14 Laboratory Guide in Zoology 



vided with short filamentous processes called cilia, which 

 are outgrowths of the ectosarc. In some species, these cilia 

 remain during the entire life of the animal, while in others 

 they are present only in the young, being replaced in later 

 life by peculiar organs called tentacles. The Paramecium, 

 Vorticella, Stylonychia, etc., are examples of this class. 



