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



adhaerens grows in dense masses on perpendicular or slanting ledges 

 just above low tide line at Point Caution, Pear Point, and Kanaka Bay. 

 In several places where the water washes over the rocks at very 

 low tide, Polysiphonia species are very abundant. This is specially true 

 at Turn Rock and Goose Island. Hormiscia tetraciliata (8) is some- 

 times found growing on pebbles just above low water in such quantities 

 that the pebbles seem to be covered with a coat of green. The best 

 examples of this condition are found in a small cove on Point Caution 

 and at Kanaka Bay. Cladophora scopaeformis and Cladophora spinescens 

 are also found with Hormiscia in several places. Ahnfeldtia plicata and 

 A. coccinna were found on the bottom of a chasm on the shore of Goose 

 Island near Cattle Point. 



Table 4. Composition of the XJlva Association 



DOMINANT SPECIES 



Ulva lactuca Hedophyllum sessile 



Cladophora arcta 



PRIMARY SPECIES 



Odonthalia aleutica Halosaccion glandiforme 



Soranthera ulvoidea Enteromorpha linza 



Amphiroa tuberculosa Corallina officinalis 

 Polysiphonia sp. 



SECONDARY SPECIES 



Gigartina redula exasperata Monostroma fuscum 



Plocamium coccineum Codium mucronatum 



Ceramium rubrum Codium adhaerens 



Cladophora scopaeformis Hormiscia tetraciliata 



Cladophora spinescens Iridaea laminarioides 



Ahnfeldtia plicata Colpomenia sinuosa 



Ahnfeldtia coccinna Hildenbrandtia sp. 



4. The Laminariaceae Association 



Under this group is included everything in the sublittoral zone below 

 the Ulva association and above and including the Nereocystis beds. The 

 group is named after the family which includes nearly all of the more 

 important species, with the exception of Cystophyllum geminatum. 



Perhaps after further study it may be possible to subdivide this 

 association into several, but as most of the species grow below the sur- 

 face of the water at low tide on rocky shores where tide currents are 

 usually very swift, so that it is difficult to dredge the algae, it has 

 seemed best not to subdivide this association at present. The area occu- 

 pied by this association forms a broad belt of varying depth and width. 

 The upper limit is near the lowest low tide line, and the lower limit 



