Strabo, Geography

Now as for the tribes themselves which speak the same language, the ancients set one of them, the Cataonians, by themselves, contradistinguishing them from the Cappadocians, regarding the latter as a different tribe; and in their enumeration of the tribes they placed Cataonia alter Cappadocia, and then placed the Euphrates and the tribes beyond it so as to include in Cataonia Melitene, which lies between Cataonia and the Euphrates, borders on Commagene, and, according to the division of Cappadocia into ten prefectures, is a tenth portion of the country. Indeed, it was in this way that the kings in my time who preceded Archeläus held their several prefectures over Cappadocia. And Cataonia, also, is a tenth portion of Cappadocia. In my time each of the two countries had its own prefect; but since, as compared with the other Cappadocians, there is no difference to be seen either in the language or in any other usages of the Cataonians, it is remarkable how utterly all signs of their being a different tribe have disappeared. At any rate, they were once a distinct tribe, but they were annexed by Ariarathes, the first man to be called king of the Cappadocians.