610 ALLIS. [Vou. XII- 
nerve lying on the outer surface of Az” and Ao’. Here, how- 
ever, it is twisted inward and downward and, although still broad 
and thin, lies imbedded in and between the fibres of Ao! at 
their insertion, so that the thin edge of the nerve is presented 
superficially. Continuing downward and forward in this posi- 
tion, along the inner surface of the articular and dentary, it grad- 
ually becomes rounded in outline and issues from the hollow of 
the mandible, at its extreme front end, through a long longitu- 
dinal opening (mzéfr., Figs. 6 and 7, Pl. XX) between the den- 
tary, below, and Meckel’s cartilage and the lower edge of the 
splenial, above. Beyond this point it extends to the tip of the 
mandible lying along the inner surface of the dentary median 
to Meckel’s cartilage and immediately below the lower edge of 
the splenial. It is in this part of its course closely associated 
with the r. buccalis facialis which lies immediately median to it, 
the two often appearing as asingle nerve. Between them there 
is, however, no interchange of fibres, and they are easily separ- 
ated in dissection. 
The first branch given off by the maxillaris inferior, ~./af.do, 
leaves the nerve from its outer surface before it has separated 
from the maxillaris superior, that is, it arises from the truncus 
trigeminus, but from that portion of the truncus that contains 
the fibres destined for the inferior division of the nerve. It is 
given off immediately after the truncus enters the orbit and 
runs outward and forward to the inner surface of the levator 
arcus palatini near its front edge. There it separates into two 
parts, an inner, posterior portion and an outer, anterior one. 
The inner, posterior portion runs backward and slightly upward 
along the inner surface of the muscle, sending branches into 
it and lying between it and the lateral wall of the cranium 
immediately above the united first and second divisions of the 
levator maxillae superioris. It reaches the front edge of the 
hyomandibular near its upper end, and, running along the outer 
surface of that bone, along the line separating the dilatator 
operculi and the posterior portion of the levator arcus palatini, 
sends branches to those two muscles. The other or outer por- 
tion of the nerve runs outward around the front edge of the 
levator arcus palatini, and then backward along the outer sur- 
