74 THE SKELETON OF THE HORSE 
external acoustic process projects outward through a deep notch in the ventral 
margin of the squamous temporal below the temporal crest. A little further back 
is the mastoid process, crossed in its upper part by a groove for the posterior 
meningeal artery. 
The orbital region comprises the orbit and the pterygo-palatine fossa. The 
Nuchal crest 
Occipital Parietal crest 
Interparietal — 
Parietal — 
Squamous temporal ~ 
Masks 
4 
- A® 
4 ‘t : 3 
phy % Coronoid process 
3 
& Zygomatic arch 
Frontal = Supraorbital process 
— 
Supraorbital foramen 
Malar Orbit 
Lacrimal 
Facial crest 
Maxilla 
Nasal 
Infraorbital foramen 
Nasal process of premaxilla 
Body of premaxilla 
Foramen incisivum 
Fic, 47.—Sxuuvt or Horse; Dorsat View. 
1, Parieto-occipital suture; 2, squamous suture; 3, parietal suture; 4, parieto-frontal suture; 5, frontal suture; 
6, naso-frontal suture; 7, naso-lacrimal suture; 8, lacrimo-malar suture; 9, lacrimo-maxillary suture; 10, maxillo- 
malar suture; 11, naso-maxillary suture; 12, nasal suture. 
orbit is a cavity which incloses the eyeball, with the muscles, vessels, and nerves 
associated with it. It is not separated in the skeleton from the temporal fossa. 
The axis of the orbit (Axis orbite), taken from the optic foramen to the middle of 
the inlet, is directed forward, outward, and slightly upward. The medial wall 
(Paries medialis) is complete and extensive. It is concave and-smooth, and is 
formed by the frontal and lacrimal and the orbital wing of the sphenoid. In its 
