Description Loeblich, A. R., Tappan, H. N., 1987: Foraminiferal genera and their classification. Van Nostrand, Reinhold Co. New York 1728 pp. Plate 299, Figs. 10-11: M. Permian (Akasakan), Akasaka Limestone, Akasaka, Japan. 10, sagittal section of topotype, x 20; 11, axial section of topotype, x 20 (from Thompson, 1948).