j^cklace-shells and Winkles 



21 I 



"produced the Velelke, wliicli were seen apparently 

 issuing from its mouth. For such a mode of life 

 their shell must be thin and light, and to enable 

 them to float unnoticed by sea-birds and flshes it is 



Violet Sea-snail (lanlMna) with its float 



b, a bubble about to be joined to the float; c, shell; I, float; 

 J), foot; t, head 



coloured violet, the lower whorls, which are most 

 exposed from above when the creature floats, being 

 of a darker tint, whilst the upper whorls may be 

 white. The mouth of the shell floats uppermost, and 



