TABLE A9.

Morphology of trophozoite forms of flagellates

Species	Size (length [μm])	Shape	Motility	No. of nuclei	No. and positions of flagella	Other features
Pentatrichomonas hominis	6–20; usual range, 11–12	Pear shaped	Nervous, jerky	1 (not visible in unstained mounts)	3–5 anterior, 1 posterior	Undulating membrane extending the length of the body
Chilomastix mesnili	6–24; usual range, 10–15	Pear shaped	Stiff, rotary	1 (not visible in unstained mounts)	3 anterior, 1 in cytosome	Prominent cytostome extending 1/3–1/2 the length of the body; spiral groove across ventral surface
Giardia lamblia (G. duodenalis, G. intestinalis)	10–20; usual range, 12–15	Pear shaped	“Falling leaf”	2 (not visible in unstained mounts)	4 lateral, 2 ventral, 2 caudal	Sucking disk occupying 1/2–3/4 of the ventral surface; median bodies lying horizontally or obliquely in lower part of body
Enteromonas hominis	4–10; usual range, 8–9	Oval	Jerky	1 (not visible in unstained mounts)	3 anterior, 1 posterior	One side of body flattened; posterior flagellum extends free posteriorly or laterally
Retortamonas intestinalis	4–9; usual range, 6–7	Pear shaped or oval	Jerky	1 (not visible in unstained mounts)	1 anterior, 1 posterior	Prominent cytostome extending ∼1/2 the length of the body