Gress : Fossil Plants of the Dakota. 285 



Table No. 2 (see p. 284) is taken from Clements, " Plant Successions," 

 1 91 6, and shows the Cretaceous period, epochs, and formations, ap- 

 proximately in their relation to each other at the present time. 



In comparing the two tables it will be seen that changes have been 

 made, as additional formations have been discovered and named, and 

 new correlations have been made in the light of recent investigations. 



In reviewing these tables, outlines, and expressions of opinion of 

 various authors, it is seen that there is still some uncertainty about 

 the correlation of the Dakota Formation, and that progress is still 

 being made in such correlation. 



We can conclude, however, that the Dakota Formation is pretty 

 closely related to the Raritan, Amboy, Woodbine, Tuscaloosa, and 

 Washita of the Atlantic and Gulf region, while the Magothy, Midden- 

 dorf, and Eutaw may be somewhat younger. The Patoot and Atane 

 beds of Greenland and the Mill Creek beds of Canada are evidently 

 of about the same age. In Europe it is closely related to the Ceno- 

 manian or the lowermost division of the Upper Cretaceous. (See Dr. 

 Horion's description of the structure and relation of the Aachen beds 

 in his " Notice sur le Terrain Cretacee de la Belgique et de la 

 France," 2me. Serie, XVI, 1859, pp. 635-666.) In South America, in 

 the southwestern part of Patagonia, a dicotyledonous flora, apparently 

 of about the same age as that of the Dakota formation, has been 

 found, and this has been included in the Cenomanian division of the 

 Upper Cretaceous. (See Lapparent, Traite de Geologic, Vol. Ill, 1906, 

 p. 1409.) 



Annotated List of Species. 



CONIFERALES. 



Family TAXACE.^. 



Genus Brachyphyllum. 



I. Brachyphyllum crassum Lesquereux (?). 



Thuites crassns Lesquereux. Cretaceous and Tertiary Floras, U. S. Geological 



Survey, VIII, 1883, p. 32. 

 Brachyphyllum crassum Lesquereux, The Flora of the Dakota Group, U. S. 



Geological Survey, Monograph XVII, 1892, p. t,2, PI. 2, fig. 5 ; Newberry, 



The Flora of the Amboy Clays, L^ S. Geological Survey, Monograph XXVI, 



1895, p. 51, PI. 7, figs. 1-7. 



