HOW TO KNOW THE SEAWEEDS 



19b Thallus whip-like, essentially unbranched; cortical hairs and para- 

 physes not in clumps. Fig. 30, 32 Chorda (in part) 



Fig. 32. Chorda filum (Linnaeus) Lamouroux 



An entire plant, X 0.3, showing the un- 

 branched, whip-like form. Young, growing plants 

 will show, when held in water, an outer cover- 

 ing of delicate, colorless hairs which fall away 

 with age. The terminal parts of old plants ore 

 usually partly decayed. This species which is 

 widespread on both sides of the north Atlantic 

 occurs commonly near low tide level and be- 

 low from New Jersey northward, usually at- 

 tached in groups on stones or shells. Another 

 species, C. tomentosum Lyngbye, is more dense- 

 ly covered with hairs and occurs north of Cape 

 Cod. Some adult forms of Chorda are more 

 or less hollow and will key out best under step 

 91b. 



Figure 32 



38 



