HOW TO KNOW THE SEAWEEDS 



93a Thallus commonly constricted, brown in color, totally unbranched. 

 Fig. 127 Scytosiphon lomentaria 



Fig. 127. Scytosiphon lomentaria (Lyngbye) C. 

 Agardh 



An entire plant of one of the larger, clearly 

 constricted forms, X 0.5. This is a common 

 plant along both the Pacific and Atlantic coasts, 

 and occurs in a variety of forms in different 

 habitats. Some forms, especially at high inter- 

 tidal levels may be unconstricted. Among these 

 there are both slender cylindrical forms and 

 some which are quite strongly flattened, al- 

 though hollow. The brown color and unbranched 

 habit are distinctive. 



93b Thallus not constricted although often of 

 somewhat irregular diameter, reddish or 

 purplish in color, occasionally branched at 

 the base and sometimes proliferous above. 

 Fig. 128 Halosaccion Tamentaceum 



Figure 127 



Fig. 128. Halosaccion ramentaceum (Linnaeus) J. 

 Agardh 



Part of a plant showing branching of lower 

 stipe part and the beginning of some prolifera- 

 tions from one tubular axis, X 0.8. Plants of this 

 species are gregarious on stones and shells near 

 low water mark from northern Massachusetts 

 through Maine. They may reach 30-40 cm. long. 



Figure 128 



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