International Commission on Zoological Nomenclature:
Op. — see: OPINIONS
Direction — see: DIRECTIONS
Xi
Xilocopa Latreille 1802, Hist. nat. Fourmis: 432 (suppressed under the plenary power for the purposes of the Principle of Priority but not for those of the Principle of Homonymy). Opinion 743
Xiphias Linnaeus 1758, Systema Naturae, Ed. 10, vol. 1, p. 248 (gender: masculine) (type species, by monotypy: Xiphias gladius Linnaeus 1758, Systema Naturae, Ed. 10, vol. 1, p. 248) (Osteichthyes). Opinion 75
Xiphisura Brünnich 1771, Zool. Fund.: 184 (an incorrect original spelling for Xiphosura Brünnich 1771). Opinion 320
Xiphiurus Smith 1847, Illustrations of the Zoology of South Africa, Pisces, pl. xxxi (suppressed under the plenary power for the purposes of the Principle of Priority but not for those of the Principle of Homonymy). Opinion 1200
Xiphocaridina Bouvier 1909, C.R. Acad. Sci., Paris, 148: 1729 (a junior objective synonym of Paratya Miers 1882). Opinion 470
Xiphocaris von Martens 1872, Arch. Naturgesch., 38(1): 139 (gender: feminine) (type species, by monotypy: Hippolyte elongatus Guérin-Méneville 1856, in Sagra, Hist. Cuba, Hist. nat., 7: xx) (Crustacea, Decapoda). Opinion 470
Xiphopenaeus (emendation under the plenary power of Xiphopeneus) Smith 1869, Trans. Connect. Acad. Arts Sci., 2: 27 (gender: masculine) (type species, by monotypy: Xiphopeneus harttii Smith 1869, Trans. Connect. Acad. Arts Sci., 2: 27, valid name: Penaeus kroyeri Heller 1862) (Crustacea, Decapoda). Opinion 864
Xiphopeneus Smith 1869, Trans. Connect. Acad. Arts Sci., 2: 27 (ruled under the plenary power to be an incorrect original spelling for Xiphopenaeus Smith 1869). Opinion 864
Xiphosura Brünnich 1771, Zool. Fund.: 208 (suppressed under the plenary power for the purposes of the Principle of Priority but not for those of the Principle of Homonymy). Opinion 320
Xiphosura Gronovius 1764, Zoophylac. gronov., 2: 220 (included in a work rejected for nomenclatural purposes). Opinion 320
Xiphosura Meuschen 1778, Mus. gronov.: 83 (included in a work rejected for nomenclatural purposes). Opinion 320
Xiphosura Scopoli 1777, Introd. Hist. nat.: 405 (a junior homonym of Xiphosura Brünnich 1771). Opinion 320