2 PROTOZOA. 



Subclass 1. Flagellata. 



Typically small forms with a definite anterior 

 end with one or more flagella. All types of 

 nutrition represented. 



Order 1. Pantostomina. 



Nutrition holozoic. Cell more or less amoeboid. 

 One or several flagella. (Mastigamoeba ; Mul- 

 ticilia.) 



Order 2. Protomonadina. 



Nutrition holozoic, saprophytic or parasitic. 

 One flagellum or a principal flagellum and one 

 or two accessory flagella. (Monas, Cercomonas, 

 Bodo, Trypanosomes, Choanoflagellates.) 



Order 3. Polymastigina. 



Three to eight flagella usually of nearly equal 

 length. Entozoic. (Trichomonas.) 



Order 4. Euglenpidina. 



Typically large complex forms with one prin- 

 cipal flagellum, mouth aperture and vacuole 

 system. Frequently provided with stigma and 

 chlorophyll apparatus for holophytic nutrition. 

 (Euglena, Peranema, Phacus.) 



Order 5. Chromomonadina. 



Small forms with one or two flagella, and usu- 

 ally one or two large chromatophores. Typic- 

 ally holophytic. (Dinobryon, Chilomonas, 

 Cryptomonas.) 



Order 6. Phytomonadina. 



Holophytic forms enclosed in cellulose envelope. 

 Colony formation common. Usually two fla- 

 gella. (Sphserella, Gonium, Volvox.) 

 Subclass 2. Dinoflagellata. 



Two flagella, one of which encircles the cell. 

 Test of cellulose plates. Typically holophytic. 

 Subclass 3. Cystoflagellata. 



Large marine forms, with locomotion by a 

 typical flagellum and a "tentacle," or by rhyth- 

 mic contractions of the body. (Noctiluca, 

 Craspedotella.) 

 CLASS 3. Sporozoa. 



Without flagella or cilia in the adult period of 

 the life-cycle. Reproduction is by spore-for- 

 mation. All are endoparasites. 



