MESOZOIC CHANGES IN FAUNAL GEOGRAPHY. 383 
the Eocene of Asia is too little known for any comparison with 
the California Eocene to have value. 
The distribution of Upper Cretaceous fossils on the West 
Coast seems to conform to the climatic zones* as they existed 
in Africa and Europe, California and British Columbia having 
the central European type, while Lower California and Mexico 
have the equatorial type with //ppurites and Buchiceras. 
After the Cretaceous, and indeéd before the end of it, the 
faunas seem to have been limited closely to their present ranges. 
SUMMARY. 
From the foregoing pages the following conclusions are 
reached : 
At the beginning of the Upper Devonian some widespread 
disturbance occurred, opening up connection between the Ameri- 
can and Eurasian seas. 
The Lower Carboniferous fauna of California was developed 
directly out of Devonian predecessors with the addition of some 
Eurasian elements by migration. 
The Upper Carboniferous fauna was developed out of that of 
the Lower Carboniferous, but still with intermigration with the 
Russian and Asiatic regions, so that the California Carboniferous 
resembles the Eurasian even more than it does that of the east- 
ern United States. 
The Lower Triassic fauna of the West is entirely foreign, hav- 
ing migrated in from unknown regions, but having reached nearly 
simultaneously the western part of America, the Salt Range in 
India, and northern Siberia, but having been cut off from central 
Europe. 
The Middle Trias of the West already begins to show rela- 
tionships to the Mediterranean province of Europe, showing a 
connection in that direction, while the similarity to the faunas of 
the Arctic Trias province is disappearing. 
In the Upper Trias the nearest faunal affinities are with the 
Himalayan and the Mediterranean provinces. 
1M. NEUMAYR: Klimatische Zonen wahrend Jura und Kreide Zeit. 
