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b. Sheltered Coast. 

 The Stictyosiphon- Association. 



At Ihe low water mark and below, and on non-tidal coasts di- 

 rectly below Ihe surface of the sea to a depth of from 4 to 6 feet, 

 in some piaces even still farther down, \ve meet with an associa- 

 tion which consists of a great many difFerent species of algæ. It 

 corresponds to the Co/a///na-formalion on exposed coasts; Ihe Coral- 

 lina officinalis is moreover often found scattered in the vegetation. 

 On account of the great difference between the algæ belonging to 

 this association, the colour of the vegetation varies greatly according 

 to which algæ predominate at each place. It may be sometimes the 

 Ulvaceæ, sometimes the brown, sometimes the red algæ. Their ample 

 ramifications and bushy form are characleristic of the algæ which grow 

 here. Where these marks are absent, they at least grow gregariously, 

 in dense tufts. This tuft-like growth is also due perhaps to the faet, 

 that this association grows on a stony bottom, especially on pebbles. 

 Most often one stone carries one alga, its neighbour another. 



Green algæ typical of this association are: Enteromorpha Linza, 

 Acrosiphonia albescens, Urospora Wormskioldii, Enteromorpha intesti- 

 nalis, Monostroma fnscum etc. ; brown algæ : Chordaria flagelliformis, 

 Dictyosiphon foeniculaceus , Stictyosiphon tortilis, Scytosiphon lomen- 

 tarius, Phyllitis fascia, Punctaria plantaginea, different forms of Ecto- 

 carpus litoralis; Ectocarpus siliculosns, Castagnea virescens, Chorda fdum, 

 Fucus inflatus, and sometimes Laminaria saccharina and Leathesia 

 difformis epiphytically on Corallina officinalis. Amongst the red algæ 

 are: Ceraminm rnbrnm, Cystocloniiim purpurascens, Rhodomela subfusca 

 and R. lycopodioides, Polysiphonia Brodiæi and P. nrceolata, Dnmontia 

 fdiformis, Chondruscrispns,RhodymeniapaImata, and, more rarely,Ha/o- 

 saccion ramentaceum, Antithamnion floccosum and Laurencia pinnatifida. 



At Strender in Skaalefjord, which is not subject to high and low 

 tides, this association is beautifully developed. There is a large flat 

 area covered with shallow water, from 2 to 6 feet deep. In the imme- 

 diate vicinity of the land, I found a rather broad helt of Acrosiphonia 

 albescens, which was partly laid bare on the day when I visited the 

 place, the water being extremely low and the weather fine and calm. 

 Next to that, there came a variety of algæ of difFerent colours, with 

 the Corallina officinalis as a fairly frequent subvegetation. There 

 were large, red tufts of Ceraminm rnbrum, Rhodomela lycopodioides, 

 Dumontia fdiformis, Cystoclonium purpurascens etc, together with some 



