fl> o s t e I i a 215 



outgrowths or distinct midrib. There 

 is a well-marked stipe, and the sori are 

 somewhat irregularly disposed upon the 

 surface of the leaf. 



Hedophyllum. The leaves are almost 

 sessile upon the holdfast, and spread 

 out like those of a cabbage. Other- 

 wise the plants closely resemble the 

 type of Laminaria. 



Pleurophycus. Here is classified a 

 Lamznarm-like plant with wrinkled leaf 

 and strong, wide, strap-like midrib, upon 

 which the sori are produced. 



Pterygophora. This is a perennial 

 plant, the stipe of which becomes very 

 strong and massive, and shows distinct 

 rings of growth. At the tip is borne a 

 single leaf with indistinct midrib and 

 eroded tip. Springing from the stipe 

 below this terminal lamina are numer- 

 ous ribbon-like leaves with rounded 



