Fig. 58. Binary fission of Eiiglypha alveolata, x about 450. From Hegner 

 and Taliaferro, after Schewiakoff. A, B, C, D, Successive stages in the mitosis, 

 with formation and occupation of a new shell. 



att. 



ah. 



Fig. 59. Arcelladiscoides, x 500. From Leidy. A, Seen from above. B, Seen 

 from the side, optical section, ott. thread attaching animal to inner surface 

 of shell; f.vac food vacuole; g.vac. gas vacuole; nu. nucleus; op. edge of 

 opening into shell ; ^^. pseudopodia; j/?. shell. 



