CRANIAL NERVES OF SIREN LACERTINA 283 
Although the cranial nerve components have been worked out 
in but few Urodele amphibians, yet the uniformity in the branch- 
ing of the peripheral portions of the trigeminal nerve makes it 
possible in our present state of knowledge to represent this ar- 
rangement by a definite scheme. 
Nervus trigeminus 
A. Radices: 
I. Radix spinalis 
II. Radix mesencephalica 
III. Radix motor 
B. Ganglia: 
“Ganglion gasseri (cum g. trigemini) 
C. Rami: 
I. Ramus ophthalmiecus profundus 
1. Ramulus ophthalmicus profundus minor 
2. Ramulus nasalis internus 
3. Ramulus nasalis externus 
4. Ramulus palatinus profundus 
5. Ramuli ciliares 
II. Ramus mandibularis 
1. Ramuli musculares 
2. Ramulus malaris 
3. Ramulus labialis 
4. Ramulus mandibularis externus 
4a. Rm. alveolaris 
5. Ramulus intermandibularis 
III. Ramus maxillaris (with r. buccalis VII forming truncus infraorbitalis) 
IV. Ramus oticus (?) (with r. ophthalmicus superficialis VII forming trun- 
cus supraorbitalis) 
THE FACIAL AND AUDITORY NERVES 
1. Roots of the facial and auditory nerves 
The fibers of this complex arise by two groups of rootlets. 
The more dorsal group, (figs. 21, 22, 30, 31, VIZ Ul.), which com- 
prises the lateral line fibers of the seventh nerve, arises by three 
rootlets. The dorsal of these three rootlets enters what may be 
termed the lateral line lobe (Ul., figs. 20, 21) of the medulla oblon- 
gata. Its fibers, on entering, lose their sheaths so soon that 
their destination can be surmised only. They appear to end al- 
most directly opposite the point of entrance, turning slightly 
posteriorly. The other two rootlets enter the brain somewhat 
