lo6 THE MUSCLES. 



small bundle (Fig. 63, p") from near the dorsal end of the 

 frontal process of the maxillary bone, in common with the 

 next. The two slips thus formed unite craniad and are inserted 

 partly into the integument on the outer side of the wing of the 

 nose, partly into the skin of the upper lip, lateroventrad of the 

 nose, and partly into the pad on which the whiskers are located, 

 in connection with the next. 



(2) The angular head (caput angulare), or levator labii 

 superioris proprius (Fig. 63, q; Fig. 64, /) is much larger 

 than the last. It takes origin from a small tubercle at the 

 cranial border of the orbit, close to the origin of the orbicularis 

 oculi. The fibres diverge from their origin to their insertion 

 among the whiskers and in the fibrous pad on which the 

 whiskers rest. 



Action. Erects the whiskers and raises the upper lip. 



M. caninus or levator anguli oris (Fig. 64, /'). 



Origin in a depression on the lateral surface of the maxil- 

 lary bone, just craniad of the last premolar tooth. The fibres 

 pass craniad, diverging, toward the whiskers, and have their 

 insertion into the pad of tissue on which the whiskers rest. 



Action. Retracts the whiskers and raises the upper lip. 



M. buccinator. A thin muscle against the mucous mem- 

 brane of the upper lip, partly united with the orbicularis oris 

 and lying beneath M. caninus. 



Origin on the outer surface of the superior maxillary bone 

 in the depression between the infraorbital foramen and the first 

 premolar tooth. The fibres pass ventrad, diverging, and 

 mingle with those of the deep part of the orbicularis oris. 



Relations. Outer surface with the caninus and with the 

 orbicularis oris. Inner surface with the mucous membrane of 

 the upper lip. 



Action. Raises the upper lip. 



M. myrtiformis (probably corresponds to a part of the 

 human M. nasalis) (Fig. 64, //). A thin sheet of muscle-fibres 

 lying craniad of the levator labii superioris alaeque nasi and 

 passing from the whiskers to the nose and upper lip. It is dis- 

 tinguishable from the alaeque nasi by the direction of the 

 fibres. 



