HOW TO KNOW THE FRESH-WATER ALGAE 



45a Cells cylindrical or elongate-ovoid, scattered throughout amorphous 

 mucUage. Fig. 39 COCCOMYXA 



Fig. 39. Coccomyxa dispar Schmidle, cells in 

 the tips of gelatinous strands. 



There are three recorded species of this 

 genus but only Coccomyxa dispar Schm. 

 seems to have been found in this country, 

 forming gelatinous masses of varying extent 

 on damp soil, on wet wood, or more rarely 

 free-floating. It has been found attached in a 

 wooden flume of swiftly flowing water. 



Figure 39 



45b Cells shaped otherwise 46 



46a Cells elliptical or nearly spherical, arranged in 2's and 4's within 

 ungelatinized walls of mother-cell; pigment spot (eye-spot) usually 

 evident. Fig. 40 .... PALMELLA— STAGE OF CHLAMYDOMONAS 



Fig. 40. Palmella-stage of Chlamydo- 

 monas. 



Chlamydomonas (Fig. 27) often be- 

 comes quiescent in unfavorable habi- 

 tats, or as a normal stage in its life 

 history. The cells adhere to a substrate, 

 lose their flagella, but continue to di- 

 vide, sometimes forming extensive gela- 

 tinous masses. The cells are arranged 

 Figure 40 in 2's or 4's and are surrounded by 



mucilaginous sheaths, thus somewhat re- 

 sembling Palmella (Fig. 36). In this form Chlamydomonas is often 

 mistaken for Gloeocystis (Fig. 41). Laboratory aquaria often contain 

 Chlamydomonas in this stage. The cells may become actively motile 

 again by developing new flagella. 



46b Cells spherical (sometimes oval) irregularly scattered throughout 

 mucilage; orange-colored oil globules sometimes present; red eye- 

 spot lacking 47 



40 



