(Psittacidae; Ϯ Black-headed Parrot P. melanocephalus) Genus Pionus Wagler, 1832, parrot; Gr. -ιτης -itēs  resembling; "Genus Pionites Heine [Caica (!) Less. 1831]." (Heine 1890); "Pionites Heine, in Heine and Reichenow, Nomencl. Mus. Hein. Orn., 1890, p. 231.1  Type, by subsequent designation, Psittacus melanocephalus Linné. (Salvadori, Cat. Bds. Brit. Mus., 20, 1891, p. 358.)  ...   1 Pionites Heine is a substitute name for "Caica Lesson, 1831," which, however was then employed only in the vernacular sense, "Les Caïcas," for a group of four species viz— Psittacus pileatus Gmelin, Psittacus vulturinus Kuhl, Psittacus melanocephalus Linné and Psittacus leucogaster Kuhl. Lesson did not use Caïca in a nomenclatural sense until 1842, and when he did so it was for a species quite different from any of the foregoing. Bonaparte used Caica in 1850 as the generic name of Psittacus melanocephalus Linné, but this action was of course invalid by reason of Caïca Lesson 1842." (Peters 1937, III, 210).
Synon. Caica.

Search for more names on the Key to Scientific Names in Ornithology by James A. Jobling.
Recommended citation
Jobling, J. A. (2019). Key to Scientific Names in Ornithology. In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2019). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from www.hbw.com on 21 January 2019).