306 
ANATOMY OF THE HORSE. 
these are bounded laterally by the lateral nasal sutures^ formed by 
the junction of the nasal with the maxillaiy bones, both superior 
and anterior. The nasal peak is the uni+ed apices of the nasal 
bones, the anterior nasal opening; which 
aperture is bounded laterally by the superior convex surfaces of 
the anterior maxillary bones, and in front is oviform and conti¬ 
nued into the superior rnaxillary sijfnphysisy through which runs 
the foramen incisivum: lastly, the superior alveolar processes; 
and the incisive teethy ranged in a row and fixed within the alveolar 
cavities* 
THE POSTERIOR SURFACE is entirely CRANIAL : it is 
bounded, superiorly, by the occipital cresty and, inferiorly, by the 
occipital hole; it presents the occipital tuberosityy and on its 
sides the broad posterior occipital depressions, deeply and rug¬ 
gedly pitted by muscular attachments; also, projecting from the 
postero-lateral parts of the foramen magnum, the occipital con¬ 
dyles. 
‘ THE INFERIOR SURFACE comprises— 
1. The inferior cranial region, which is bounded, 
posteriorly, by the occipital hole and condyles ; anteriorly, by the 
vomer and palate bones; laterally, by the zygomatic arches. 
Proceeding from behind forwards, we observe—1st, along the me¬ 
dian line, the basilar processy impressed by the basilar fissure; 
the condyloid foramina on its sides, near the roots of the condyles; 
a semicircular prominence denoting its j unction with the sphenoid 
bone; the body of the sphenoid bone, its articulation with that of 
the ethmoid, and a small semilunar portion of the latter left visi¬ 
ble within the crescentic border of the vomer. 2d, On either 
side, the occipital styloid process; between it and the condyle, the 
occipital notch; in front of the notch and root of the occipital sty¬ 
loid projection, THE PETROUS PORTION of the temporal bone— 
exhibiting, posteriorly, the posterior mastoid process, having at 
its root the external orifice of the aqueduct of the vestibule; di¬ 
rectly in front, the auditory process and meatus, at the inner side 
of which is the hyoideal process; behind the meatus are the 
mastoid cellsy projecting from the inner and anterior part is the 
slender temporal styloid process, having at its root the Eustachian 
opening and styloid foramen. In front of, and rather outwardly 
to the petrous portion, we observe,— the anterior mastoid process ; 
at its root, the mastoid foramen ; extending outwardly, in front of 
it, the glenoid cavity, bounded anteriorly by the temporal articu¬ 
lar process. Thejoramen lacerum is the large irregular opening 
formed by the occipital, temporal, and sphenoid bones, compre¬ 
hending the temporo-occipital and spheno-occipital hiatus, and 
traversed by the internal carotid arteiy, the jugular vein, the 
