RED ALGy^. 247 



plant in deep water, all along our coast, north of 

 Boston. It grows, attached to rocks and stones, in 

 the bottom of the sea, and to the stems and roots of 

 Lamifiaria. It will be found in great abundance 

 on all open beaches where the waves have deposited 

 it, brought up from the depths. 



The frond is three to six inches in extent, one- 

 sixteenth to one-eighth of an inch wide, flattened, 

 tough, cartilaginous, irregularly, pinnately branched 

 from the edges, branches likewise flattened and 

 branched from their edges, all in one plane. Plate 

 XVII., is an exact copy of a specimen in my herbarium, 

 and very fairly represents the beauties of this plant, 

 as well as the pinnate method of branching, common 

 to the genus. 



The peculiarity of the species is the dissimilarity 

 of the opposite pinnae on the ultimate branches. 

 From the branches there will spring forth on one 

 side a beautiful little plume or pinna, while exactly 

 opposite to it, will be a short, curved, undivided 

 spine-like process, somewhat thickened, and often 

 toothed on the outer edge ; all the ultimate divisions 

 stand out almost at right angles to the branches. 

 The color is red. A perennial, perfect in summer; 

 adheres, but rather imperfectly to paper. It need 

 not be looked for soath of Cape Cod, but it is 



