The plain was destitute of water and of trees except in the immediate vicinity of the river, and was only intersected by a hill-ridge covered with low brushwood.

On this ridge Jugurtha awaited the Roman army.

His troops were arranged in two masses; the one, including a part of the infantry and the elephants, under Bomilcar at the point where the ridge abutted on the river, the other, embracing the flower of the infantry and all the cavalry, higher up towards the mountain-range, concealed by the bushes.
On debouching from the mountains, the Romans saw the enemy in a position completely commanding their right flank; and, as they could not possibly remain on the bare and arid crest of the chain and were under the necessity of reaching the river, they had to solve the difficult problem of gaining the stream through the entirely open plain of eighteen miles in breadth, under the eyes of the enemy's horsemen and without light cavalry of their own.

Metellus despatched a detachment under Rufus straight towards the river, to pitch a camp there; the main body marched from the defiles of the mountain-chain in an oblique direction through the plain towards the hill-ridge, with a view to dislodge the enemy from the latter.

But this march in the plain threatened to become the destruction of the army; for, while Numidian infantry occupied the mountain defiles in the rear of the Romans as the latter evacuated them, the Roman attacking column found itself assailed on all sides by swarms of the enemy's horse, who charged down on it from the ridge.