190 SKELETON OF THE DOG 
extensively with the corresponding process of the malar. The articular surface 
for the condyle of the mandible consists of a transverse groove which is continued 
upon the front of the large postglenoid process. Behind the latter is the lower 
opening of the temporal canal. There is no condyle. The mastoid part is small, 
but bears a distinct mastoid process. The external acoustic meatus is wide and 
very short, so that one can see into the tympanum in the dry skull. The bulla ossea 
is very large and is rounded and smooth; its medial side is united to the basilar 
part of the occipital bone. Above this junction and roofed in by the union of the 
petrous part and the basioccipital is the petro-basilar canal (Canalis petrobasilaris) ; 
this transmits a vein from the floor of the cranium to the foramen lacerum posterius. 
The latter opens into a narrow depression behind the bulla ossea. It transmits the 
Inter parietal bone 
$ 
Parietal bone 
Squamous temporal bone 
Parietal crest 7 
Frontal bone 
Zygomatic process of Ai 
temporal bone l 
Coronoid process 
Frontal crest 
Supraorbital process 
Zygomatic process of 
malar bone 
Lacrimal bone 
Malar bone 
Marilla 
Infraorbital foramen Nasal bone 
Nasal process of premaxilla 
Canine tooth 
Body of premarilla 
Incisor teeth 
Fic. 209.—Skutt or Doa; DorsaL VIEW. 
ninth, tenth, and eleventh cranial nerves. The carotid canal branches off from 
the petro-basilar, passes forward lateral to it through the medial part of the bulla 
ossea, and opens in front at the carotid foramen; it transmits the internal carotid 
artery. The Eustachian opening is immediately lateral to the carotid foramen. 
The muscular and hyoid processes are extremely rudimentary. The petrous part 
projects into the cranial cavity and forms a sharp prominent petrosal crest. The 
medial surface presents a deep floccular fossa above the internal acoustic meatus. 
The anterior surface is also free. The anterior angle is perforated by a canal for 
the fifth cranial nerve (Canalis nervi trigemini). 
The body of the sphenoid bone is flattened dorso-ventrally. The hypophyseal 
fossa is shallow, but the dorsum sells is well developed and bears posterior clinoid 
processes. A pair of anterior clinoid processes (Processus clinoidei orales) pro- 
