1898—1902. No. 21. LICHENS. 51 
Notes on the systematic list. 
The foregoing list shows that the district, which includes Arctic 
America, Greenland, Spitsbergen and Iceland, has about 500 lichens re- 
corded for it. I have no doubt that more will still be found. My in- 
clusion of the lichens of Greenland, Spitsbergen and Iceland in a list 
of those brought back by the Second Norwegian Expedition to Arctic 
America is, I consider justified. The enumeration of lichens given above 
will thus give us a fairly complete picture of the lichen-vegetation of 
Ellesmere Land and King Oscar Land. 
To show in what relation the lichen-floras of these four districts 
stand to one another I have compiled a few statistical notes, comparing 
the lichens found in Arctic America, Greenland, Spitsbergen and Iceland. 
This list enumerates a total of 495 arctic lichens. Of these there 
have been recorded for 
Arctic America . 2. 1... . «258 or 51.1% 
Greenland . . .. . . . . . 3888 or 682 - 
Spitsbergen . . . . . . . . 206 or 41.6 - 
Tedland, . 2 2 + « « » « » » BSL or Ls + 
It must be mentioned also that of this total of 495 lichens we have 
recorded as occurring in 
Arctic America only. . . . 57 or 11.5% species 
Greenland only . . . . . 77 or 15.5 - 
Spitsbergen only . . . . . 33o0r 6.6 - 
* Tedland only. a wa « 4. Shor Fa- 
Only 84 or 16.9 °%/o of the total of 495 lichens are found to be com- 
mon to Arctic America, Greenland, Spitsbergen and Iceland. 204 or 
41.2°/, of the total are confined to one only of the four districts. It 
would have been possible and very interesting to compare with this the 
lichens of Alaska or the temperate parts of America, but I have rather, 
