134 SKELETON OF THE OX 
the foramen orbito-rotundum. The posterior one is the foramen ovale, which 
transmits the mandibular nerve. The orbital wing is thick and is overlapped by 
the frontal in such manner as to appear externally to divide into two branches; 
the anterior part joins the ethmoid at the sphenopalatine foramen, and contains a 
small sinus which communicates with an ethmoidal meatus. The temporal wing is 
small, but forms a prominent thick pterygoid crest. The pterygoid process is 
wide, and there is no alar canal. The sphenoidal sinus is absent in the calf and 
small in the adult; it communicates by one or two small openings with an ethmoidal 
meatus, and so with the nasal cavity. 
Fie. 132.—CRanNIAL AND ORBITAL REGIONS OF SKULL OF Ox. 
The horn core, supraorbital process, and greater part of zygomatic arch have been sawn off: A, Frontal bone; 
A’, A”, temporal and orbital parts of same; B, parietal bone; C, squamous temporal bone; D, D’, orbital and facial 
parts of lacrimal bone; 2, malar bone; F, maxilla; G, perpendicular part of palatine bone; 1, occipital condyle; 2, 
paramastoid process; 3, temporal crest; 4, temporal condyle; 5, postglenoid process; 6, external opening of temporal 
canal; 7, meatus acusticus externus; 8, bulla ossea; 9, stylo-mastoid foramen; 10, muscular process of temporal bone; 
11, tip of basilar tubercle; 12, foramen ovale; 13, foramen orbito-rotundum; 14, optic foramen; 15, ethmoidal foramen; 
16, orbital opening of supraorbital canal; 17, pterygoid crest; 18, ridge of orbital wing of sphenoid; 19, pterygoid proe- 
sacci lacrimalis; 23, root of supraorbital 
ess of sphenoid; 20, hamulus of pterygoid bone; 21, lacrimal bulla; 22, fossz 
process; 24, processus cornus (section); 25, frontal eminence. 
The ethmoid bone has an extensive perpendicular plate. The lateral mass 
consists of five endoturbinates and eighteen ectoturbinates (Paulli). The largest 
ethmoturbinate is so extensive as to be termed a third or middle turbinate bone; it 
projects forward between the dorsal and ventral turbinates. The lamina lateralis 
appears to a small extent externally in the pterygo-palatine fossa, forming part 
of the dorsal margin of the sphenopalatine foramen. 
The interparietals are primitively paired, but unite before birth. As already 
mentioned, fusion occurs before or shortly after birth with the parietals and supra- 
occipital. The bone has no intracranial projection. 
The parietal bones do not enter into the formation of the roof of the cranium. 
