PLATE XXVI. 



A. RivuLARiA, page 222. 



Fig. 1, R. alra, on a stone ; the natural size. 2, ver- 

 tical section of a frond. 3, filament from the same ; 

 magnijied. 



B. ScHizoTHRix, page 223. 



Fig. 1, S. Cresswellii, on a stone ; the natural size. 

 2, filaments from the same ; magnijied. S, portion 

 of a filament ; very highlg magnijied. 



C. Calothrix, page 223. 



Fig. 1, C. con/ervicola, growing on Ceramium ruhrum ; 

 the natural size. 2, filaments fi-om the same ; mag- 

 nijied. 3, small fragment of a filament ; highly 

 magnijied. 



D. MicRocoLEUS, page 227. 



Fig. 1, M. anguiformis ; the natural size. 2, a sheath ; 

 magnijied. 3, filament from the same ; highly mag- 

 nijied. 



E. Lyngbya, page 225. 



Fig. 1, L. majuscula ; the natural size. 2, portion of 

 a filament ; magnijied. 



F. OsciLLATORiA, page 228. 



Fig. 1, stratum of O. insignis, as it appears to the eye. 



2, filament of the same species ; highly magnijied. 



3, filament of O. nigro-viridis ; magnijied. 



