Genus Ptychogena A. Agassiz, 1865
Ptychogena A. Agassiz, 1865: 137, type species Ptychogena lactea A. Agassiz, 1865 by monotypy.
in part Stegopoma Levinsen, 1893: 177, type species Lafoea plicatilis M. Sars, 1863 (Totton, 1930).
References: Edwards (1973), Bouillon et al. (2006).