CRANIAL NERVES OF SIREN LACERTINA 309 
eral cutaneous fibers of the ramus jugularis VII. This inadequacy 
led to a search which resulted in the discovery in the roots of the 
facial nerve of what the writer has interpreted as a general cuta- 
neous component of that nerve. 
From its passage through the [Xth ganglion the peripheral 
course of the ramus communicans is around the posterior wall of 
the ear capsule, over the stilus of the columella and along the 
dorsal border of the latter, thence along the lateral wall of the ear 
capsule, medial to the inner division of the depressor mandibulae 
muscle, to its junction with the ramus jugularis VII. It joins 
the jugularis immediately after the latter emerges from the facial 
canal. The lighter colored fibers of the communicans may be 
traced some distance peripherally in the jugularis before being 
lost in the larger mass of motor fibers. Fischer (’64, p. 147) 
calls the communicans in Siren ‘“‘das Kopftheil des Sympathicus, ”’ 
believing that it passes from the IX—Xth ganglion into the VIIth 
ganglion, rather than into the jugularis VII. 
4. The first branchial nerve 
The glossopharyngeal or first branchial nerve divides as it 
emerges from its ganglion into two distinct trunks, the ramus pre- 
trematicus and the ramus posttrematicus which pass out over the 
anterior end of the subvertebral rectus muscles. The ramus pre- 
trematicus, wholly communis in constitution, passes posteriorly 
and laterally to the medial border of the ceratohyal bar, 
thence anteriorly and ventrally, ventral to the hyo-columellar 
ligament and lateral to the columella (fig. 14,prt. [X), along the 
dorsal border of the ceratohyal and at the dorso-lateral border of 
the pharynx and mouth (fig. 13). At about the level of the poste- 
rior end of the jaw it divides into twomainnerves (fig. 11), one of 
which passes along the lateral border of the ceratohyal, supplying 
the lateral wall of the mouth and part of the tongue; the other is 
distributed to the floor of the mouth and the dorsal part of the 
tongue. 
As the ramus pretrematicus, on emerging from the ganglion, is 
shifting from a posteriorly to an anteriorly directed course, it 
gives off a number of small pharyngeal branches, some passing 
JOURNAL OF MORPHOLOGY, VOL. 24, No. 2 
