170 SKELETON OF THE PIG 
is deeply notched. The condyle is concave in the transverse direction. The post- 
glenoid process is absent, but the articular surface is bounded behind and medially 
by a crest. There is no temporal canal. The external acoustic meatus is very 
long and is directed dorso-laterally. The bulla ossea is large, compressed laterally, 
and bears a pointed muscular process in front. A narrow space intervenes between 
the bulla and the basilar part of the occipital bone, so that the foramen lacerum 
resembles that of the horse. The small hyoid process is situated in a deep de- 
pression in front of the root of the paramastoid process, and the stylo-mastoid 
foramen is lateral to it. The petrous part presents no important differential fea- 
tures. The squamous part (including the root of the zygomatic process) contains 
an air-cavity, which is continuous with the sphenoidal sinus. 
The sphenoid bone is short and resembles that of the ox in general. The body 
is narrow. The hypophyseal or pituitary fossa is very deep, and is limited behind 
by a prominent dorsum sell; the dorsum bears lateral projections, the posterior 
clinoid processes (Processus clinoidei aborales). The foramen ovale is absent, 
being included in the foramen lacerum anterius. The other foramina are like those 
of the ox. The pterygoid process is broad and twisted. Its base is not perforated 
and its free edge is thin and sharp. It concurs with the pterygoid and palate bones 
in the formation of the pterygoid fossa (Fossa pterygoidea), which opens backward 
and is not present in the horse or ox. The sphenoidal sinus is very large and oe- 
cupies the body, the temporal wings, and a great part of the pterygoid processes 
in the adult; it is continued into the temporal bone as mentioned above. 
The ethmoid bone has a relatively long perpendicular plate, which is marked 
by ridges corresponding to the ethmoidal meatuses. The cribriform plate is ex- 
tensive and very oblique, so that it and the crista galli are almost in line with the 
basi-eranial axis. A linear series of relatively large foramina is found on either 
side of the crista. The lateral mass consists of five endoturbinates and eighteen 
ectoturbinates (Paulli). The lamina lateralis concurs in the formation of the 
pterygo-palatine fossa. The lamina transversalis separates the fundus of the 
nasal cavity from the naso-pharyngeal meatus. 
FACE 
The maxilla is extensive. Its facial surface forms a longitudinal groove, 
which is continued upon the premaxilla in front and the facial parts of the lacrimal 
and malar behind. The infraorbital foramen—sometimes double—is large and 
is situated above the third or fourth cheek tooth. The alveolus for the canine 
tooth produces a ridge (Juga canina) at the anterior end which is very pronounced 
inthe boar. The facial crest extends forward from the root of the zygomatic proe- 
ess and fades out behind the infraorbital foramen; in some specimens it is prom- 
inent and thin-edged, in others it is rounded and projects little. The zygomatic 
process is short but stout and buttress-like; it is overlapped laterally by the malar. 
The maxillary tuberosity forms in the young subject a long bulla, which occupies 
most of the pterygo-palatine fossa and contains the developing permanent molars; 
after the eruption of the teeth the tuberosity flattens and joins the vertical part of 
the palate bone. The palatine process is very long and is marked in its anterior 
part by transverse grooves (Sulci palatini transversi) corresponding with those of 
the mucous membrane of the palate. The anterior palatine foramen is near the 
junction with the palate bone; from it the palatine groove can be traced distinctly 
along the entire length of the process. The alveolar border presents a large alveolus 
for the canine tooth at its anterior end; behind this are seven alveoli for the cheek 
teeth, which increase in size from first to last. The maxillary foramen and infraor- 
bital canal are very large. The maxillary sinus is small. 
The body of the premaxilla is narrow and prismatic. It presents three alveoli 
for the incisor teeth, which are separated by short intervals and diminish in size 
