SHELLS. 55 



The body. The right side. 



back. left side, 



front. operculum. 



Teacher. Describe to me each part and its 

 position. 



Child. The spire is composed of the upper 

 whorls, and is situated at the upper part of the 

 shell. 



The whorls are the parts that roll round and 

 form the spire. 



The first whorl is the smallest whorl, and is 

 at the top of the spire. 



The body whorl is the largest whorl, and is at 

 the base of the shell. 



The suture is the seam formed by the meeting 

 of the whorls. 



The apex is the top of the spire. 



The base is the opposite extremity to the apex, 

 and is situated either at the lowest part of the 

 aperture, or at the end of the beak, when the 

 shell is canaliculated. 



The aperture, or mouth, is the entrance to the 

 cavity of the shell. 



The lips are the edges of the mouth. 



The columellar lip is the lip nearest the colu- 

 nella. 



The outer lip is the outer edge of the mouth. 



The columella is the pillar round which the 

 fvhorls form their spiral volutions. 



The front is that part of the shell in which 

 the mouth is situated. 



The back is opposite to the front. 



The right side is that part of the shell which 



