500 



PROTOZOOLOGY 



Fig. 230. a, Teuthophrys trisula, X330 (Wenrich); b, Metacystis 

 Iruncata, X270 (Cohn); c, Vasicola ciliata, X250 (Kahl); d, Pelatradus 

 grandis, Xl70 (Penard) ; e-g, Didinium nasutuni, Xl70 (Kudo); 

 h, D. balbianii, X290 (Biitschli); i-k, Mesodinium pulex (i, X670; 

 j, oral view; k, oral tentacles, X1330) (Noland); 1, m, M. acarus 

 (1, XG70; m, oral tentacles, X1330) (Noland); n, Askenasia volvox, 

 X530 (Faure-Fremiet); o, Cyclolrichium meunieri, X780 (Powers). 



ole posterior; feeds on other ciliates, especially Paramecium; 

 fresh or salt water. Several species. 



D. nasutum (Miiller) (Fig. 230, e-g). 80-200ai long; endoplasm 

 highly granulated ; with 2 girdles of pectinelles ; fresh water. 



D. balbianii (Fabre-Domergue) (Fig. 230, h). 60-1 OOju long; a 

 single girdle of pectinelles near anterior end; fresh water. 



