618 ALIAS. VoL. XhE 
off while the nerve lies in the groove on the median surface of 
the articular. The nerve then comes to the upper surface of 
the thickened lower edge of the articular at the point where 
the branch ~ghs of the maxillaris inferior trigemini issues . 
from the hollow of the mandible. In that position, lying im- 
mediately ventral to the median edge of Meckel’s cartilage, it 
runs forward, sending branches to organs 8, 7, 6, 5, and 4. 
Beyond this last branch, at the point where the maxillaris 
inferior trigemini issues from the hollow of the mandible, the 
externus issues from beneath Meckel’s cartilage, and, passing 
immediately ventral to r. ghi trigemini, continues forward along 
the inner surface of the dentary, sending branches to organs 3, 
2, and a. 
The r. mandibularis facialis internus enters the canal between 
the preoperculum and symplectic with the externus, lying in 
front of that nerve, but it issues along the anterior instead of 
along the posterior edge of the latter bone, between it and the 
posterior edge of the quadrate, and reaches the inner surface of 
the palato-quadrate arch. It then turns forward, crosses inter- 
nally the lower end of the quadrate, enters the mandible oppo- 
site thé articular cup of the quadrate, and, lying between the 
splenial and the vertical part of Meckel’s cartilage, near the 
upper edge of the latter, continues forward to the tip of the 
mandible. It lies dorsal to the origins of the geniohyoideus 
inferior and intermandibularis, and may receive, near the hind 
edge of the former, an anastomosing branch or branches from 
the maxillaris inferior trigemini, as already described. 
The r. hyoideus facialis, after leaving the main truncus facia- 
lis, runs downward and backward along the outer surface of the 
hyomandibularis, passes through a canal between that bone and 
the preoperculum, and issues on the inner surface of the gill- 
cover beyond the hind edge of the cartilaginous interspace that 
lies between the ventral edge of the hyomandibular and the 
dorsal edge of the symplectic. The opening of the canal lies 
immediately ventral to the ventro-posterior process, or corner, 
of the hyomandibular, and immediately dorsal to the articular 
cup for the hyoid, and the nerve, continuing downward and 
backward internal to the suboperculum and interoperculum, 
