766 



PROTOZOOLOGY 



posterior; a micronucleus; contractile vacuole terminal, with eight 

 long collecting canals which reach the middle of body; in fresh water. 



U. turbo (Miiller) (Fig. 326, c). 50-80/z long; unique movement. 

 Fission (Kidder and Diller, 1934). 



Genus Urozona Schewiakoff. Ovoid, both ends broadly rounded; 

 a distinct constriction in the ciliated middle region; ciliary band 

 composed of 5-6 rows of cilia, directed anteriorly and arranged longi- 

 tudinally; cytostome with a membrane; rounded macro nucleus and a 

 micronucleus posterior ; contractie vacuole subterminal ;in freshwater. 



Fig. 326. a, Dexiotrichides centralis, X500 (Kahl); b, Cyrtolophosis 

 mucicola, X670 (Kahl); c, Urocentrum turbo, X200 (Biitschli); d, Urozona 

 butschlii, X440 (Kahl); e, Uronema marinum, X490 (Kahl); f, g, U. pluri- 

 caudatum, X940 (Noland); h, Homalogastra setosa, X450 (Kahl); i, j, 

 Stokesia vernalis, X340 (Wenrich); k, Ophryoglena collini, X150 (Liechten- 

 stein); 1, 0. pyriformis, X180 (Rossolimo); m, 0. intestinalis, X55 

 (Rossolimo). 



