SKULL OF THE OX AS A WHOLE 123 



to the two angles of that of the horse. The thyroid cornua do not fuse with 

 the body. 



SKULL OF THE OX AS A WHOLE 



The skull of the ox is more clearly pyramidal than that of the horse, and is 

 shorter and relatively wider. The cranium is quadrangular and larger externally 

 than in the horse; its large size is due mainly to the great extent of the frontal sinus, 

 and does not affect the cranial cavity, which is smaller than in the horse. 



The superior or frontal surface is formed by the frontals, nasals, and pre- 

 maxillae. The frontal part is quadrilateral and verj- extensive, the greatest width 

 being at the orbits. It presents a central depression on its anterior part, and on 

 either side are the supraorbital grooves and foramina. Behind is the median frontal 

 eminence, and at the lateral angles the " horn-cores "' project in horned cattle. The 

 nasal part is very short. The osseous nasal aperture is wide. The premaxilliB 

 do not bend doAMiward as in the horse; they are relatively thin and weak, and are 

 separated by an interval which has a Avide anterior part in place of the foramen 

 incisivum. 



The lateral surface is more triangular than in the horse. The temporal fossa 

 is confined to this surface. It is deep and narrow, and its boundaries are more 

 complete. It is limited above by a crest which extends from the postero-external 

 angle of the frontal to the supraorbital process, and is analogous to the sagittal 

 crest of the horse. Behind it is bounded by the temporal crest. It is clearly 

 marked off from the orbit by the rounded posterior orbital ridge and the pterygoid 

 crest. The zygomatic process is short, weak, and flattened, and is formed by the 

 temporal and malar only. Its condyle is convex and is wide from before backward. 

 The glenoid cavity and postglenoid process are small. The orbit is encroached 

 upon below by the lacrimal bulla, and presents the orifice of the supraorbital canal 

 behind. The margin is completed behind by the frontal process of the malar; its 

 lower part is prominent and rough, not smooth and rounded as in the horse. The 

 pterygo-palatine fossa is much larger, deeper, and more clearly defined. It has a 

 long narrow forward extension (maxillary hiatus) between the vertical plate of 

 the palate bone internally and the maxilla and lacrimal bulla externally; thus the 

 sphenopalatine and maxillary foramina are deeply placed. The preorbital region 

 is short but relatively high. A tuberosity and curved line take the place of the 

 facial crest. The infraorbital foramen is situated above the first cheek tooth and is 

 often double. 



The basal surface is short and wide, especially in its cranial part. The occipi- 

 tal condyles are limited in front bj^ transverse ridges. The tubercles at the junc- 

 tion of the occipital and sphenoid are large. The condyloid fossae contain two 

 foramina, the hypoglossal below and in front, and the condyloid above and behind; 

 other inconstant ones occur. The paramastoid processes are short and convergent. 

 The foramen lacerum is slit-like. The bulla ossea is a large, laterally compressed 

 prominence. The muscular processes are usually long and narrow triangular plates, 

 with one or two sharp points. The external auditory process is directed almost 

 straight outward. A curved plate extends downward from it and joins the bulla 

 ossea internally, completing the deep cavity which receives the articular angle of 

 the hyoid bone. The chief external opening of the temporal canal is in front of 

 this plate, and an accessory one lies behind it. The infratemporal fossa is small, 

 and presents the foramen ovale. The posterior nares are very narrow, and the 

 vomer does not reach to the level of their margin. The hard palate is wide, and 

 forms about three-fifths of the entire length of the skull. A small central part 

 only of its posterior border enters into the formation of the posterior nares; the 

 lateral parts are notched and just above them are the posterior palatine foramina. 



