Chapter 14 

 Order 3 Polymastigina Blochmann 



THE Zoomastigina placed in this group possess 3-8 (in one 

 family up to a dozen or more) flagella and generally speak- 

 ing, are minute forms with varied characters and structures. 

 Many possess a cytosome and one to many nuclei and the body 

 is covered by a thin pellicle which allows the organism to change 

 form, although each species shows a typical form. The cyto- 

 plasm does not show any special cortical differentiation; in many, 

 there is an axial structure known as axostyle or axostylar fila- 

 ments (p. 61). In forms with an undulating membrane, there 

 is usually a rod-like structure beneath the membrane which is 

 known as costa (Kunstler). Parabasal body of various forms occur 

 in many species. The majority of Polymastigina inhabit the di- 

 gestive tract of animals and nutrition is holozoic or saprozoic 

 (parasitic). Asexual reproduction is by longitudinal fission, some- 

 times multiple. Encystment is common, and the cyst is responsi- 

 ble for infection of new hosts through mouth. Sexual reproduction 

 has not been definitely established. 



With 1 nucleus Suborder 1 Monomonadina 



With 2 nuclei Suborder 2 Diplomonadina (p. 272) 



With more than 2 nuclei Suborder 3 Polymonadina (p. 274) 



Suborder 1 Monomonadina 



Without axial organella 



With 3 flagella Family 1 Trimastigidae 



With 4 flagella 



None undulates on body surface. . T 



Family 2 Tetramitidae (p. 263) 



One undulates on body surface 



Family 3 Chilomastigidae (p. 264) 



With more than 4 flagella Family 4 Callimastigidae (p. 265) 



With axial organella 



Without undulating membrane. .Family 5 Polymastigidae (p. 265) 

 With undulating membrane. .Family 6 Trichomonadidae (p. 269) 



Family 1 Trimastigidae Kent 



Free-swimming or attached; with 3 flagella; no cytostome; free- 

 living in fresh or salt water, coprozoic or parasitic. 



260 



