228 NORTH-WEST AFRICA. culled kbur-el-juhala, or "pagan graves," are mostly of smaller size than the dolmens of like origin still existing in Brittany and La Vendee, from which it has been inferred that the megalithic industry of Algeria was either just beginning or already declining. But the officers engaged in the triangulation of the district between La Calle and Suk-Ahras have discovered sepulchral slabs of enormous size, scarcely inferior to those of Gavr'innis and Lockmariaker in Brittany. Besides the slabs and raised stones, there occur all sorts of megalithic structures : the cromlech or circle of stones, the cairn, the barrow crowned with a dolmen, terraces encircled by flights of steps, underground chambers hewn in the live rock, cupped stones, sacrificial altars ; rows of /lauufs, or subterranean cells ; kushas, or tombs in the form of cylindrical ovens topped with a large slab ; basinas, or mounds composed of concentric layers rising in the form of step pyramids. In the Algerian Sahara largo sepulchral urns have been found placed mouth to mouth, the head and body occupying one, the legs the other. The remains of resinous wood associated with earthenware, and still more the worked flints scattered here and there, not only on the heights skirting the Wed Ili<>-h, but even on the hamadas and in the desert between Tugurt and Ghadames, are amongst the facts regarded by geologists as undoubted indications of recent changes in the climate of Africa. Near Hammam-el-Meskhutin, the Roknia graves, belonging partly to the bronze age, contain thousands of molluscs disposed in hori- zontal hners. According to Bourguignat, many species then living in the country have ceased to exist, or have become very rare ; one species even became gradually modified during the period of the Roknia tombs. Since that epoch of worked flints and polished hatchets, used by peoples living in a more humid climate, the mega- lithic industry has been continued throughout the historic period down to recent times. In many burial-places the rude stone implements of the natives have been found associated with Roman stela?, shafts of columns, slabs co^red with Libyan or bilingual inscriptions. Under the kbur-el-juhalas and kushas, numerous skeletons have been found, nearly always resting on the left side and with the knees bent up to the breast. The mode of intermient is always the same, whatever be the objects deposited with the dead — coarse earthenware, flint instruments, silver, copper, bronze, or iron rings and armlets. Not many skulls have been collected ; but those already measured suffice to show that at this prehistoric epoch, before the arrival of Romans, Vandals, Byzantines, or Arabs, there existed amongst those now collectively grouped as aborigines two perfectly distinct cranial types. Both were dolichocephalic, or long-headed ; but one was a tall, the other a short race, the former being further distinguished by the posterior position of the crown and of the diameter of greatest breadth, as well as by more prominent zygomatic arches, nasal apophyses, and frontal ridges. The same cranial conformation still charac- terises most of the Biskri and of the nomads surrounding the oases. These men also differ from their neighbours in the structure of the skeleton, which when leaning against a wall prevents them from applying the outstretched arms close to the surface, a considerable space being always left behind the humerus.
