THE MUSCLES OF THE PIG—-MUSCLES OF THE FACE 359 
B. PLANTAR GROUP 
The gastrocnemius and soleus resemble those of the horse. 
The superficial flexor is more fleshy than in the horse. Its tendon termi- 
nates as in the forelimb. 
The deep flexor in general resembles that of the horse, but the tibialis poste- 
rior (superficial head) is distinct and is larger than in the horse. The flexor digitalis 
longus (medial head) is also larger, while the flexor hallucis longus (deep head) is 
smaller. The common tendon ends like that on the forelimb. 
The synovial sheaths and burs of the muscles of the leg and foot are shown in 
Figs. 312-315. 
THE MUSCLES OF THE PIG 
MUSCLES OF THE FACE 
The facial cutaneus is pale, thin, and difficult to separate from the skin. 
The orbicularis oris is little developed. 
The levator nasolabialis is thin and pale, and is undivided. 
The levator labii superioris proprius may well be termed the levator rostri. 
It has a large pennate belly, which arises in the preorbital fossa. The tendon ends 
on the anterior part of the os rostri. A muscular slip connects it with the premaxilla. 
The zygomaticus arises on the fascia over the masseter and ends at the angle 
of the mouth. 
The depressor labii inferioris separates from the buccinator only near the 
angle of the mouth; it ends by a number of tendinous branches in the lower lip. 
The dilatator naris lateralis is well developed. It arises under the levator 
rostri and ends by a tendinous network around the nostril. 
The transversus nasi is represented only by a few fibers which cross over the 
os rostri. 
The depressor rostri arises on the facial crest. It has a long strong tendon 
which passes below the nostril and turns dorso-medially to meet the tendon of the 
opposite side and end in the skin of the snout. It depresses the snout and con- 
tracts the nostril. 
The malaris is absent, and the other palpebral muscles present no special 
features. 
MANDIBULAR MUSCLES 
The masseter is thick. 
The pterygoideus medialis is wide at its insertion. 
The pterygoideus lateralis is large and distinct. 
The digastricus has only one belly and has no connection with the hyoid bone. 
It ends on the medial and lower surface of the mandible, in front of the groove for 
the facial vessels. 
HYOID MUSCLES 
The mylo-hyoideus consists of two more or less distinct layers, the superficial 
one being the transversus mandibule. 
The occipito-hyoideus and kerato-hyoideus are small. 
The hyoideus transversus is absent. 
The omo-hyoideus and sterno-hyoideus are referred to in connection with the 
muscles of the neck. 
