cover 1867 (Aug.) envelope (seal torn away) from Georgetown to Berbice bearing perf. 12½-13 4c. blue cancelled by "A03" obliterator and showing despatch c.d.s. on reverse; 1868 (8 Mar.) envelope (202x90mm., folded and creases) from New Amsterdam to Demerara, marked "Book Post", bearing perf. 12½ tied by "A04" obliterator, showing arrival c.d.s. at left and despatch d.s. on reverse, and 1873 (18 June) locally addressed envelope (faults) bearing perf. 12½-13 2c. tied by neat "DEMERARA" c.d.s. An interesting trio