follows that line by the summits of Velina Mogila, the 'col' 531, Zmailica Vrh, Sumnatica, and rejoins the administrative boundary of the Sandjak of Sofia between Sivri Tas and Cadir Tepe.
From Cadir Tepe, the frontier, taking a south-westerly direction, follows the watershed between the basins of the Mesta Karasu on the one side and the Struma Karasu on the other, runs along the crests of the mountains of Rhodope called Demir Kapu, Iskoftepe, Kadimesar Balkan, and Aiji Gedük up to Kapetnik Balkan, and thus joins the former administrative frontier of the Sandjak of Sofia.
From Kapetnik Balkan the frontier is indicated by the watershed between the valleys of the Rilska reka and of the Bistrica reka, and follows the ridge called Vodenica Planina, descending into the valley of the Struma at the junction of this river with the Rilska reka, leaving the village of Barakli to Turkey. It ascends then south of the village of Jelesnica, and reaches by the shortest line the chain of Golema Planina at the summit of Gitka, and rejoins there the former administrative frontier of the Sandjak of Sofia, leaving, however, to Turkey the whole of the basin of the Suha reka.
From Mount Gitka the western frontier goes towards Mount Crni Vrh by the mountains of Karvena Jabuka, following the former administrative limit of the Sandjak of Sofia in the upper part of the basins of Egrisu and of the Lepnica, ascends with it the crests of Babina Polana, and reaches Mount Crni Vrh.
From Mount Crni Vrh the frontier follows the watershed between the Struma and the Morava by the summits of the Streser, Vilogolo, and Mesid Planina, rejoins by the Gacina, Crna Trava, Darkovska, and Drainica Plan, then the Descani Kladanec, the watershed of the High Sukowa and of the Morava, goes straight to the Stol, and descends from it so as to cut the road from Sofia to Pirot, 1,000 metres north-west of the village of Segusa. It ascends in a straight line the Vidlic Planina and thence Mount Radocina in the chain of the Kodza Balkan, leaving to Servia the village of Doikinci, and to Bulgaria that of Senakos.From the summit of Mount Radocina the frontier follows