The Botany of Iceland - 01.12.1912, Side 112

98
H. JÓNSSON
the vegetation, as I have thought it better to designate the algal
Benthos taken as a whole by this word, and to call it the “algal
region.”
I have also avoided the term “formation.” The algal formations
established by Kjellman and others are not real formations, but
only associations (Warming, 72, p. 171), and the entire marine
algal vegetation is given as a subformation of marine algæ (Halo-
nereid; Warming, 72, p. 169). I do not think that the term “forma-
tion” should be used in connection with the algal region in any
other sense than tliat in which it is used in connection with land
vegetation. As the term “facies” cannot be used in English to de-
note a vegetation-unit (Warming, 72, p. 146, foot-note) I have
avoided it.
I divide the vegetation in each of the three zones into asso-
ciations, and where I think they are closely allied I combine them
into communities.
Sometimes by the suffix “etum” is meant the subordinate part
of an association, and sometimes a vegetation-unit which almost
corresponds with an association.
ACCOUNT OF THE MARINE ALGAL VEGETATION AND THE
SEA-GRASS VEGETATION.
A. The Marine Algal Vegetation.
a. The Littoral Zone.
aa. The Photophilous or strictly Littoral Communities.
1. The Prasiola stipitata-association.
2. The Community of Filiform Algæ.
3. The Community of Fucaceæ.
4- The Pelvetia-Fucus-spiralis-belt.
+ -t- The Fucus-belt.
4. The Enteromorpha-association.
5. The Acrosiphonia-association.
bb. The Shade-vegetation.
6. The Hildenbrandia-association.
7. The Rhodochorton-association.
cc. The Vegetation of Tide-pools.
b. The Semi-littoral Zone.
8. The Monostroma-association.
9. The Chorda-association.