440 FLORA OF THF. LARAiriE GRorP. 



last Aiiiiii;il Keport of tlie Geological Survey (lSS3-'84, p. 440) I showed 

 that 354 Senouiau species were then kiiowu, a flora slightly larger than 

 that of the Laramie group. The princii)al localities from which this 

 flora is (Icrivcd arc: the Iron sands of Aix-la-Chapelle, the Crcdncria 

 beds of r>Ianketd)iirg and Qiiedlinhnrg in the Harz Mountains, numer- 

 ous deposits in Westphalia, the Gosau formation in Austria, the Lig- 

 nites of Fuveau in Provence, France, the beds of Patoot, Greenland, 

 and those of the Peace and Pine Elvers, British America, and of Van- 

 couver and Orcas Islands on the Pacific coast. All of these beds are 

 quite definitely fixed in the u])i)er Cretaceous, those of ilurope being 

 well known. As regards the others. Professor Heer states that those of 

 Patoot i»ossess a molluscan fauna identical with that of the Fox Hills 

 group of North America, and Mr. G. M. Dawson correlates those of the 

 interior of British America with the Niobrara of Meek and Hayden, and 

 those of the Pacific coast with the Fox Hills. All authorities agree, 

 however, that all these beds are lower than the Laramie, and Dawson 

 makes our Fox Hills the equivalent of the Maestricht and Faxoe beds, 

 the white chalk, Danian, or extreme upper Cretaceous of Europe. 



EXPLANATION OF THE TABLE OF DISTRIBUTION. 



The following table aims to give all the fossil plants which have 

 been thus far authentically described and recorded (1) in the Laramie 

 group as above defined, (2) in the Senonian as last described, and (3) 

 from the beds that have been unanimously referred to the Eocene. 

 This last naturally excludes the Green River group, which is regarded 

 as the American Eocene of the West by nearly all authorities except 

 Mr. Lesquereux. As this one prominent author assigns the Laramie 

 group (as defined by him) to the Eocene and places the Green Eiver 

 deposits in a higher formation, and as it is chiefly to test this (juestion 

 that the table and its discussion are intended, it would manifestly viti- 

 ate the argument to prejudge the question by adding the Green River 

 group to the accepted Eocene. 



In preparing this extensive table it has been my aim to embody in it 

 as large an amount of information bearing not only upon the age and 

 synchronism of the Laramie group but also upon all the collateral 

 problems arising out of a study of the flora of that group as could be 

 condensed into that amount of space. The plants are systematically 

 arranged according to the latest botanical classifications, the names of 

 the subordinate groups being entered in their proper places and dis- 

 tinguished by ditterent type. The genera occupy separate lines and 

 the number of species represented in each genus is given in each col- 

 umn on those lines, the occurrence of species in the several formations 

 being denoted by the customary sign { + ) employed by most authors 

 for this object. 



In the vertical arrangement the Laramie group is placed first merely 



