MORPHOLOGY AND TAXONOMY OF MASTIGOPHORA 287 



The pseiidopodia may be axopodia or lobopodia, the axial fila- 

 ments and radiating pseiidopodia of the former resemblino; the 

 motile organs of the Heliozoa. The lobopodia may be finger-form 

 (Mastir/amceba, Masfigella) or ray-like (Actinomonas, Pteridomonas, 

 etc.), and are frequently limited to either anterior or posterior end. 



Flagella vary in number from one to many and dimorphism occurs 

 in some forms (Pteridomonas, Cercobodo, Bodoysis). Vacuoles are 

 invariably simple and either fixed or migratory as in Amoeba. 



Nutrition is holozoic, or occasionally saprozoic; solid particles 

 are ingested at any part of the body in some forms; in Dlmorpha 

 the algal cells serving as food are killed by the pseudopodia and 

 seized by short pseiidopodia from the body. 



^/ 



Fig. 137. — Types of Rhizomastigidce. -4, Mastigamccha asjxra. B, Actinomonas 

 mirahilis; f, flagella; v, pseudopodia. (Fiom Calkins after F. E. Schultze and Sav. 

 Kent.) 



Reproduction is by longitudinal division in motile (Multicilia) 

 or in resting phases (Mastigamoeba sefosa). 



The individuals are naked and free-swimming or amoeboid and 

 creeping, save when attached by stalks as in Pteridomonas or 

 ■Actinomonas (Fig. 137). Pseudopodia are varied; sometimes ray- 

 like or branching (Pteridomonas), sometimes lobose (Mastigamoeba, 

 Mastigella) sometimes axopodia (Dimorpha). The flagellum is 

 simple as a rule but the swimming flagellum may be accompanied 

 by one or two secondary flagella (Pteridomonas) or by a trailing 

 flagellum {Cercobodo, Bodoysis) or the latter may pass through the 



