EXTERNAL ANATOMY OF THE HORSES HEAD. 199 



^■y g. A strip of the palate, dissected up, to exhibit the position of 



the vessels and nerve beneath. 

 hf h. The cheeks. 

 i, L The molars, or grinding teeth. 



EXTERNAL ANATOMY OF THE HORSE^S HEAD. 



PLATE III. Fig. 1. 



a, a. The orbicularis muscles, surrounding the eye, and destined 

 for the purpose of closing the eyelids. 



b. The nasalis labii superioris takes its rise from a depression 

 at the junction of the superior maxillary and malar bones, 

 and extending to the angle of the nostril. Its use is to 

 raise the lip, and dilate the nostrils. 



c. Dilator magnus^ or great dilator, which assists in the office 

 of retracting the upper lip and in dilating the nostrils. 



d. Dilator naris lateralis, or side dilator of the nostrils, reversed 

 to exhibit the vessels and nerves which it covers, extending 

 from the covering of the nasal and frontal bones to the 

 angle of the mouth and side of the nostril. Its office is to 

 retract the upper lip, and dilate the nostrils. 



e. The zygomaticus, extending from the zygomatic arch and 

 masseter to the corner of the mouth, for the purpose of 

 drawing back the angle of the mouth. 



/, g. The orbicularis oris, or circular muscle of the mouth. This 



muscle surrounds the mouth for the purpose of closing the 



lips and dilating the nostrils. ^ 



k. The buccinator, or trumpeter muscle, extending from the 



inside of the mouth and cheeks to the angle of the mouth, 



to draw it back. 

 i. Depressor labii inferioris, or puller down of the under lip, 



attached to the sides of the under lip to pull it down. 

 j. Branches of nerves, with small blood-vessels. 

 k. The parotid duct, penetrating the cheek to discharge the 



saliva into the mouth. 

 I. See letter r, and explanation. 



m. The vein and artery passing under the zygomatic arch. 

 n, A branch of the fifth pair of nerves, the sensitive nerve of 



the face, emanating from under the parotid gland. 



