08 SEA MOSSES. 



III. Frond narrow, compressed or flattened. 

 Frond forked or branched, thick, tough, one 



to two feet long. " Rockweed." Fucus. 



IV. Frond filiform or thread-like. 



i. Frond Unbranchcd. 



Frond four to six inches long. Sometimes 

 inflated and constricted ; always covered 

 with minute dark dots. Color, yellow 

 olive. Asperococcus. 



Long, ten to twenty feet, elastic, much at- 

 tenuated at each end. Cho?'da. 



2. Frond Branched. 



(a.) Branches mostly simple. 

 Long in proportion to main stem, parts as large 



as pack-thread. Color black. Cliordaria. 

 Short in proportion to main stem. Color, 

 olive or full green. Castagnea. 



(b.) Branches, naked, divided and sub-divided. 



Stem and branches repeatedly forking. Color, 

 yellowish olive, dotted over with minute 

 dark colored warts, frond six inches high. 



Stilopliora. 

 Frond one to two feet long, intricately 

 branched ; branches at last very small. 



Dictyosiphon. 



