(τὸ Μάσιον ὄρος
, Strab. xi. pp. 506, 527; Ptol. 5.18.2
), a chain of mountains which form the northern boundary of Mesopotamia, and extend in a direction nearly east and west. They may be considered as connecting the great western mountain known by the name of Amanus, between Cilicia and Assyria, and the Niphates, on the eastern or Armenian side.
The modern name is Karja Baghlar.
Strabo states, that M. Masius is in Armenia, because he extends Armenia somewhat more to the W. and S. than other geographers.
A southern spur of the Masian chain is the mountain district round Singara (now Sinjar