noun, plural spir·u·lae [spir-yuh-lee, -oo-lee] /ˈspɪr yəˌli, -ʊˌli/.
Origin of spirula
Examples from the Web for spirula
A series of Chambers joining each other, as in Nautilus, Spirula, &c.A Conchological Manual|George Brettingham Sowerby
The latter is partly straight and partly convoluted, nearly as in Spirula.A Manual of Elementary Geology|Charles Lyell.
They originate at the aboral extremity where they remain in Spirula (fig. 18).
After a gale, on looking amongst the wrack cast up by the highest waves, large numbers of our Spirula will be found.Beautiful Shells of New Zealand|E. G. B. Moss
A mollusk whose shell is cast upon the shore by thousands, but the animal of which is very rare, is the Spirula.