(Chapter 33) Footnote 63:

The 1555 edition completes this sentence “with the inner side of the posterior surface of the calcaneus assisting here.” The figure references of the 1555 edition continue inaccurately (see prec. note), identifying this concave medial area as “x in the 6th table of muscles” and the muscle subsequently mentioned as “f, g in figs. 1, 7, 9.”