( 110 ) 



scarcely adhering to the paper in drying. Colour, a dark rather dull 

 purplish red. Favellee lateral on the upper branches, with an involucre 

 of two to four ramuli, three to four times as long as the favellse, 

 coloured, spinous, and attenuated at the base like those on the branches; 

 the favellse two or three together, or " two- to three-lobed." Tetraspores 

 large, scarcely immersed in joints of the upper branches. 



The present species closely resembles in habit small specimens of 

 C. ruhrum, and has no very distant resemblance in the mass to Rhodo- 

 meJa subfusca, from both of which, however, its microscopic characters 

 are abundantly distinct. From the former species it is readily known 

 by its smaller size, more slender and numerous ramuli, and the minute 

 but distinct spines ; the latter character, and the coloured cells per- 

 vading the whole of the ai-ticulation, readily distinguish it fi'om all the 

 preceding species. 



The south and west of England, and one or two stations on the Irish 

 coast, are the only habitats of which we have heard, but it is not 

 unlikely that it may be found far from uncommon when better known to 

 observers in other parts of the country. 



EXPLANATION OF PLATE CV, 



Fig. 1. — Ceramium flahelUgeruin, natural size. 

 2. — Apex of a branch. 

 3. — Ramulus with favella. 

 4. — Portion of a ramulus with tetraspores. 

 5. — Tetraspore from same. All magnified. 



