<P> The groove for the transverse sinus is separated from the innermost of the mastoid cells by a very thin lamina of bone, and even this may be partly deficient . </P> <P> The superior border of the mastoid part is broad and serrated, for articulation with the mastoid angle of the parietal . </P> <P> The posterior border, also serrated, articulates with the inferior border of the occipital between the lateral angle and jugular process . </P> <P> Anteriorly the mastoid portion is fused with the descending process of the squama above; below it enters into the formation of the ear canal and the tympanic cavity . </P>

Prominent mastoid process on skull male or female