_a_, Body; _b_, lingual process; _c_, thyroid cornu and cartilage,
_c′_; _d_, small cornu; _e_, middle cornu; _f_, great cornu; _g_,
muscular angle of _f_. (Ellenberger-Baum, Anat. d Haustiere.)
]
The two halves of the =mandible= do not fuse completely even in advanced
age. The symphyseal surfaces are extremely rough and are marked by
reciprocal projections and cavities. The body is shorter, wider, and
flatter than in the horse, and has eight round and relatively shallow
alveoli for the lower incisors. The interalveolar border is long,
curved, thin and sharp. There are no alveoli for the canine teeth, which
are absent. The anterior part of the ramus constitutes a long narrow
neck. The mental foramen is further forward than in the horse, and is in
the posterior end of a fossa. The rami diverge more, so that the
submaxillary space is wider than in the horse. They are also more
strongly curved, and the angle is more pronounced. The molar part is not
so high, especially in its anterior part. Its lower border is convex in
its length. Its upper border bears six alveoli for the lower cheek
teeth; the first is quite small, and they increase in size from before
backward. The vertical part is much smaller than in the horse and its
posterior border is relatively thin below, concave and wider above. The
mandibular foramen is about in the middle of its inner surface, and a
groove for the lingual nerve curves downward and forward from it. The
condyle projects inward further than in the horse, and is concave from
side to side. The coronoid process is extensive and curves backward.
The =hyoid bone= has a short tuberous lingual process. The middle cornua
are almost, as large as the small cornua. The great cornua are narrow,
except at the ends. The upper end divides into two branches, which
correspond to the two angles of that of the horse. The thyroid cornua do
not fuse with the body.