At Heraclea in Pontus, and in Rhegium, they say there are fish obtained by digging, especially in places near rivers, and such as are well watered; and that it sometimes happens that when these places dry up at certain seasons, the fish shrink under the earth, and then when this dries up still more, they, in search of humidity, enter into the mud; then when this becomes dry, they remain in the moisture, like animals which continue in their holes; but, when they are dug up before the waters come on, they then move.