Zygomatico-auricularis ([Fig. 90], 11).—Arises from the internal surface of the great zygomatic, passes towards the pinna of the ear, and goes to be inserted into the external part of the base of the pinna, below its opening, to a prominence which corresponds to the antitragus of the human ear. It is to this antitragus, but proceeding from another direction, that the parotido-auricular muscle is inserted ([Fig. 90], 15).
With regard to the cervico-auriculars, they are all three present. The superior, or superficial, situated behind the interscutellar portion of the external temporo-auricular, has its origin on the median line of the neck; thence it passes towards the pinna of the ear, blending its fibres with those of the interscutellar muscle, and is inserted into the scutiform cartilage and the internal surface of the pinna.
Such are the principal muscles of the ear in the carnivora; it would seem to us superfluous to dwell on the others of this region, so that we will here conclude the study of the muscles in general, and that of the myology of the head in particular.
CHAPTER III
EPIDERMIC PRODUCTS OF THE TERMINAL EXTREMITIES OF THE FORE AND HIND LIMBS
We will first recall to mind that among the quadrupeds some are found of which the fingers and toes have their third phalanges terminated by claws—these are the unguiculates; and that in others the terminal extremity of each limb is completely encased in a horny envelope, the hoof—these are the ungulates.
In the first group, the claws remind us to a certain extent of the arrangement of the nails in man; the inferior aspect of the paws is covered by an epidermic layer, thick and protective, which may be likened to the skin, correspondingly thick, which covers in the greater part of its extent the plantar surface of the foot in the human species.
In the second group, the surface by which the third phalanx rests on the ground is correspondingly protected, but this time by a layer of horn which belongs to the hoof.