30 H. MØLHOLM HANSEN 
of the country E., N., N. W., S. W., and S. Iceland. The designation 
algeng, hjer & hvar, or sjaldgæf after each species denotes whether 
the species is common, scattered or rare. For each of the 5 parts of 
the country have been added up the species of the respective groups 
1) which are absent, 2) which are scattered to rare or 3) which are 
common within the area. The investigation has been carried out for 
the flora as a whole, for thé main groups, Å and E, and for the sub- 
groups under these two groups, and the result expressed in percent of 
the species number of the group in question has been given in table 6. 
The means for all parts of the country are given below in the table. 
The A group has more common species, less rare or absent species 
than the E group; while on an average 15,4 p. c. of the species of the 
A group are absent in each part of the country, the same figure 
for the E group is 22,9 p. c. For the commonly occurring species the 
proportion of A to E is as 54.7 to 38.8. 
If next we turn to the subgroups, the table shows that A 2 has 
the greatest number of common species, while A 3 and especially 
A 1 show a smaller number. Of the E subgroups, E 4 has the 
greatest number of common species, 62,8 p.c., E 1 the smallest number, 
8,6 p.c. E3 and E2 occupy an intermediate position with 54,0 p. c. 
and 32.5 p. c. respectively of common species. The numerical values 
for the rarer and absent species entirely confirm the sequence. In 
addition the table shows the quantitative conditions of the flora 
and species groups in the 5 Icelandic areas. The A group occurs 
most frequently to the east and north, the E group to the south 
and south-west. In the A group this is due especially to A 2, in 
the E.group, to E2 and E 1. 
Aided by the above-mentioned tables we can now give the 
following description of the distribution of the Icelandic species 
groups in northern Europe and the arctic regions. 
The E group comprises species of common occurrence in Cen- 
tral Europe. The species have their main distribution to the south 
of or below the forest limit, the 20 p.c. Ch biochore. The various 
species, however, transcend this limit in varying degree in conse- 
quence of which the following 4 subgroups may be distinguished. 
E 1 requires the greatest amount of heat. In England, Denmark, 
northern Germany, and southern Scandinavia the E 1 species are 
of common occurrence. In Finland they only occur in the most 
southerly part, in northern Scandinavia only or principally on shel- 
