This is seen very distinctly in the map of the district made on my return home: for many of the ridges seem to be broken off more or less abruptly by the level ground, and then to be continued on the other side of the plain. It seemed impossible to avoid the conclusion that by some great convulsion in long-past geologic ages a vast rent and depression had been made across the lines of hills in a diagonal direction; while the water-worn and wasted remains of some few of these towards the south, forming a line of low detached hills, suggested that probably the action of water, either as an arm of the sea running up the Ankay valley, or a great river, had completed what was commenced by more violent agencies. The unmistakable evidence of former volcanic action, in the presence of extinct craters and lava streams to the west, north and north-east of the plain, seems to show what was the agency which caused this great depression of the surface. [Sidenote: A NATURAL EMBANKMENT] Half-an-hour brought us to the end of the promontory, which was like an enormous dyke or sea-wall, one face having a steep slope, and the other a long gentle rise. It was a pleasant and smooth level road along the top of this great natural embankment to the north-west. From it we had a delightful view, for the great flat surface of the plain looked like an immense green lake, from which the distant eastern line of hills seemed to rise like shores out of a green expanse of water. The high mountains beyond these were lit up by afternoon sunlight, and the western side or a still larger and higher promontory to the east of us, broken up by lateral buttresses, produced charming effects of light and shadow, and variety of colour. At the head of the bay formed by these two long points we could see the high rounded hill which rises above Ampàrafàravòla, and after a time the little town itself began to show above the plain.