HOW TO KNOW THE SEAWEEDS 

 24a Branching pinnate and opposite. Fig. 40 Desmarestia (in part) 



Fig. 40. Desmarestia viridis (Miiller) Lam- 

 ouroux 



A small portion of a plant to show the 

 opposite branching of the slender, cylin- 

 drical axes. Most of the species of Des- 

 marestia are flattened or complanate, but 

 this one which occurs to the north of New 

 Jersey, and is also reported from Cali^ 

 fornia, is cylindrical. Two other cyhndrical 

 species (D. media (Agardh) Greville and 

 D. farcta Setchell & Gardner) occur in the 

 Puget Sound area of Washington, usually 

 in infratidal habitats. 



Figure 40 



24b Branching not pinnate 25 



25a Branches all of irregular lengths, without the formation of very 



distinct percurrent axes in the plant as a whole. Fig. 41 



Haplogloia andersonii 



Fig. 41. Haplogloia andersonii (Farlow) Lev- 

 ring 



A small portion of the upper part of a 

 plant, X 1.5, to show the irregular multifari- 

 ous branching and the dense covering of fine 

 hairs over the whole surface of the thallus. 

 The structure of the growing apex of this 

 plant is shown in Fig. 19. Occasional at low 

 tide levels along the entire Pacific Coast. In 

 the middle parts of its range it is known to 

 begin its development late in the winter and 

 to mature and disappear again by the be- 

 ginning of summer. 



Figure 4) 



44 



