Loeblich, A. R., Tappan, H. N., 1987: Foraminiferal genera and their classification. Van Nostrand, Reinhold Co. New York 1728 pp. Plate 140, Figs. 26-27: U. Cretaceous (Santonian), Tomsk district, W. Siberia, Russia. Side and apertural views, x 80 (from Podobina, 1975). courtesy of Michael Hesemann https://foraminifera.eu
