Cover franked with single 1927 30c on 20c sepia AIR 'Surcharge' issue (SG 521) tied by SERVICIO AEREO VILLAHERMOSA cds dated 7 JUL 1933. Addressed to USA with fine strike of 'R.A.C. No. 2 R.M.' (Ruta Aerea Contratada - route no. 2 - Veracruz - Merida) airmail route marking on front and MEXICO CITY transit mark on reverse.