The table-land consists of a series of fertile plains, of varying size and elevation separated from each other by upland tracts or mountains, and it is drained almost entirely by the river Iris (Yeshil Irmak) and its numerous tributaries, the largest of which are the Scylax (Tchekerek Irmak) with many affluents and the Lycus (Kalkid Irmak), all three rising in the highlands near, or on, the frontier of Armenia Minor and flowing first in a westerly and then in a north-westerly direction to merge their waters in a joint stream, which (under the name of the Iris) pierces the mountain-wall and emerges on the east of Amisus (Samsun).
Above St Louis, pierces the dunes at flood time and reaches the sea, 50 m.
The clays of the Rolling Downs formation overlie a series of sands and drifts, saturated with water under high pressure, which discharges at the surface as a flowing well, when a borehole pierces the impermeable cover.
The larva pierces the vessels of the plant with sharp processes at the hinder end of its body.
It then pierces through the mountains of northern Herzegovina, traverses the Narenta valley, and runs almost parallel with the coast to Trebinje, Ragusa and the Bocche di Cattaro.