Ancillus
"Coquille libre, univalve, cylindrique; à spire apparente, sommet élevé, tours de spire calleux; bouche allongée, moins longue que le tèt, élargie a la base; columelle lisse, mais très-calleuse; lèvre extérieure obtuse; base échancrée; plusieurs plis réeunis à la base de la columelle.".
Gray's (1847: 140) mentioning of Ancilla buccinoides Lamarck, 1803, as single species does not constitute designation of a type species, as suggested by Maxwell (1975). Anyway, the lamarckian species was fixed as type species in the original description of the genus-group taxon (by monotypy).
As stated by Pacaud, Merle & Pons (2013: 42), this is an unjustified emendation (masculin) of Ancilla Lamarck, 1799. However, it was used extensively as a valid genus-group taxon. Ancillus "De Montfort" of authors is here listed by its earliest valid name, Spirancilla Vokes, 1935.