592 AVEIELS: [VoL. XII. 
upper, lateral chamber of the eye-muscle canal, and hence, 
although lying inside the cartilaginous cranium, lies outside 
the cranial cavity, properly so-called. From the ganglion arise 
the nine large nerves that form the trigemino-facial complex, 
as generally described, and several smaller nerves which may 
be considered as belonging to one or other of the nine principal 
ones. Of the nine principal nerves, three are commonly con- 
sidered to belong to the trigeminus, two to the dorsal root of 
the facialis, and four to the ventral root of the facialis. The 
three nerves that are assigned to the trigeminus are, the r. 
ophthalmicus superficialis trigemini plus the portio ophthal- 
mici profundi, or trigeminus I; the r. maxillaris superior trige- 
mini, or trigeminus II; and the r. maxillaris inferior trigemini, 
or trigeminus III. The two nerves that are assigned to the 
dorsal root of the facialis are, the r. ophthalmicus superficialis 
facialis, and the r. buccalis facialis, of which the r. oticus is 
properly a branch (No. 3, p. 516). The four nerves that are 
assigned to the ventral root of the facialis are, the r. palatinus 
facialis, the r. hyoideus facialis, the r. mandibularis internus 
facialis, and the r. mandibularis externus facialis. As the 
latter nerve innervates only the canal organs and the surface 
pit organs of the operculo-mandibular portion of the lateral 
canal system (No. 3, p. 518), and as it arises in Amia (Allis) 
and in Rana (Strong) as a branch of the so-called dorsal root 
of the facialis, and in sharks (Ewart) as a part of that root 
or as a separate dorsal root, it should be added to the dorsal 
branches. The rami maxillaris superior and maxillaris inferior 
trigemini together form the truncus maxillaris trigemini, which 
is in Amia very short; and the rami hyoideus, mandibularis 
internus, and mandibularis externus facialis together form the 
truncus hyoideo-mandibularis facialis, which is somewhat 
longer. The mandibularis externus and mandibularis internus, 
although arising from different roots, are at first intimately 
associated with each other, and after separating from the 
truncus hyoideo-mandibularis they together form the truncus 
mandibularis facialis. The ophthalmicus superficialis trigemini 
and the ophthalmicus superficialis facialis always arise separately 
from the ganglionic complex and are, the portio minor and the 
