HOW TO KNOW 'THE SEAWEEDS 

 115b Branching pinnate. Fig. 152 Corallina 



Fig. 152. Corallina officinalis Linnaeus 



Part of an example of the large ro- 

 bust Pacific coast form (var. chilensis), 

 X 1. Various environmental forms of 

 this species may be encountered along 

 the whole Pacific Coast and from Long 

 Island northward through New Eng- 

 land. At least three other species 

 may be found along the Pacific of 

 which the smaller and more densely 

 branched C. vancouveriensis Yendo is 

 the most abundant and widespread. 



Figure 152 



116a Segments very short; intergenicular medulla unizonal. Fig. 153. 

 Lithothrix aspergillum 



Lithothrix aspergillum J. E. Gray 



A small portion of a plant bearing a single lateral 

 conceptacle and showing the very short, cylindrical seg- 

 ments (intergenicula) X 5. The unizonal intergenicular 

 medulla can be observed by decalcifying a small piece 

 and crushing it out carefully on a slide so as to make 

 the elongate medullary cells visible. 



A common tufted plant 3 to 12 cm. high on rocks and 

 in tide pools along the entire Pacific Coast. 



Figure 153 



117 



