World Register of Marine Species (WoRMS)
Proteonina difflugiformis var. testacea (Flint, 1899)
Hayward, B.W.; Le Coze, F.; Vachard, D.; Gross, O. (2026). World Foraminifera Database. Proteonina difflugiformis var. testacea (Flint, 1899). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=736773 on 2026-08-27
Flint, J. M. (1899). Recent Foraminifera : a descriptive catalogue of specimens dredged by the U.S. Fish Commission steamer Albatross. Report of the United States National Museum. [1897]: 249-349.