256 Shell Life 



colour aofree with the veined rocks to wliich the 

 Purple clings. In this connection it is interesting to 

 note that Linnaeus must have been struck by the 

 pebble-like appearance often assumed by this species, 

 for he called it lapilliis (a little stone or pebble). 

 As in the case of the Periwinkle, already referred to, 

 this stoniness has relation to the hard knocks littoral 

 species experience in stormy weather, when they may 

 be dashed off the rocks and churned up among actual 

 stones. 



The animal is of the pattern usual among the 

 family, yellowish in colour, more or less tinged with 

 brown. It attacks limpets in much tlie same manner 

 as that adopted by the Sting- winkle ; but its favourite 

 food is the Mussel, whose shell can be perforated much 

 more rapidly than that of the Limpet. According to 

 Spence Bate, a mussel-shell keeps the enterprising 

 Purple busy for a couple of days, and then it has 

 the reward of its patience in the succulent flesh of 

 the bivalve. But it must not be supposed that the 

 Purple lias its own way entirely in this matter of 

 dainty feeding; it has a Nemesis in the form of a 

 Starfish who is also fond of Mussel. The Starfish 

 may be poetically regarded as taking revenge for the 

 Purple's depredations on the mussel-beds. The Star- 

 fish has no means of forcing open the Purple shell as 

 he does with the Oyster, but silently and slowly he 

 creeps to a spot where several Purples are within 

 reach of his long fingers, and laying hold of them 

 with the delicate suckers of his under-side he brings 

 them all beneath his central mouth. Then his 

 stomach is turned inside out and envelops the Purples, 

 wliich are dissolved out of their shells, in spite of the 



