1915 



Muenscher; on Algal Associations 



69 



Where the shores are very rocky and the water is somewhat rougher, 

 Hedophyllum sessile is found quite abundant in the Ulva association. 

 Examples of this condition are seen on Turn Rock, Minnesota Reef, and 

 along the west shore between Kanaka Bay and Roche Harbor. Halosaccion 

 glandiforme usually forms rather conspicuous societies near the low tide 

 line. Soranthera ulvoidea is found growing on Odonthalia aleutica near 

 the low tide line in large areas and in great numbers. Odonthalia aleutica 

 is also very abundant near the low tide line in regions where the water 

 is a little rough. Amphiroa tuberculosa and Corallina officinalis are very 

 prominent at the low tide line and just below it, on wave-beaten shores 

 such as Kanaka Bay. In this location Hildenhrandtia sp. is found grow- 

 ing on Phyllospadix scouleri (Plate 13). 



Some of the secondary species of this association often form rather 

 distinct societies. Codium mucronatum is found on rocks near the low 

 tide line on Minnesota Reef, Turn Island, Kanaka Bay, and north of 

 Deadman's Bay. In the last named place this Codium was found grow- 

 ing on limestone ledges and on wooden jDiles in great abundance. Codium 



PLATE 13 



Map showing the scarcity of algae on the sandy bottom of False Bay. The 

 map covers an area roughly %-% mile each way. The numbers correspond to 

 those in the list beginning on page 76. 



