THE SKULL 159 
since the basal lamella of the ventral turbinate bone curves ventro-medially, joins 
the palatine bone, and is separated only by a narrow hiatus from the nasal plate of 
the palatine process of the maxilla. The anterior palatine foramen is at the trans- 
verse palatine suture. The anterior end of the palatine process tapers to a point. 
The maxillary sinus resembles that of the ox, but is relatively small. 
The premaxilla has a narrow and pointed body. The palatine process is ex- 
tremely narrow in front and is grooved laterally. The palatine fissure is long and 
narrows to a very acute angle behind. 
The palatine bone resembles that of the ox, but there is no air-cavity in its 
horizontal part. The spheno- 
palatine foramen is large and Occipital bone — Parietal bone 
oval. Paes 
The pterygoid bone is 
very bread above and narrow 
below, where it ends in a sharp- 
pointed hamulus. 
The nasal bone tapers to 
a point at its anterior end, 
which is not notched. 
The facial part of the 
lacrimal bone has an elongated 
quadrilateral outline; in front 
of the orbit it forms, with the 
adjacent part of the malar, the 
external lacrimal fossa (lossa 
lacrimalis externa) which 
lodges a cutaneous cul-de-sac 
known as the infraorbital or 
lacrimal pouch. The bone here 
may be more or less cribriform. 
The lacrimal bulla is relatively 
| small, is usually cribriform, 
and has a pointed posterior 
_ end; the maxillary sinus ex- 
tends into it. The orbital 
margin forms a distinct promi- 
nence, and behind the latter is 
the fossa for the lacrimal sac. 
| The facial part of the Fig. 162.—SKULL oF SHeep; DorsaL View. 
malar bone is extensive and 
quadrilateral. Its upper part concurs in the formation of the external lacrimal 
fossa; this area is limited below by a curved crest which continues backward on 
| the zygomatic process. The latter divides into two branches, as in the ox. 
The turbinates and the vomer resemble those of the ox. 
The mandible differs from that of the ox chiefly in that the ventral border of 
the ramus, from the body to the angle, is only slightly curved. 
On account chiefly of the limited extent of the frontal sinuses, the cranial 
cavity corresponds to the external form of the cranium more closely than is the case 
in the ox. It is ovoid, and is much longer relatively, but has a much shorter dorso- 
ventral diameter than that of the ox. The parietal bone forms a distinct ridge on 
the lateral wall between the cerebral and cerebellar compartments, but, on the other 
hand, the petrous temporal projects very little into the cavity. 
The nasal cavity resembles that of the ox, but is relatively narrow (especially 
anteriorly), and there is no large hiatus in the nasal plate of the maxilla. 
Temporal crest 
Coronoid process 
Frontal bone 
Orbit 
Supraorbital 
foramen 
Malar bone 
Lacrimal bone 
Facial tuberosity 
Mazilla 
Nasal bone 
Nascl process of pre- 
maxilla 
Palatine process of pre- 
maxilla 
Palatine fissure 
Body of premazxilla 
Incisor teeth 
