1915 Muenscher; on Algal Associations 73 



thamnion floccosum, Ectocarpus siliculosus typicus and Porphyra nereo- 

 cystis are frequently found on large plants of Nereocystis. Enteromorpha 

 linza is quite common on the bulbs of old Nereocystis plants. Desmarestia 

 aculeata media and D. aculeata are sometimes found on the lower por- 

 tions of the stipe of Nereocystis and other algae. Z). ligulata herbacea 

 is sometimes found on pebbles and shells in the deeper beds of Nereo- 

 cystis, but it grows more profusely in deeper water. Scytosiphon lomen- 

 tarius has been collected on Newhall's Point and on Turn Island at 

 very low tide. Gigartina radula exasperata and Nitophyllum ruprechti- 

 anum may be found throughout this association, but not in very great 

 abundance. Other species which occur in this association, but seldom 

 m very large numbers, are listed with the secondary species. 



Table 5. Composition of the Laminariaceae Association 



DOMINANT SPECIES 



Nereocystis luetkeana 



PRIMARY SPECIES 



Alaria valida Laminaria bullata 



Alaria sp. Laminaria saccharina 



Costaria costata Cystophyllum geminatum 



Agarum iimbriatum Cymathaere triplicata 



SECONDARY SPECIES 



Pleurophycus garderi Gigartina radula exasperata 



Egregia menziesii Rhodymenia pertusa 



Laminaria bullata subsimplex Nitophyllum ruprechtianum 



Hedophyllum subsessile Antithamnion floccosum pacificum 



Desmarestia aculeata Sarcophyllis californica 



Desmarestia aculeata media Ectocarpus siliculosus typicus 



Desmarestia ligulata Porphyra nereocystis 



Enteromorpha linza* Iridaea laminarioides 



Scytosiphon lomentarius Coilodesme californica 



5. The Zostera Association 



Besides the four algal associations which have been mentioned, eel- 

 grass {Zostera marina) often forms large and dense "meadows" in quite 

 shallow sandy bays. These plants grow in places where they are almost 

 uncovered at low tide. Wherever Zostera is found, one is usually sure 

 to find Porphyra naiadum growing as an epiphyte on its leaves. 



In several places, near Brown Island, Westcott Bay, and near False 

 Bay, Zostera plants are covered with so much Porphyra that the whole 

 plants look red. The older leaves of Zostera are nearly always covered 

 with filamentous diatoms. Ulva lactuca and Enteromorpha linza have 



♦Rather abundant in late summer on old plants of Nereocystis leutkeana. 



