54 MORPHOLOGY OF IXYKRTKBRATK TYPES 



11. Examine the prepared slide with a cross-section through 

 an acontium. Make a drawing showing the row of nematocysts. 



12. Additional exercise. Touch a live Metridium with the 

 end of a pencil until at least one acontium is projected through 

 a cinclide. Make a sketch showing the animal in this con- 

 dition. 



