68 SPECIES OF ALG^E. 



95. SPH^EROZYGA. 



Filaments in 2-4 in. long, vertical, closed tubes, % in. thick, more 

 or less attached ............ saccata^ 290 



Filaments straight, in a definite gelatinous sheath; joints subspher- 

 ical, spores cylindrical . . , ...... Smithii, 290 



Filaments equal, curved or coiled in thin bluish stratum, 



Hassallii, 289 

 Filaments subsolitary or associated, bluish, variously curved, 



polysperma, 289 



96. APHANIZOMENON. 



One species ............... flos-aqua, 291 



97. NODULARIA. 



One species ............... paludosa, 291 



98. CYLINDROSPERMUM. 



Spores about 1 4/* in diam.; cells 3-4;* . . . macrospermum, 292 



a. Diameter of cells about 4^ ...... : . . . flexuosum, 292 



a. " " " " 3>w; terminal cells with flexible, hair-like 



filaments .... ........ comatum, 293 



99. CRENOTHRIX. 



One species .............. polyspora, 294 



100. CHAM^ESIPHON. 



Length 16-17;* ............ incrustans, 295 



........... confervicola, 295 



101. LYNGBYA. 



In brackish water; filaments rigid, curved; cells 3-4 times wider 

 than long, diam. 20-2 8yw, ....... astuarii, 296 



On moist ground or wet rocks (a). 



Aquatic (g). 



Marine ....... majuscula, 297; vermicularis. Omitted. 



a. Stratum bright green; filaments S-ioju in diam. . arenarium, 299 



a. Not pure green (b). 



b. Stratum blue green (c], 



b. Stratum blackish green (e). 



b. Stratum blue, red, purplish, olive, brown or becoming yellow (/). 



