The =superior surface= shows the wide outward curve of the zygomatic arches, and the great extent of the temporal fossæ. The latter are separated by the sagittal crest, which in the larger breeds is very strong and prominent, and is continued by the diverging frontal ridges to the supraorbital processes. The frontal and nasal regions are centrally depressed, and are more or less concave in profile. The nasal region is narrow and is terminated in front by a nasal notch. In the extreme brachycephalic breeds the differences are very striking. The cranium is strongly convex in both directions and is considerably longer than the face. The sagittal crest is more or less effaced and is formed by the interparietal only. The parieto-frontal crests are separated by an interval behind and diverge to the supraorbital processes, so that the temporal fossæ are widely separated. The frontal region is wide, strongly convex, and has a shallow central depression. The nasal region is very short, relatively wide, and centrally depressed. In profile there is a marked depression at the fronto-nasal junction, producing what is termed by fanciers the “stop” of the face. On the =lateral surface= the great extent of the temporal fossa is seen. The orbit communicates freely with the fossa, the posterior part of the orbital margin being absent in the dry skull. The axis of the orbital cavity forms a much smaller angle with the median plane than in the horse and ox. A distinct crest marks the limit between the orbital cavity proper and the extensive pterygo-palatine fossa. The preorbital region is somewhat triangular, concave in its length, and convex from above downward. The infraorbital foramen is on its lower part above the third cheek tooth. In extreme brachycephalic breeds the orbit is relatively very large and the preorbital region extremely short but high. In the bulldog the lower jaw protrudes beyond the upper—a condition known as prognathism. The opposite condition, brachygnathism, is seen in the dachshund. [Illustration: FIG. 126.—SKULL OF BRACHYCEPHALIC DOG, DORSAL VIEW WITHOUT MANDIBLE. ] Striking features on the =basal surface= of the cranium are the width and flatness of the basioccipital, the small size of the paramastoid processes, the large size and rounded shape of the bulla ossea, and the grooved form of the articular surfaces for the mandible. The posterior nares are long and narrow and are not divided by the vomer. The hard palate is usually about half the length of the skull. It is commonly marked by a median crest or rough line, and on each side are the anterior and accessory palatine foramina and the palatine grooves. The width is greatest between the fourth pair of cheek teeth, and here there is in most skulls a pronounced depression on either side. The length, width, and contour vary greatly in different breeds.