different date, there is nothing to suggest which flora is the older. Many of the differ* 

 ences which at first seemed to be striking have now proved to be due merely to the 

 comparative rarity of certain plants at one or other of the localities. The plants peculiar 

 to Brunssum are now comparatively few. 



All these localities lie between latitudes 50° 50' and 51° 20'; so that their floras 

 are strictly comparable. The Cromerian localities are somewhat further north, in latitude 

 52° 30'; but being nearer to the Atlantic, Cromer would probably lie on the same 

 isothermal line. 



14 



