RHODOMELACE^. 107 



specimens of which were gathered by the late Sir John 

 Richardsonj before his first Arctic expedition. Dr. Har- 

 vey, whose description of it I have copied verbatim,, sug- 

 gests that it may be a variety of P. fibrillosa, and men- 

 tions three or four other species that it more or less 

 resembles. 



Polysiphonia elongella. The divaricate Poly- 

 siphouia. 



Pronds from two to five inches high, growing singly, or 

 two or three together ; stem, at the base, about as thick as 

 a bristle, rigid, above, more slender and flexuose ; branches 

 irregularly forked, spreading, springing from wide axils ; 

 brancblets slender, tufted, and of a blood-red colour ; ar- 

 ticulations visible throughout the frond, about as long as 

 broad, except those in the lower part of the stem, and at 

 the tips of the brancblets, which are shorter. Spores in 

 large, egg-shaped, stalked conceptacles ; tetraspores im- 

 mersed in the brancblets. 



This is not a very common species, but has been found 

 in several places, both on our northern and southern 

 shores. It is biennial, and grows during the greater 

 part of the year on rocks or small Sea-weeds, at and 

 beyond low-water mark. It varies very much in ap- 

 pearance according to the season in which it may be 

 gathered. Dr. Harvey writes, "The winter and sum- 

 mer aspects of a deciduous tree are not more different 

 from each other than are specimens of this beautiful 

 plant collected at opposite seasons." 



Polysiphonia elougata. Lobster-horn Poly- 

 siphonia. 



Fronds from four to twelve ijiches high, growing singly, 



