have discovered at intervals certain feij, or cavities, corresponding with the underground passage of the waters.
The overflow of moisture oozes up in an extensive sebkha, or saline depression, which takes the form of a crescent in a southern gulf of the sea of sands. At times travellers find some difficulty in traversing this saline plain, owing to the soft or bogey nature of the ground. Round about the sebkha, which stretches north and south for a distance of some 60 miles, are disposed the oases and erected the fortified ksurs, to the number of about eighty. They appear to have been formerly even still more numerous, for here and there are met the vestiges of ruined villages in
the midst of now-abandoned plantations, which still yield a few dates without artificial irrigation.
The inhabitants of Gurara, a name by which is more specially understood the district lying north and east of the sebkha, belong for the most part to the Zenata branch of the Berber race. The Meharsa tribe, however, which occupies the northern oasis of Tin-er-Kûk, is of Arab descent, and families of the Ulâd Sidi Sheikh confederacy frequently pitch their tents in this oasis round about the palm groves of the town of Tabelkusa.
In the Sherwin oasis, which lies west of the sebkha, the population, noted for its valour, is also to a large extent Arab. The whole group of oases encircling the
