16 



SHELL GALLERY. 



voracious. This is one of the groups of shells that have continued 

 to exist from Paleeozoic times. 

 Case 38. The " Violet Snails " {lanthinidce) are found floating about in 



every ocean, excepting in cold regions, with the spire of the shell 

 downwards, and the bottom, being more exposed to the action of 

 light, is more deeply tinted than the upper part. They feed upon 



Fiff. 10. 



Cyprxa leucodon. Case 32. 



Jelly-fish, and construct a gelatinous raft, filled with air-bubbles, 

 to the underside of which the females attach their eggs. 



