To the north and west of these tribes no further towns are mentioned; and as the Caledonii extend on the west along the entire length of the territories of the Vacomagi, their eastern boundary formed the line of demarcation between the tribes of the more plain and fertile districts, who had advanced one step in the progress of social life in the possession, even at this early period, of settled habitations and determined limits, and the wilder tribes of the mountain region, among whom nothing deserving the name of town in its then acceptation was known to the Romans. Ptolemy states that the Caledonii extended from the ‘Lemannonius Sinus,’ or Loch Long, to the ‘Varár Aestuarium’ or Beauly Firth, thus ranging along the entire boundary of the Highland portion of Scotland. On the west they had the remarkable chain of hills termed in the early historical documents ‘Dorsum Britanniae,’ Drumalban, or the backbone of Scotland, a native term apparently presented in a Greek form in Ptolemy’s καληδόνιος δρυμός, and converted by his Latin translator, who, puzzled by the term δρυμὸς, recognised in it only an unusual Greek word signifying an oak wood, into ‘Caledonius Saltus’ or Caledonian Wood. That this range of hills was at all times a forest in the highland acceptation of the term, having its southern termination at the head of Lochs Long and Lomond, there is no doubt. North of the Caledonii, on the other side of the Varar or Beauly Firth, lay the ‘Canteæ’ or ‘Decantæ,’ possessing the whole of Ross-shire save the districts on the west coast. Sutherland proper was possessed by the ‘Lugi’ and ‘Mertæ.’ Along the west coast, from the Firth of Clyde northwards, were the ‘Epidii’ in Kintyre and Lorn. Beyond them the ‘Creones’ or ‘Croenes,’ extending probably from the Linnhe Loch to Loch Carron. Beyond them the ‘Carnones,’ occupying probably the western districts of Ross-shire. Beyond these again, in the west of Sutherland, the ‘Caerini;’ and along the northern termination of Scotland, including Caithness and the north-west of Sutherland, were the ‘Curnavii.’ Such were the northern tribes of Britain as described by the geographer Ptolemy in the second century, and such the knowledge the Romans now possessed of their position, and of the towns they occupied. [Sidenote: A.D. 139. First Roman wall between the Forth and Clyde. Establishment of the Roman province in Scotland.]