terranean, whether in Algeria, Spain, the south of France, Italy, Greece, Asia Minor, Sicily, or the islands of the Mediterranean generally, wherever the bones of extinct mammalia, such as the elephant, rhinoceros, and hippopotamus, have been found, it is not in the modern deltas of rivers or in the alluvial plains, now overflowed when the waters are high, that such fossil remains present themselves, but in situations corresponding to the ancient gravels of the valley of the Somme, in which the bones of the mammoth and the oldest type of flint implements occur.
If the Egyptian monarch, therefore, who sent Hanno to circumnavigate Africa, or some earlier king than he, had commanded his admiral to sail past the Pillars of Hercules, and then northwards as far as he could penetrate, leaving, before he set out on his return, some monument to commemorate to after ages the Ultima Thule of his expedition at the most northern point reached by him, and if we had now discovered an obelisk of granite left by him at that era on the platform of St. Acheul, near Amiens, its foundations might well have occupied the precise position which the Gallo-Roman tombs now hold, as shown in fig. 21 a (p. 138). If they had dug deep enough to exhume some teeth of the elephant, they might easily have seen that they differed from the teeth of their African species, and were distinct, like many other accompanying bones, from the animals then inhabiting the valley of the Somme, or that of the Nile. The flint implements would then have lain buried in the old gravel as now, and the only geological distinction between those times and ours would be a diminished thickness of peat bordering the Somme, the upper layers of which would not contain, as now, Roman antiquities, and some beds below, in which Celtic hatchets now occur, would have been wanting; but, with this slight exception, the valley would have worn the same aspect as at the era when the Romans subdued Gaul.
