176 THE RING OF NATURE 



we find right at the edge of high-water mark a 

 shell of the same shape, but perfectly smooth and 

 usually rejoicing in olive or orange or some kindred 

 bright colour. The characteristic shape of the 

 Littorinas we find to be a large round body whorl 

 and a tiny sharp spire. The eye that has once 

 taken the characters in cannot be mistaken when 

 other shells conforming or otherwise present 

 themselves to view. But the point about the 

 smooth one, L. palliata, as it is called, is that it is 

 almost an amphibian. Many individuals must 

 sometimes live for days at a time out of water, 

 and it is scarcely fanciful to say that this snail 

 is about to follow our garden snail, exchange its 

 gills for lungs, and take up a purely terrestrial life. 



L. litorea, the common winkle which we find a 

 little below the line where the smooth ' sea snail ' 

 is common, has proved itself a traveller of some 

 merit. A gasteropod of the Old World, and thus 

 as much a British shell as any we have, it has 

 travelled along the existing or prehistoric shores 

 of Iceland and Greenland, and within the last two 

 centuries has invaded America from the north, 

 getting with difficulty round Cape Cod, but now 

 having reached Newport and New York. 



A little below the winkle line, but overlapping 

 it somewhat, we find a shell of quite another 

 family, the purple or dog-winkle. It is exceedingly 

 variable in colour, now yellow, now white, now 

 brown or red, and sometimes striped not merely 

 in two colours but in three, red, white and black, 



