We have, also, certain proofs that primitive tribes, during this period, did not take up their abode in natural caverns exclusively, but that they were able to make for themselves more convenient sheltering-places under the cover of some great overhanging rock. In various regions of France, especially in Périgord, numerous ancient open-air human settlements have been discovered. They must have been mere sheds or places of shelter, leaning against the base of some high cliff, and protected against the inclemency of the weather by projections of the rock which, more or less, hung over them, forming a kind of roof. The name of _rock-shelters_ has been given to these dwellings of primitive man. These wild retreats are generally met with in the lower part of some valley in close proximity to a running stream. They, like the caverns, contain very rich deposits of the bones of mammals, birds and fishes, and also specimens of hatchets and utensils made of flint, bone, and horn. Traces of hearths are also discovered. One of the most remarkable of these natural shelters belonging to the reindeer epoch has been discovered at Bruniquel, in the department of Tarn-et-Garonne, not far from Montauban. [Illustration: Fig. 40.--Rock-shelter at Bruniquel, a supposed Habitation of Man during the Reindeer Epoch.] On the left bank of the river Aveyron, under the overhanging shelter of one of the highest rocks of Bruniquel and in close proximity to a _château_, the picturesque ruins of which still stand on the brow of the cliff above, there was discovered, in 1866, a fire-hearth of the pre-historic period; this hearth and its surroundings have afforded us the most complete idea of one of the rock-shelters of man during the reindeer epoch. This rock, known by the name of Montastruc, is about 98 feet high, and it overhangs the ground below for an extent of 46 to 49 feet. It covers an area of 298 square yards. In this spot, M. V. Brun, the Director of the Museum of Natural History at Montauban, found a host of objects of various descriptions, the study of which has furnished many useful ideas for the history of this epoch of primitive humanity. By taking advantage of the photographic views of the pre-historic settlement of Bruniquel, which M. V. Brun has been kind enough to forward to us, we have been enabled to compose the sketch which is presented in fig. 40 of a rock-shelter, or an open-air settlement of man in the reindeer epoch.