. An introduction to the study of mammals living and extinct. Mammals. EQUID^ 389 chiefly in consequence of the immense size of the face as compared with the hinder or true cranial portion. The basal line of the cranium from the lower border of the foramen magnum to the incisor border of the palate is very nearly straight. The orbit, of nearly circular form, though small in proportion to the size of the whole skull, is distinctly marked, being completely surrounded by a strong ring of bone with prominent edges. Behind it, and freely communicating with it beneath the osseous bridge (the postorb
. An introduction to the study of mammals living and extinct. Mammals. EQUID^ 389 chiefly in consequence of the immense size of the face as compared with the hinder or true cranial portion. The basal line of the cranium from the lower border of the foramen magnum to the incisor border of the palate is very nearly straight. The orbit, of nearly circular form, though small in proportion to the size of the whole skull, is distinctly marked, being completely surrounded by a strong ring of bone with prominent edges. Behind it, and freely communicating with it beneath the osseous bridge (the postorbital PMi,. Fig. 163.—Side view of skull of Horse, with the bone removed so as to expose the whole of the teeth. VMx, Premaxilla; Ux, maxilla; li^a, nasal; Ma, malar or jiigal; i, lachrymal; Ft, frontal; Sg, squamosal; Pa, parietal; OG, occipital condyle; ^"p, paroccipital process; ii, i2, and i3, the three incisors ; c, the canine ; pwii, the situation of the rudimentary first premolar, which has heen lost in the lower, but is present in the upper jaw; pm2, p7rt3, and pm4, the three fully developed premolars; m^, m2, and m3, the three true molars. process of the frontal) forming the boundary between them, is the small temporal fossa occupying the whole of the side of the cranium proper, and in front is the great flattened expanse of the " cheek," formed chiefly by the maxilla, giving support to the long row of cheek-teeth, and having a prominent ridge running forward from below the orbit for the attachment of the masseter muscle. The lachrymal occupies a considerable space on the flat surface of the cheek in front of the orbit, and below it the jugal or malar does the same. The latter sends a horizontal or slightly ascending process backwards below the orbit to join the under surface of the zygomatic process of the squamosal, which is remarkably large, and, instead of ending as usual behind the orbit, runs forwards to join the greatly developed postorbital proc
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Keywords: ., bookauthorly, bookcentury1800, bookdecade1890, booksubjectmammals
