The expression used in the Periplus M.E. has attracted a certain amount of attention. It is generally held to mean ‘a legal mart where foreign trade was officially allowed and taxed’ (E. H. Warmington, Commerce between the Roman Empire and India, pp. 53, 57): and this translation has sometimes been made the ground of comparison with the treaty ports of China or the échelles of the Levant. On closer examination of the usage of the Periplus M.E. it seems difficult to accept this meaning, and possible to suggest another.