west of this verdant depression, which was formerly a lacustrine basin, the Guir is separated from tho Zis basin by one of the dreariest and most dreaded regions in the desert. Although sometimes culled the Hamada-el-Kebir, or "Great Hamâda," it cannot. compare in extent with many other plateaux of the Sahara, being scarcely 60 miles broad; but it is extremely difficult to traverse, owing to the small sharp stones strewn over the surface. Its mean altitude is about 2,600 feet, rising very
gradually from the banks of the Wed Guir westwards, and falling suddenly towards the Tafilelt oases. On the verge of the desert between Tafilelt and the Algerian frontier stand the two religious cities of Es-Saheli, on the upper Guir, and Kenatsa, near the source of the Wed Kenatsa. The former is governed by a "chief of chiefs" of the Nassiria order, who has a right toa share in all the offerings made to the members of the other confraternitics. Kenatsa also has a zawya of the Sidi Bu--
