THE LITTLE ATLAS AND BANI RANGES. 858 East of the Wed Drua stretches a hilly region, which forms a continuation of the South Oran border ranges. Some of the crests uHsume the fantastic forms of crenelluted walls, towers, or pyramids. IJecween Figuig and Tufili'lt, Rohlfu observed one so like the nave of a church flunked with its belfrv that for a moment he believed himself the victim of an optical delusion. West of the Great Atlas the secondary chains are no longer disposed in the direction of the main axis, but branch off irregularly towards the coast. One of these, beginning at the Bibawan Pass, near the western extremity of the Atlas, attains in some of its j^caks heights of t)ver 3,300 feet, and under the name of the Jebel Iludid, or " Fire Mountain," falls down to the coast between Mogador and the mouth of the Wed Tensift. Over the district between Mogador and Maroceo are also scattered isolated tables, like those in Eastern Mauritania, between Ghadamcs and the Mzab, all at the same level, and evidently the remains of an older surface layer broken into detached fragments by atmospheric agencies. But while some rocky formations thus become weathered, others continue to grow, probably under the peculiar action of rain water. The plain of Maroceo is in this way covered with a crust of tufa, which fills up all the irregularities of the surface, varying in thickness from a few inches to three feet, and in many places presenting the appearance of agate. Such is its consistency, that by excavating the earth beneath it, the natives are able to form caves, or matamoras, as the Spaniards call them, in which cereals and other provisions are preserved. On the Maroceo coast fragments of lavas and volcanic ashes are also found enclosed in rocks of recent formation. These debris had their origin perhaps in the craters ol the Canary islands, whence they were wafted by the trade winds across the intervening marine strait. The Jebkl Aian and Beni Hassan Uplands. Of the lateral ridges branching from the Great Atlas on the Atlantic slope, the loftiest and most extensive is the Jebel Aian, which takes its origin towanls the northern extremity of the main range, and which separates the Upper Sebu from the Upper Um-er-Rbia Valley. The Jebel Aian, which is often covered T^ith snow, forms the central nucleus whence ramify the various branches of these almost unknown uplands. None of the heights have yet been measure<l, and the whole region is held by independent Berber tribes, who neither pay tribute nor military service to the empire. North Maroceo is occupied by mountain masses indirectly connected with the Atlas system. On the one hand the Wed Sebu, flowing to the Atlantic, on the other the Moluya, a tributary of the Mediterranean, enclose with their several affluents a quadangular space, in which the ridges are not disposed in the nonual direction of the general orogniphic system. A depression, probably about 1,000 feet high, separates the two regions on the route from Fez to Tlemcen, a great p:irt of the intermediate space being occupied by hills of reddish argiUaceoufl formation.
