The Botany of Iceland - 01.12.1912, Page 83

H. JÓNSSON : MARINE ALGAL VEGETATION
69
to the definition liere employed. The Siberian Sea, however,
comes nearest to it. From here 23 species are known (14), of
which 9 (39%) are arctic, 11 (48%) subarctic and 3 (13%) boreal-
arctic. This district is at the boundary between arctic and sub-
arctic. Regarded superficially it may appear strange that none of
the districts are arctic, but on closer inspection this is easily under-
stood, the reason being that some of the districts (14) are too large
and consequently aciiuire a mixed character. In tliis respect I shall
merely point out, for instance, that hotli Spitzbergen and East
Greenland (and probably West Greenland) ought to be divided into
two districts.
As already mentioned, none of the districts recorded in Table 6
is arctic. East Greenland, Spitzbergen and West Greenland have almost
the same percentage as regards the arctic species (Table 6), and as
this percentage is rather higli in proportion to that of the boreal
species, these districts could be termed arctic-subarctic, in contra-
distinction to E. Iceland where the arctic percentage is four times
less than the percentage of the boreal species. The boreal dist'ricts
recorded here (Table 6, p. 70) should, strictly speaking, be called
cold-boreal.
If we call the first three groups (in Table 6) A and the three
last B the percentages will be as followrs: —
E. Greenl. Spitzb. W.Greenl. E. Icel. Finm. SW. Icel. S. Icel. Fær. Nordl.
A....... 81 77 72 63 46 42 30 29 27
B....... 19 23 28 37 54 58 70 71 73
As the table shows, SW. Iceland agrees most closely with Fin-
mark, while S. Iceland and the Færöes are nearly alike, as Börge-
sen (12, p. 804) also supposes.
If we take Iceland as a whole, wre get 143 species (red and
brown algæ collectively), 10 (7 %) arctic, 21 (15 %) subarctic (sub-
division I), 29 (20 %) subarctic (subdivision II), 17 (12 %) boreal-
arctic, 56 (39%) cold-boreal and 10 (7 %) warm-boreal. These íigures
are almost the same as tliose given for Finmark (see Table 6) and
differ, essentially from the figures given for SW. Iceland, only
by the higher percentage of arctic and wTarm-boreaI species. If, on
tlie other liand, we take the lirst three groups collectively and
the three last groups in a similar manner, we obtain the same
percentages as for SW. Iceland. On combining different parts of the
coast, as for instance, E. Iceland and N. Iceland, wre get almost the