Riverine Emerald (Agyrtria fluviatilis), John Gould The present species is placed, according to the arrangement set forth by Mr. Elliot, in oye section of the genus in which the crown of the head is dull green, and the under beicoyais white with a central streak of brown or green. 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."