Antecedently to the river system, which seems to have been a great southern Nile flowing from the sources of the Zambesi away south to the Orange River, there existed a state of fluvial action of greater activity than any we see now: it produced prodigious beds of well-rounded shingle and gravel. It is impossible to form an idea of their extent. The Loangwa flows through the bed of an ancient lake, whose banks are sixty feet thick, of well-rounded shingle. The Zambesi flows above the Kebrabasa, through great beds of the same formation, and generally they are of hard crystalline rocks; and it is impossible to conjecture what the condition of the country was when the large pot-holes were formed up the hillsides, and the prodigious attrition that rounded the shingle was going on. The land does not seem to have been submerged, because marine limestones (save in the exceptional cases noted) are wanting; and torrents cutting across the ancient river beds reveal fresh-water shells identical with those that now inhabit its fresh waters. The calcareous tufa seems to be the most recent rock formed. At the point of junction of the great southern prehistoric Nile with an ancient fresh-water lake near Buchap, and a few miles from Likatlong, a mound was formed in an eddy caused by some conical lias towards the east bank of this rent within its bed, and the dead animals were floated into the eddy and sank; their bones crop out of the white tufa, and they are so well preserved that even the black tartar on buffalo and zebra's teeth remain: they are of the present species of animals that now inhabit Africa. This is the only case of fossils of these animals being found _in situ_. In 1855 I observed similar fossils in banks of gravel in transitu all down the Zambesi above Kebrabasa; and about 1862 a bed of gravel was found in the delta with many of the same fossils that had come to rest in the great deposit of that river, but where the Zambesi digs them out is not known. In its course below the Victoria Falls I observed tufaceous rocks: these must contain the bones, for were they carried away from the great tufa Lake bottom of Seshéké, down the Victoria Falls, they would all be ground into fine silt. The bones in the river and in the delta were all associated with pieces of coarse pottery, exactly the same as the natives make and use at the present day: with it we found fragments of a fine grain, only occasionally seen among Africans, and closely resembling ancient cinerary urns: none were better baked than is customary in the country now. The most ancient relics are deeply worn granite, mica-schist, and sandstone millstones; the balls used for chipping and roughing them, of about the shape and size of an orange, are found lying near them. No stone weapons or tools ever met my eyes, though I was anxious to find them, and looked carefully over every ancient village we came to for many years. There is no flint to make celts, but quartz and rocks having