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ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Phaeophyceae 



Brown or olive-colored plants, filamentous or parenchymatous, of 

 very varied fomis; accessory pigments partially masking the chlorophyll, 

 in definite chloroplasts ; sexual and asexual plants similar or different m 

 habit, one stage sometimes nearly or quite suppressed; asexual reproduc- 

 tion chiefly by biflagellate zoospores, in some groups by aplanospores ; 

 sexual reproduction by biflagellate isogametes or with various degrees of 

 sexual specialization and differentiation. 



Ectocarpaceae 



Plants filamentous, branched, basally attached, generally free above; 

 reproduction in intercalary or lateral organs partly or completely replac- 

 ing branchlets, ordinarily asexually by zoospores produced in unilocular 

 sporangia, and sexually by motile iso- or anisogametes produced in pluri- 

 locular gametangia ; the alternating generations of separate plants. 



KEY TO GENERA 



1. Gametangia and sporangia terminating branches or taking their 

 places in the plant system Ectocarpus 



1 . Gametangial cells small, in clusters lateral to the axis ; unilocular 

 sporangia intercalarj', solitaiy Zosterocarpus 



Members of this family, and more specifically of the genus Ectocarpus, 

 were not common at the places visited on the expeditions included in this 

 study. A few more collections were secured than are here recorded, and 

 in some the material was fruiting, but, for various reasons, it is not 

 thought suitable for either identification or description at the present 

 time. Minute creeping and endophytic types in the collections have not 

 yet been investigated. 



ECTOCARPUS Lyngbye, 1819 



Plants sometimes microscopic, sometimes large and forming extensive 

 soft tufts; filaments uniseriate, attaching by a disklike holdfast or by 

 rhizoidal extensions of the basal cells, creeping or erect, sparingly to 

 freely, generally alternately, branched, the branches similar to the axis, 

 sometimes terminating in hairlike tips; sporangia lateral, gametangia 

 lateral or terminal, sometimes hair tipped. 



