Work found, with species-group names introduced therein:
Schilder, F. A. 1931a. Zwei neue Trivia (Cypraeacea: Eratoidae). Archiv für Molluskenkunde 53 42-44, pl. 3. [Stated date: 01 Jan 1931; true date: pre 21 Jan.] Trivia (Niveria) hybrida, see Pusula hybrida (Schilder, 1931)