126 SEA MOSSES. 



II. Frond flattened or compressed. 

 'i. Fro7id forked, 

 {a.) Small, short, wedge-shaped, once or twice 



forked. 

 (i.) Frond thick, smooth, purple or green. 



"Irish Moss," Chondrus. 

 (ii.) Frond channeled, more or less covered 



with papillm, dark. Gigartina. 



(iii.) Frond stalked, thin, narrow, red. 



Gymnogongrus. 

 {b^ Frond long, narrow, partly cylindrical, 

 many times divided. Gracilaria. 



2. Frond pinnately divided. 

 Plant small, pinnse and pinnulae, fine 



and set in one plane. Ptilola. 



3. Frond irregularly divided. 



Frond forking and branching irregularly, 



_ profusely, mostly in one plane, from a 



marginal point. Euthora. 



Ill Frond filiform or thread-like. 



(From size of sewing cotton to that of 

 wrapping twine, branched). 

 I. Plants whose ultimate branchlets taper to both 

 ends. 

 (a.) Plants with one main or leading stem. 



