Sudan. (Nigeria - Trans-Atlantic Mail). 1942. Air Mail envelope bearing Sudan SG 46, 10p black and purple tied by Port Sudan date stamp '4th June' with 'Sudan Censorship/ 12' green label tied by triangular 'Passed Censor/ Sudan' cachet in violet, endorsed 'via Trans-Atlantic route' and routed via Nigeria with framed 'Censor' in violet on face and Lagos transit on reverse '12th June 42.
Single franking sent on the 'Horseshoe' route, Trans- Africa and over the Atlantic.