Monticola rufiventris -- Chestnut-bellied Rock Thrush. Alternate name on piece: Petrocincla erythrogastra [Chestnut-bellied rock-thrush] Layout drawing, birds well finished; 4 notes on form; several sketches in margins, not relevant; oval frame sketched roughly around the picture area; large letter B. Title in pencil by Sotheran, bookseller. Artist's name(s): Gould, John; Richter, Henry Constantine.