1895 - 96 .] Mr F. J. Cole on Nerves of Chimmra monstrosa. 55 
roof of the mouth, and to the mouth in the immediate neighbourhood 
of the teeth of the upper jaw. 
(g.) Chorda tympani . — This is a conspicuous nerve arising just 
distal to the palatine, and is distributed to the sides and floor of 
the mouth. It receives a branch from the facial proper as described 
above. 
The facial, then, is to a great extent a typical cranial nerve. It 
has four dorsal sensory branches (superficial ophthalmic, buccal, 
external mandibular, and hyomandibular), two visceral branches 
(palatine and chorda), and prae- and post-branchial branches (?). 
Eighth Nerve . — Arises from the side of the medulla by a single 
root situated in the angle formed by the root of the buccal and the 
ventral root of the superficial ophthalmic of the Vllth. It imme- 
diately expands into a large ganglion, and gives off the usual 
ampullary and vestibular branches. The vestibule contains a hard 
caleareous otolith of a very curious shape. 
Ninth Nerve . — As figured by Hubrecht * in his memoir on the 
skull of the Holocephali , this nerve emerges from the cranium by 
a separate foramen. It arises from the medulla by a main root 
and two rootlets under cover of the root of the lateralis, and 
expands into an obvious ganglion immediately on emerging from 
the cranium. From the ganglion a very fine dorsal branch is sent 
up to the skin, but this does not innervate any sense organs of the 
lateral line. There are three pharyngeal branches, but none of 
these correspond to the pharyngeals of the vagus in their precise 
distribution. There are prse- and post-branchial branches to the first 
and second demi-branchs respectively, on the hyoid and first 
branchial arch, and both of these are continued ventrally on to the 
pharynx, thus forming two accessory pharyngeal branches, or five 
in all. Two nerves are also given off which accompany and supply 
the first branchial arch. 
Tenth Nerve .— -The vagus in Chimcera is in a specially interesting 
condition, and is more primitive than in any other vertebrate. 
Without any dissection beyond mere exposure, four ganglia are to 
be easily distinguished, and were it not that the ganglion of the 
third branchial lies under, and is obscured by that of the second, 
* Niederland. Archiv f. Zool., Bd. 3. Except that the foramina for the 
Yth and Vllth are confused, Hubrecht’s figure is perfectly accurate. 
