'Dromedary' in the Bible

And he writeth in the name of the king Ahasuerus, and sealeth with the signet of the king, and sendeth letters by the hand of the runners with horses, riders of the dromedary, the mules, the young mares,

The runners, riding on the dromedary, and the mules, have gone out, hastened and pressed by the word of the king, and the law hath been given in Shushan the palace.