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PROTOZOOLOGY 



posterior prolongation slightly curved; a prominent ridge on the con- 

 vex side, extending to posterior end; longitudinally striated; usually 

 one circular paramylon body near center; flagellum as long as body. 

 P. longicauda (Ehrenberg) (Fig. 119, b). 120-170/* by 45-70/*; 

 usually slightly twisted ; a long caudal prolongation ; flagellum about 



Fig. 119. Species of Phacus (Allegre and Jahn). a, Phacus pleuronedes 

 and an end view, X800; b, P. longicauda, X500; c, P. pyrum and an end 

 view, X880; d, P. acuminata and an end view, XI 300; e, P. monilata, 

 X800; f, P. torta, and an end view, X800; g, P. oscillans, X1400. 



one discoidal paramylon body central; pellicle longitudinally stri- 

 ated. 



P. pyrum (E.) (Fig. 119, c). About 30-50/1 by 10-20/*; circular in 

 cross-section; with a medium long caudal prolongation; pellicle ob- 

 liquely ridged; stigma inconspicuous; two discoid paramylon bodies; 

 flagellum as long as the body. 



