Loeblich, A. R., Tappan, H. N., 1987: Foraminiferal genera and their classification. Van Nostrand, Reinhold Co. New York 1728 pp. Plate 254, Figs. 1-2: U. Carboniferous (Namurian), USA. 1, Morrowan, Kearny Formation, Kearny County, Kansas, sagittal section, x 75 (from Thompson, 1944); 2, Morrowan, Marble Falls Limestone, Marble Falls, Texas, axial section of holotype, x 100 (from Thompson, 1942). courtesy of Michael Hesemann https://foraminifera.eu
