(Chapter 15) Footnote 52:

Pollux is the 2nd century AD author of an Onomasticon, a thesaurus of Greek terms arranged by subjects, of which only an epitome survives. Vesalius probably used the 1520 Giunta edition, where there is a paragraph peri\ traxh/lou kai\ sfondu/lou, “On the neck and the vertebra” (2.131), in which it is stated “The first of the vertebrae, the one that twists with the neck, is called e)pistrofeu/j, twister. ... In its sides there are two hollows, one on each side, in which rest two protruding eminences below the cerebellum, called the korw=nai.”