u.irub. 



jioiST-, ^"'y'g&ps,' 



..._>*-^ 



IS.Trachelius 19.0f>hryoglena 



FIG. 19. Various forms of Ciliata. qa shows part of a colony, b a single zooid, 

 and c a couple of nematocysts ; a. anus ; c. (in 18) cuticle ; c. (in 19) excretory 

 canals ; c. vac. contractile vacuole ; f. vac. food vacuole ; g. gullet ; nig. nn . 

 meganucleus ; ml. nit. micronucleus ; ntth. mouth ; nu. nucleus ; ntc. nematocyst ; 

 /. (in 15) a Paramoecmm seized by Didimium ; t. tentacle; u. mb. undulating 

 membrane ; vac. non-contractile vacuole ; vst. vestibule. (From Biitschli's Pro- 

 tozoa^ after various authors.) E 



