42 LESSON VIII. 



Teacher. The animals of these shells with 

 two valves use these pieces for a very similar 

 purpose, to exclude the water. Now that you 

 have found out the distinguishing character of 

 these classes, I will give you their names. Those 

 shells which are composed of only one valve are 

 called univalves, from the Latin, un us one, and 

 valve. Shells composed of two valves are 

 called bivalves from bis the Latin for twice, and 

 valve. Shells composed of more than two 

 valves are called multivalves, from mult us, the 

 Latin for many, and valve. 



QUESTIONS ON THE MOLLUSCA 

 AND THE SHELL. 



Questions will be given at each division of the subject, 

 which the children should be able to answer well without 

 assistance, before they proceed to a new part. 



1. Describe the animals called mollusks. 



2. Which of the different senses do they 

 possess ? 



3. How do they move on land ? 



4. By what means do they move in the sea ? 



5. Describe the different methods by which 

 they render themselves stationary. 



6. Describe the organs by which they feed 

 themselves. 



7. Name the two classes into which the mol- 

 lusks are divided. 



