The Sarcodina 235 



Fig. 5. 24. Dimastigamoebidae. AM. Naegleria gruberi: A. Unusually 

 elongated amoeba. B. Amoeba with four nuclei. C. Flagellate stage, from 

 living. D. Flagellate with three nuclei. E, F. Cysts with one and three nuclei. 

 G. Amoeba leaving cyst. H. Cyst showing several pores and unusual separa- 

 tion of inner and outer membranes. I-M. Stages in development of flagellate 

 (M) from amoeboid stage (I). A-G, xl600 (after Wilson); H, x2400 (after 

 Wenyon); I-M, xl215 (after Rafalko). N-P. Naegleria (Vahlkampfia) tachy- 

 podia (Glaser): rounded amoeba, two blepharoplasts on nuclear membrane 

 (N), x2010; amoeba, from living (O), xlI20; flagellate (P), x2010 (after 

 Pietschmann). Q. Dimastigamoeba simplex MorofE (20-40 X 10-12^), flagellate 

 stage showing long trailing fiagelluxn (after M.). 



Until it is shown that the type species o£ Vahlkampfia has a flagellate 

 phase, there is no justification for placing this genus in the family 

 Dimastigamoebidae as now constituted. "Vahlkampfia" tachy podia Glaser 

 does show a flagellate stage (HI) closely resembling that of N. gruberi 



