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HANDBOOK OF PROTOZOOLOGY 



cyst, becoming covered by two or three cyst walls. The contents 

 multiply into several multinucleate bodies. Cosmopolitan. 



Pelomyxa villosa (Leidy) (Fig. 81, d). Similar to the last 

 species, but much smaller; 250 microns long. With numerous 

 villi at the posterior extremity. In a similar habitat. 



Genus Vahlkampfia Chatton and Lalung-Bonnaire. The 

 characteristics are: The nucleus contains a large endosome and 

 peripheral chromatin, and divides by "promitosis" (p. 45). 

 The cyst is uninucleate. It is a small amoeba, exhibiting snail- 

 like movement and possessing a perforated wall when encysted. 

 Body small, not exceeding 50 microns when fully extended. 

 Ordinarily one broad pseudopodium is formed in the direction 

 of movement,. although it cannot be made a basis for taxonomic 

 consideration. ,' 



Fig. 82 a. Vahlkampfia Umax. X500. 



b. V. pdluxent. X500 (After Hogue). 

 c, d. Hartmannella hyalina. X700 (After Dobell). 

 c, tropbozoite; d, cyst, both stained. 



Vahlkampfia Umax (Dujardin) (Fig. 82, a). Body 30 to 40 

 microns long. Fresh water; soil. 



Vahlkampjifi patuxent Hogue (Fig. 82, h). The amoeba was 

 found in the alimentary canal of the oyster. Fairly uniform in 

 size being about 20 microns long during the first few days of 

 artificial cultivation, but later reaching as long as 140 microns 

 in diameter. Ordinarily one large pseudopodium composed of 

 the ectoplasm is seen, presenting a broad fan-shape> In culture, 

 pseudopodium-formatiouv is explosive. Holozoic on^bacteria. 

 No contractile vacuoles. Multiplication by fission or budding. 

 Encystment rare; the cyst contains a single nucleus. 



Genus Hartmannella Alexeieff. This genus ilicludes small 

 amoebae with the following nuclear characteristics. Th? 

 nucleus is vesicular. A large endosome is located in the center 

 ahd numerous chromatin granules are scattered along the 



