HOW TO KNOW THE FRESH-WATER ALGAE 



338a Cells spherical, 2 within a globular envelope. See Fig. 222 



CHLOROBOTRYS 



338b Cells spherical, many within a gelatinous matrix. Fig. 239 



GLOEOBOTRYS 



Fig. 239. Gioeobotrys limneticus (G. M. Smith) 

 Pascher. 



The chief difference between this genus 

 and Chlorobotrys (Fig. 222) is the presence of 

 a definite mucilaginous sheath about the cells 

 to form colonies. The species illustrated at 

 one time was assigned to Chlorobotrys; de- 

 scribed from the open water plankton of lakes. 



Figure 239 



339a (335) Cells forming loose cushions, in multiples of 2 or 4. Fig. 240. 

 CHLORELLIDIOPS1S 



Fig. 240. Chlorellidiopsis separalibis 

 Pascher. 



Although cells of this species are 

 sometimes solitary they usually occur 

 in closely grouped clusters on the 

 walls of other algae. There are 2 

 parietal chromatophores and at least 

 1 dark red oil-spot in the mature cells. 

 Only 1 species reported from this 

 country. 



Figure 240 



339b Cells arranged otherwise 340 



340a Wall in 2 sections which separate to liberate spores (new cells) 

 and which persist nearby; (cells may be incidentally colonial be- 

 cause of gregarious habit). See Fig. 223 DIACHROS 



340b Wall in 1 piece, breaking down irregularly to liberate spores; 



(cells incidentally clustered to form colonies). See Fig. 224 



BOTRYDIOPSIS 



143 



