ZOOMASTIGINA 



63 



Order PROTOMONADINA 



Zoomastigina with one or two flagella; amoeboid movement, if 

 present, not active over the whole surface of the body ; and no extra- 

 nuclear division centre. 



Monas (Fig. 47 C). Two unequal flagella. Ingestion at base of 

 flagella. Except for absence of chromatophores much resembles 

 Ochromonas among the Phytomastigina and is probably related to 

 that genus. In fresh waters and infusions. 



Bodo (Fig. 47 D). Two rather unequal flagella, of which one trails 

 freely behind and is used for temporary anchoring. Ingestion at a 

 spot near the base of the flagella. In infusions and coprozoic. 



—fl- 



% 



-u.me. 



-nn. 



B 



~~p.by. 



Fig. 48. A diagrammatic comparison of various Trypanosomidae. A, Her- 

 petomonas. B, Leishmania. C, Crithidia. D, Trypanosoma, ba.gr. basal 

 granule;^, flagellum; nu. nucleus; p.by. parabasal body; u.me. undulating 

 membrane. 



Oikomonas (Fig. 47 B). One flagellum. Ingestion of food as in 

 Monas. This genus bears the same relation to certain uniflagellate 

 Chrysomonadina that Monas bears to Ochromonas. In fresh waters 

 and soil. 



Trypanosomidae (Fig. 48). Parasites, with one flagellum; a slender, 

 usually pointed shape; a strong pellicle without ingestion spot; a 

 parabasal body; and no contractile vacuole. This family, which con- 

 tains many dangerous parasites of man and domestic animals, appears 

 to have originally infested invertebrates and to have obtained access 



