KEY TO THE GENERA. 133 



{c.) Stem branched and forked; end of 

 branches beset with many short, stout, 

 oval or obtuse ramuli. Chylodadia, 



2. Frond finer and more elaborately divided, 

 {a.) Stem robust, branches irregular; ultimate 

 ramuli, clustered in bunches; black. 



Rhodomela. 

 {d.) Frond delicate, many times finely and 

 pinnately divided ; color, brown or black. 

 Polysipho7iia. 

 (c.) Frond delicate, finely pinnated, brilliant 

 pink- Callithamnion. 



