KEY TO THE GENERA OF THE PACIFIC 

 COAST.* 



I. Frond, leaf-bearing. 



1. Stem flattened, rough, leaves oh each 

 edge, air vessels in the stems of some of 

 the leaves ; plant many feet, sometimes 

 many yards long. Phyllospora. 



2. Plant from a few to several hundred 

 feet long. Stem cylindrical, slender, 

 branched, leaves on opposite sides of 

 the stem. Air vessel in each leaf stalk. 

 Root, large, much branched. 



Mac7'ocystis 



3. Stem long, slender, cylindrical, elastic, 

 terminated in a large rounded air vessel 

 which is crowned with a large tuft of 

 long, slender leaves. Root branched. 



Neieocystis. 



4. Stem short, stout, cylindrical, surmounted 

 at top with a large tuft of deeply 

 ribbed leaves. Postehia. 



' Only those genera whicli hsve species peculiar to this coast are included 

 in this Key, ail the rett are in the other. 



