Work found, with species-group names introduced therein:
Dautzenberg, P. 1889. Contribution a la faune malacologique des Iles Açores. Résultats des Campagnes Scientifiques du Prince de Monaco 1 1-112, pls. 1-4. [Stated date: 15 Oct 1889.] Bulla guernei, see Roxania pinguicula (Seguenza, 1879)