Pronunciation: (spir'yu-lu, -oo-lu), [key]
—pl. -laePronunciation: (-lē"). [key]
any cephalopod of the genus Spirula, having a flat, spiral shell that is partly inside and partly outside the posterior part of the body.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.