CHAPTER XI 



ORDER 2 PROTOMONADIDA BLOCHMANN 



THIS ORDER contains small Zoomastigina with one, two, or 

 sometimes three flagella. The body is in many cases plas- 

 tic, having no definite pellicle, and in some cases it is amoeboid. 

 The method of nutrition is holozoic, saprozoic, or parasitic. 

 The order includes a heterogeneous lot of Protozoa, mostly 

 parasitic, whose affinities to one another are very incompletely 

 known. Reproduction is, as a rule, by longitudinal fission, al- 

 though budding or multiple fission has also been known to 

 occur. Sexual reproduction, though reported in some forms, 

 has not been confirmed. 



In dividing the Protomonadida into ten families. Calkins' 

 scheme has been chiefly followed : 



With one flagellum 



Protoplasmic collar present 



Collar entirely enclosed in jelly Family 1 Phalansteriidae 



Collar not enclosed in jelly 



Without any lorica Family 2 Choanoflagellidae 



With lorica Family 3 Bicosoecidae 



Protoplasmic collar absent Family 4 Trypanosomatidae 



With two flagella 



Undulating membrane present; parasitic Family 5 Cryptobiidae 



Undulating membrane absent 



Flagella of equal length Family 6 Amphimonadidae 



Flagella of unequal length 



One primary flagellum, the other secondary Family 7 Monadidae 



One primary flagellum, the other trailing Family 8 Bodonidae 



With three flagella; one primary, two trailing Family 9 Trimastigidae 



With four flagella; two long, two short Family 10 Costiidae 



Family 1 Phalansteriidae Kent 



Genus Phalansterium Cienkowski. Body small and ovoid; 

 with a flagellum and a narrow collar. Numerous individuals are 

 embedded in gelatinous substance which assumes a dendritic 

 form. The flagella protrude. Fresh water. 



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