The Botany of Iceland - 01.12.1916, Síða 46

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or species in question is found; where no figure is added it means,
that the genus or species in question has only been found in one
sample.
The following are some of the more conspicuous characterising
forms on Rodophyceae:
Rhabd. arcuat in 12 samples = 9.6 %, Cocconeis and Gramma-
tophora each in 11 samples — 8.9%, Licmophora and Synedra each
in 6 samples = 4.8 %.
Phæophyceæ Numher 1 of samples j
1 Ascocyclus 108 1 Frag. vitrea.
2 Ectocarpus 38 Biddulphia aur., Gomphonema exiguum, Frag. striat. (3),
3 Elachista 8 Hyalodiscus scoticus, Licmophora, Navicula rhom- bica, Podosira, Rhabd. arc. (2), Rhoicosph. cur., Synedra (5). Rhabd. arc. (2).
4 Fucus 6 Isthmia, Rhabd. arc.
5 Isthmoplea 6 Frag. striat., Synedra.
fl Laminaria 1 Grammatophora, Podosira, Navic. (Schizonema).
7 Leptonema 2 Rhoicosph. curv., Synedra.
8 Lithoderma 4 Frag. striat., Grammatopliora, Licmophora (3).
9 Myrionema 6 Biddulphia aur., Cocconeis (2), Frag. vitrea, Podosira,
10 Phyllitis 7 Rhabd. min. Cocconeis (2), Frag. striat.
11 Pogotrichum 9 Biddulphia aur., Cocconeis, Podosira, Rhabd. arc., Sy-
12 Punctaria 1 nedra (2). Frag. striat., Synedra.
13 Ralfsia 8 Diploneis incurvata.
14 Sphacelaria 7 Cocconeis (3), Rhabd. min.
15 Stictyosiphon 4 Licmophora.
The following are some of the more conspicuous and charac-
terising forms on Phaeophyceae: Synedra 10 samples, or 9.3% of
the samples, Cocconeis 8 samples or 7.4%, Fragilaria striat. 7
samples or 6.5 %, Rhabd. arc. 6 samples or 5.6 %.
The following are some of the more conspicuous, characterising
forms on the Chlorophyceae: Cocconeis 19 samples or 20.6 % of
the samples, Fragil. striat. and Synedra each 6 samples or 6.6 %, Lic-
mophora and Rhabd. arc. each 5 samples or 5.4 %.
It appears therefore, that on the Rhodophyceae, Rhabd. arc.
and to some extent also Cocconeis and Grammatophora principally
are the characterising forms; on the Phaeophyceae the Synedra