CHAPTER XVI.. The Pholas, Etc. (rock-Borers).

THE PHOLAS, ETC. (ROCK-BORERS).

Pholades at home--Habits of the Pholas--P. crispata--The pedal organ--Finny gourmands--How is the boring operation performed?--Various theories on the subject--Mr Clark, Professor Owen--The Pholas at work--The boring process described from personal observation--Author's remarks on the subject--Pholas in the tank--Conclusion, 241