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 forehmb. 



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 digitahs 

 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 bursas 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 difflcult 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 pemiate 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 mecUal 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 mandibulse. 



The occipito-hyoideus and kerato-hyoideus are small. 



The hyoideus transversus is absent. 



The omo-hyoideus and stemo-hyoideus are referred to in connection with the 

 muscles of the neck. 



