100 



COMEARATLVE OSTEOLOGY. 



to the shape of the horns, which, they support. These are the flints or horti 

 cores, which are porous in their structure, especially at the roots ; they are very 

 rough, covered by thick periosteum, and contain sinuses, large canals, ancF 

 foramina, through which pass arteries and veins, and wiiich are continuou? 

 with the largely-developed frontal sinuses ; the latter extend from the orliit 

 to the extremities of the cores, and nearly as far backwards and downward? 

 as the foramen magnuui. The superior surface of the frontal bone is flat and 

 broad, especially in the male. The supraorbital foramina are double, place J 

 very far backwards, and continued by a groove which extends backwards and 

 forwards^ j^The frontal arch articulates with the malar portion, of the zygoma/' 



FiC. 20, 



SKTLL OF AN Ux. —Superior Aspect. 



a. Frontal crest; b, Lateral crest; c c c, Horn ccfre, 



d, N'asal peak ; e. Supraorbital foraoiina: .Bones T— 



li Frontal ; 2> Lachrymal ; 3 Malar ; 4. Superior mazil> 



lary ; 5.- N'asal; 6. Premaxilla, with Incisive-openiugs. 



The parietal bone is transversely elongated, and recurved at its extremftie^ 

 It V8 placed below the frontal crest, extending under and siipportipg the coresj 

 and entering the temporal fossa to articulate with the sphenoid and temporal 

 bones. Beneath the crest posteriorly it forms with its fellow the inter- parietal 

 euiure. 



The Wormian bone exists, fused with the occipital and parietals. It is 

 described as " wanting," by some authorities. 



The occipital bone is not visible when the skull is viewed superiorly, being 

 concealed by the prominent frontal crest. It is much wider from side to side, 

 but smaller than in the horse. It has neither crest nor tuberosity, the condyles 

 being less prominent, but wider ; the styloid processes are shorter, but broader,, 

 and curved inwards. The basilar process is short and thick, with a lai^e 

 basilar groove, and two rough prominences for muscular attachmeat anteriorly ! 

 J'he condyloid foram{na^are_double, sometimes triple.^ 



