88 INVERTEBRATE ZOOLOGY 
animals. These soon die in its grasp, and their disintegrated 
remains are swept into the mouth by the ciliated tentacles. An 
oecium is a disc-like structure which, in some parts of the 
colony, lies in front of a zocecium. It serves as an egg-capsule 
in which the embryo develops. A single embryo will be found 
in each. 
Ezercise 3. Find a zoccium with an avicularium attached and 
draw them. 
Exercise 4. Find a zocecium with an ocecium attached and draw 
them. 
