2 1 2 Shell Life 



to steady the creature in this position it fabricates a 

 kind of raft by the excretion of slime in Avhich it 

 imprisons bubbles of air. To the under-surface of 

 this raft the egg-capsules are attached, and on 

 examination of tliese it will usually be found that 

 those nearest to the animal contain eggs, those in the 

 middle young with fully formed shells, wliilst those 

 near the farther end are broken and empty, the 

 young ones having departed. When touched, the 

 Violet-snail exudes a violet fluid which clouds the 

 water around. They have no power to rise or sink 

 at will. At least two species — /. rotundata and /. 



Violet-snail and float — sid« 



coiniminis — drift to our shores. They have no eyes, 

 and are sometimes termed the " Blind Snails of the 

 Sea." 



The Wentletraps (Scalaina) are well known not by 

 reason of our several British species, but because of the 

 high commercial value attached formerly to the Large 

 Wentletrap (S. jwetiosa) from China. Rumphius 

 records that in 1701 this shell sold for forty guineas; 

 iifby-two years later the price had fallen 50 per 

 cent, and since then there has been so continuous a 

 slump in Wentletraps that a few shillings are now 

 sufficient to purchase a good specimen. The shells 

 are distinct from those of any other of our native 



