The status of the genera Ammodiscus Reuss, 1862, and Involutina Terquem, 1862, is discussed on the basis of their revision by Bornemann, 1874, and Loeblich and Tappan, 1954. Ammodiscus Reuss is retained for agglutinated planispiral evolute species, similar to the type species Ammodiscus infimus Bornemann, 1874 (not Strickland, 1846) = Ammodiscus siliceus (Terquem), 1862. Involutina Terquem is restricted to those planispiral calcareous species, with lateral umbilical filling, similar to the type species Involutina jonesi Terquem and Piette (1862) = Involutina liasiina (Jones), 1853.

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