312 BIOLOGY OF THE PROTOZOA 



Group 2 



1. Axostyle vibrates in endoplasm; four to 



eight posterior flagella 2 



Axostyle rigid; three anterior, one traihng 



flagellum 3 



Axostyle rigid, protruding; four anterior 



flagella Genus Trichomastix 



2. Axostyle attached at posterior end. .Genus Pyrsonympha 

 Axostyle free at posterior region. . .Genus Dinenympha 



3. Axostyle does not project; flagella central, 



apical Genus Devescovina 



Axostyle projects; flagella apical, not 



central Genus Foaina 



Group 3 



With three anterior flagella all equal . . Genus Chilomastix 



With four equal, anterior flagella Genus Tetra chilomastix 



Group If. 



1. Undulating menil:)rane in cytostome; three 



anterior flagella Genus Cyathomostix 



Undulating membrane on body margin ... 2 



2. Two free, anterior flagella Genus Ditrichomonas 



More than two anterior free flagella 3 



3. Three free, anterior flagella Genus Tritrichomonas 



More than three anterior flagella 4 



4. Four free, anterior flagella Genus Trichomonas 



Five free, anterior flagella Genus Pentatrichomonas 



Group 5 



1. With trailing flagellum Genus Eutrichomastix 



Without trailing flagellum 2 



2. With three anterior flagella Genus Protrichomonas 



With more than three anterior flagella .... 3 



3. With four anterior flagella Genus Polymasfix 



With six anterior flagella Genus Hexamastix 



Tribe II. Diplozoa. With two mouths and sets of kinetic elements. 



1. Cytostomes united to form one Genus Giardia 



Cj'tostomes separated 2 



2. Trailing flagella absent 3 



Trailing flagella present 5 



3. Four flagella Genus Gyromonas 



More than four flagella 4 



4. Six flagella Genus Trigonomonas 



Eight flagella Genus Trepomonas 



5. Food taken only at posterior end 6 



Food taking general; no mouth Genus Octomitus 



6. Posterior end with two lateral mouth 



grooves Genus Trigonomonas 



Posterior end with l^ilabiate, movable 



snout^ Genus Urophagus 



Tribe III. Polyzoa. Multiple nuclei and kinetic elements (polymasti- 

 gonts) 



1. Nuclei symmetrically placed, each with 



kinetic complex 2 



Nuclei less numerous than kinetic com- 

 plexes Genus Calonympha 



2. Nuclei in a single stratum Genus Stephanonympha 



Nuclei in two strata; huge axial strand 



Genus Diplonympha 



