Gavia immer -- Common Loon; Great Northern Loon, Colimbo mayor, plongeon huard. Alternate name on piece: Colymbus glacialis [Great northern diver] Layout drawing, birds well finished; detail sketch in margin; 2 notes on form. Title in pencil by Sotheran, bookseller. Artist's name(s): Gould, John; Richter, Henry Constantine.