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 IjuUa ossea. It transmits the 



Interparietal bone 



Parietal bone 



Squamous te?nporal bone 



Parietal crest ^^J |i sKk „ 



trontal bone 



Zygomatic process of 

 temporal hone 



Coronoid process 



Frontal crest 

 Supraorbital process 



Zygomatic process 



malar bo 



Lacrimal bo. 



Infraorbital foramen. 



Nasal process of premaxilla 



Canine tooth 

 Incisor teeth 



Malar bone 

 Maxilla 



Nasal bone 



Body of premaxilla 



Fig. 209. — Skull of Dog; Dohsal 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-ventralljr. The hypophyseal 

 fossa is shallow, but the dorsum sellse is well developed and b^ars posterior clinoid 

 processes. A pair of anterior clinoid processes (Processus clinoidei orales) pro- 



