In the British Museum there is a gold coin issued by the Zanj rebels, hitherto inedited, and consequently of sufficient historical importance to warrant special publication. There is, so far as the present writer is aware, only one other coin (also in gold) surviving as a witness of that disastrous Slave Revolt which is estimated to have cost over 1,000,000 lives. This latter coin was published by Casanova in the Revue Numisrnatique (1893, pp. 510-516) and is now in the Paris Cabinet. By kind permission of the Conservateur I have been enabled to have it photographed. The mint, in both instances is the same, but the specimen in the British Museum is three years earlier in date, and preserves for us a more complete portion of the peculiar reverse marginal legend, that enables us to emend to a great extent the conjectural rendering suggested by Casanova in his article above mentioned.