PROTOZOA 



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Subclass 2. Spirotricha. 



With adoral zone of membranelles right- 

 wound toward the mouth. Peristome not 

 drawn out like a funnel. Includes as chief 

 orders Heterotrichida, Oligotrichida and 

 Hypotrichida. (Spirostomum, Stentor, 



Oxytricha, Stylonychia, Euplotes. Halteria.) 



Subclass 3. Peritricha. 



With adoral zone of membranelles left- 

 wound toward the mouth. Cilia usually 

 limited to those in the adoral zone. (Vor- 

 ticella, Zoothamnium, Carchesium, Epis- 

 tylis.) 



Subclass 4. Chonotricha. 



Adoral zone right- wound toward the mouth. 

 Peristome drawn out like a funnel. (Spiro- 

 chona.) 

 Class 2. Suctoria (Acinetaria, Tentaculifera) . 



Usually possessing cilia only during embry- 

 onic stages. Tentacles adapted for piercing 

 and sucking are present in the adults. 

 (Podophrya, Ephelota, Acineta.) 

 Subphylum 4. Sporozoa. 



Without cilia or flagella in the "adult" period 

 of the life cycle. Reproduction is by spore 

 formation (multiple fission). All are endo- 

 parasites. 

 Class 1. Telosporidia. 



Sporulation phase of the life cycle is dis- 

 tinct and follows the trophic phase. 



Subclass 1. Gregarinina. 



Typically lumen-dwelling parasites of in- 

 vertebrates. Reproduction by sporogony 

 alone or by sporogony and schizogony. 

 Order 1. Eugregarinida. 



Comprises most of the gregarines. Sporozo- 

 ites, usually 8 in number, formed only after 

 sexual phenomena. (Monocystis, Gregar- 

 ina.) 

 Order 2. Schizogregarinida. 



Parasites of the digestive tract of arthro- 

 pods, annelids and tunicates. With an 

 asexual cycle. (Schizocystis.) 



