818 GEOLOGY 



lower part of the Oligocene-Miocene series (Patagonian beds) is 

 marine, while the upper part (Santa Cruz) is of fresh-water on 

 The terrestrial faunas of this region are strikingly similar to the 

 Miocene and later faunas of Australia and New Zealand. This 

 relationship has caused speculation as to an Antarctic continent 

 connecting these regions. 



Arctic latitudes and climate. Miocene beds are somewhat 

 widely distributed in the Arctic regions and seem to be largely of 

 terrestrial origin, with the fossil floras indicating a warm tem- 

 perate climate. Forty-six of the 137 species of plants found in 

 North Greenland 1 (Lat. 70 and less) , including species of sequoia 

 and magnolia, are also found in central Europe, and the floras of 

 Spitzbergen and Grinnell Land were hardly less luxuriant. 



Curiously enough the Miocene plants of Alaska, Kamschatka. 

 and Japan indicate a climate cooler than that of the higher latitudes. 

 It seems probable that this apparent discrepancy is the result of 

 imperfect correlation, the fossils indicating these inharmonious 

 conditions not being contemporaneous. The fauna of New Zea- 

 land is distinguished by the great size of some of its mollusr:m 

 shells. Both the flora and fauna have a tropical aspect, the fruit 

 of the palm having been found as far south as latitude 45. 



THE LIFE OF THE MIOCENE 

 The Land Plants 



The mid-latitude flora of the Miocene records the gradual dis- 

 appearance of subtropical types, and an increase of deciduous trees. 

 This is particularly true of North America, where the flora caiii 

 resemble that of to-day in somewhat lower latitudes, and is indeed 

 its predecessor. An important feature in North America was 

 increase in the grasses, with its appropriate effect on mammals. 



How far the gradual removal to the south of the forms no\\ 

 regarded as tropical or subtropical, and how far the concentration 

 at the north of the forms that now characterize those latit 

 were the result of a natural segregation of the previously mingled 

 forms, and how far the result of changes of climate, it is per!. 

 unsafe to say; it has usually been attributed to the latter. 



1 Heer, Flora Fossilis Arctica, 1868-83, and Q. J. G. S., ls7s. Th 

 some question as to the Miocene age of these fossils. 



