There has been, and to some extent remains, confusion over the valid genus name for a group of slugs in the family Veronicellidae, either Vaginulus Férussac, 1822 or Vaginula auctt., often cited as of Berthold, 1827 or sometimes as of Blainville, 1828. We show that Vaginula was first made available as an emendation of Vaginulus Férussac by Hoffman in 1925 (Article 33.2.1 of the Code) and that all previous usages of the name were therefore incorrect subsequent spellings. However, Hoffman's emendation was unjustified (Art. 33.2.3). Vaginulus Férussac is the valid name and Vaginula Hoffman is a junior objective synonym. Vaginula Hoffman is also a junior homonym of Vaginula Risso, 1826 (Protozoa, Foraminifera) and of Vaginula Sowerby, 1833 (Gastropoda, Pteropoda).