Feb., 1920] The Protozoa of Mirror Lake 125' 



SUBCLASS SUCTORIA. 

 Family Podphryidce. 



Sphaerophrya urostylae Maupas. 



This animal was infrequent in one collection of algae taken- 

 on January 24 at the spring's entrance into the larger pond 

 (Station E). 



Diameter 48/^. 



Podophyra libera Perty. 



Several individuals were taken on February 21, among algae 

 from a submerged stone (Station G). Some were conjugating. 

 The nucleus was oval and coarsely granular; four contractile 

 vacuoles were present. All the animals taken were without 

 stalks. A young individual of this species is shown in Figure 7 

 on Plate III. The protoplasm was hyaline and the cell contained. 

 three contractile vacuoles. 



Diameter of the largest 98/i. 



Family Acinetidce. 



Acineta mystacina Ehrenberg. 



This species was taken on December 3 in sediment from 

 Station B, in February among algae from the submerged stone 

 at Station G, during March in sediment from Station F and in 

 algae from Station H. This species was the most common of 

 the Sudor ia in Mirror Lake. The tentacles were capable of 

 great extension, often reaching 272)U in length. These were 

 very efficient in paralyzing prey; and it was not uncommon to 

 see a ciliate struggling at the end of a tentacle and after a time 

 become motionless. 



Diameter 48-56/^; length of lorica when present 128iu. 



