HOW TO KNOW THE FRESH-WATER ALGAE 



32a (23)— Flagella 6-8. Fig. 29 POLYBLEPHAR1DES 



Fig. 29. Polyblepharides fragariitormis Hazen, showing 

 3 of the 4 contractile vacuoles at the anterior end. 

 (Redrawn from Hazen.) 



Apparently there are only 2 species on record for this 

 genus. They possess 6-8 flagella and several contractile 

 vacuoles at the anterior end. 



Figure 29 



32b Flagella 2-4 33 



33a Flagella 2 34 



33b Flagella 4. Fig. 30 PYRAMIMONAS 



Fig. 30. Pyramimonas tetrarhynchus Schmar. a, 

 'front' view; b, end view showing points of 

 attachment of the flagella. 



This is Pyramidomonas of some authors; con- 

 tains at least 8 species all of which are 4-lobed 

 when seen in end view, with a flagellum at- 

 tached in each of the four depressions between 

 th'3 lobes. 



Figure 30 



34a Cells ovoid but with lobes or flanges, appearing 6-angled when 

 seen in end view. Fig. 31 STEPHANOPTERA 



Figure 31 



Fig. 31. Stephanoptera gracilis (Ar- 

 ^tari) G. M. Smith, a, 'front' view; 

 b, end view, showing point of 

 attachment of flagella. 



This genus takes its name from the 

 fact that it is crown-shaped or 6- 

 lobed when seen on end; the flagel- 

 la being centrally attached in the 

 anterior end. 



35 



