168 EDWARD W. BERRY 



to Europe, where Eocene plant beds are so common, about as 

 quickly as it did to North America. This fact and the large num- 

 ber of American Eocene species fortify the conclusion that the 

 early ash was an American product. 



However, the ash was well on its way toward Europe for dur- 

 ing the succeeding Oligocene the leaves and fruits are found at a 

 large number of localities on that continent, from the amber 

 beds on the shores of the Baltic to the gypsum beds along the 

 shores of the Gulf of Lyons. Ten different forms of Oligocene 

 ash are known and these are all European, since Asia remains 

 unknown and in North America the deposits of Oligocene age 

 are largely marine marls or limestones along the continental 

 borders or flood plain and channel deposits in the interior in which 

 fossil plants seem to be rarely found. Two fruits of Oligocene 

 ashes from Europe are shown on the accompanying plate. 



Passing to Miocene times, which succeeded those of the 

 Oligocene, we find Fraxirius, like most of the other tree genera, 

 to have been widespread, diversified and common, and probably 

 more abundant than at the present time — their geographical 

 range was certainly more extensive then than now. Over thirty 

 different ashes are known from Miocene deposits. They are 

 found in North America in Oregon on the west coast and in 

 Virginia on the east coast. A hint at their probable abundance 

 at this time in the Rocky Mountain region is given to us by the 

 lake deposits at Florissant, Colorado, where the fortunate preser- 

 vation of the sediments of this tiny lake basin furnish an un- 

 paralleled picture of the insect and plant life of Miocene times 

 in that region. 



No less than seven species of ash have been discovered in these 

 Florissant beds, thus indicating that the ash was much more 

 abundant and diversified at that time than would otherwise 

 have been suspected from a consideration of the rather infrequent 

 Miocene plant beds of other parts of North America. Fraxinus 

 is present in all of the more important Miocene plant bearing 

 deposits throughout Europe, and it appears to have been es- 

 pecially abundant in late Miocene times along the shores of the 

 Mediterranean and in the uplands of central France, southern 



