FACE 191 



ject back from the roots of the orbital wings. The latter are relatively small and 

 are crossed laterally by a crest, which is continued forward upon the palatine bone. 

 The temporal wings are extensive and articulate dorsally with the parietals. Per- 

 forating the roots of the wings are the following foramina, named from before back- 

 ward: The optic passes through the orbital wing. The foramen orbitale is a little 

 lower and is at the junction of the wings. The foramen rotundum opens into the 

 alar canal, which passes through the root of the short but wide pterygoid process. 

 The foramen ovale is near the posterior border of the temporal wing. There is no 

 sphenoidal sinus. 



The ethmoid bone is highly developed. The cribriform plate is extensive, 

 and the olfactory fossa are very deep. The crista galli is little developed, and often 

 incomplete. The perpendicular plate is long. The lateral masses are greatly 

 developed and project into the frontal sinus. There are four large endoturbinates 



Fig. 210. — Chanxa.l and Orbital Regions of Skull of Dog. The Zygomatic Arch Has Been Sawn Off. 

 A, Occipital bone; B, interparietal bone; C, parietal bone; D, squamoua temporal bone; E, E' , temporal and 

 orbital parts of frontal bone; F, F' , orbital and temporal wings of sphenoid bone; G, perpendicular part of palatine bone; 

 ff, pterygoid bone; 7, lacrimal bone; /.maxilla; 1 , parietal crest ; 2, nuchal crest; 3, occipital condyle; 4, paramastoid 

 process; 5, stylo-mastoid foramen; 6, bulla ossea; 7, meatus acusticus externus; 8, articular surface for condyle of 

 mandible; 9, section of root of zygomatic process of temporal bone; 10, alar canal; 11, foramen orbitale; 12, optic 

 foramen; 13, ethmoidal foramen; 14, posterior palatine foramen; 15, sphenopalatine foramen; 16, entrance to lacrimal 

 canal; 17, supraorbital process; 18, zygomatic process of malar bone (section); 19, maxillary foramen; 20, last molar 

 tooth. 



and six ectoturbinates. The lamina lateralis is extensive and forms the medial wall 

 of the maxillary sinus. Its ventral border joins the palatine process of the maxilla 

 and the horizontal part of the palate bone. A shelf-like plate extends inward from 

 its lower part and concurs with the similarly incurved part^of the palatine bone in 

 forming the lamina transversalis, which divides the olfactory fundus of the nasal 

 cavity from the naso-pharyngeal meatus. 



Face 

 The maxilla is short, but very high posteriorly. The facial crest is absent. 

 The infraorbital foramen is over the alveolus for the third premolar. The frontal 

 process fits into a deep notch between the nasal and orbital parts of the frontal 

 bone, and the middle part of the posterior border lies along the orbital margin. 

 There are more or less pronounced ridges, juga alveolaria, over the canine and 

 molar teeth. The zygomatic process is short and thin; it is completely overlapped 

 laterally by the malar, and is perforated by a number of foramina (Foramina 



