4*6 PROTOZOA [CH. 



Phylum PROTOZOA. 



The Protozoa are classified as follows : 



Class I. RHIZOPODA. 



Protozoa devoid of a cuticle and capable of emitting pseudopodia. 

 Order 1. Amoebidea. 



Naked forms devoid of a shell. 

 Order 2. Thalamophora. 



Rhizopoda which secrete a shell protecting at least part of the 

 surface of the body. Ex. Arcella, Difflugia, Gromia, Polystomella. 

 Order 3. Radiolaria. 



Rhizopoda with an internal capsule, i.e. a membranous 

 shell protecting the inner part of the body. Outside this a 

 lattice-like shell of flinty needles. The pseudopodia are delicate 

 filamentous and interlacing. Ex. Heliosphaera. 

 Order 4. Heliozoa. 



Rhizopoda with stiff radiating pseudopodia. A lattice-like 

 shell present or absent. Ex. Actinosphaerium, Actinophrys. 



Order 5. Mycetozoa. 



Rhizopoda of large size with numerous nuclei and with 

 coarse branching pseudopodia which form networks ; they form 

 spores with cellulose walls. 



Sub-order 1. Endosporeae. 



Spores formed inside a sporangium 



Sub-order 2. Exosporeae. 



Spores constricted from finger-like processes 



Class II. FLAGELLATA. 



Protozoa provided with one or several flagella. When two 

 nuclei are present one is situated near the base of the flagellum 

 and is related to its activity. 



Order 1. Rhizomastigina. 



Forms capable of emitting pseudopodia. 

 Order 2. Silieoflagellata. 



Forms with one flagellum and a latticed siliceous shell. 



