54 



LESSON X. 



Genus. CONUS. Plural, Coni. 



CONE. 



THE party should have before them a variety 

 of univalve shells, amongst which there should 

 be a large proportion of such Cones as have the 

 characteristics of the genus well defined.* 



Teacher. I have brought a variety of shells 

 for you to examine ; what is the point of re- 

 semblance which unites them all in one class ? 



Child. They are ail composed of one valve ; 

 they are all univalves. 



Teacher. From these univalve shells select 

 those which appear to you to be similar in their 

 general appearance, and in the form of their 

 mouths. 



Child. We have done so. 



Teacher. Explain to me what you have done. 



Child. We have selected those shells which 

 have the same general appearance, and a similar 

 kind of mouth. 



Teacher. What was the common point of 

 resemblance in all the shells which I have set 

 before you ? 



* It is very important in teaching children to draw out the 

 generic character of shells, to set before them specimens in 

 which the distinguishing features are strongly and clearly 

 marked ; their ideas will then be distinct, vivid, and perma- 

 nent. After this they may proceed to the examination of 

 shells, which, combining the qualities of different genera, 

 form the connecting links between them. 



