368 INTEODUCTION TO CONCHOLOGY. 



the other. Whether these openings are casual or designed, 

 we know not ; but it is certain that considerable numbers 

 of these little anchorites have sometimes been discovered 

 within a few inches of each other. 



The pillars which supported the proud temple of Serapis 

 at Puteoli, are so completely perforated by these industrious 

 creatures, as to present the appearance of honey- combs. 

 Strange comment on the vanity of man ! The sculptured 

 columns of a temple, where busy feet were once heard, and 

 to which active multitudes resorted, are now desolate and 

 overthrown, a shelter to innumerable mollusks ! 



In some species the reticulations of the shell are so deli- 

 cate as to resemble the finest lace ; in others, they may be 

 compared to small basket-work ; and in the P, costata, or 

 Eibbed Fholas, the shell is covered with regular, elevated, 

 jagged, or scalloped ribs, gracefully disposed. But in all, 

 we see the same subserviency to an especial use. The shell 

 of the Pholas, if constructed in a similar manner to that of 

 the Xautilus, Pearl-mussel, or garden Snail, would be Httle 

 adapted to the habits of an animal which has frequently to 

 excavate a tunnel through hard substances. An ovate or 

 oblong form is consequently the best that could be adopted; 

 and the points with which it is covered and adorned, are 



