Guy’s Hermit (Phaëthornis Guy), John Gould A lengthened, but well-proportioned form, with wings and tail in every way in unison, renders this species of Phaéthornis one of the most elegant members of the genus yet discovered. At the same time, the changes of plumage, to which it appears to be subjected, are both numerous and perplexing; some specimens having the head much browner than others, the stripes down the throat more rufous, and the sides of the throat more extensively glossed with green: considerable difference occurs also in the form and colouring of the tail, some having the apical half of the lateral feathers nearly uniform black, and of a somewhat short and rounded form, with the prolonged portion of the central feathers very narrow; while in others, the lateral feathers are margined with white, and have the prolonged portion of the central tailfeathers broader and longer. 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."