280 H. W. NORRIS 
capsule. The ramulus nasalis internus emerges from the nasal 
capsule on the median border of the latter, in the midst of the 
internasal or Jacobson’s gland, between the capsule and the inter- 
nasal cartilage (fig. 3). Here it breaks up into many small twigs 
(nervi ophthalmici anteriores of Wilder) which innervate the skin 
at the side of the snout, anterior to the nasal capsule. (b) A sec- 
ond branch (op. 3), ramulus nasalis externus, runs laterally 
around, pressed close against the anterior wall of the eyeball 
(figs. 2, 7, 8). This may arise as a single branch which soon 
divides, or as two branches, distinct from each other from their 
origin, approximately equal in size, or very unequal. On reaching 
the posterior border of the nasal capsule the nasalis externus has 
divided into three or four divisions, one of which enters the cap- 
sule and runs along the inner border of the lateral wing, as de- 
scribed by Wilder, later emerging through the cartilage (figs 6, 15) 
to be distributed with the other branches to the skin, lateral to 
the nasal capsule. (c) The ventral of the three terminal branches 
of the ramus ophthalmicus profundus (op.4) is the one that 
anastomoses with the ramus palatinus VII (figs. 7, 8). The 
ophthalmic-palatine anastomosis in Siren is fundamentally on 
the same plan as that described in Amblystoma by Coghill (’02, 
pp. 223, 229) and in Amphiuma by the writer (’08, p. 535). The 
two nerves, the branch of the ramus ophthalmicus profundus and 
the ramus palatinus, on approaching each other, divide, each into 
two branches, which unite in pairs in such a way that the result- 
ing nerves each contain profundus and palatine fibers, One of 
these two nerves is lateral and runs along the lateral border of the 
nasal epithelium; the other extends anteriorly, medial to the nasal 
epithelium. 
In Siren the profundus-palatine anastomosis is modified, first 
by an anastomosis between the profundus constituent (op.4) 
and a branch (buc.2 + mz.2) of the infra-orbital trunk of the facialis 
of lateralis and general cutaneous composition; second by the 
fact that the palatine divides into lateral and medial portions far 
posteriorly, shortly after leaving the trunk common to it and the 
ramus alveolaris VII, by which it has emerged from the skull; 
third by the introduction from the infraorbital trunk of maxil- 
laris fibers. 
