192 Shell Life 



It was this fact, probably, that led some of the 

 earlier naturalists to contend that the Limpet never 

 wandered from the particular spot it had selected in 

 early life, though Aristotle had recorded its food- 

 seeking excursions more than two thousand years 

 before. Not only do they do this whilst still covered 

 by the sea, but after the tide has receded and whilst 

 the rocks are still wet. At such times I have often 

 listened to the noise made by hundreds of Limpets 

 dragging their shells over the rough acorn barnacles, 

 and to the rasping sound produced by tlie radula as 

 it scraped the minute vegetation off the rock. 



There is no need to say anything of the importance 

 of the Limpet as food and bait, except that on some 

 parts of our coast this is very great, many tons of the 

 moUusk being consumed yearly by the poor. Judging 

 from the contents of the shell-heaps {Kohken-mid- 

 dings) left near their former rude dwellings by the 

 aboriginal inhabitants of these islands, the Limpet 

 had a much greater importance as a food in earlier 

 days. 



There are several well - marked varieties of the 

 Common Limpet which have distinctive names given 

 to them, and certain of these have been elevated to 

 the rank of species by some writers. The var. 

 elevata has a smaller, rounder, and higher shell ; 

 var. picta is smaller and thinner, with alternate 

 blue and reddish rays ; intermedia is smaller, flatter, 

 and oval, with yellow centre inside and out, the 

 animal dark - coloured ; depressa, much flatter, more 

 oblong, ribs finer and sharper, beak nearer front, 

 centre of interior orange ; cceridea, flat, roundish oval, 

 ribs delicate, somewhat irregular, interior dark blue. 



