According to other authors, some of the fibres of this muscle constitute the small zygomatic.
Fig. 91.—Myology of the Ox: Muscles of the Head.
1, Masseter; 2, orbicularis palpebrarum; F, frontalis; 3, zygomaticus major; 4, lachrymal (this muscle is sometimes described under the name of small zygomatic); 5, levator labii superioris proprius; 6, levator labii superioris alæque nasi; 7, levator anguli oris or caninus; 8, orbicularis oris; 9, buccinator; 10, maxillo-labial; 11, zygomatico-auricularis; 12, external temporo-auricularis; 14, parotid gland; 15, parotido-auricularis; 16, inferior maxillary bone.
Levator Labii Superioris Proprius ([Fig. 90], 5; [Figs. 91], [92]).—Also named by veterinarians the supramaxillo-labial, or again, the proper elevator of the upper lip, this muscle arises from the external surface of the superior maxillary bone, passes under the superficial elevator, which we shall study in the succeeding paragraph, and goes to be inserted into the thickness of the lip, to which its name indicates that it belongs.
The peculiarities of this muscle in different animals are the following:
In the dog and the cat it arises behind the infra-orbital foramen.
In the pig it arises from a depression below the orbital cavity, and its fleshy body is terminated in front by a strong tendon in the upper part of the snout, in which it divides into fasciculi.
In the ox it arises from the maxillary spine.