Feb., 1920] The Protozoa of Mirror Lake 109 



Order Phytoflagellida. 



Family Chrysomonadidce. 



Dinobryon sertularia Ehrenberg. 



Early in October in the green sediment from the leaves at 

 Station A these colonies were abundant. One colony was 

 taken in November in algae scraped from submerged posts 

 (Stations I and I'). 



Synura uvella Ehrenberg. 



This colonial protozoan was common throughout the fall in 

 sediment from Station B and it was common in one collection of 

 filaments of dead Oedogonium (Station H) in November. Many 

 colonies contained only eight individuals, others as many as 32. 



Diameter of colony 56-1 28/i. 



Family CryptomonadidcB. 



Cryptomonas ovata Ehrenberg. 



This species was abundant in March among Oedogonium 

 filaments at Station H, in sediment from the stone near the 

 outlet of the larger pond (Station K), and on alga-covered 

 poplar roots (Station D). It was not seen during the time 

 when ice covered the lake. 



Length 56jli. 



Chilomonas paramaecium Ehrenberg. 



Although infrequent in new collections of floating Spirogyra 

 (Station C), and in algae scraped from the posts (Stations 

 I and I'), it was very abundant in cultures which had become 

 foul. It multiplied rapidly as decay proceeded and the bacteria 

 increased. 



Length 21-27/1 ; width 9-1 Iju. 



Family Chlamydomonadidce. 



Carteria multifilis (Fresenius). 



This minute green flagellate caused the water in the smaller 

 pond to assume a bright green color during a few days in October. 

 Some interesting observations were made on its behavior in 

 relation to light. During the day the organisms tended to 



