Prof. K. A. von Zittel—On the Mammalia. 508 
Tragulide, Deer, Bears, and Apes, gives to this fauna rather a 
Miocene than a Pliocene stamp, and justifies the opinion of Cope, 
who places these beds in the Upper Miocene. They contain the 
following genera :— 
PERISSODACTYLA. Camelus. ? Geomys. 
Hipparion (E.) Pliauchenia. ? Thomomys. 
Merychippus. Cosoryx. 
Protohippus. CARNIVORA. 
Pliohippus. PROBOSCIDIA. (Fissipedia. ) 
Equus (E.) Mastodon (E.) A lurodon. 
Tapiravus. Canis (E.) 
Aphelops. . RODENTIA. Leptarctos. 
Eucastor. Stenogale. 
ARTIODACTYLA. Mylagaulus. : Mustela (E.) 
Merychyus. Hesperomys. Brachypsales. 
Merycocherus. Palezolagus. Lutra (E.) 
Protolabis. Punolax. Pseudelurus. 
Procamelus. 
The Loup Fork beds share with Hurope the genera Equus, Hip- 
parion, Mastodon, Canis, Mustela, and Lutra, and with South Asia, 
Camelus. On the whole, this fauna is somewhat further removed 
from that of the Old World; the specialization of peculiar North 
American forms, already indicated in the Lower and Middle Miocene, 
has made visible progress. The bond between the two provinces of 
the Northern hemisphere has become looser. 
In South America the Araucanian Formation of Ameghino may 
correspond with the Older European Pliocene. At Monte Hermoso, 
near Bahia Blanca, it has yielded about sixty species of Mammalia, 
which are divided amongst the following genera :— 
MARSUPIALIA. PERISSODACTYLA. * Typotherium. 
Didelphis. * Tapirus (N.) * Pachyrucos. 
A (Antaodon.) 
EDENTATA. *Floppidium (N.) RODENTIA. 
Gravigrada. Macrauchenia. * Myopotamus. 
Lestodon. *Epitherium. *Tribodon. 
*Megatherium. *Eumysops. 
*Scelidotherium. ARTIODACTYLA. *Dicelophorus. 
Pseudolestodon. *Auchenia (N.) * Phthoramys. 
Diodomus. * Eoauchenia (N.) * Platemys. 
* Paraceros (N.) *Pithanotomys. 
GLYPYODONTIA. Lagostomus. 
* Glyptodon. PROBOSCIDIA. Megamys. 
Hoplophorus. *Mastodon (N.) *Orthomyctera. 
*Plohophorus. * Microcavia. 
* Panochthus. TOXODONTIA. *Paleocavia. 
Neuryurus. Toxodon. * Diocartherium. 
FPlaxhaplus. *Trachytherus. * Phugatherium. 
: * Trigodon. * Hydrocherus. 
DASYPODA. Xotodon. Caviodon. 
Chlamydotherium. 
Dasypus. TYPOTHERIA. CARNIVORA. 
* Dasypotherium. Protypotherium. *Canis (N.) 
Proeuphractus. 
Futatus. 
The Autochthonous Marsupials, Edentates, Perissodactyla, Toxo- 
donts, Typotheria, and Rodents contain genera, in part handed over 
