Phanaeus ducalis Castelnau, 1840: 79 . Available name.

Type specimens: Unknown to us, but certainly, the description was based on a syntypic series (rather than a holotype), since Castelnau (1840) described sexual dimorphism.

Type locality: ‘ Brésil ’ (Castelnau 1840).

Nomenclatural history: To our knowledge, the first author to cite P. ducalis among the synonyms of C. ensifer was Lacordaire (1856), who thought this name referred to male of this species; this synonymy was endorsed by all subsequent revisers and cataloguers (e.g., Nevinson 1892; Gillet 1911; d’Olsoufieff 1924; Pessôa 1934; Blackwelder 1944; Edmonds & Zídek 2010). No syntypes of this name were found and, therefore, a lectotype designation is not possible at the moment. For more details, see the discussion above on P. sylvanus .