No.3.] MUSCLES AND NERVES IN AMIA CALVA. 609 
between the premaxillary and the external dermal bones, and 
along the edge of the upper lip. The other main branch of 
the nerve turns inward and forward above the premaxillary 
and crosses the depression in that bone that forms the bottom 
of the front end of the nasal pit. The nerve here lies ona 
level with the outer edges of the bone and hence somewhat 
above the bottom of the pit, extending across it immediately 
under the front end of the olfactory tissue. In this part of its 
course several branches are given off, all of them running for- 
ward or forward and inward under the buccalis and above the 
premaxillary to the dermal and subdermal tissues toward the 
end of the snout. The branches form numerous anastomoses 
with each other and with other terminal branches of the nerve 
and also with a terminal branch of the palatinus anterior facialis 
which, having traversed the cartilaginous base of the skull, 
issues by a foramen between the inner edge of the septomaxil- 
lary and the inner edge of the olfactory perforation of the pre- 
maxillary, and reaches the upper surface of that last bone (af, 
Figs. 21 and 25, Pls. XXIV and XXV, and paf-fr, Figs. 8 and 
10}, PSX XT). 
One small branch of this branch of the palatinus facialis was 
traced into one of the teeth of the premaxillary. 
ft. Ramus Maxillaris Inferior Trigemini. 
The maxillaris inferior (#72?) is the largest of the three main 
divisions of the trigeminus. It runs at first downward, outward, 
and forward, and then downward, outward, and backward around 
the front edges of the muscles Lms!, Lms2, Do, and Am. It 
then runs downward and backward along the outer surfaces of 
A! and Az" to the upper edge of Az’, at about one third the 
distance between the insertion of the muscle and its origin. 
Here it turns downward and then downward and forward 
between A2! and A2", and entering the hollow of the mandible 
reaches the inner surface of the coronoid process of Meckel’s 
cartilage near its anterior edge and at the posterior end of the 
surface of insertion of Aw’. In its course up to this point it 
has been a broad, thin, ribbon-like nerve, the flat surface of the 
