The Mastigophora 185 



Fig. 4. 45. Hexamitidae. A. Urophagus rostratus (Stein) Klebs, xl200 

 (after K.). B. Hexamita pitheci (da Cunha and Muniz) Wenrich, from Ma- 

 cacus rhesus: paired nuclei, axostyies and flagella; x3465 (after W.). C. Hexa- 

 mita gigas Bishop, from a leech (Haemopsis sangiiisugae); elongated nuclei, 

 two axostyies, food vacuoles; x2640 (after B.). D. Trigonomonas compressa 

 Klebs, x833 (after K.). E, F. Gyromonas ambulans Seligo, narrow and broad 

 surfaces; x945 (after S.). G. Trepomonas agilis Dujardin; two comma-shaped 

 nuclei, paired flagella, ingested bacteria; x2500 (after Bishop). H. Giardia 

 muris (Grassi), showing axostyle, paired nuclei, parabasal bodies, and flag- 

 ella; concave ventral area indicated in outline; x2550, schematic (after 

 Kofoid and Christiansen). 



45, B, C), Trepomonas Dujardin (19; Fig. 4. 45, G), Trigonomonas Klebs (153; Fig. 4. 

 45, D), and Urophagus Klebs (Fig. 4. 45, A). It is possible that Urophagus should be 

 considered a synonym of Hexamita. 



Order 4. Trichomonadida 



These flagellates have an axostyle, a parabasal body (not a kineto- 

 plast), and a mastigont of 3-6 flagella (147). One flagellum is a trailing 

 flagellum which may or may not form part of an undulating membrane. 

 Each mastigont is typically associated with one nucleus, although a 

 partial or complete dissociation has occurred in certain multinucleate 

 species. A paradesmose appears in mitosis. Members of the order, as now 

 known, are uninucleate or multinucleate, not binucleate. 



