464 Prof. K. A. von Zittel—On the Mammaiia. 
of the fossil Cetacea in the Miocene of Europe and in that of the 
United States (New Jersey, Maryland, Virginia, Georgia, Carolina). 
These contain the following genera :— 
EUROPE. NorTH AMERICA. 
CETACEA. SIRENIA. CETACEA. 
Squalodon. Halitherium. ? Delphinodon. 
Champsodelphis. Rhytiodus. ? Phocogeneus. 
Trachyacanthus. Metaxytherium. Squalodon. 
Delphinopsis. Miosiren. Zarhachis. 
Lleterodelphis. Prohaticore. Lxacanthus. 
Priscodelphinus. Cetophis. 
Schizodelphis. CARNIVORA. Lophocetus. 
Macrochirifer. (Pinnipedia. ) Priscodelphinus. 
? Cetorhynchus. Pristiphoca. khabdosteus. 
Beluga. Monatheriun. A gabelus. 
Physodon. Prophoca. Balenoptera. 
Hoplocetus. Mesotaria. 
Llesiocetus, SIRENIA. 
Cetotherium. ? Hemicaulodon. 
For the Middle Miocene land mammalian fauna also there is not 
wanting a parallel in North America. Hitherto only the extreme 
West, in the territories of Oregon, Nevada and Washington, has 
yielded those remains, in part so wonderfully preserved, which 
compose the John-Day fauna. The abundant occurrence of Rhino- 
ceros, Aceratherium, Anchitherium, Steneofiber, Sciurus, Lepus and 
Galecynus shows that European genera could, at that time, still 
wander to the Pacific Ocean, and even although certain specifically 
American families, like the Oreodontide and the Camelidz, have 
experienced a further evolution and increase in number, there are, 
nevertheless, not wanting representative forms from which a common 
origin and the former connection of both continents may be inferred. 
To the oldest horn-bearing mammal in Europe (Dicroceras) corre- 
sponds in North America Blastomeryx, to the remarkable Macrotherize 
and Chalicotheriz of the old world, the American genus Moropus, 
and also between the Rodents and Carnivora of both continents there 
are many related links, although the lists mostly contain other names, 
which, however, mainly indicate similar forms. The fauna of the 
John-Day beds contains the genera mentioned below : '— 
PERISSODACTYLA. Agriocherus. CARNIVORA. 
Anchitherium (E.) Merycocherus. (Fissipedia.)} 
Aceratherium (E.) Blastomeryx. Temnocyon. 
Rhinoceros. Galecynus (E.) 
(Diceratherium) (E.) RODENTIA. flyenocyon. 
Moropus. Allomys. Oligobunis. 
Sciurus (E.) Lnhydrocyon. 
ARTIODACTYLA. Steneofiber (E.) Nimravus. 
Boocherus. FPleurolicus. Pogonodon. 
Cheenohyus. Lintoptychus. Archelurus. 
Bothrolabis. Hesperomys, Hoplophoneus. 
2? Thinohyus. Paciculus. 
Coloreodon. Paleolagus. 
Lepus (E..) 
1 The genera to which the letter (E.) is affixed occur also in Europe. 
