"But they sure don't have much in them for the size of the shell."

The size and shape of the shell therefore has some effect on the sound you hear.

The size of the white shell varies between 20mm and 35mm.

The size of the shell is up to 150 mm in length.

The maximum reported size of the shell is 6.7 mm.

The adult shell size of this species is about 60 to 90 mm.

Maturity is reached at half maximum shell size after 1 year.

The size of an adult shell varies between 20 mm and 30mm.

The size of an adult shell varies between 20mm and 75 mm.

The size of an adult shell varies between 13 mm and 159mm.