66 Puget Sound Marine Sta. Pub. Vol. 1, No. 9 



Table 1. Composition of Endocladia Association 



DOMINANT SPECIES 



Endocladia muricata Porphyra perforata 



PRIMARY SPECIES 



Enteromorpha linza Gigartina mamillosa 



SECONDARY SPECIES 



Fucus evanescens Gloiopeltis furcata 



Prionitis lyallii* Rhodoraela larix* 



Chaetomorpha sp. Calothrix Crustacea 



Cylindrospermum stagnalef Anabaena variabilisf 



2. The Fucus Association 



The most conspicuous of the littoral associations is the Fucus Asso- 

 ciation of which Fucus evanescens and Gigartina mamillosa are the dom- 

 inant species. This association forms a belt about two and one-half 

 meters high along the shore line. Fucxis is present on all rocky shores, 

 but on gravelly beaches it is replaced by Gigartina, which, however, is 

 much smaller and less abundant. On exposed shores where the water 

 is very rough, such as False Bay, Kanaka Bay and Deadman's Bay, 

 the plant body of Fucus is often very different. Here the plant has 

 very slender branches and the receptacles are long and narrow compared 

 with the broad flat branches of the plants of more quiet shores. 



Porphyra perforata and Gloiopeltis furcata form the two most 

 Important primary species of this association. In tide pools Prionitis 

 lyallii occurs ; and in places which remain more or less moist Microcladia 

 borealis is rather common. Among the secondary species may be men- 

 tioned Rhodomela larix growing in tide pools with Colpomenia sinuosa 

 on it. In a number of places Dermocarpa fucicola was found growing 

 as an epiphyte on Fucus. . In some places where the water flows swiftly 

 over the rocks Polysiphonia (several species) is often found, specially 

 near the lower limits of this association. In several places, as Point 

 Caution, Pear Point and Eagle Point, where the rocks become much heated, 

 Bangia atropurpurea fusco-purpurea and Porphyra perforata seem to 

 take almost complete possession. Along the west shore and on the rocks 

 about Kanaka Bay, it is not uncommon to find Hedophyllum sessile in the 

 lower region with Fucus. 



Where the rocky shore is replaced by a sandy beach Fucus disap- 

 pears. This is true in several places along the Island, but the most 



♦Growing in tide pools. 

 •j-Probablv fresli water forms. 



