278 H. W. NORRIS 
V and the dorsal lateral line trunk pass out dorso-laterally (figs. 
10, 11). The ramus ophthalmicus profundus, however, runs di- 
rectly anteriorly from the Gasserian ganglion in a gap between the 
orbito-sphenoid cartilage medially and the base of the petrosal 
laterally. The coalescence of the two cartilages farther anteriorly 
converts the gap into a groove, inverted trough-like (fig. 11), 
but not a canal as described by Wilder. On its complete emer- 
gence from the cranium the ramus ophthalmicus profundus lies 
between the ventral part of the orbito-sphenoid cartilage medially 
and the origin of the anterior ventral part of the temporal muscle 
laterally (fig. 10). It maintains this position between the car- 
tilage, and more anteriorly the orbitosphenoid bone, and the tem- 
poral muscle, undivided, until the optic foramen is passed. A 
little anterior to this foramen a large branch (fig. 9, op./), the 
ramus ophthalmicus profundus minor of Wilder, is given off dor- 
sally, which, with its branches, supplies the skin of the dorsal 
part of the head for some distance anterior and a little posterior 
to the eye. The trochlearis comes into close relationship with 
a posteriorly directed twig of this branch (fig. 8). For some 
distance, before entering the superior rectus muscle, the dorsal 
division of the oculomotor nerve runs along in close contact with, 
or indistinguishably fused with the dorsal border of the ramulus 
ophthalmicus profundus minor. When the oculomotor branch 
enters its muscle there is an appearance of other fibers also enter- 
ing the muscle, but coming from the ramulus ophthalmicus pro- 
fundus minor, possibly constituting a superior ciliary nerve. But 
these fibers were not traced into the eyeball. 
The ramulus ophthalmicus profundus minor of Siren evidently 
corresponds to a large branch (Va.) in Spelerpes described and 
figured by Miss Bowers. In Spelerpes the trochlearis nerve 
unites with this ramulus; also from this branch what is plainly a 
superior ciliary nerve is given off to the eyeball. Dorsally, as 
in Siren, the ramulus supplies.the skin of the dorsal surface, 
posterior and anterior to the eye and running anteriorly, parallels 
in a general way the course of the ramus ophthalmicus superfi- 
cialis VII. Coghill describes a number of small branches of the 
ramus ophthalmicus profundus in Amblystoma (0.p.V.2 and 3) 
