THAUMATIAS CHIONURUS, Gould.
White-tailed Emerald.
Trochilm Thaumatias ?) chionura, Gould in Proc. o f Zool. Soc., 1850, p. 162.
I h a v e before had occasion to remark how different are the species inhabiting Mexico, or the country to the
northward of the Isthmus of Panama, from those of the southern portions of the continent of South America,
and the present species may be cited as a striking instance in point; for while it is of precisely the same
form as its near allies, the well-known Thaumatias albirostris and T. bremrostris of Brazil, in colouring it is
very different from both of those birds; in fact it may be said to differ from every other known species of
Humming-Bird, from the great amount of white which pervades the under surface and the tail-feathers.
It is a native of the warmer parts of Chiriqui, near David, in the province of Veragua, at an altitude
of from two to three thousand feet; and is another of the many interesting discoveries made by
M. Warszewiez, who met with it in the locality above named, and from whence he transmitted the
specimens figured in the accompanying Plate.
The male has the upper surface very dark grass-green; the central tail-feathers bronzy green; lateral
tail-feathers white, largely tipped with black; throat pale shining green; flanks greenish; centre of the
abdomen and under tail-coverts white; upper mandible black, base of the lower mandible fleshy white.
The upper surface of the female is the same as in the male, hut somewhat paler; the lateral tail-feathers
white, crossed by an oblique band, instead of being tipped with black; throat and under surface white.
The Plate represents a male and two females on the Sobralia macrantha, of the natural size.