AGE OF THE UGNITIC DETERMINED BY ITS FLORA, 313 



to the geological distribution of the plants, I have marked upon the pages 

 of explanations, and after the name of each species, numbers indicating tlie 

 geological divisions which they represent, while the table of distribution 

 shows the localities from which the plants are derived and the groups to 

 which they are referred. 



This table of distribution will be easily understood. The references 

 to species of geological groups, either European or American, are not equally 

 precise. They are marked by the note of interrogation (?), or by the excla- 

 mation point (!), according to the degree of relation or of identity, both 

 being either positive or more or less indefinite. 



