RHODOMELACE.E. 103 



Polysiphonia furcellata. Forked Polysiphonia. 



Fronds growing in dense, tangled tufts, five or six inches 

 long, about as thick as a bristle below, gradually tapering 

 upwards, much divided into forked branches, which spring 

 from spreading, rounded axils ; tubes about eight ; articu- 

 lations in the lower parts of the fronds, from three to five 

 times as long as broad, in the upper, of about equal length 

 and breadth. Spores in somewhat globular, stalkless con- 

 ceptacles ; tetraspores in distorted branchlets. 



This species grows on rocks in deep water, and is very 

 rare. When fresh it is of a bright brick-red colour. It 

 is a summer annual. 



SuBDrvrsioiS' 2. — Primary tubes four. 



Polysiphonia urceolata. Pitcher-shaped Poly- 

 siphonia. 



Fronds growing in tufts, connected by root-like fibres, 

 erect, rigid, from three to nine inches long, much and irre- 

 gularly branched ; articulations, of the lower part of the 

 stem, about as long as broad, of the branches, from three to 

 five times as long as broad, and of the upper branchlets, 

 shorter than broad. Spores in pitcher-shaped, stalked con- 

 ceptacles ; tetraspores in the upper part of the branchlets. 



This elegant plant is abundant all round our coast. It 

 grows, during summer, on rocks near low-water mark, 

 and in deep water, on the stems of Laminaria digita- 

 ta, the specimens found in the former situation being 

 usually larger and more robust than those in the latter. 

 The most obvious characters of the species are the short 

 articulations of its stem, which are marked by two broad 

 tubes, and its bright red colour. It is annual. 



