68 



SPECIES OF ALG^. 



95. SPHjEROZYGA. 



§ 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 



One species 

 One species 



96. APHANIZOMENON. 



97. NODULARIA. 



98. CYLINDROSPERMUM. 



§ Spores about 14/^ in diam.; cells 3-4;^ 



§ " " ^oix(a). 



a. Diameter of cells about \jx . 



a. 



. . flos-aqucR, 291 



paludosa, 291 



macrospermum, 292 

 . . flexuosum, 292 



H ti 



filaments 



3ju; terminal cells with flexible, hair-like 

 . . . . comatum, 293 



One species 



Length 16-17/^ 

 25-35/^ 



99. CRENOTHRIX. 



100. CHAMiESIPHON. 



polyspora, 294 



incrustans, 295 

 confervicola, 295 



lOI. LYNGBYA. 



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

 than long, diam. 20-28/^, astuarii, 296 



§ On moist ground or wet rocks (a). 

 § Aquatic {g). 



§ Marine . majuscula, 297; vermicularis . Omitted. 



a. Stratum bright green; filaments 8-io/i in diam. . arenarium^ 299 



a. Not pure green (V). 



b. Stratum blue green (c). 



b. Stratum blackish green (e). 



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



