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HANDBOOK OF PROTOZOOLOGY 



10 to 50 microns in diameter; the cyst wall possesses several 

 openings. 



Naegleria histadialis (Puschkarew) (Fig. 7-9, d-f). Similar 

 in size, but the cyst wall smooth. 



Genus Trimastigamoeba Whitmore. The flagellate stage 

 bears three flagella of nearly equal length. The vesicular 

 nucleus with a large endosome. The amoeboid stage is small, 



Fig. 79 a-c. Trophozoite, flagellate phase and cyst (all stained) of 

 Naegleria gruberi. X750 (After Alexeieff). 



d-f. Similar stages of N. bistadialis. X750 (After Kiihn). 



g-j. Trophozoite, flagellate phase, cyst and excystation of 



Trimastigamoeba philippinensis. X950 (After Whitmore). 



being less than 20 microns in diameter. Uninucleate cyst with 

 smooth wall. Coprozoic. One species. 



Trimastigamoeba philippinensis Whitmore (Fig. 79, g-j). 



Family 2 Amoebidae Doflein 



These amoebae do not show flagellated stage (monophasic). 

 They are free-living in fresh or salt water, in damp soil, moss, 

 etc. One, two, or many nuclei occur. Contractile vacuoles 

 usually present in fresh-water forms. Multiplication by 

 binary or multiple fission. Encystment is widely spread. The 

 life-history is not well known. 



Genus Amoeba Ehrenberg. Body large; often one milli- 

 meter in diameter. With short blunt lobopodia. As a rule, a 

 single contractile vacuole, and typically one nucleus. Nuclear 

 structure can be used for specific differentiation to a certain 



