80 ALLEN 
is reached it curves cephalad, following along the interhyal, 
but above the minor hyoidean artery and the ramus hyoideus. 
When the preopercular is reached the course of this vein is 
dorsad behind the ramus hyoideus and when a little past the 
middle of the preopercular, it passes with the nerve to the outer 
surface of the hyomandibular through a foramen between the 
hyomandibular and the preopercular. Here it receives a ven- 
tral branch from the posterior part of the adductor mandibule 
muscle, which follows along the outer surface of the preoper- 
cular. The main stem then leaves the hyoidean ramus and 
continues obliquely cephalad a little ventrad of the levator 
arcus palatini and between the superficial and profundus por- 
tions o yadductor mandibule, to unite with the facialis-man- 
dibularis vein. ‘The combined trunk proceeds dorsad for 
a short distance between the ramus mandibularis V and the 
facial artery to the floor of the orbit; where it receives the 
facialis-maxillaris vein. 
Fracialis-maxillaris Veins (Pls. I and III, figs. 1, 17, and 18; 
F.Max.V.). — Each of these vessels has its origin from a dorsal 
and a cephalic branch. The larger dorsal branch arises as an 
anastomotic vein from the orbito-nasal vein (see fig. 18); pass- 
ing beneath the nasal sac some little distance cephalad of the 
corresponding artery it receives at the level of the ventral surface 
of the nasal sac a rather large vein coming from the region of 
the palatine arch; and then continuing ventrad a short distance 
the main stem passes under the maxilla artery and unites with 
the maxilla vein. The maxz/la vein (Pls. I and III, figs. 1 and 
17; Max.V.) has its source in a superficial and a profundus 
branch from the premaxilla, which unite in the region of the 
vomer. In its caudal course it receives several branches from 
the ‘anterior part of the adductor mandibule muscle. After 
uniting with the dorsal branch from the region of the nasal sac 
the facialis-maxillaris vein proper crosses over the small facialis- 
maxillaris artery, and continuing caudad between the ramus 
maxillaris V or ramus maxillaris superior and the facialis- 
maxillaris artery in the adductor arcus palatini from which it 
receives several branches, it unites with the combined trunk of 
the mandibular and hyoidean veins in the posterior part of the 
orbit to form the external jugular trunk. 
