Placopsilina cenomana d'Orbigny 1850

 Loeblich, A. R., Tappan, H. N., 1987: Foraminiferal genera and their classification.  Van Nostrand, Reinhold Co. New York 1728 pp. Plate 65, Figs. 11-12: U. Cretaceous (Cenomanian), Czechoslovakia. 11, Longitudinal section, x 40; 12, exterior of attached specimen, x 15 (from Perner, 1892). courtesy of Michael Hesemann https://foraminifera.eu

Image source: Cushman, J.A. 1920. The Foraminifera of the Atlantic Ocean. Part 2. Lituolidae. Bull. U.S. Natl. Mus. 104.

Image source: Cushman, J.A. 1910. A Monograph of the Foraminifera of the North Pacific Ocean. Part I. Astrorhizidae and Lituolidae. Bull. U.S. Nation. Mus 71: xiv+134 pp.