Terebra Turriitella is a very common species of vegetarian marine snail inhabiting the shallow areas of the world’s oceans. It’s shell can grow up to seven inches long in the warm and tropical waters of the Philippines. The cooler water of sub-tropical and temperate regions limit Terebra Turritella’s shell growth to less than a few inches.

The word ‘Terebra’ is Latin and refers to ‘a screw shaped device used by ancient Romans for starting a breach in a fortified wall’. ‘Turritella’ comes from the Latin word ‘turritus’ meaning ‘turreted’ or’ towered’. The common English names for the Terebra Turritella Shell are: Auger Shell, Tower Shell, Turret Shell, Unicorn Shell, Screw Shell, Common Screw Shell and Great Screw Shell. I’m sure there are many others.

Most people are attracted to a particular shell because of it’s exterior size, shape, color, texture and, in some cases, smell. Some shells are coveted because they are rare or unusual in some way. This isn’t the case concerning the outward appearance of the Common Screw Shells. They’re just different shades of beige or brown and are generally dismissed by serious shell collectors as ‘beneath their notice’.

Michael found this attitude amusing. He had discovered that the air inside many different species of small shells can be resonated using an ancient and obscure technique used to make whistle sounds with acorn caps. (The ‘acorn cap whistle skill’ is believed to have originated somewhere in the temperate regions of the world, sometime after the end of the last ice age, but no one knows for certain.)

He also discovered that the Great Screw Shell can be played as a flute, capable of releasing an octave and a half of perfect diatonic and chromatic musical notes, after pitch holes are introduced into the shell’s body of whorls. The sounds produced by this new wind instrument closely resemble the sounds produced by Native American Flutes,  pan pipes, ocarinas and recorders.