Green-headed Sapphire (Eucephala chlorocephala), John Gould This species has some characters in common with the one I have called Eucephala smaragdo-cærulea, but it differs from that bird in several particulars of sufficient importance to warrant its being regarded as distinct: in the first place, there is no blue whatever on the chin and upper part of the breast, those parts being clear green like the remainder of the under surface; in the next, the under tail-coverts are white with a stain of olive-brown in the centre of each feather, while the same feathers in the E. smaragdo-cerulea are green; and lastly, the upper tail-coverts are bronzy brown in the present bird, and bright green, even brighter than that of the back, in the other. This illustration has been restored to its original vibrancy by enhancing colors and removing unwanted marks. A monograph of the Trochilidæ, or family of humming-birds was published between 1849 and 1887 by English ornithologist John Gould. This monumental work depicts and describes all the known species of hummingbirds at the time - comprising 418 lithographic plates and information on 537 species."