HEAD AND NECK OF THE HORSE 



149 



what wider floor. The nasal septum constitutes the medial wall. The 

 lateral wall is very uneven as the result of the projection of the 

 turbinated bones and the labyrinth of the ethmoid into the cavity. 

 The dorsal turbinated bone (concha nasalis superior) is broader at its 

 posterior end and more tapering anteriorly than the ventral turbinated 



Superior nasal meatus. 

 Dorsal concha. 



Middle nasal meatus. .^^ 



Ventral concha. - 



Naso-laclirymal duct. 

 N. infraorhitalis. 



Nasal septum. - 

 Maxillary sinus. - 



Inferior nasal meatus. 

 A. palatina major.- 



Parotid duct. 

 A. lingualis. -- 



M. buccinator. " 

 M. depressor labii inferinris. 



A. labialis inferior. -_ 



N. alveolaris inferior. - 

 Submaxillary duct. ' 

 M. mylohyoideus 



A. sublingualis 



^ V. facialis. 



- M. zygomaticus. 



- A. facialis. 



N. buccalis dorsalis. 



N. buccalis ventralis. 



M. cutaneus. 



X. lingualis. 



'N. hypoglossus. 

 ^M. genioglossus. 

 M. geniohyoideus. 

 Fig. 64.— Transverse section of the face at the level indicated by E in Fig. 1 (looking forward). 



M. digastricus. 



bone (concha nasalis inferior). The labyrinth of the ethmoid forms an 

 irregularly conical mass insinuated between the posterior ends of the 

 two turbinated bones. 



The intrusion of the turbinated bones divides the nasal cavity into 

 passages, the meatus ^ nasi. The superior meatus (meatus nasi 

 superior) is narrow, and bounded by the superior concha and the nasal 

 and frontal bones. The middle meatus (meatus nasi medius), bounded 

 by the two conchas and the maxilla, is slightly wider and does not 

 extend so far back as the upper meatus. It is into the posterior part 

 1 Meatus [L], a going or passing, a passage. 



