The Violet Snails 



shoreward. It occasionally happens that a purple band is painted 

 on the beach, the shattered fragments of purple shells. Even 

 those which escape breaking by the surf are unable to get back to 

 their element because the foot is not adapted to such effort. 

 The sun kills them and birds devour them. It is generally 

 years before another school of lanthina is wrecked on the same 

 beach. 



Violet snails are often met far off shore. But I fancy that 

 only skilled observers would see the little fleet. The elongated 

 raft is but a small group of bubbles on the surface. At one end 

 of it the head and foot of the mollusk come nearly out of the 

 water, but they look transparent. The mouth of the shell is 

 turned upward, and the exposed outer whorl where the body lies 

 is coloured a deep violet which blends with the deep blue of the 

 sea. The apex is farther from the surface, and is a paler violet. 

 The precious eggs are quite out of sight. 



The chief enemies of the violet snail are sea birds that skim 

 and scan the surface for food. Against them Nature has given 

 this little creature adequate "protective coloration" to enable 

 it to escape detection. It has no eyes, and the only defence it 

 offers when disturbed is to exude a little cloud of violet ink. 



For its food special provision is made. Small jelly-fishes 

 which like the surface of the sea swarm in numbers so great that 

 the violet snail has but to thrust out its prehensile proboscis 

 to catch them. 



Off our Florida coasts the genus Vellela abounds, each indivi- 

 dual a cake of jelly, bright blue, transparent, hung below with 

 short streamers and above hoisting a three-cornered sail. This 

 is a hydroid colony, like the Portuguese man-of-war. The 

 violet snail seizes one with its snout, and tears it to shreds with 

 its remarkably large rasping tongue. It is a surprise to see so 

 delicate a mollusk tackling a "jelly-fish" four or five inches long, 

 and well provided with protective stingers. 



Barnacles, which attach themselves to its shell, are occasion- 

 ally eaten by lanthina. A blue crustacean lives on the float, 

 asking nothing of its host but lodging and free transportation. 

 Some contend that the young of the violet snail, as they hatch, 

 get on the raft of their mother and secrete little floats before 

 they are equipped for life in the water. This is doubtful, for 

 each is born with a swimming apparatus. 



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