Note 1748 — BOOK VIII. THE NATURE OF THE TERRESTRIAL ANIMALS.
John Bostock translation
The account of the two heads is obviously incorrect; the idea has risen from the two extremities being nearly of the same size and appearance. It has been supposed, that there were certain serpents, with the power of moving with equal facility in both directions; and that the name, Ἀμφίσβαινα, was derived from this circumstance.—B.