30 ANATOMY OF THE HORSE. 



a vaulted, demi-arched, oblong plate, called the palatine process 

 or bony palate, which forms the partition between the cavities of 

 the nose and mouth : posteriorly, this plate denticulates with 

 the palate bone; anteriorly, with the anterior maxillary bone. 

 The surface is bounded along the outer side by the alveolar pro- 

 cesses, and between it and them runs a groove for the conduit of 

 the palatine artery. 



The Superior or Nasal Surface forms the outer side and half 

 of the floor of the nasal cavity. Like the inferior surface it is 

 concave, but unevenly so, being more excavated towards the 

 posterior than the anterior part : in fact, the broad channel 

 formed by both bones constitutes three-fourths of the bony pari- 

 etes of the nasal cavity. To a longitudinal spine running along 

 either side of this channel is attached the inferior turbinated 

 bone, dividing it laterally into two canals, named the inferior 

 and middle meatus. At the supero-posterior part of the nasal 

 chamber, behind the superior turbinated bone, the maxillary 

 sinus opens through an oval aperture into the middle meatus : 

 within the meatus itself, anteriorly to this, arched over by a 

 little transverse eminence, is the orifice of the lachrymal con- 

 duit, which is traversed by the lachrymal duct. 



Extremities. The Posterior swells into a large rounded 

 protuberance, the maxillary tuberosity ; between which and the 

 palate bone is a hiatus presenting three apertures : one is the 

 posterior palatine foramen ; another, the anterior palatine fora- 

 men and conduit leading to the palato-maxillary canal ; the 

 third is that of the infra-orbital canal, leading to the foramen 

 of the same name. To the outer side of the tuberosity is the 

 malar process, articulating with the malar and lachrymal bones 

 and the zygomatic process of the temporal. The Anterior or 

 Dental Extremity is pyramidal and laminous, and contains an in- 

 curvated, conoid, alveolar cavity for the lodgement of the tusk : 

 it denticulates with the anterior maxillary bone. 



Borders. The Superior or Nasal is laminous to be united to 

 the nasal bone ; and has a mortise in its fore part to receive the 

 border of the anterior maxillary bone. The Inferior or Alveolar 

 Border presents two parallel plates divided by transverse septa 

 into six quadrangular cavities, the alveoli, for the implantation 

 of the molar teeth. Behind the last molar tooth is the alveolar 

 tuberosity, a rugged eminence giving attachment to the ptery- 

 goideus internus. The Internal or Palatine Border denticulates 

 with its fellow. 



Connection — With the squamous temporal and nasal bones ; 

 and with the anterior maxillary, malar, lachrymal, palate and 

 inferior turbinated bones. 



