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PROTOZOA 



Class 1. Actinopod. 



Chiefly spherical floating forms with slender 

 unbranched radiating pseudopodia supported 

 by an internal axial filament. 



Subclass 1. Heliozoa. 



Fresh-water forms without a "central cap- 

 sule" separating ectoplasm and endoplasm. 

 (Actinosphaerium, Actinophrys, Clathru- 

 lina.) 



Subclass 2. Radiolaria. 



Marine forms with a central capsule. (Thal- 

 assicola.) 

 Class 2. Rhizopoda. 



Forms with branched, rootlike pseudopodia. 

 Locomotion chiefly by creeping. 



Subclass 1. Proteomyxa. 



Forms with raylike pseudopodia frequently 

 branching and with no axial filaments. (Nu- 

 clearia.) 



Subclass 2. Mycetozoa. 



Semiterrestrial forms with myxopodia and 

 Plasmodium formation. (Stemonitis.) 



Subclass 3. Foraminifera. 



Chiefly marine forms with reticulose pseudo- 

 podia and complex tests. (Lecythium, Glo- 

 bigerina.) 



Subclass 4. Amoebaea. 



Simple amoeboid forms, typically with 

 lobose pseudopodia; with or without a 

 simple test. (Amoeba, Arcella, Difflugia.) 

 Subphylum 3. Infusoria. 



With motile organs in the form of cilia dur- 

 ing all or part of the life cycle. Nucleus 

 generally dimorphic (macronucleus and 

 micronucleus) . Reproduction is by simple 

 transverse division or by budding. 



Class 1. Ciliata. 



With cilia throughout the life history. 

 Subclass 1. Holotricha. 



Cilia are of approximately equal length and 

 equally distributed over body. Trichocysts 

 frequently present. No adoral zone of mem- 

 branelles. (Opalina, Prorodon, Lacrymaria, 

 Coleps, Lionotus, Nassula, Frontonia, Col- 

 pidium, Didinium, Paramecium). 



