SOLIPEDA. 
715 
Osteology.— Skull. The head of the horse ters*, namely, by the great enlargement be- 
is at once recognisable by the following charac- tween the orbits {fig. 496. a a), by its slightly 
Fig. 495. 
a, b, c, d, e, fi, os frontis ; b, supra-orbital foramen ; — h, i, k, parietal bone ; — l, o, p, q, occipital bone ; 
I, occipital protuberance ; p, condyle ; o, paramastoid process ; q, basilar portion ;—r, s, t, u, w, x, temporal 
bone ; r, zygomatic portion ; x, suture with the malar bone ; t, glenoid cavity ; u, mastoid process ; w, 
tympanic ring ;—1, 2, 3, 4, 5, 6, lacrymal bone ; 2, position of the nasal duct ; — 7, 8, 10, malar bone ; — 
II, 11, 12, 13, 14, superior maxillary; 12, infra-orbital foramen;—15, intermaxillary;—16, nasal bone ; — 
17, 18, 19, 19, 20, inferior maxillaiy ; 18, mental foramen ; 19, 19, coronoid process ; 20, condyle. 
Fig. 496. 
A, a, a, b, c, c, d, d, f f g, g, frontal bones ; A, 
frontal suture ;—h, h, i, i, It, parietal bones ; — in, n, n, 
■occipital ; — 0,0,0, p, q, r, temporal bones ; 0, o, o, 
zygomatic processes ; r, suture with the malar ; — 
s, s, t, u, u, nasal bones ;—ic, x, y, z, lacrymal bone ;— 
1, 1, 2, 2, 3, 3, malar bones ; — 4, 4, 5, 5, 6, superior 
maxillary bones; 5, 5, infra-orbital foramina; 6, 
palatal process ; — 7, 8, 9, intermaxillary bones ; 8, 
nasal process ; 7, palatal suture ; 9, foramen in the 
suture ; 10, incisor teeth ;—16,18, 18, inferior max¬ 
illa ; 18, 18, summits of coronoid processes. 
convex profile, by the length of the face, which 
is more than double that of the cranium, and by 
the vertical depth of the lower jaw, which is 
more than that of the whole cranial portion 
of the skull. The temporal ridges, prolonged 
backwards from the post orbital apophyses, ex¬ 
tend as far as the middle of the parietal bones, 
and there form a short sagittal crest upon the 
mesial line of the skull, whence, proceeding 
backwards, they diverge and extend as far as 
the occipital ridge, which is truncated above 
(as is the case in the paehydermata generally), 
and projects over the posterior surface of the 
occiput. The intermaxi Hades are prolonged 
considerably beyond the nasal bones, which 
last, by their points, arch over the cavity of 
the nostrils to a considerable extent. The 
temporal arch is comparatively very short, 
nearly straight, and is situated entirely in the 
posterior third of the skull. 
As regards the individual bones of the 
skull, it may be observed that the two firontals 
{fig. 496. a, a,fi g) remain distinct from each 
other after the parietals become consolidated 
into one piece; they are of remarkable breadth 
between the orbits, and posteriorly penetrate 
to a considerable depth between the parietal 
bones. The ossa parietalia {fig. 495. h, i) 
give off on each side of the cranium a pointed 
* Cuvier, Ossemens fossiles, t. ii. p. 108.