The Posterior Aural Branch ascends between the retra-hens auris muscle and bone, and supplies the integuments covering the mastoid process, and the temporal and retrahens auris muscles.

Before its bifurcation the posterior auricular sends branches to the parietes of the external auditory canal, to the parotid gland, and to the digastric and stylo-hyoid muscles.

In the operations of cutting down on the facial nerve, in order to remove a portion of it after its exit from the stylo-mastoid foramen, the trunk of this artery must have been usually divided, together with its stylo-mastoid branch.

Mr. Harrison saw a case in which it was tied in front of the mastoid process, for aneurism by anastomosis on the external surface of the pinna,óbut without success.