(Chapter 26) Footnote 7:

Here Vesalius is dependent upon a passage in De usu partium (3.202.14-203.16, May 1968 pp. 170f.) where Galen argues against Eudemus’ statement that the metatarsus and the metacarpus are both composed of five bones. On this Eudemus, a contemporary of Herophilus, see von Staden 1989, p. 63.