C. A. Hargrave

“ The gigantic Tridacna is the largest mollusk known to have lived on the earth since the Silurian Age. It is found on the bottom of the shallow parts of the ocean, and the large individuals have no longer the power to move about. They lie on one side, and all about them the corals build up until King Tridacna is sometimes found in a well-like hole in the coral formation. From the known rate of coral growth, the age of the mollusk can be approximately determined. Some are certainly more than one hundred years old, This king has a small domain, but in it he is in undoubted control. ”