No. 3.] 



THE MUSCULATURE OF CHITON. 



62 



low level) of the group or 

 shell next anterior to the 

 group in the section repre- 

 sented. 



horizontal protractor muscles 

 of the buccal mass. 



region of attachment of these 

 muscles. 



radula surrounded by the rad- 

 ula sheath. 



radula exposed where the rad- 

 ula sheath and oesophagus 

 communicate. 



radiate muscles to the anterior 

 lip. 



radiate muscles to the posterior 

 lip. 



lateral projection of the radula 

 sheath dorsal to the carti- 

 lage. 



ventral protractors of the buccal 

 mass. 



ventral transverse muscles of 

 the cartilages. 



y-shaped muscle of the radula. 



