What is "provannidae"

Provannidae is a family of deep water sea snails, marine gastropod mollusks in the superfmaily Abyssochrysoidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005 and updated in 2008 by Kaim et al.).

The genera Provanna and Desbruyeresia have smaller and slender shells, while the shells of Alviniconcha and Ifremeria are larger and swollen. The shells of these two last genera house a hypertrophied ctenidium large quantities of symbiotic bacteria.