An oblong rectangle placed upright, or on its side, and covered with regular zigzags, represents a canal.

Lest one should be in doubt as to its meaning, fishes and crocodiles are put in, to show that it is water, and nothing but water.

Boats are seen floating upright upon this edgewise surface; the flocks ford it where it is shallow; and the angler with his line marks the spot where the water ends and the bank begins.

Sometimes the rectangle is seen suspended like a framed picture, at about half way of the height of several palm trees (fig.

174); whereby we are given to understand a tank bordered on both sides by trees.
Sometimes, again, as in the tomb of Rekhmara, the trees are laid down in rows round the four sides of a square pond, while a profile boat conveying a dead man in his shrine, hauled by slaves also shown in profile, floats on the vertical surface of the water (fig.