AMOEBINA 



349 



with one broad pseiidopodium by which the organism undergoes 

 rolling movement; cytoplasm undifferentiated; numerous vacuoles 

 and nuclei; various inclusions often color the body brown to black 

 and make it appear opaque; symbiotic protophytan, Cladoihrix 

 pelomyxae Veley, occurs regularly; cysts with 2-3 envelopes (Stole); 

 feeds on plant matter; polysaprobic, in still stagnant water, creeping 

 on the muddy bottom. Central Europe, Great Britain, North America. 





Ms. 



Fig. 163. a, Pelomyxa palustris, Xl30 (Kiihn); b, P. villosa, X420 

 (Leidy); c, Vahlkampfia Umax, X830 (Kudo); d, V. patuxent, X830 

 (Hogue); e, f, Acanthamoeba hyalina, X1170 (Dobell); g, h, A. castel- 

 lanii, X1590 (Hewitt). 



P. villosa (Leidy) (Fig. 163, h). Similar to the last-named species, 

 but somewhat smaller; with numerous short and papillary villi at 

 posterior extremity; during locomotion, 120ju-1.25 mm. long; in the 

 ooze of freshwater bodies. Europe, North America. 



P. carolinensis Wilson, Monopodia! forms 1-5 mm. long; polypo- 

 dial (feeding) forms 1-2 mm, in diameter; ectoplasm near the tips 

 of expanding pseudopods; endoplasm contains up to 1000 or more 

 nuclei which are circular in front view, 20/i in diameter, and ellipsoid 

 in profile; fluid and food vacuoles, crystals, many contractile vacu- 



