Loeblich, A. R., Tappan, H. N., 1987: Foraminiferal genera and their classification. Van Nostrand, Reinhold Co. New York 1728 pp. Plate 32, Figs. 16-18: U. Silurian (Ludlovian), Ural Mountains, Russia. 16, 17, Holotype, from opposite sides, x 60; 18, paratype, x 60 (from Chernykh, 1969). courtesy of Michael Hesemann https://foraminifera.eu
