PLATE XI. 



A. Odonthalia, page 77. 



Fig. 1, O. den tat a; a branch, the natural size. 2, 

 tuft of ceramidia. 3, spores from the same. 4, tuft 

 of stichidia. 5, a tetraspore ; all magnified. 



B. Rhodomela, page 78. 



Fig. 1, Branch of R. suhfusca ; the natural size. 2, 

 small ramulus with young ceramidia. 3, a cera- 

 midium. 4, stichidia (borne in winter). 5, a tetras- 

 pore. 6, cross section of the frond • all magnified. 



C. BosTRYCHiA, page 79. 



Fig. 1, B. scorpioides ; the natural size. 2, apex of a 

 branch. 3, cross section of the frond. 4, longitudi- 

 nal section of the same ; magnified. 



D. Rytiphl^a, page 80. 



Fig. 1, R. pinastroides ; the natural size. 2, ramuli 

 bearing stichidia. 3, a stichidium. 4, raiiiuli bear- 

 ing ceramidia. 5, a ceramidium. 6, longitudinal 

 section of the frond j all magnified. 



