306 BIOLOGY OF THE PROTOZOA 



Flagella directed alternately from both 



sides Genus Platydorina 



3. Cells in meridional plane only Genus Stephanosphcera 



■ Cells distributed on or in a gelatinous mat- 

 rix 4 



4. Colonies of sixteen closely united cells 



Genus Pandorina 

 More than sixteen cells , not closely asso- 

 ciated ^ 5 



5. Individuals do not form a superficial layer 6 

 Individuals form a superficial layer of cells 



Genus Volvox 



6. Cells not differentiated, thirty-two in 



number Genus Eudorina 



Cells different in size , somatic and germinal 



Genus Pleodorina 



Ordeb V. EUGLENroA. 



1. With chromatophores and, usually, stig- 



mata Family 1. Euglenid.e 

 Without chromatophores 2 



2. Without stigmata 3 



With stigmata 5 



3. With one flagellum _. . . . 4 



With two flagella, one directed posteriorly 



Family 3. HeteronemiD/E 



4. Single flagellum directed anteriorly 



Family 2. Astasiid^e 

 Single flagellum directed posteriorly Genus Clautriavia 



5. One species of genus Astasia Species A. ocellata 



Family 1. Euglenidee. 



1. Flagellum single, form rigid or metabolic. . 2 



Two flagella, body metabolic Genus Euirepiia 



Three flagella ; commensal in tadpole intes- 

 tine Genus Euglenomorpha 



2. Solitary, without gelatinous stalk 3 



Stalked and colonial in resting phase Genus Colacium 



3. Test or shell absent 4 



Test or shell present 6 



4. Rigid or metabolic; paramylum varied 



Genus Euglena 

 Rigid, never metabolic 5 



5. Cylindrical; lateral paramylum bodies ring- 



form Genus LepocincUs 



Flattened ; paramylum body usually single, 



central Genus Phacus 



6. Test simple or spinous 7 



Test thick; two band-formed chromato- 

 phores Genus Cryptoglena 



7. Test rigid; spines frequent; free-swimming 



Genus Trachelomonas 



Test flexible; attached at base Genus Ascoglena 



Family 2. Astasiidae. 



1. Cells distinctly metabolic 2 



Cells rigid 6 



