SUBKINODOM PROTOZOA. 39 



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



present siliceous ; no central capsule. 



{a) Shell wanting. Actinophrys, Aotinosphcerium, Vampy- 



rella, Microgromia. 

 (6) Shell present. Clathrulina. 



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



usually present and siliceous (rarely horny) ; central capsule 

 present. 



(a) Shell wanting. Thalassicolla, Sphcerozoon. 

 (6) Shell siliceous. Actinomma, Heliosphmra. 

 (c) Shell horny. Acanthomeira. 



II. Class Sporozoa. — Parasitic ; without pseudopodia, flagella or cilia. 

 1. Order Qregarinida. — Parasitic in cavities of the body especially of 



Invertebrates or in the cells especially of Vertebrates. 

 3. 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. — Moiias, Cercbmonas, Chlamydomonas, 

 Euglena, Volvox. 



(b) With collar. — Codosiga, Dinobryon. 



3. Order Dinoflagellata. — ^"With shell composed of cellulose. Cera- 

 tium. 



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

 lated, marine. Noctiluca, 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). Paramaeciuin, Colpoda, Colpidium, Chilodon, 



Opalina. 

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



{Heterotricha). Stentor. 

 (e) Cilia limited to anterior end of body (Peritricha). Vurti- 



cella. 

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



tricha). 8tylonychia. 



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



with immovable processes. Podophrya, Adneta. 



LITERATUKE. 



0. Butschli. Protozoa. Bronn's Klassen u. Orduungen des Thierreichs. Leip- 

 zig u. Heidelberg, 1883-87. 

 W. S. Kent. A Manual of the Infusoria. London, 1880-83. 



