72 SPECIES OF ALG^E. 



107. SPIRULINA. 



A continuous, twisted, ring-like band . . . . . . duplex, 323 

 Not continuous but filamentous (a). 



a. In stagnant water; diameter 7-8/1 Jenneri, 323 



a. In sulphur springs; diameter 4-5 /* tenuissima, 323 



108. SPIRILLUM. 



One species undula, 324 



109. GLCEOTHECE. 



One species confluens, 325 



IIO. APHANOTHECE. 



a. More or less globose, size of a cherry, usually floating, 



prasina, 325 

 a. Gelatinous, 4-6 mm thick, in small masses; wet ground, 



pallida, 325 



I IT. SYNECHOCOCCUS. 



One species; on wet rocks (zruginosus, 326 



112. MERISMOPEDIA. 



a. Rarely more than 4-64 cells, 3-5^ diam glauca, 326 



a. Often of 256 geminate cells, 4-4.5^ diam. . . . convoluta, 326 



113. CCELOSPH/ERIUM. 



One species Keutzingianum, 327 



114. CLATHROCYSTIS. 



One species ceruginosa, 327 



115. GOMPHOSPH^RIA. 



One species aponia, 328 



Il6. MICROCYSTIS. 



One species; on moist timbers, ground, tree trunks, protogenita, 328 



117. ANACYSTIS. 



a. Cells iyw in diam.; thallus light brown brunnea, 329 



a. Cells 2-3/j diam. " glaucous or pale bluish . pulvereus, 329 

 a. Cells 3-4/4 " " globular, margins colorless, 



marginata, 329 



1 1 8. POLYCYSTIS. 



One species icthyoblabe, 330 



