PLATE XXVII. 



A. MONORMIA, page 231. 



Fig. 1, portion of the gelatinous fronds, as they appear 

 to the eye. 2, part of a frond ; magnified. 3, fila- 

 ment from the same ; highly magnified. 



B. HORMOSPORA, page 235. 



Fig. 1, young, and Jig. 2, full-grown plant 

 mosa. 3, spore from the same ; all highly 



of H. ra 



u-grown pant o . ra 

 same ; all highly magnified 



C. SPIRULINA, page 229. 



Fig. 1, S. tenuissima ; the stratum as it appears to the 

 eye. 2, filaments from the same ; very highly mag- 

 nified. 



D. SPH^ROZYGA, page 232. 



Fig. \ , stratum of S. Carmichaelii, as it appears to the 

 eye. 2, a young and an old filament of the same 

 species; very highly magnified. 



E. SPERMOSEIRA, page 233. 



Fig. 1, stratum of S. litorea, as it appears to the eye. 

 2, filaments from the same ; highly magnified. 



