SUBK1NGDOM PROTOZOA. M 



2. Order Heliozoa. Pseudopodia slender, with axial support; shell if 



present siliceous ; no central capsule. 



(a) Shell wanting. Actinophrys, Actinosphcerium, Vampy- 



rella, Microgromia. 



(b) Shell present. Clatlirulina. 



3. Order Radiolaria. Pseudopodia slender with axial support; shell 



usually present and siliceous (rarely horny) ; central capsule 

 present. 



(a) Sliell wanting. TTialassicotta, Sphcerozoon. 



(b) Shell siliceous. Actinomma, Heliosphcera. 



(c) Shell horny. Acanthometra. 



II. Class SPOROZOA. Parasitic ; without pseudopodia, flagella or cilia. 



1. Order G-regarinida. Parasitic in cavities of the body especially of 



Invertebrates or in the cells especially of Vertebrates. 



2. Order Myxosporidia. Parasitic usually in the skin, sometimes in 



internal organs of fishes. 



3. Order Sarcosporidia. Parasitic in the muscle-fibres of Mammalia. 



III. Class FLAGELLATA. Provided with one or more flagella. 



1. .Order Autoflagellata. Without shell, protoplasm not especially 



vacuolated. 



(a) Without collar. Monas, Cercomonas, Chlamydomonas, 

 Euglena, Volvox. 



(b) With collar. Codosiga, Dindbryon. 



2. Order DinoflageUata. With shell composed of cellulose. Cera- 



tium. 



3. Order Cystoflagellata. Without shell, protoplasm highly vacuo- 



lated, marine. Noetiluea, Leptodiscus. 



IV. Class INFUSORIA. Provided with cilia or immovable processes. 



1. Order Ciliata. Provided with cilia in adult stage. 



(a) Cilia of nearly uniform length all over the body (Holo- 

 tricha). Paramcetium, Colpoda, Colpidium, Chilodon, 

 Opalina, 



(b) Cilia around anterior end of body longer than the rest 



(Heterotriclia) . Stentor. 



(c) Cilia limited to anterior end of body ( Peritrichd) . Vorti- 



cella. 



(d) Cilia or setae only on ventral surface of the body (Hypo- 

 tricha). Stylonychia. 



2. Order Suctoria. With cilia only in the young stages, in the adult 



with immovable processes. Podophrya, Acineta. 



LITERATURE. 



0. Biitschli. Protozoa. Bronn's Klassen u. Ordnungen des Thierreichs. Leip- 

 zig u. Heidelberg, 1883-87. 

 W. S. Kent. A Manual of the Infusoria. London, 1880-82. 



