THE BUTTERFLY. 



185 



one, belong under this second head. The hydra is the 

 sample of ccelenterata that we have studied. 



Annuloida means ring-like. The animals that are 

 classed under this head have usually been placed with 

 the protozoa, ccelenterata, and annulosa (the animals 

 whose bodies are made up of rings). Most of the annu- 

 loida live in the sea or the intestines of other animals, 

 so but few of you could get specimens for examination ; 

 and it is hard to study an animal from pictures alone. 

 The starfish and tape-worm are two of the more com- 

 mon samples of the annuloida. The starfish, which is 

 not a fish at all, used to belong to the radiata, the old 

 name for the second division (ccelenterata) and the 

 tape-worm was classed with the annulosa. But the 

 starfish you can see only on the sea or in an aquarium, 

 and the tape-worm you will hardly find outside a medi- 

 cal museum ; so we pass these by for the present, to learn 

 about the common animals — those that you can see al- 

 most every day, no matter how far from the sea-shore 

 you may live. 



Annulosa is the name given to those animals whose 

 bodies are made up of rings. Annulus means ring. 

 We have studied two samples of the annulosa ; first, a 

 crayfish, or lobster, which is also called a crustacean, 

 because it is covered by a crust, or shell ; but it should 

 not be called a fish, because all fish have backbones. 



