Ungu- 

 lates, Platygonus, Pliauchenia. Proboscidean : Mastodon. Carnivores : Caniniartes, 

 Borophagus, ? Felis ! 



The preceding list of genera has been prepared for this place, for the most part, by 

 W. B. Scott. 



The more important publications on North American Tertiary Mammals and their 

 historical relations, are those of Leidy on the Mammalian Fauna of Dakota and Nebraska 

 (1869), and other memoirs ; Marsh, on the Introduction and Succession of Vertebrate life 

 in America (1877), and his many earlier and later papers ; Cope, on horizons of Extinct 

 Vertebrates (1878), on the Origin of the Fittest (1887), and his other various publications ; 

 H. F. Osborn, on The Rise of the Mammalia of North America (1893), and other memoirs ; 

 and papers by W. B. Scott. 



FOREIGN. 



Notwithstanding the catastrophe that produced over the continental seas 

 the wide exterminations of species which closed Mesozoic time, Europe in 

 the earlier part of the Tertiary era was much like Europe of the Cretaceous 

 period. In the interval there had been emergencies and a widening of the 

 areas of dry land ; yet nearly half the continent south of the parallel of 55° 

 remained under salt water, or was barely emerged. There were freqiient 

 oscillations during the progress of the Eocene ; but in its later part the sea 

 had great extent over southern Europe, covering, in part, the sites of the 

 chief mountain ranges and spreading largely over Asia. Great Britain was 

 still continuous with Europe, and the London-Paris basin was one of the 

 large local seas ; but that basin had narrowed limits in southeastern England 

 and also in France. After the Eocene the conditions were changed by the 

 making and partial elevation of the Pyrenees and large emergencies else- 

 where, but part of the region of the Alps and Juras was still producing rocks 

 for the finishing of the mountains. 



The contrast with Tertiary North America was great. There was no 

 localized sea-border belt of accumulating deposits ; and what it had of inte- 

 rior lakes were estuarine or lacustrine in alternation with marine conditions. 



