Ixiv. PRESIDENT'S ADDRESS. 



emergence, produced an abundant vegetation. Later on, 

 it was again submerged, when fluvio-marine conditions pre- 

 vailed. These fossil Dicotyledonous plants were not confined 

 to America. Bohemia, Moravia, Harz, Saxony, Westphalia, 

 Aix-la-Chapelle, and Toulon and its neighbournood have fur- 

 nished rich series from the Middle Cretaceous beds, in which 

 Nordenskiold found them also in the Arctic regions. Among 

 the most noteworthy genera of the Dakota-flora, Lesquereux 

 catalogues Liquidambar, the Sweet Gum, which grows both in 

 Europe and America, the Poplar which made its appearance very 

 early in Greenland, increasing in number of species throughout 

 the Cretaceous and Tertiary period. The Willow followed a little 

 later, and was followed by the Beech t Oak, and Chestnut 

 (Castanea). The Plane Tree, of which Europe has now only 

 one species, is largely represented in the Cretaceous beds. The 

 Tulip Tree is the sole survivor of a genus which had several 

 species at that period. Magnolia, which was well represented in 

 the Cretaceous age, is equally so in America at the present 

 day, as is also the Walnut family. The Tertiary flora has 

 affinities with the Cretaceous on the one hand, and with the 

 modern on the other. The Lamarie series, which is Tertiary, 

 occupies two extensive areas in Canada, separated by a 

 tract of older Cretaceous rocks, over which it is likely they 

 extended, and subsequently were removed by denudation. The 

 eastern part extends along the United States boundary for some 

 distance. The western is overlaid by Miocene deposits, con- 

 taining Mammalian remains. This series is determined by the 

 passage-beds between the Cretaceous and Tertiary beds, and 

 may be divided into two groups, the upper and the lower, the 

 former are wholly argillaceous, the latter partly arenaceous and 

 partly argillaceous. They contain no Mammalian remains. Two 

 Ferns of the upper group are remarkable proofs of the persistence 

 of species; they were discovered side by side in the Upper 

 Cretaceous beds of the west of the Red River. One of these, 

 Onoclea sensibilis, or the sensitive fern of Eastern America, has 

 apparently continued in America until the present day. It occurs 



