(Trochilidae; Ϯ Rufous-gaped Hillstar U. bougueri) Gr. ουρα oura  tail; χροα khroa, χροας khroas  colour, appearance  < χρως khrōs, χρωτος khrōtos  complexion; "UROCHROA BOUGUERI.  Pied-tail.   ...   THE discovery of this new and very remarkable Humming Bird is due to the researches of M. Bourcier, who, during his late visit to Ecuador, obtained many new species and much valuable information respecting the Trochilidæ.  The present is certainly not among the least important of these discoveries, the bird being of large size and possessing several characters peculiar to itself; at the same time, it must be admitted that its colours are not so contrasted or lustrous as those of some of its congeners.  Its general contour and the form of its bill and wings rendering it impossible to associate it with the members of any previously established genus, and the colouring of its tail—black, interspersed with white—presenting a character quite unique; I have been induced to constitute it the type of a new genus" (Gould 1856).

Gr. λευκουρος leukouros  white-tailed  < λευκος leukos  white; -ουρος -ouros  -tailed  < ουρα oura tail.
● (J. Gmelin 1789) ex “White-tailed Fly-catcher” of Latham 1783 (syn. Myiomela leucura).
● ex “White-tailed Thrush” of Latham 1783 (Oenanthe).
● ex “Gros-bec du Canada” of d’Aubenton 1765-1781, pl. 135, fig. 1 (subsp. Pinicola enucleator).
● ex “Black Sandpiper” of Pennant 1768, and Latham 1787 (syn. Tringa ochropus).