1917 



Muenscher; Key to Phaeophyceae 



273 



23. RALFSIA Berkeley 



1. Ralfsia verrucosa (Aresch.) J. Ag. Sp. 1 : p. 62. Fig. 33 



Plants forming dark brown or black crustaceous expansions of in- 

 definite extent resembling tar spots ; composed of a horizontal layer of 

 cells from which arise the short vertical filaments which are united to 

 each other forming a solid cushion-like mass ; sporangia in sori over the 

 surface of the plant. 



Common, forming dark brown spots on rocks in tide pools and in 

 the lower littoral zone. It is possible that not all of our specimens belong 

 to this species. 



24. NEREOCYSTIS Postels & Ruprecht 



1. Nereocystis Luetkeana (Mertens) Post, & Rupr. Algar. p. 9. 



Fig. 31 



Holdfast of many branched hapteres forming a dense cluster about 



one or two dm. in diameter; stipe from three to fifteen meters long, 



Nereocystis 

 Luetkeana 



Egregia 

 Menziesii 



Macrocystis 

 pirifera 



PLATE 61 



Fig. 34. Diagrammatic sketch of plant showing general form of 

 plant. X about 0.01, but parts are not quite in proportion. 



Fig. 35. Sketch showing a portion of a flattened branch with small 

 air bladders and several kinds of blades. X about 0.33. 



Fig. 36. Sketch of a portion of a branch showing several blades 

 with basal air bladders. X about 0.07. 



