Spirula \Spir"u*la\, n. [NL., dim. of L. spira a coil.] (Zo["o]l.) A genus of cephalopods having a multilocular, internal, siphunculated shell in the form of a flat spiral, the coils of which are not in contact.
spirula n : a small tropical cephalopod of the genus Spirula having prominent eyes and short arms and a many-chambered shell coiled in a flat spiral [syn: {Spirula peronii}]