46 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [VolY. 



Stamtian and Aqtjitanian. White Exver. 



AnthracotJierium. 



Oreodontidce. 

 Anoplotheriidce. 

 EyopotamidcB. Merycopater. 



Poebrotherium. 

 LopMomeryx. Sypertragulm. 



Amphitragulus. 

 Leptomeryx (Pliospli.). Leptomeryx. 



DremotJwrium. 



Hypisodus. 



The Falunian epocli includes in tlie large sense tlie Langhian, Helve- 

 tian, and Tortonian divisions, embracing the rich deposits of the OrM- 

 anais, of Simorre, and of Sansan. We have here the true Miocene fauna, 

 of which the following genera are characteristic : Edentata, Macrothe- 

 rium;Vr6bosGidea,,Dinotherium, Mastodon; Perissodactyla, Ancliitlierium, 

 Listriodon; Artiodactyla, Falceomeryx, Dicrocerus, Procervtchis ; * Car- 

 nivora, AmpMcyon, Hycenarctos, ? Ifachcerodus ; Quadrumana, Pliopi- 

 tJiecus. The ancient genera Anthracotherium and Ccenotherium continue 

 throughout, and the existing genera Armcola, Lutra, and 8ns appear. 

 The succeeding epoch, the Oeningian, including with it the horizons 

 of Epplesheim and Pikermi, presents the additional genera Dorcathe- 

 rium, Helladotherium, several genera alhed to Antilope, with Hippotlie- 

 rkim, the huge edentate AncylotJierium, and the monkey MesopWiecus. 



It is from these materials that we must determine by comparison the 

 American Loup Fork epoch, whose deposits are widely spread, and 

 whose fauna is of well-marked character. Although called by my pre- 

 decessors Pliocene in age, I have insisted that it should be referred to 

 the Miocene series, and I think that the evidence to that effect, which I 

 have produced, wiU be found conclusive. Nevertheless, here, as in other 

 American Tertiary horizons, the element of geographical peculiarity en- 

 ters, and diminishes the number of identical types. 



Falunian. Loup Fokk. 



Steneofiher. Steneofiber. 



\.] 



Morotherium. 



Macrotherium. 



AncylotJierium. 



AmpMcyon. AmpliicyonA 



Dinotherium. Ccenohasileus. 



Tetralopliodon. Tetralopliodon. 



Acerathermm. ApJielops. 



AncMtherium. 



Listriodon. 



*Gaudry, 1878; Dicrocerus Cope, 1874 (not Lartet)j Merycodus et Cosoryx Leidy, 

 nomina nuda. 

 t Ccmia ursinus Cope. 



