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b. Sheltered Coast. 

 The Stictyosiphon- Association . 



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

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

 in some places even still farther down, we meet with an associa- 

 tion which consists of a great many different species of algae. It 

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

 lina officinalis is moreover often found scattered in the vegetation. 

 On account of the great difference between the algae belonging to 

 this association, the colour of the vegetation varies greatly according 

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

 Ulimcece, sometimes the brown, sometimes the red algae. Their ample 

 ramifications and bushy form are characteristic of the algae 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 fact, 

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

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



Green algae typical of this association are: Enteromorpha Linza, 

 Acrosiphonia albescens, Urospora Wormskioldii, Enteromorpha intesti- 

 nalis, Monostroma fnscnm etc. ; brown algae : Chordaria flagelliforinis, 

 Dictyosiphon foeniculaceus , Stictyosiphon tortilis, Scytosiphon lomen- 

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

 carpus litoralis; Ectocarpus siliculosus, Castagnea virescens, Chorda fihim, 

 Fncus inflatns, and sometimes Laminaria saccharina and Leathesia 

 difformis epiphytically on Corallina officinalis. Amongst the red algae 

 are: Ceramium rubrnm, Cystoclonium purpurascens, Rhodomela subfnsca 

 and R. lycopodioides, Polysiphonia Brodicei and P. urceolata, Dnmontia 

 fdiformis, Chondruscrispus,Rhodyn\eniapalmata^2in^^ more rarely, //a/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 belt 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 algae of different colours, with 

 the Corallina officinalis as a fairly frequent subvegetation. There 

 were large, red tufts of Ceramium rubrum, Rhodomela lycopodioides, 

 Dnmontia fdiformis, Cystoclonium purpurascens etc., together with some 



