168 THE PURPURA A$V ITS HABITS. 



Mussel society, and plays sad havoc among its mem- 

 bers. This crawling rascal is the wolf of all Mussel- 

 dom flocks. Young and old alike experience the 

 blighting effects of his villanous propensities. The 

 name of this obnoxious personage is Purpura Lapil- 

 lus (Common Whelk). What, the reader will ask in 

 surprise, a univalve prey upon a bivalve? Is that 

 possible? It is, unfortunately, too true. 



If we take a Mussel in our hand we shall find it 

 perfectly impossible to force its valves asunder, with- 

 out the aid of a strong knife or other instrument; 

 yet the Common Whelk, fleshy and insignificant crea- 

 ture though it be, will consume the animal within, 

 and make the valves fly open in a brief space of 

 time, by means of its soft tongue. But leaving 

 such general remarks, let us suppose we are standing 

 before a boulder covered with these mussels. Num- 

 bers of gaping shells may be at intervals perceived 

 still attached to the rock, but with the interior of 

 each valve so empty and smooth, that we could 

 scarce believe they had ever embraced a living occu- 

 pant. On taking up one of the valves and closely 

 examining it, do you observe nothing peculiar about 

 it now? ' No/ Take up the other then, and submit 

 it to a similar inspection. Well, what do you see 

 now? * Nothing/ you still reply, 'unless it be a 

 peculiar little hole about the size of a pin's head, 

 which surely is of no importance/ That little hole 

 was of vital importance to the poor mollusc, for 



