HOW TO KNOW THE SEAWEEDS 



94b Axes and branches usually 1 mm. or less in diameter; cortex as 

 seen in transection composed of more or less isodiametrical cells 

 without evident arrangement in rows or filaments 95 



95a Thallus brownish; percurrent axes evident; medulla only partially 

 hollow, or only in older parts. (See Fig. 77). . Dictyosiphon (in part) 



95b Thallus reddish; percurrent axes usually not evident; medulla hol- 

 low throughout, although sometimes with filaments around the 

 cavity. Fig. 130 Lomentaria baileyanc 



Figure 1 30 



Fig. 130. Lomentaria haileyana (Harvey) Farlow 



Part of a plant to show the slender form and lack of percurrent 

 axes, X 1.2. This species is usually loosely tufted, 3 to 7 cm. high, 

 in sheltered places from Cape Cod to Florida. 



99 



