202 NORTH-WEST AFRICA. the surface of the land being characterised not by continuous well-defined chains, but by parallel ridges frequently interrupted by intervening depressions. In the west a coast range running close to the sea is broken at intervals by semicircular inlets excavated by the waves. Farther east the work of erosion has been still more extensive, and here the coastline runs almost uniformly west and cant, so that the parallel ranges running south-west and north-east develop a regular series of headlands, all of which project in a north-easterly direction seawards, and shelter from the north and north-west winds several seaports, such as Dellys, Bougie, Collo, Stora, Bona, and others. These highlands contract gradually towards the east, from a breadth of 210 miles under the meridian of Oran, to 135 under that of Constantine. The Suhel, as the western coast ranges were formerly collectively known, is separated from the other uplands by a broad depression disposed parallel with the ^lediterranean, and stretching with little interruption from the heights of ()ran to the foot of the Miliana hills. The escarpments of the plateau, which on the west follow in uniform parallel lines south of this depression, and which on the east terminate in a series of headlands along the coast, arc skirted southwards by numerous dricd-up lacustrine basins, such as Eghris south of Mascara, lieni-Sliman between Medea and Aumale, and Wed Sahel south of Jurjura. Increasing in altitude as they recede from the coast, these plains form the outer terraces of the upland plateaux of Central Algeria. The Jebol, a term applied collectively to the border ranges, nowhere exceeding 0,000 feet, except in the Jurjura district, constitutes, with the maritime zone, the so-called " Tell," or " hilly country ; " but in these uplands are situated all the fertile valleys and grassy slopes, whence the absurd identification of the word toU with the Latin tclhis, as if this region were the productive land in a pre- eminent sense. At the same time, such is the fertility of its soil, and the abundance of the rainfall, that a population of some fifteen millions might easily be supported on the thirty-eight million acres of the Tell. Towards the ill- defined frontier of Marocco, the plain enclosed between the northern highlands and those skirting the Sahara is at least 120 miles broad, with a mean elevation of about 3,500 feet. Perfectly level in appearance, it really forms a slightly depressed cavity, where are collected the spring and rain waters, replaced in the dry season by extensive saline tracts. Farther east, the gradually contracting upland plain is divided by central ridges into several distinct basins, and towards the Tunis frontier it loses altogether the character of a zpne of separation between the northern and southern highlands. In this part of Algeria the surface is almost exclusively occupied with a succession of ridges all disposed in the normal direction from south-west to north-east. From Marocco to the neighbourhood of Batna the system of southern border chains retains its distinctive character throughout the greater part of its course, and it was to these ranges between the upland plateau and the depression of the Sahara that was formerly applied the title of the " Great Atlas." Yet their mean altitude does not exceed that of the northern highlands, although one of their summits in the Jebel Aures forms the culminating point of Algeria. The true natural limits
