(Chapter 6) Footnote 120:

Galen’s primer on the bones, written for beginners ( De ossibus ad tirones), ends as follows: “It seems to me that this is all beginners need to know about bones and the construction of the skeleton, and that there is no need to discuss now any small bones found in other parts, as in the heart, larynx, and nose, and in some of the digits which are called sesamoids, or anything else of the kind.” (tr. Singer 1952, p. 775). But the text as we have it mentions no such occipital process.