Rohlfs, Friedrich Gerhard (1831-1896). Autograph Letter in German Signed "Gerhard Rohlfs" Dated at New York 29 Nov. 1875 and Addressed to most Likely his American Agent Regarding two Lectures Rohlfs is Planning in the United States."[With] A Carte de Visite Sized Albumen Photograph of Rohlfs ca. 1875 (9 x 5.5 cm) Signed in Black ink on Bottom of the Original Paper Mount. New York, 29 Nov. 1875.