Sharf rivers, and which terminates in Algeria in the Tlemcen mountains. The Jebel Aïashin itself falls rapidly northwards, terminating abruptly in the stupendous cliffs of the Jebel Terneit, which rises nearly 7,000 feet above the surrounding plains. This imposing rampart, forming the northern extremity of the whole

Fig. 158. — Crests And Passes of the Atlas South of Marrakesh.

system, presents a striking contrast to the boundless plateaux, which here appear to have been gradually levelled by the action of the streams and glaciers formerly descending from the Atlas.

South of the Jebel Aïashin the main range, still unvisited by any European