HOW TO KNOW THE FRESH-WATER ALGAE 



368b Cells ovoid or pear-shaped, separated and evenly spaced within 

 the colonial envelope; without scales in the wall; flagella 2, of 

 unequal length. Fig. 264 UROGLENOPS1S 



Fig. 264. Uioglenopsis ameiicana (Cal- 

 kins) Lemm. 



J^£S^ ^ 0,(3 .0 d A fi^ 



^ 



.-y^^V? b ~& ft 



iss ^ <? * ® ® 



or 



a. q*- 



'-« -© 







*K«*f 



This species frequents bodies of water 

 ^c^Jff that are contaminated with sewage and 

 organic wastes. The colonies are large 

 and contain several hundreds of cells, 

 are sometimes mistaken for Volvox (Fig. 

 15) but is quickly differentiated by the 

 &\»*5? yellow-brown color of the plate-like (not 



cup-shaped) chromatophores. 



m 



Figure 264 



369a (366) Cells elongate-ovoid or pear-shaped, compactly arranged 

 side by side in radiate fashion in 1 plane to form a plate with a 

 small opening in the center of the colony; motile by 2 flagella. 

 Fig. 265 CYCLONEXIS 



Fig. 265. Cyclonexis annularis Stokes. (Re- 

 drawn from Stokes). 



The flat, disc-like colony of compactly ar- 

 ranged, pear-shaped cells is very distinctive. 

 The flagella are relatively coarse and can 

 be seen easily when the colony is quiescent. 

 There are 2 elongate, lightly pigmented chro- 

 matophores. 



Figure 265 



369b Cells not as above; contained in a vase-shaped envelope, 1 or 2 

 such envelopes arising from the mouth of the one below to form 

 a branched series. See Fig. 243 DINOBRYON 



370a (365) Individuals furnished with pseudopodia (colony sometimes 

 loosely formed and only temporary) 37 1 



370b Individuals not furnished with organs of locomotion; colonies 

 non-motile 373 



155 



