KEY TO THE GENERA. 133 



(r.) Stem branched and forked \ end of 

 branches beset with many short, stout, 

 oval or obtuse ramuH. Chylocladia, 



2. Frond finer and more elaborately divided, 



(dr.) Stem robust, branches irregular ; ultimate 

 ramuli, clustered in bunches ; black. 



Rhodomela. 

 (Jf.) Frond delicate, many times finely and 

 pinnately divided; color, brown or black. 



Polysiphonia, 

 {e.) Frond delicate, finely piilnated, brilliant 

 pink. Callil/iamnion, 



