CATECHISM OF CONCIIOLOGY. 



Q. What is meant by Multivalves? 



A. Multivalves signify those shells which are 

 composed of more than two pieces, as the Pholas. 

 They are either parasitical, that is, attached to 

 other substances as the genus Lepas, or unattach- 

 ed, as Chiton and Pholas. 



Q. Of what do Bivalves consist ? 



A. Bivalves consist of two distinct parts united 

 by an hinge, as the oyster. 



Q. How are Univalves formed ? 



A. Univalves are formed of one entire part, a* 

 the common snail. 



CHAP. III. 



GENERIC CHARACTER OF 

 MULTIVALVES, 



Q FROM what are the generic characters of 

 the Multivalves derived ? 



A. From the situation and number of the 

 valves. 



