1955 O.H.M.S. envelope to Chingola with a MANKOYA, NORTHERN RHODESIA 18 MY 55 datestamp. An oval 'DISTRICT COMMISSIONER, MANKOYA, 18 MAY 1955' with the name 'J. N. March' applied. Mankoya is a village in Barotseland, the mail taken from there by runners to Mongu. An uncommon cancel, and a fine and unusual inter District Commissioner cover.