HOW TO KNOW THE FRESH-WATER ALGAE 



375a Cells in clusters of 2-4-8-16 within an irregularly globose colonial 

 investment. Fig. 268 CHRYSOCAPSA 



Fig. 268. Chrysocapsa planctonica (West 

 & West) Pascher. (Redrawn from 

 Smith). 



The colonies of this species are globu- 

 / lar, or nearly so, the mucilage clear 

 and transparent, the cells with brown- 

 ish chromatophores. This is the only 

 species reported which is common, but 

 another one, C. paludosa (West & West) 

 Pascher, with oval cells has been re- 

 corded. 



Figure 268 



375b Cells 16-32-64 within a wide, flat colonial mucilage, the cells radi- 

 ally arranged in 1 plane; colonial mucilage impregnated with 

 granular substance. Fig. 269 CHRYSOSTEPHANOSPHAERA 



Fig. 269. Chrysostephanosphaera globu- 

 litera Scherff. 



Figure 259 



This colony of brown cells is disc- 

 like and is enclosed by a wide gelatin- 

 ous matrix which invariably contains 

 dark granules of what is regarded as 

 metabolic waste products. Only 1 spe- 

 cies is known from this country. 



376a (4) Plants filamentous, thread-like (the thread of cells called a 

 trichome; trichome and sheath, if present, called a filament). . .377 



376b Plants not definitely filamentous; cells globular, rod-shaped, or 

 angular from mutual compression; solitary, in floating colonies, or 

 forming cushion-like masses in which a suggestion of filamentous 

 arrangement may be apparent 421 



377a Trichome coiled or spiralled in a regular fashion 378 



377b Trichomes otherwise, straight or irregularly twisted (occasionally, 

 however, Oscillatoria (Fig. 277) may become twisted about itself 

 to form a regular spiral) 381 



157 



