In the fresh state the foramen is occupied by a dense fibrous membrane which is perforated by apertures for the various structures transmitted. Thus there are three openings in front for the internal carotid artery, the mandibular nerve, and the middle meningeal artery; these are (from within outward) the foramen caroticum, ovale, spinosum. (B) BONES OF THE FACE The bones of the face (Ossa faciei) are the Maxilla, Premaxilla, Palatine, Pterygoid, Nasal, Lacrimal, Malar, Superior Turbinal, Inferior Turbinal, Vomer, Mandible, and Hyoid. The last three are single, the others paired. THE MAXILLAE The =maxillæ= are the principal bones of the upper jaw and carry the upper cheek teeth. They are situated on the lateral aspect of the face, and articulate with almost all of the facial bones and the frontal and temporal also. For description each may be divided into a body and two processes. The =body= (Corpus maxillæ) presents two surfaces, two borders, and two extremities. The =external= or =facial surface= (Facies lateralis) is somewhat concave in front and convex behind. On its posterior part is a horizontal ridge, the =facial= or =zygomatic crest= (Crista facialis); in a skull of medium size its anterior end is about an inch and a half (3 to 4 cm.) above the third or fourth cheek tooth, and it is continued behind by a corresponding ridge on the malar bone. About two inches (5 cm.) above and a little in front of the anterior end of the crest is the =infraorbital foramen= (Foramen infraorbitale); this is the external opening of the infraorbital canal. In the young horse the anterior part of the surface is convex over the embedded parts of the teeth. As the latter are extruded the surface flattens and becomes concave in old subjects. The =internal= or =nasal surface= (Facies nasalis) is concave dorso-ventrally; it forms the greater part of the lateral wall of the nasal cavity. Its upper part is crossed obliquely forward and downward by the shallow =lacrimal groove= (Sulcus lacrimalis), which contains the naso-lacrimal duct; in the adult the posterior part of the groove is converted into a canal, which is continuous with that on the inner surface of the lacrimal bone. Below the groove is the =inferior turbinal crest= (Crista conchalis inferior), to which the inferior turbinal bone is attached. Lower down and parallel with the turbinal crest is the =palatine process=, which projects inward like a shelf. Behind this the surface is rough for articulation with the palate bone; this area is crossed by a groove which concurs with a furrow on the palate bone in the formation of the =palatine canal=. The posterior part of the bone is excavated to form part of the maxillary sinus. The =superior border= is irregular and scaly. Its anterior part is grooved and its posterior part beveled for articulation with the nasal process of the premaxilla and the nasal and lacrimal bones.