HOW TO KNOW THE FRESH-WATER ALGAE 



367a Cells bearing 2 long, rigid, rod-like processes at the anterior end. 

 Fig. 262 CHRYSOSPHAERELLA 



Fig. 262. Chrysosphaerella longispina 

 Lauterb. 



This distinctive organism is easily- 

 identified by the curious long rods, 

 borne in pairs on each cell. The 

 chromatophores are brownish-yellow. 

 Although widely distributed the species 

 (only 1 reported) seems to be rather 

 rare in occurrence. 



Figure 262 



367b Cells without such rods 



368 



368a Cells elongate-ellipsoid or elongate pear-shaped, rather compact- 

 ly arranged in the colony; cell wall with minute silicious scales in 

 the anterior end; flagella 2, of equal length. Fig. 263 .... SYNURA 



Fig. 263. Synura uvella Ehr. a, colony; 

 b, single cell showing silicious spi- 

 cules in membrane. 



This species is very common in hard 

 water lakes and may be so abundant 

 as to produce disagreeable odors and 

 tastes in water supply reservoirs. The 

 chromatophores are golden brown and 

 mask the small spicules in the walls at 

 the anterior end of the cell. These can 

 be determined by proper focusing on 

 colonies that are quiescent. There is 

 another species with longer and nar- 

 rower cells, S. Adamsii G. M. Smith, that 

 is of more rare occurrence. 



Figure 263 



154 



