The Cranial Nerves of Varanus bivittatus. 455 
1. Ramus superior is a strong branch which arises from the 
main stem before the latter has fully emerged from the brain cavity. 
It turns dorsally, erosses the dorsal surface of musc. bursalis, and 
enters musc. rectus superior in its posterior border at a point not 
far from its origin. 
2. Ramus inferior consists of the remainder of the nerve. 
It is distributed as follows: 
a) Ramus eiliaris, also a strong branch, is the first to separate 
from ramus inferior and arises just beyond the separation of the 
two main rami. Turning immediately in a dorsal direction it lies 
between muse. bursalis, ventrally, and musc. rectus superior, dorsally, 
at which point it forms a spindle-shaped swelling (the eiliary gan- 
glion) which is entered on its external border by a branch of smaller 
size from ramus ophthalmicus V, which nerve lies dorsal to nervus 
oculomotorius in this region. From the eiliary ganglion, two nerves 
arise, one very strong, the other very fine and hard to discover. 
These eiliary nerves run anterior a short distance and enter the 
bulbus oeuli, near one another at a point not far posterior and ven- 
tral to the entrance of Nervus opticus. The main stem of 2) then 
bends ventrally and gives off b&e. 
b) Ramus to musec. rectus inferior separates from ramus inferior 
at the point where the latter, coming from under musc. bursalis, 
erosses ventrally musc. rectus inferior, near its point of origin from 
the interorbital septum. As the nerve passes over the ventral sur- 
face of the latter muscle, rami are given off in the form of five or 
six fine branches and following the ventral surface of the muscle 
laterally for a short distance, they become distributed among its fibres. 
ec) Ramus to muse. rectus medialis. As soon as the remaining 
part of ramus inferior has crossed the surface of muse. reetus in- 
ferior it divides into two branches of about equal size. One of 
these turns medially where it comes at once into contaet with the 
interorbital septum and makes a sharp turn dorsally, lying close to 
the septum until it reaches the median surface of muse. rectus 
medialis where it breaks up into fine branches which are distributed 
to the fibres of this muscle. Ramus inferior terminates in: 
d) Ramus to muse. obliquus inferior, which runs from the point 
of division direetly anterior, near the interorbital septum, over the 
ventral surface of the Harderian gland, covered only by the mem- 
branous roof of the mouth, to the place where muse. obliquus inferior 
cerosses the ventral surface of the gland. Here the nerve enters 
