Gorgeted Sun Angel (Heliangelus strophianus), John Gould Although the Heliangelus strophianus presents the general appearance of H. Clarissæ, it nevertheless possesses several peculiarities by which it may be at once distinguished from that species: thus, it is a larger and more powerful bird; has a shorter bill; a more distinctly defined and whiter gorget; the tail entirely steel-black, with elongated outer feathers, giving that organ a forked form; the crown of the head green; the lower part of the back strongly tinged with brown; and the sides of the chest and lower part of the abdomen of a deeper grass-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."