Squires, R.L. (1995) First fossil species of the chemosynthetic-community gastropod Provanna: localized cold-seep limestones in upper Eocene and Oligocene rocks, Washington. Veliger38(1): 30-36, figs. 1-18.
First fossil species of the chemosynthetic-community gastropod _Provanna_: localized cold-seep limestones in upper Eocene and Oligocene rocks, Washington