PLATE IX. 



Fiat. PAGE 



1 . Polysiphonia parasitica 101 



1 a, branchlet with spores, magnified. 



1 b, branchlet with tetraspores, magnified. 



2. Gelidium corneum 150 



2 a, branchlet with spores, magnified. 



2 b, branchlet with tetraspores, magnified. 



3. Halymenia ligulata 189 



3 a, section of frond with spores, magnified. 



4. Griffithsia corallina 317 



4 a, part of branch with tetraspores, magnified. 

 4 b, spore-clusters, magnified. 



