Taxonomic notes on hummingbirds (Aves: Trochilidae) 2. Popelairia letitiae (Bourcier & Mulsant, 1852) is a valid species

—Popelairia letitiae (Bourcier & Mulsant. 1852), known from two specimens supposedly from Bolivia, appears to be a valid species. Analysis of plumage color and morphometries indicates that P. letitiae does not represent an immature plumage or geographic variant of Discosura longicauda. although this species and P. letitiae may be sister taxa. No credible evidence for a hybrid origin of P. letitiae was discovered. "Letitia's Coquette" is proposed as the common English name for P. letitiae. Known from two specimens of vague provenance, Popelairia letitiae (Bourcier & Mulsant, 1852), has been neither observed nor collected during the 20th century. This fact alone is reason enough to question the taxonomic validity of Letitia's Coquette, as many nominal trochiline taxa of comparable rarity have proven to be hybrids (Meyer de Sehauensee 1947; Graves 1996, 1997a, 1997b, 1998a). Nonetheless, the systematic status of P. letitiae remains unchallenged (Mulsant & Verreaux 1876. Elliot 1878, Boucard 1893, Cory 1918, Simon 1921, Peters 1945, Morony et al. 1975. Sibley & Monroe 1990). although Salvin (1892) may have been the last taxonomic authority to critically examine the type specimen. The relevance of this issue was brought to the forefront by the inclusion of P. letitiae in a recent survey of threatened avian species (Collar et al. 1992). Here I offer an appraisal of the systematic status of P. letitiae. Despite its current placement in the genus Popelairia (Peters 1945, Morony et al. 1975, Sibley & Monroe 1990), letitiae more closely resembles Discosura longicauda in plumage color (Elliot 1878). Generic Limits in the Trochilidae are based primarily on male plumage trails (Taylor 1909). This has resulted in a proliferation of genera (» = 109), more than 1/4 of which are monospccific (Sibley & Monroe 1990). Zimmer (1950) advocated merging all band-rumped coquettes and thorn tails in a single genus, Lopkornis. Even under a narrow interpretation of generic limits, Popelairia would have been merged with Discosura if not for the racket-lipped rectrices of the latter (Elliot 1878). In that eventuality, Popelairia Reichenbach 1854 would become a junior synonym of Discosura Bonaparte 1850. In order to avoid nomenclatural confusion, however, I use the binomial. Popelairia letitiae. tlvroughout this paper.