(Chapter 25) Footnote 49:

The 1555 edition omits the Greek name. Galen mentions sesamoid bones “in some of the digits” at the end of De ossibus; likewise in De usu partium 3.137.19 and 3.164.19, they are mentioned briefly as “so-called sesamoid bones” protecting the finger joints. In both works Galen indicates the nomenclature is not his own, but it is unattested in earlier writers. This particular sesamoid was probably a piece of ossified cartilage.