A FEW MORE MOLLUSKS. 



107 



They feed on animal matter 

 instead of vegetable. You no- 

 tice in both the pictures a little 

 canal, or open tube, at the 

 bottom of the shell. You can 

 see the same plainly in Figure' 

 64, which is the picture of an- 

 other Purple. All the shells 

 that have this canal belong to 

 animals that are carnivorous, 

 while those that have round 

 openings, like Figure 56, be- Figure ec. 



long mostly to herb-eat- 

 ing mollusks. 



Purples are so called 

 because a rich dye used 

 to be obtained from sim- 

 ilar mollusks that lived 

 in the Mediterranean 

 Sea. Perhaps you have 

 all read of this famous 

 dye, which was known 

 as "Tyrian Purple." 



The finest Purples of 



our coast live in the 



northern waters, where 



Figure 67. some of them are very 



