ORIGIN AND DISTRIBUTION OF MAMMALS 299 



which is cei'tainly represented also by scattered remains in Florida and Oregon. 

 In time both stages come between the European Upper Miocene and Lower 

 Pliocene, for generally a strict correlation of the North American and European 

 faunas appears scarcely justifiable, and we are rather dealing with an alternation 

 in time. The Canidae are represented by Aelurodon, Amphicyon, Dinocyo'ii, Cards, 

 Ischyrocyon ; the Mustelidae by Mustela, Futorius and Potamotherium, Lutra and 

 Brachypsalis ; the Felidae by Machairodus and Fseudaelunis ; the Froboscidea by 

 several well-characterised species of Tetrahelodon (Trilophodon) ; the Ehinoceridae 

 by the last but very abundant species of Teleoceras, Feraceras and Aphelops. 

 The number of the described species of the Equidae, Frotohippms and Neohippjarion, 

 from these deposits is very large, but with these there have also been preserved 

 more primitive forms, Hypohippus, Farahippus and Merychippus. Among artio- 

 dactyls occur Suidae — Flatygonus, Frosthenops — and Camelidae — Frocamelus, 

 Frotolabis and Pliauchenia. The Agriochoeridae gradually become extinct with 

 the genera Fiwnerycochoerus and Merychyiis, while Falaeomeryx-like deer, such as 

 Blastomeryx and the antilocaprid Merycodus, become rather numerous. Finally, 

 the rodents are represented by the genera Sclurus, Falaeardomys, Dipoides, 

 Sigmogomphms, Mylagaulus, Epigauliis, Geomys, Hesperomys, Fanolax and Lepus. 



As the lower limits of the European Miocene may best be taken the fresh- 

 water deposits of Ulm and Mainz, which are characterised by the presence of 

 Helix rugulosa. Of the same age also are the freshwater limestone of St. 

 Gerand-le-Puy, the asphalts of Pyrimont-Challonges, Savoy, and the lignites of 

 Briix. Of Oligocene types there still occur here especially numerous Caeno- 

 therium and Fcdaeochoerus, besides the carnivores, Falaeogale, Flesidis, Stenogale, 

 Amphidis and Gephcdogale ; also the last marsupials. The perissodactyls — 

 Chalicotherium, Faratapirus, Aceratherium and Diceratherium — are only advanced 

 developmental stages of previous types. The same remark applies to the 

 Cervicornia, Amphitragulus and Dremothermm. Among the carnivores, Amphi- 

 cyon, Fotamotherium and Herpestes are conspicuous ; among rodents, Steneofiher, 

 Flesiospermophilus, Myoxus, Cricetodon and Titanomys. Their derivation from 

 types previously represented in Europe seems in some respects doubtful, at 

 least for part of these genera. The insectivores and bats are closely related to 

 living forms, and belong in part even to existing genera. The Anthraco- 

 theriidae are now represented by a new type, Bradiyodus. 



After this period the sea again took possession of a great part of the middle 

 of the European continent, so that remains of land mammals in the Middle 

 Miocene are somewhat rare, and are only preserved in greater number in places 

 which were not submerged, such as near Tuchorschitz in Bohemia and on the 

 Jurassic plateau of Solenhofen, Bavaria. They belong to a fauna which agrees 

 essentially with that of the Upper Miocene, but has still in common with that 

 of the Lower Miocene the genera Brachyodus, Falaeochoerus, Amphicyon, Cepkalo- 

 gale, and Flesidis. The Caenotheriidae are almost, the marsupials completely, 

 extinct. Of the deer — Falaeo7neryx — the smaller are already characterised by 

 the possession of antlers ; the rhinoceroses — Aceratherium, Diceratherium — are 

 evidently in part the direct successors of previous types, but a new form, 

 Brachypotherium, occurs with them. The most important event, however, is 

 the first appearance of the Froboscidea in Europe of the genus Tetrahelodon. 

 In the sands near Orleans there also occurs Dinotherium, besides Anchitherium, 

 and even already an anthropoid ape, Fliopithecus. The marine Miocene, unlike 

 the Oligocene, contains not only Sirenia — Halitherium still with Metaxytherium — 



