SEA SHELLS THAT BUILD NESTS. 199 



either dead or alive. It shines in the dark with a 

 bluish-white hght of such intensity that one immersed 

 in milk has served for a sort of lamp, lighting up the 

 faces of those about it ; and of such permanence that 

 one kept in honey remained luminous for over a year. 

 Indeed, an eminent naturalist, speaking of eating this 

 moUusk, says : " Those who eat the pholas would ap- 

 pear in the dark as if they were swallowing phos- 

 phorus. A fisherman dining on this delicacy appeared 

 to be giving them an exhibition of five-eating on a 

 small scale." The perforations produced in stone by 

 this moUusk have furnished important testimony of 

 the sinking and upheaval of the earth during the pres- 

 ent geological period. " Pozzuolo," says the author of 

 The Ocean World, " in Italy, touches on Solfaterre 

 on the Lake Avernus, and is not far from Vesuvius, 

 and in the bay is that monument of other days erro- 

 neously called the Temple of Serapis. It was proba- 

 bly a thermal sanitarium, established for its mineral 

 waters, although the world has now agreed to call it a 

 temple. However that may be, the building has been 

 nearly leveled by the hand of Time, aided consider- 

 ably, no doubt, by the hand of man, and the ruins 

 now consist of three magnificent columns about forty 

 feet high. But the curious and important fact is that 

 these columns at about ten feet above the surface are 

 riddled with holes and full of cavities bored deeply 

 into the marble, occupying a space of about three feet 

 on each column. 



The cause of these perforations is not doubtful. 

 In some of the cavities the shell of the operator is 



