_Keefar_, is the sandy arid plain, which, occasionally watered by the winter's revivifying refreshing and fructifying rains, produces spring herbage, where the Nomade tribes pasture their flocks in the neighbourhood of the oases. _Falat_, is the region of sands in the immensity of steril wastes. But all these distinctions are arbitrary, and can be predicated of tracts of country lying on the North Coast of Africa, as well as the boundless Sahara. On the coast of Tripoli we have the oasis, the arid plain, and the groups of sand-hills of eternal sterility. Captain Lyon enumerates in the same way as the talebs, the various names which the Arabs apply to different regions of The Desert. _Sahara_ is sand alone, forming a plane surface, which agrees with the hypothesis of Ben-ej-Jiramy. _Ghoud_ is groups of sand-hills of indefinite height, situate on the borders of stony plains, where the wind has formed and collected them. _Sereer_, is generally plains, whence the sand-hills have been swept, and where alone sand-hills are found. _Wâr_, is a rough plain, covered with large detached stones, lying in confusion, and very _difficult_ to pass over, which is the meaning of the appellation. It is applied to all difficult traverse. _Hateea_, is a spot possessing the power of fertility; indeed, those patches of land which are the germs of the oases, now producing small stinted shrubs scattered at intervals, from which camels browse a scanty meal, or travellers make their Desert fire. _Wishek_, is productive sand-hills and plains, where the wild palm and lethel-tree grow. _Ghabah_, distinguishes cultivated Sahara, sometimes a portion of the oases, but mostly where there are no inhabitants. So near Touat, there is a cultivated place called Ghabah, and without inhabitants. But the people of Ghadames call also their gardens Ghabah. Sibhah, is the usual name for all salt plains, sometimes called _Shot_ in Algeria, being mostly sandy salt marshes. Like the Sibhah of Emjessen, and "The Lake of Marks," in Tunis, the saline particles are often combined with earths or sand so closely as to form a substance resembling stone, and equally hard to break or cut through. With this _salt_ stone houses are built. _Wady_, is the designation of all long deep depressions of the surface, and is used indifferently for a valley, a bed of a river, or torrent, or ravine. These wadys are almost always dry, except one or two months in the winter. _Gibel_, is applied to all hills and mountains. It is quite evident, from the above enumeration, that these various terms can be equally applied to the coast and other regions of land, not comprehended within the assigned limits of The Sahara, and are therefore not peculiar to The Great Desert of Sahara.