RIVERS OF ALGERIA. 218 trians and riders. Nevertheless, the weds are not so completely exhausted as they seem to be, for below the dry surface there is often un underground bed, in which the water oozes through the sand and develops small pools above such obstacles aa rocky ledges or artificial dams. In the extreme north-west, the Muroceo frontier is marked by the little Wed Ajerud. But the tirst important stream is the Tafna, which receives some atiluents from Marocco, but whose farthest source is in the Tlemcen hills, within the Algerian frontier. Although not more than 90 miles long, the Tafna has suc- ceeded in excavating a channel through a scries of gorges, through the Tlemcen, the Traras, and some intervening ridges. The Isser, its chief tributary, pursues a similar course from its rise on the southern slope of the Tlemcen range to the confluence. Formerly the extensive low-lying plain skirted northwards by the Oran coast ranges was flooded, and of this old lacustrine basin there still remains the great sebkha of Misserghin, or Oran, besides some other saline depressions and marshy tracts fed by the Sig and the Habra. These two streams, jointly forming the Macta, which flows to Arzen Bay, rise on the northern scarp of the Central Algerian plateau, and reach the plain through a series of abrupt windings in the transverse fissures of the intervening hills. The longest river in Algeria is the Shelif, whose farthest headstream, the Wed Namus, rises in the Jebel Amur, beyond the whole region of central plateaux. After its junction with the Nahr Wassal from Tiaret, it pierces the northern border chains through the Boghar defile, and flows thence between the Warsenis and Dahra ranges to the coast a little to the north of Mostaganera. But although it has a total course of at least 420 miles, the Shelif has a smaller discharge at low water than many Pyrenean torrents flowing to the Garonne. The Mazafran, with its famous afiluents the Shiffa, the Harrash, and the Hamiz, which water the Mitija district, are all mere streamlets, indebted for their celebrity to their proximity to Algiers, to the battles fought on their banks, the towns and fertile tracts occupying their basins. More voluminous arc the Isser, whose lower course forms the western limit of Great Kabylia, and the Seban, fed by the snows of the Jurjura highlands. The Wed Sahel, or Summan, which has a longer course but smaller discharge than the Seban, rises to the south of the same moun- tains, flowing thence north-east to the Bay of Bougie. In spite of its name, the Wed-el-Kebir, or " Great River," which reaches the coast between the Jijeli and Collo headlands, is great only relatively to the small coast streams. One of its aflluents, the Bu-Merzug, or Ampsagas of the ancients, for a long period formed under the Romans the frontier line between the province of Africa and Mauritania. We.st of this Wed-el-Kebir of Constantine, two other rivers bear the same name, one rising in the Guelma hills, and flowing to the Mediterranean south of Cape de Fer, the other descending from the Khumirian highlands in Tunisia. Between these two eastern kebirs flows the far more important Sey bouse, which falls into the Gulf of Bona with a more constant discharge than any other
