84 MARINE ALG^E 



branching ; spore-masses sometimes form knotty bunches on the side of 

 branches. It resembles a large Cystoclonium jmrpurascens. It is charac- 

 teristic of Long Island Sound, and is not found north of Cape Cod, but 

 common from there southward along the whole Atlantic coast. (Plate 

 XXI.) 



S. Covlteri. This species is common on the Pacific coast, and dif- 

 fers from JR. tenera in having a more pronounced leading stem, and 

 branches shorter and crowded at the top of the frond. 



GENUS Eucheum,a 



E. isiforme. Frond grows in tufts a foot or more in diameter ; stems 

 branch in all directions from a central point, and taper gradually to the 

 end ; secondary branches spread to all sides ; all branches swollen at 

 intervals and armed with several spines spreading from a conical base ; 

 color dark red, becoming on exposure orange or yellow, and at length 

 semi-transparent and horn-like ; substance firmly cartilaginous. Abun- 

 dant at Key West. 



ORDER RHODYMENIACEJE 



SUBORDER SPKEBOCOCCEJE 

 GENUS Gvacilaria 



G. multipartita ("many times divided"). Frond four to twelve 

 inches long ; starting from a short, cylindrical stem, it flattens and 

 broadens as it rises, dividing in an irregular, forking manner, or cleft 

 into palmate segments which broaden as they rise, and which divide in 

 the same manner j often cleft or branched on the edges ; conical spore- 

 masses scattered over the frond during July and August ; dingy purple 

 in color. The plant is variable and sometimes is difficult to determine. It 

 is common from Cape Cod southward. A narrow variety is most abun- 

 dant in Long Island Sound. In Florida and on the California coast there 

 are broad varieties which may be mistaken for Rhodymenia. (Plate 

 XXI.) 



GENUS Hypnea 



H. muscif&rmis ("moss-like"). Frond. six to twelve inches long; 

 main stern running through, thick below and tapering to the size of a 

 bristle ; much and irregularly branched, especially at the base ; branches 

 wide-spreading in every direction, and longest at the base ; branches 

 branch again in the same manner ; all parts beset with short, horizontal 

 spines ; color purplish-red. A characteristic feature, by which the plant 

 can easily be distinguished, is that the ends of the long branches are 

 naked and are turned over like a hook, or nearly twisted. It is found 

 washed ashore, often in large, intricately twisted tufts, from Cape Cod 

 southward and on the Pacific coast. 



