Muscles of Mastication

The masseter is not so large as in the horse; a considerable part of it arises on the facial tuberosity and is directed obliquely backward and downward, so that it would draw the lower jaw forward as well as upward.

The temporalis conforms to the temporal fossa, and is therefore longer and entirely lateral in position.

The pterygoidei are not quite clearly separated; their direction is more oblique, and the origin of the pterygoideus internus is nearer the median plane than in the horse.

The stylo-mandibularis is absent.

The digastricus has a tendinous origin on the paramastoid or styloid process of the occipital bone; its bellies are short and thick. It does not perforate the stylo-hyoideus. The two digastrici are connected beneath the root of the tongue by a layer of transverse muscle-fibers (Transversus mandibulæ).