232 EDWARD W. BERRY 



Greenland to Alabama along the Atlantic coast and furnishes a 

 striking illustration of the difference between Cretaceous and 

 present day climates. 



There are about twenty-five Eocene species of walnut well 

 distributed over the northern hemisphere. They extend from 

 the Mexican Gulf region to Alaska and Greenland in North 

 America and from Saghalin Island off the east coast of Asia to 

 western Europe in the old world. 



The Oligocene walnuts are not quite so plentiful as are those 

 of the Eocene and are almost entirely confined to the old world. 

 This is undoubtedly an expression of the incompleteness of the 

 geological record in North America since there are practically 

 no known Oligocene plant beds in this country. 



The Miocene has furnished upwards of two score species, the 

 majority of which are old world forms distributed from Japan 

 to western Europe. This again being due more to lack of records 

 in America rather than to the absence of the genus. In this 

 country nuts are preserved in the curiosuly isolated lignite de- 

 posit near Brandon, Vermont. There are species in Idaho, 

 several in California and Oregon, and four in Colorado in the 

 late Miocene at Florissant. Both fruit and leaves are frequently 

 found associated in the various Tertiary deposits and nuts also 

 occur with the leaves in some of the Cretaceous deposits. 



The Pliocene species are also numerous, a number of them sur- 

 viving from Miocene times. In all about twenty-five forms have 

 been recorded from the Pliocene deposits and several of these 

 are very close if not identical with still existing species. From 

 the upper Pliocene of Germany nuts have been collected in the 

 lignite deposits which are exactly like those of the existing Ameri- 

 can species Juglans nigra and Juglans cinerea. 



Walnuts are not common in Pleistocene deposits but the fruit 

 of Juglans regia Linne is recorded from the Pleistocene of southern 

 France, and our own black walnut, Juglans nigra Linne, has 

 been found in the late Pleistocene of Maryland and in the Pleis- 

 tocene river terraces of Alabama. Both of these occurrences are 

 based upon the characteristic nuts preserved in the impure peat 

 of buried swamp deposits. 



