168 BRITISH SEA-WEEDS. 



Var. e. sobolifera. Frond with a stem, and very nar- 

 row, much divided branches, which expand into wedge- 

 shaped, jagged lobes, and become fringed at the tip. 



The last is the only form which I have observed to be 

 very constant. 



Rhodymenia palmetta. The little Palm Rhody- 

 menia. 



Fronds red, fan-shaped, more or less forkedly cleft, ex- 

 panding from a cylindrical stem into linear, wedge-shaped 

 segments, with broad, rounded interstices, and a flat mar- 

 gin. Spores angular, contained in stalkless conceptacles, 

 which are either marginal or scattered over the frond ; 

 tetraspores cruciate, forming deep red patches on the tips of 

 the segments. 



This little plant grows on rocks, shells, and the stems 

 of large sea-weeds, in deep water. It is less common 

 than R. palmata, but is found in many localities. Spe- 

 cimens bearing spores differ considerably from those 

 with tetraspores. In the former the frond is small, 

 with short, crowded segments, and is borne on a long, 

 simple stem ; while in the latter it is spreading, and the 

 stem branches almost from the base. There is a variety 

 of this species, with a simple or once-forked, narrow 

 frond, rising from a fibrous root, which Professor Agardh 

 calls Nicceensis. It is not common, and resembles Phyl- 

 lophora Brodicei. 



Genus LXXII. EUTHORA. 



Frond flat, membranaceous, forkedly-pinnate, composed 

 of two series of cells ; those within large, oblong, those on 

 the surface coloured, minute. Spore-threads very numer- 



