72 SPECIES OF ALGM. 



107. SPIRULINA. 



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

 § Not continuous but filamentous {a). 



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



a. In sulphur springs; diameter 4-5 }i tenuis sirna, 323 



a 



108. SPIRILLUM. 



One species . . . undula, 324 



109. GLCEOTHECE. 



One species . . . confluens, 325 



no. APHANOTHECE. 



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



prasina, 325 

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



pallida, 325 



HI. SYNECHOCOCCU.S. 



One species; on wet rocks a.ruginosus, 326 



112. MERISMOPEDIA. 



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



a. Often of 256 geminate cells, 4-^.^fi diam. . convoluia, 326 



113. CCELOSPH^RIUM. 



One species . Keutzingianum, ^2"] 



114. CLATHROCYSTIS. 



One species . ... aruginosa, 327 



115. GOMPHOSPH^RIA. 



One species . . . . . aponia, 328 



116. MICROCYSTIS. 



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



117. ANACYSTIS. 



a. Cells I /^ in diam.; thallus light brown . . . . brunnea, 329 



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

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



marginata, 329 



118. POLYCYSTIS. 



One species ... . icthyoblabe, 330 



