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 contamsa 

 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. 



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Fig. 132. — Chantal and Orbital Regions op Skull of Ox. 

 Tte horn core, supraorbital process, and greater part of zygomatic arcla have been sawn oH: 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; E, 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; S, bulla ossea; 9, stylo-mastoid foramen; 10, nauscular 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 proc- 

 ess of sphenoid; 20, hamulus of pterygoid bone; 21, lacrimal bulla; 22, fossa sacci lacrimalis; 23, root of supraorbital 

 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 (PauUi). 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. 



