Loeblich, A. R., Tappan, H. N., 1987: Foraminiferal genera and their classification. Van Nostrand, Reinhold Co. New York 1728 pp. Plate 245, Figs. 1-5: Bogush and Yuferev. L. Carboniferous (Visean), USSR. 1, M. Visean, sagittal section, x 40 (from Rozovskaya, 1963); 2, axial section, x 40 (from Ayzenverg et al., 1968); 3, U. Visean, central Karatau, sagittal section (from Bogush and Yuferev, 1962); 4, 5, side and apertural views, x 22 (from Rauzer-Chernousova and Fursenko, 1959). courtesy of Michael Hesemann https://foraminifera.eu
