348 MULTIVALVE SHELL-FISH. 



boring into stones ; yet, by patience and perseverance, 

 it can penetrate into the most callous substances, by 

 the assistance of a fleshy member resembling a tongue. 

 With this soft and yielding instrument it perforates 

 marble and the hardest stones ; and when, whilst small 

 and naked, it has effected an entrance, it then enjoys 

 an undisturbed life of ease, existing upon the sea-water 

 that enters into the aperture, and increasing in ttie 

 till it attains about eight inches in length.- Thus im- 

 mured in its narrow mansion, which it regularly in- 

 creases according to its size, it soon acquires a callous 

 covering, which does not appear essential for its de- 

 fence, as they are so small, when they begin to form 

 their subterraneous habitation, that the passage to it 

 resembles the stem of a tobacco-pipe, and their dwell- 

 ing may not inaptly be compared to the bole. 



At Ancona, in Italy, this fish is found in the greatest 

 abundance ; they are likewise to be met with in Nor- 

 mandy and Poitou in France : some few have been 

 discovered upon the coast of Scotland ; and their flesh 

 is considered as a luxurious treat. 



CHAP. IX. 



OF FROGS, TOADS, AND LIZARDS. 

 OF FROGS AND TOADS IN GENERAL. 



THE external figure of the frog is too well known to 

 require being particularly described : its active powers are 

 astonishingly great, when compared with its unwieldy 

 shape ; it is the best swimmer of all four-footed animals ; 

 and Nature has finely adapted it for those ends, the arms 

 being light and pliant, the legs long, and endowed with 

 great muscular strength. 



