W 
The Cranial Nerves of Varanus bivittatus. 461 
posterior and internal portion of the muscle. Each of these branches 
in turn divides into a large number of finer branches which pene- 
trate the whole body of the muscle. 
©  e) Ramus ad mm. pterygoideum et pterygomandibularem arises 
from the ventral surface of the main stem of mandibularis a short 
distance distally to (b) and comprises two strong branches. One of 
these erosses medially under the main stem of mandibularis and 
runs diagonally posterior and ventral to os pterygoideum, where it 
enters musc. pterygo-mandibularis and spreads with two main divi- 
sıons, anterior and posterior, and many finer ones, into the mass of 
this thiek and heavy musele. The other division of ramus (e) runs 
direetly anteriorally and divides into fine branches in musele ptery- ; 
goideus. 
B. Portio alveolaris inferior. As the general course of this nerve 
has been discussed above, the enumeration of the branches will be 
suffieient. They are as follows: 
- a) Ramus recurrens eutaneous is the largest branch of this 
group. It arises from the posterior surface of nervus mandibularis, 
just before the latter passes over os pterygoideum. Taking a postero- 
ventral course branch (a) enters very soon a special canal in the 
os supra-angulare and emerges posteriorally a short distance further, 
{rom its external surface and divides into an anterior and a posterior 
division to innervate with groups of fine fibres the skin covering 
m. pterygo-mandibularis. 
b) Ramus cutaneous externus is given off from portio alveolaris 
immediately after the latter enters the alveolar canal. The branch 
runs anterior and dorsal through a special canal in os supra-angulare, 
and emerges from the external surface of this bone ventral to the 
coronoid process. It innervates the outer skin in this region through 
several fine branches. 
As the portio alveolaris inferior passes through its canal in the 
os dentale, it is joined by the chorda tympani VII, which comes 
from the posterior direction, through a special canal in the os arti- 
eulare. After this union two branches are given off.through special 
canals in the inner surface of the mandible: 
v c) Ramuds ad musculum mylohyoideum eomprising a bundle of 
fine fibres, and — 
d) Ramus museularis et glandularis, a fine branch which sends 
a number of fibres to muse. genioglossus in the anterior region of the 
jaw elose under the outer skin and to the glauds under tongue. 
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