BONES OF THE CRANIUM 



117 



mentioned, fusion occurs before or shortly after birth with the parietals and supra- 

 occipital. Xo distinct tentorium osseum is present. 



The parietal bones do not enter into the formation of the roof of the cranium. 

 They constitute the upper part of the posterior wall, and bend sharply forward 



Fig. 90. — Skull of Ox, Basal View, Without Mandible. 

 F, Pterygoid bone; G, horizontal and G' , perpendicular part of palate bone; H, occipital bone; J, malar 

 bone; A', sphenoid bone; O, maxilla; P, vomer; Sch., squamous temporal; St., frontal bone; Z, premaxilla; 

 1, for. magnum; 2, occipital condyle; S, parama.stoid (styloid) process of occipital; 4, hypoglossal and condy- 

 loid foramina; 5, for. lacerum; 6, pharyngeal tubercles; 7, bulla ossea; 8, muscular process (left one is removed 

 to expose for. ovale); 9, hyoid process; iO, ext. auditory meatus; ii, zygomatic process; i;2, external opening of 

 parieto-temporal canal; 13, postglenoid process; 14, temporal condyle; 15, for. ovale; 16, for. lac. orbitale 4- 

 for. rotundum; 17 , optic foramen; 18, ethmoidal foramen; 19, orbital opening of supraorbital canal; 20, ptery- 

 goid crest; 21, hamulus of pterygoid bone; 22, lacrimal bulla; 23, temporal process of malar; 24, pterygoid 

 process of maxilla; 25, sphenopalatine foramen: 26, maxillary foramen; 27, posterior palatine foramen; 28,. 

 anterior palatine foramen; 29, accessory palatine foramina; 30, palate process of maxilla; 31, interalveolar 

 border; 32, palatine cleft; 33, palate process of premaxilla; 34, fissura incisiva; 35, facial tuberosity; 36, pos- 

 terior nares. (Ellenberger-Baum, Anat. d. Haustiere.) 



along the lateral wall, forming part of the wall of the temporal fossa. The line of 

 inflection is marked by the prominent parietal crest, which is continuous with the 

 temporal crest below. The parietals are excavated to form part of the frontal 

 sinuses in the adult animal. 



